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Renard A, Pérez Lombardini F, Pacheco Zapata M, Porphyre T, Bento A, Suzán G, Roiz D, Roche B, Arnal A. Interaction of Human Behavioral Factors Shapes the Transmission of Arboviruses by Aedes and Culex Mosquitoes. Pathogens 2023; 12:1421. [PMID: 38133304 PMCID: PMC10746986 DOI: 10.3390/pathogens12121421] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/23/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023] Open
Abstract
Arboviruses, i.e., viruses transmitted by blood-sucking arthropods, trigger significant global epidemics. Over the past 20 years, the frequency of the (re-)emergence of these pathogens, particularly those transmitted by Aedes and Culex mosquitoes, has dramatically increased. Therefore, understanding how human behavior is modulating population exposure to these viruses is of particular importance. This synthesis explores human behavioral factors driving human exposure to arboviruses, focusing on household surroundings, socio-economic status, human activities, and demographic factors. Household surroundings, such as the lack of water access, greatly influence the risk of arbovirus exposure by promoting mosquito breeding in stagnant water bodies. Socio-economic status, such as low income or low education, is correlated to an increased incidence of arboviral infections and exposure. Human activities, particularly those practiced outdoors, as well as geographical proximity to livestock rearing or crop cultivation, inadvertently provide favorable breeding environments for mosquito species, escalating the risk of virus exposure. However, the effects of demographic factors like age and gender can vary widely through space and time. While climate and environmental factors crucially impact vector development and viral replication, household surroundings, socio-economic status, human activities, and demographic factors are key drivers of arbovirus exposure. This article highlights that human behavior creates a complex interplay of factors influencing the risk of mosquito-borne virus exposure, operating at different temporal and spatial scales. To increase awareness among human populations, we must improve our understanding of these complex factors.
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Affiliation(s)
- Aubane Renard
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche Pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34394 Montpellier, France; (A.R.); (D.R.); (B.R.)
| | - Fernanda Pérez Lombardini
- Fauna Silvestre y Animales de Laboratorio, Departamento de Etología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México (UNAM), Ciudad de México 04510, Mexico; (F.P.L.); (M.P.Z.); (G.S.)
- International Joint Laboratory IRD/UNAM ELDORADO (Ecosystem, Biological Diversity, Habitat Modifications, and Risk of Emerging Pathogens and Diseases in Mexico), Merida 97205, Mexico
| | - Mitsuri Pacheco Zapata
- Fauna Silvestre y Animales de Laboratorio, Departamento de Etología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México (UNAM), Ciudad de México 04510, Mexico; (F.P.L.); (M.P.Z.); (G.S.)
- International Joint Laboratory IRD/UNAM ELDORADO (Ecosystem, Biological Diversity, Habitat Modifications, and Risk of Emerging Pathogens and Diseases in Mexico), Merida 97205, Mexico
| | - Thibaud Porphyre
- Laboratoire de Biométrie et Biologie Évolutive, VetAgro Sup, Campus Vétérinaire de Lyon, 69280 Marcy-l’Etoile, France;
| | - Ana Bento
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA;
| | - Gerardo Suzán
- Fauna Silvestre y Animales de Laboratorio, Departamento de Etología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México (UNAM), Ciudad de México 04510, Mexico; (F.P.L.); (M.P.Z.); (G.S.)
- International Joint Laboratory IRD/UNAM ELDORADO (Ecosystem, Biological Diversity, Habitat Modifications, and Risk of Emerging Pathogens and Diseases in Mexico), Merida 97205, Mexico
| | - David Roiz
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche Pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34394 Montpellier, France; (A.R.); (D.R.); (B.R.)
- International Joint Laboratory IRD/UNAM ELDORADO (Ecosystem, Biological Diversity, Habitat Modifications, and Risk of Emerging Pathogens and Diseases in Mexico), Merida 97205, Mexico
| | - Benjamin Roche
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche Pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34394 Montpellier, France; (A.R.); (D.R.); (B.R.)
- Fauna Silvestre y Animales de Laboratorio, Departamento de Etología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México (UNAM), Ciudad de México 04510, Mexico; (F.P.L.); (M.P.Z.); (G.S.)
- International Joint Laboratory IRD/UNAM ELDORADO (Ecosystem, Biological Diversity, Habitat Modifications, and Risk of Emerging Pathogens and Diseases in Mexico), Merida 97205, Mexico
| | - Audrey Arnal
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche Pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34394 Montpellier, France; (A.R.); (D.R.); (B.R.)
- Fauna Silvestre y Animales de Laboratorio, Departamento de Etología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México (UNAM), Ciudad de México 04510, Mexico; (F.P.L.); (M.P.Z.); (G.S.)
- International Joint Laboratory IRD/UNAM ELDORADO (Ecosystem, Biological Diversity, Habitat Modifications, and Risk of Emerging Pathogens and Diseases in Mexico), Merida 97205, Mexico
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Christofferson RC, Turner EA, Peña-García VH. Identifying Knowledge Gaps through the Systematic Review of Temperature-Driven Variability in the Competence of Aedes aegypti and Ae. albopictus for Chikungunya Virus. Pathogens 2023; 12:1368. [PMID: 38003832 PMCID: PMC10675276 DOI: 10.3390/pathogens12111368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Temperature is a well-known effector of several transmission factors of mosquito-borne viruses, including within mosquito dynamics. These dynamics are often characterized by vector competence and the extrinsic incubation period (EIP). Vector competence is the intrinsic ability of a mosquito population to become infected with and transmit a virus, while EIP is the time it takes for the virus to reach the salivary glands and be expectorated following an infectious bloodmeal. Temperatures outside the optimal range act on life traits, decreasing transmission potential, while increasing temperature within the optimal range correlates to increasing vector competence and a decreased EIP. These relatively well-studied effects of other Aedes borne viruses (dengue and Zika) are used to make predictions about transmission efficiency, including the challenges presented by urban heat islands and climate change. However, the knowledge of temperature and chikungunya (CHIKV) dynamics within its two primary vectors-Ae. aegypti and Ae. albopictus-remains less characterized, even though CHIKV remains a virus of public-health importance. Here, we review the literature and summarize the state of the literature on CHIKV and temperature dependence of vector competence and EIP and use these data to demonstrate how the remaining knowledge gap might confound the ability to adequately predict and, thus, prepare for future outbreaks.
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Affiliation(s)
| | - Erik A. Turner
- School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA;
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Ebogo‐Belobo JT, Kenmoe S, Abanda NN, Bowo‐Ngandji A, Mbaga DS, Magoudjou‐Pekam JN, Kame‐Ngasse GI, Tchatchouang S, Menkem EZ, Okobalemba EA, Noura EA, Meta‐Djomsi D, Maïdadi‐Foudi M, Kenfack‐Zanguim J, Kenfack‐Momo R, Kengne‐Nde C, Esemu SN, Mbacham WF, Sadeuh‐Mba SA, Ndip L, Njouom R. Contemporary epidemiological data of Rift Valley fever virus in humans, mosquitoes and other animal species in Africa: A systematic review and meta-analysis. Vet Med Sci 2023; 9:2309-2328. [PMID: 37548116 PMCID: PMC10508527 DOI: 10.1002/vms3.1238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 03/29/2023] [Accepted: 07/21/2023] [Indexed: 08/08/2023] Open
Abstract
Rift Valley fever (RVF) is a severe zoonotic mosquito-borne disease that represents an important threat to human and animal health, with major public health and socioeconomic impacts. This disease is endemic throughout many African countries and the Arabian Peninsula. This systematic review with meta-analysis was conducted to determine the RVF prevalence in humans, mosquitoes and other animal species in Africa. The review also provides contemporary data on RVF case fatality rate (CFR) in humans. In this systematic review with meta-analysis, a comprehensive literature search was conducted on the PubMed, Embase, Web of Science and Global Index Medicus databases from January 2000 to June 2022 to identify relevant studies. Pooled CFR and prevalence estimates were calculated using the random-effects model. Subgroup analysis and sensitivity analysis were performed, and the I2 -statistic was used to investigate a potential source of heterogeneity. A total of 205 articles were included in the final analysis. The overall RVF CFR in humans was found to be 27.5% [95% CI = 8.0-52.5]. The overall pooled prevalence was 7.8% [95% CI = 6.2-9.6] in humans and 9.3% [95% CI = 8.1-10.6] in animals, respectively. The RVF prevalence in individual mosquitoes ranged from 0.0% to 25%. Subgroup analysis showed substantial heterogeneity with respect to geographical regions and human categories. The study shows that there is a correspondingly similar prevalence of RVF in human and animals; however, human CFR is much higher than the observed prevalence. The lack of a surveillance programme and the fact that this virus has subclinical circulation in animals and humans could explain these observations. The implementation of a One Health approach for RVF surveillance and control would be of great interest for human and animal health.
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Affiliation(s)
- Jean Thierry Ebogo‐Belobo
- Centre for Research on Health and Priority PathologiesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
- Department of BiochemistryFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | - Sebastien Kenmoe
- Department of Microbiology and ParasitologyUniversity of BueaBueaCameroon
| | - Ngu Njei Abanda
- Virology DepartmentCentre Pasteur of CameroonYaoundéCameroon
| | - Arnol Bowo‐Ngandji
- Department of MicrobiologyFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | - Donatien Serge Mbaga
- Department of MicrobiologyFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | | | - Ginette Irma Kame‐Ngasse
- Centre for Research on Health and Priority PathologiesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
| | | | | | | | - Efietngab Atembeh Noura
- Centre for Research on Health and Priority PathologiesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
| | - Dowbiss Meta‐Djomsi
- Research Centre on Emerging and Re‐Emerging DiseasesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
| | - Martin Maïdadi‐Foudi
- Research Centre on Emerging and Re‐Emerging DiseasesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
| | | | - Raoul Kenfack‐Momo
- Department of BiochemistryFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | - Cyprien Kengne‐Nde
- Epidemiological Surveillance, Evaluation and Research UnitNational AIDS Control CommitteeYaoundéCameroon
| | | | - Wilfred Fon Mbacham
- Department of BiochemistryFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | - Serge Alain Sadeuh‐Mba
- Virology DepartmentCentre Pasteur of CameroonYaoundéCameroon
- Maryland Department of AgricultureSalisbury Animal Health LaboratorySalisburyMarylandUSA
| | - Lucy Ndip
- Department of Microbiology and ParasitologyUniversity of BueaBueaCameroon
| | - Richard Njouom
- Virology DepartmentCentre Pasteur of CameroonYaoundéCameroon
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Man O, Kraay A, Thomas R, Trostle J, Lee GO, Robbins C, Morrison AC, Coloma J, Eisenberg JNS. Characterizing dengue transmission in rural areas: A systematic review. PLoS Negl Trop Dis 2023; 17:e0011333. [PMID: 37289678 PMCID: PMC10249895 DOI: 10.1371/journal.pntd.0011333] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023] Open
Abstract
Dengue has historically been considered an urban disease associated with dense human populations and the built environment. Recently, studies suggest increasing dengue virus (DENV) transmission in rural populations. It is unclear whether these reports reflect recent spread into rural areas or ongoing transmission that was previously unnoticed, and what mechanisms are driving this rural transmission. We conducted a systematic review to synthesize research on dengue in rural areas and apply this knowledge to summarize aspects of rurality used in current epidemiological studies of DENV transmission given changing and mixed environments. We described how authors defined rurality and how they defined mechanisms for rural dengue transmission. We systematically searched PubMed, Web of Science, and Embase for articles evaluating dengue prevalence or cumulative incidence in rural areas. A total of 106 articles published between 1958 and 2021 met our inclusion criteria. Overall, 56% (n = 22) of the 48 estimates that compared urban and rural settings reported rural dengue incidence as being as high or higher than in urban locations. In some rural areas, the force of infection appears to be increasing over time, as measured by increasing seroprevalence in children and thus likely decreasing age of first infection, suggesting that rural dengue transmission may be a relatively recent phenomenon. Authors characterized rural locations by many different factors, including population density and size, environmental and land use characteristics, and by comparing their context to urban areas. Hypothesized mechanisms for rural dengue transmission included travel, population size, urban infrastructure, vector and environmental factors, among other mechanisms. Strengthening our understanding of the relationship between rurality and dengue will require a more nuanced definition of rurality from the perspective of DENV transmission. Future studies should focus on characterizing details of study locations based on their environmental features, exposure histories, and movement dynamics to identify characteristics that may influence dengue transmission.
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Affiliation(s)
- Olivia Man
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alicia Kraay
- Department of Kinesiology and Community Health, University of Illinois, Urbana, Illinois, United States of America
- Institution for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Ruth Thomas
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - James Trostle
- Department of Anthropology, Trinity College, Hartford, Connecticut, United States of America
| | - Gwenyth O. Lee
- Rutgers Global Health Institute, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, United States of America
- Rutgers Department of Biostatistics and Epidemiology, School of Public Health, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, United States of America
| | - Charlotte Robbins
- Department of Anthropology, Trinity College, Hartford, Connecticut, United States of America
| | - Amy C. Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Josefina Coloma
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, California, United States of America
| | - Joseph N. S. Eisenberg
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan, United States of America
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Costa LB, Barreto FKDA, Barreto MCA, Santos THPD, Andrade MDMOD, Farias LABG, Freitas ARRD, Martinez MJ, Cavalcanti LPDG. Epidemiology and Economic Burden of Chikungunya: A Systematic Literature Review. Trop Med Infect Dis 2023; 8:301. [PMID: 37368719 DOI: 10.3390/tropicalmed8060301] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/28/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Chikungunya (CHIK) is a re-emerging viral infection endemic in tropical and subtropical areas. While the typical clinical presentation is an acute febrile syndrome, long-term articular complications and even death can occur. This review characterizes the global epidemiological and economic burden of chikungunya. The search included studies published from 2007 to 2022 in MEDLINE, Embase, LILACS, and SciELO for a thorough evaluation of the literature. Rayyan software was used for data analysis, and data were summarized descriptively and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Seventy-six publications were included. Chikungunya is widely distributed in the tropics, including Africa, Asia, South America, and Oceania/the Pacific Islands, and co-circulates with other simultaneous arboviruses such as DENV, ZIKV, and YFV. Chikungunya infection can lead to chronic articular manifestations with a significant impact on the quality of life in the long term. In addition, it generates absenteeism and economic and social losses and can cause fatal infections in vulnerable populations, mainly in high-risk patients with co-morbidities and at the extremes of age. Reported costs associated with CHIKV diseases are substantial and vary by region, age group, and public/private delivery of healthcare services. The chikungunya disease burden includes chronicity, severe infections, increased hospitalization risks, and associated mortality. The disease can impact the economy in several spheres, significantly affecting the health system and national economies. Understanding and measuring the full impact of this re-emerging disease is essential.
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Affiliation(s)
- Lourrany Borges Costa
- Programa de Pós-Graduação em Saúde Coletiva, Universidade Federal do Ceara (UFC), Ceara 60020-181, Brazil
- Faculdade de Medicina, Universidade de Fortaleza (UNIFOR), Ceara 60811-905, Brazil
| | | | | | | | | | - Luís Arthur Brasil Gadelha Farias
- Hospital São Jose de Doenças Infecciosas, Ceara 60455-610, Brazil
- Faculdade de Medicina, Centro Universitário Christus (UNICHRISTUS), Ceara 60192-345, Brazil
| | | | - Miguel Julian Martinez
- Microbiology Department, Hospital Clínic-Universitat de Barcelona, 08036 Barcelona, Spain
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic-Universitat de Barcelona, 08036 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28220 Madrid, Spain
| | - Luciano Pamplona de Góes Cavalcanti
- Programa de Pós-Graduação em Saúde Coletiva, Universidade Federal do Ceara (UFC), Ceara 60020-181, Brazil
- Faculdade de Medicina, Centro Universitário Christus (UNICHRISTUS), Ceara 60192-345, Brazil
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Nooh F, Chernet A, Reither K, Okuma J, Brattig NW, Utzinger J, Probst-Hensch N, Paris DH, Dreyfus A. Prevalence of fever of unidentified aetiology in East African adolescents and adults: a systematic review and meta-analysis. Infect Dis Poverty 2023; 12:55. [PMID: 37231500 DOI: 10.1186/s40249-023-01105-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 05/16/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND Primary health care settings and hospitals of low- and middle-income countries have few accessible diagnostic tools and limited laboratory and human resources capacity to identify multiple pathogens with high accuracy. In addition, there is a paucity of information on fever and its underlying aetiology in the adolescent and adult population in East Africa. The purpose of this study was to estimate the pooled prevalence of fever of unidentified aetiology among adolescent and adult febrile patients seeking health care in East Africa. METHODS We pursued a systematic review using readily available electronic databases (i.e. PubMed, Cumulative Index to Nursing & Allied Health Literature, Scopus, Cochrane Library and Web of Science) without language restriction from inception date of the respective databases to October 31, 2022. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Identified studies were screened for relevance. Further analyses based on pre-set eligibility criteria were carried out for final inclusion. Two reviewers independently screened and extracted data. Risk of study bias was assessed. Meta-analysis of the prevalence of fever of unidentified aetiology was performed. RESULTS We identified 14,029 articles of which 25 were eligible for inclusion, reporting data from 8538 participants. The pooled prevalence of febrile cases with unidentified aetiology was 64% [95% confidence interval (CI): 51-77%, I2 = 99.6%] among febrile adolescents and adults in East Africa. For the proportion of patients with identified aetiology, the studies documented bacterial pathogens (human bloodstream infections), bacterial zoonotic pathogens and arboviruses as the main non-malarial causative agents in East Africa. CONCLUSIONS Our study provides evidence that almost two-thirds of adolescent and adult febrile patients attending health care facilities in East Africa might receive inappropriate treatments due to unidentified potential life-threatening fever aetiology. Hence, we call for a comprehensive fever syndromic surveillance to broaden a consequential differential diagnosis of syndromic fever and to considerably improve the course of patients' disease and treatment outcomes.
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Affiliation(s)
- Faisal Nooh
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland.
- University of Basel, Basel, Switzerland.
- College of Medicine and Health Sciences, Jigjiga University, Jigjiga, Ethiopia.
- College of Medicine and Health Sciences, University of Hargeisa, Hargeisa, Somaliland.
| | - Afona Chernet
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Klaus Reither
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - James Okuma
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Norbert W Brattig
- Department Infectious Disease Epidemiology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Nicole Probst-Hensch
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Daniel H Paris
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Anou Dreyfus
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- Section of Epidemiology, University of Zürich, Zurich, Switzerland
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Skalinski LM, Santos AES, Paixão E, Itaparica M, Barreto F, da Conceição Nascimento Costa M, Teixeira MG. Chikungunya seroprevalence in population-based studies: a systematic review and meta-analysis. Arch Public Health 2023; 81:80. [PMID: 37127721 PMCID: PMC10150504 DOI: 10.1186/s13690-023-01081-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 04/06/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND Seroprevalence studies about chikungunya infection are usually conducted after epidemics to estimate the magnitude of the attack. This study aimed to estimate the seroprevalence of CHIKV by WHO region, considering the periods of introduction of the virus in these regions and its potential to lead to epidemics. METHODS We systematically reviewed Medline/Pubmed, Embase, Lilacs, Scopus and Web of Science for original articles published up to 2020. Cohort, case-control and cross-sectional studies were eligible for inclusion, based on the results of laboratory diagnosis of previous or previous and recent infection. Those conducted with symptomatic individuals were excluded. RESULTS 596 articles were identified, 197 full-text were reviewed and 64 were included, resulting in 71 seroprevalences. Most were cross-sectional studies (92%), between 2001 and 2020 (92%), with population of all ages (55%), conducted in Kenya (10.9%), Brazil (9.4%) and French Polynesia (7.8%). The pooled estimates were 24% (95%CI 19-29; I2 = 99.7%; p < 0.00), being 21% (95%CI 13-30; I2 = 99.5%; p < 0.00) for adults, 7% (95%CI 0-23; I2 = 99.7%; p < 0.00) for children and 30% (95%CI 23-38; I2 = 99.7%; p < 0.00) for all ages. The higher seroprevalences were found in African, the Americas and South-East Asian Regions. CONCLUSIONS The great heterogeneity of seroprevalences points to the persistence of viral circulation. Even where the seroprevalence is high, the population replacement and the absence of vaccines mean that the risk of virus spread and epidemics remains. REGISTRATION PROSPERO CRD42020166227.
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Affiliation(s)
- Lacita Menezes Skalinski
- Universidade Estadual de Santa Cruz, Rodovia Jorge Amado, km 16, s/n, Salobrinho, Ilhéus, CEP 45662-900, BA, Brasil.
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil.
| | - Aline Elena Sacramento Santos
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil
| | - Enny Paixão
- London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK
| | - Martha Itaparica
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil
| | - Florisneide Barreto
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil
| | | | - Maria Glória Teixeira
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil
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Chiuya T, Villinger J, Falzon LC, Alumasa L, Amanya F, Bastos ADS, Fèvre EM, Masiga DK. Molecular screening reveals non-uniform malaria transmission in western Kenya and absence of Rickettsia africae and selected arboviruses in hospital patients. Malar J 2022; 21:268. [PMID: 36115978 PMCID: PMC9482282 DOI: 10.1186/s12936-022-04287-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 09/07/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
In sub-Saharan Africa, malaria is the common diagnosis for febrile illness and related clinical features, resulting in the under-diagnosis of other aetiologies, such as arboviruses and Rickettsia. While these may not be significant causes of mortality in malaria-endemic areas, they affect the daily life and performance of affected individuals. It is, therefore, important to have a clear picture of these other aetiologies to institute correct diagnoses at hospitals and improve patient outcomes.
Methods
Blood samples were collected from patients with fever and other clinical features associated with febrile illness at selected hospitals in the malaria-endemic counties of Busia, Bungoma, and Kakamega, and screened for Crimean-Congo haemorrhagic fever, Sindbis, dengue and chikungunya viruses, Rickettsia africae, and Plasmodium spp. using high-throughput real-time PCR techniques. A logistic regression was performed on the results to explore the effect of demographic and socio-economic independent variables on malaria infection.
Results
A total of 336 blood samples collected from hospital patients between January 2018 and February 2019 were screened, of which 17.6% (59/336) were positive for Plasmodium falciparum and 1.5% (5/336) for Plasmodium malariae. Two patients had dual P. falciparum/P. malariae infections. The most common clinical features reported by the patients who tested positive for malaria were fever and headache. None of the patients were positive for the arboviruses of interest or R. africae. Patients living in Busia (OR 5.2; 95% CI 2.46–11.79; p < 0.001) and Bungoma counties (OR 2.7; 95% CI 1.27–6.16; p = 0.013) had higher odds of being infected with malaria, compared to those living in Kakamega County.
Conclusions
The reported malaria prevalence is in line with previous studies. The absence of arboviral and R. africae cases in this study may have been due to the limited number of samples screened, low-level circulation of arboviruses during inter-epidemic periods, and/or the use of PCR alone as a detection method. Other sero-surveys confirming their circulation in the area indicate that further investigations are warranted.
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Oyono MG, Kenmoe S, Abanda NN, Takuissu GR, Ebogo-Belobo JT, Kenfack-Momo R, Kengne-Nde C, Mbaga DS, Tchatchouang S, Kenfack-Zanguim J, Lontuo Fogang R, Zeuko’o Menkem E, Ndzie Ondigui JL, Kame-Ngasse GI, Magoudjou-Pekam JN, Bowo-Ngandji A, Nkie Esemu S, Ndip L. Epidemiology of yellow fever virus in humans, arthropods, and non-human primates in sub-Saharan Africa: A systematic review and meta-analysis. PLoS Negl Trop Dis 2022; 16:e0010610. [PMID: 35867659 PMCID: PMC9307179 DOI: 10.1371/journal.pntd.0010610] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 06/27/2022] [Indexed: 12/13/2022] Open
Abstract
Yellow fever (YF) has re-emerged in the last two decades causing several outbreaks in endemic countries and spreading to new receptive regions. This changing epidemiology of YF creates new challenges for global public health efforts. Yellow fever is caused by the yellow fever virus (YFV) that circulates between humans, the mosquito vector, and non-human primates (NHP). In this systematic review and meta-analysis, we review and analyse data on the case fatality rate (CFR) and prevalence of YFV in humans, and on the prevalence of YFV in arthropods, and NHP in sub-Saharan Africa (SSA). We performed a comprehensive literature search in PubMed, Web of Science, African Journal Online, and African Index Medicus databases. We included studies reporting data on the CFR and/or prevalence of YFV. Extracted data was verified and analysed using the random effect meta-analysis. We conducted subgroup, sensitivity analysis, and publication bias analyses using the random effect meta-analysis while I2 statistic was employed to determine heterogeneity. This review was registered with PROSPERO under the identification CRD42021242444. The final meta-analysis included 55 studies. The overall case fatality rate due to YFV was 31.1% (18.3–45.4) in humans and pooled prevalence of YFV infection was 9.4% (6.9–12.2) in humans. Only five studies in West and East Africa detected the YFV in mosquito species of the genus Aedes and in Anopheles funestus. In NHP, YFV antibodies were found only in members of the Cercopithecidae family. Our analysis provides evidence on the ongoing circulation of the YFV in humans, Aedes mosquitoes and NHP in SSA. These observations highlight the ongoing transmission of the YFV and its potential to cause large outbreaks in SSA. As such, strategies such as those proposed by the WHO’s Eliminate Yellow Fever Epidemics (EYE) initiative are urgently needed to control and prevent yellow fever outbreaks in SSA.
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Affiliation(s)
- Martin Gael Oyono
- Centre for Research on Health and Priority Pathologies, Institute of Medical Research and Medicinal Plants Studies, Yaounde, Cameroon
- Laboratory of Parasitology and Ecology, Department of Animal Biology and Physiology, University of Yaounde I, Yaounde, Cameroon
| | - Sebastien Kenmoe
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- * E-mail:
| | - Ngu Njei Abanda
- Virology Department, Centre Pasteur of Cameroon, Yaounde, Cameroon
| | - Guy Roussel Takuissu
- Centre for Food, Food Security and Nutrition Research, Institute of Medical Research and Medicinal Plants Studies, Yaounde, Cameroon
| | - Jean Thierry Ebogo-Belobo
- Medical Research Centre, Institute of Medical Research and Medicinal Plants Studies, Yaounde, Cameroon
| | - Raoul Kenfack-Momo
- Department of Biochemistry, The University of Yaounde I, Yaounde, Cameroon
| | - Cyprien Kengne-Nde
- Epidemiological Surveillance, Evaluation and Research Unit, National AIDS Control Committee, Douala, Cameroon
| | | | | | | | | | | | | | - Ginette Irma Kame-Ngasse
- Medical Research Centre, Institute of Medical Research and Medicinal Plants Studies, Yaounde, Cameroon
| | | | - Arnol Bowo-Ngandji
- Department of Microbiology, The University of Yaounde I, Yaounde, Cameroon
| | | | - Lucy Ndip
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
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10
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Muthanje EM, Kimita G, Nyataya J, Njue W, Mulili C, Mugweru J, Mutai B, Kituyi SN, Waitumbi J. March 2019 dengue fever outbreak at the Kenyan south coast involving dengue virus serotype 3, genotypes III and V. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000122. [PMID: 36962260 PMCID: PMC10021577 DOI: 10.1371/journal.pgph.0000122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 01/09/2022] [Indexed: 11/18/2022]
Abstract
The first description of a disease resembling dengue fever (DF) was in the 15th century slave trade era by Spanish sailors visiting the Tanzania coast. The disease, then associated with evil spirits is now known to be caused by four serotypes of dengue virus (DENV1-4) that are transmitted by Aedes mosquitoes. Kenya has experienced multiple outbreaks, mostly associated with DENV-2. In this study, plasma samples obtained from 37 febrile patients during a DF outbreak at Kenya's south coast in March 2019 were screened for DENV. Total RNA was extracted and screened for the alpha- and flavi-viruses by real-time polymerase chain reaction (qPCR). DENV-3 was the only virus detected. Shotgun metagenomics and targeted sequencing were used to obtain DENV whole genomes and the complete envelope genes (E gene) respectively. Sequences were used to infer phylogenies and time-scaled genealogies. Following Maximum likelihood and Bayesian phylogenetic analysis, two DENV-3 genotypes (III, n = 15 and V, n = 2) were found. We determined that the two genotypes had been in circulation since 2015, and that both had been introduced independently. Genotype III's origin was estimated to have been from Pakistan. Although the origin of genotype V could not be ascertained due to rarity of these sequences globally, it was most related to a 2006 Brazilian isolate. Unlike genotype III that has been described in East and West Africa multiple times, this was the second description of genotype V in Kenya. Of note, there was marked amino acid variances in the E gene between study samples and the Thailand DENV-3 strain used in the approved Dengvaxia vaccine. It remains to be seen whether these variances negatively impact the efficacy of the Dengvaxia or future vaccines.
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Affiliation(s)
- Eric M. Muthanje
- Department of Biological Sciences, University of Embu, Embu, Kenya
- United States Army Medical Research Directorate-Africa, Basic Science Laboratory, Kisumu, Kenya
| | - Gathii Kimita
- United States Army Medical Research Directorate-Africa, Basic Science Laboratory, Kisumu, Kenya
| | - Josphat Nyataya
- United States Army Medical Research Directorate-Africa, Basic Science Laboratory, Kisumu, Kenya
| | - Winrose Njue
- United States Army Medical Research Directorate-Africa, Basic Science Laboratory, Kisumu, Kenya
| | - Cyrus Mulili
- United States Army Medical Research Directorate-Africa, Basic Science Laboratory, Kisumu, Kenya
| | - Julius Mugweru
- Department of Biological Sciences, University of Embu, Embu, Kenya
| | - Beth Mutai
- United States Army Medical Research Directorate-Africa, Basic Science Laboratory, Kisumu, Kenya
| | - Sarah N. Kituyi
- Department of Biological Sciences, University of Embu, Embu, Kenya
| | - John Waitumbi
- United States Army Medical Research Directorate-Africa, Basic Science Laboratory, Kisumu, Kenya
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11
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Uncovering the Burden of Dengue in Africa: Considerations on Magnitude, Misdiagnosis, and Ancestry. Viruses 2022; 14:v14020233. [PMID: 35215827 PMCID: PMC8877195 DOI: 10.3390/v14020233] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/15/2022] [Accepted: 01/18/2022] [Indexed: 01/27/2023] Open
Abstract
Dengue is a re-emerging neglected disease of major public health importance. This review highlights important considerations for dengue disease in Africa, including epidemiology and underestimation of disease burden in African countries, issues with malaria misdiagnosis and co-infections, and potential evidence of genetic protection from severe dengue disease in populations of African descent. The findings indicate that dengue virus prevalence in African countries and populations may be more widespread than reported data suggests, and that the Aedes mosquito vectors appear to be increasing in dissemination and number. Changes in climate, population, and plastic pollution are expected to worsen the dengue situation in Africa. Dengue misdiagnosis is also a problem in Africa, especially due to the typical non-specific clinical presentation of dengue leading to misdiagnosis as malaria. Finally, research suggests that a protective genetic component against severe dengue exists in African descent populations, but further studies should be conducted to strengthen this association in various populations, taking into consideration socioeconomic factors that may contribute to these findings. The main takeaway is that Africa should not be overlooked when it comes to dengue, and more attention and resources should be devoted to this disease in Africa.
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12
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Vasmehjani AA, Rezaei F, Farahmand M, Mokhtari-Azad T, Yaghoobi-Ershadi MR, Keshavarz M, Baseri HR, Zaim M, Iranpour M, Turki H, Esmaeilpour-Bandboni M. Epidemiological Evidence of Mosquito-Borne Viruses among Persons and Vectors in Iran: A Study from North to South. Virol Sin 2022; 37:149-152. [PMID: 35234614 PMCID: PMC8922425 DOI: 10.1016/j.virs.2022.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 08/09/2021] [Indexed: 11/07/2022] Open
Abstract
The overall seroprevalence of DENV, WNV and CHIKV in Iran were 5.9%, 18.8% and 1.8% between 2017 and 2018. No proof of viral RNAs was presence in vectors. Gilan and Hormozgan were high risk regions and the elderlies were at higher risk of infection by WNV and CHIKV.
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13
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Mencattelli G, Ndione MHD, Rosà R, Marini G, Diagne CT, Diagne MM, Fall G, Faye O, Diallo M, Faye O, Savini G, Rizzoli A. Epidemiology of West Nile virus in Africa: An underestimated threat. PLoS Negl Trop Dis 2022; 16:e0010075. [PMID: 35007285 PMCID: PMC8789169 DOI: 10.1371/journal.pntd.0010075] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 01/25/2022] [Accepted: 12/09/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND West Nile virus is a mosquito-borne flavivirus which has been posing continuous challenges to public health worldwide due to the identification of new lineages and clades and its ability to invade and establish in an increasing number of countries. Its current distribution, genetic variability, ecology, and epidemiological pattern in the African continent are only partially known despite the general consensus on the urgency to obtain such information for quantifying the actual disease burden in Africa other than to predict future threats at global scale. METHODOLOGY AND PRINCIPAL FINDINGS References were searched in PubMed and Google Scholar electronic databases on January 21, 2020, using selected keywords, without language and date restriction. Additional manual searches of reference list were carried out. Further references have been later added accordingly to experts' opinion. We included 153 scientific papers published between 1940 and 2021. This review highlights: (i) the co-circulation of WNV-lineages 1, 2, and 8 in the African continent; (ii) the presence of diverse WNV competent vectors in Africa, mainly belonging to the Culex genus; (iii) the lack of vector competence studies for several other mosquito species found naturally infected with WNV in Africa; (iv) the need of more competence studies to be addressed on ticks; (iv) evidence of circulation of WNV among humans, animals and vectors in at least 28 Countries; (v) the lack of knowledge on the epidemiological situation of WNV for 19 Countries and (vii) the importance of carrying out specific serological surveys in order to avoid possible bias on WNV circulation in Africa. CONCLUSIONS This study provides the state of art on WNV investigation carried out in Africa, highlighting several knowledge gaps regarding i) the current WNV distribution and genetic diversity, ii) its ecology and transmission chains including the role of different arthropods and vertebrate species as competent reservoirs, and iii) the real disease burden for humans and animals. This review highlights the needs for further research and coordinated surveillance efforts on WNV in Africa.
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Affiliation(s)
- Giulia Mencattelli
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
- Center Agriculture Food Environment, University of Trento, San Michele all'Adige, Trento, Italy
| | | | - Roberto Rosà
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
- Center Agriculture Food Environment, University of Trento, San Michele all'Adige, Trento, Italy
| | - Giovanni Marini
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
| | | | | | - Gamou Fall
- Department of Virology, Fondation Institut Pasteur de Dakar, Dakar, Senegal
| | - Ousmane Faye
- Department of Virology, Fondation Institut Pasteur de Dakar, Dakar, Senegal
| | - Mawlouth Diallo
- Department of Zoology, Fondation Institut Pasteur de Dakar, Dakar, Senegal
| | - Oumar Faye
- Department of Virology, Fondation Institut Pasteur de Dakar, Dakar, Senegal
| | - Giovanni Savini
- Department of Public Health, OIE Reference Laboratory for WND, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy
| | - Annapaola Rizzoli
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
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14
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Bonifay T, Godaert L, Epelboin Y, Rousset D, Douine M, Hilderal H, Clavel C, Abel S, Najioullah F, Fagour L, do Socorro Mendonça Gomes M, Lacerda M, Cézaire R, Elenga N, Dramé M, Hoen B, Cabié A, Djossou F, Epelboin L. Contribution of Research in the West Indies and Northeast Amazonia to Knowledge of the 2014-2015 Chikungunya Epidemic in the Americas. CURRENT TROPICAL MEDICINE REPORTS 2021; 8:164-172. [PMID: 34178576 PMCID: PMC8214063 DOI: 10.1007/s40475-021-00242-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2021] [Indexed: 11/02/2022]
Abstract
Purpose of Review Although the chikungunya virus was discovered more than 60 years ago, it has only really been studied since the outbreak in La Reunion in 2005-2006. Ten years later, between 2014 and 2015, the chikungunya virus spread throughout the Americas, affecting millions of people. The objective of this review is to describe the contributions of research on chikungunya virus infection gained from epidemic in the West Indies and the Guiana Shield. Recent Findings Prevalence data were similar to those found in the Indian Ocean or Asia during epidemics. Clinically, there is now a better understanding of the typical, atypical, and severe forms. Several studies have insisted on the presence of neurological forms of chikungunya infection, such as encephalitis or Guillain-Barré syndrome. Cases of septic shock due to chikungunya virus as well as thrombotic thrombocytopenic purpura were described for the first time. Given the magnitude of the epidemic and the large number of people affected, this has led to a better description and new classifications of chikungunya virus infections in specific populations such as pregnant women, the elderly, and children. Several studies also described the behavior of populations faced with an emerging disease. Summary Current epidemiological data from tropical regions highlights the risk of spreading emerging diseases at higher latitudes, especially concerning arboviruses, since the vector Aedes albopictus is already established in many parts of northern countries. A better understanding of the disease and its epidemic dynamics will foster better management, the crucial importance of which was demonstrated during the COVID-19 epidemic.
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Affiliation(s)
- Timothee Bonifay
- Centre d'Investigation Clinique Antilles Guyane, INSERM 1424, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | - Lidvine Godaert
- Short-stay Unit, Department of Geriatrics, General Hospital of Valenciennes, Valenciennes, France
| | - Yanouk Epelboin
- Unité d'Entomologie Médicale, Institut Pasteur de la Guyane, French Guiana, Cayenne, France
| | - Dominique Rousset
- Virology Laboratory, National Reference Center of Arboviruses, Pastor Institute of Guyana, Cayenne, French Guiana
| | - Maylis Douine
- Centre d'Investigation Clinique Antilles Guyane, INSERM 1424, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | - Hélène Hilderal
- Centre d'Investigation Clinique Antilles Guyane, INSERM 1424, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | - Cyril Clavel
- Infectious Diseases Unit, Centre Hospitalier Louis Constant Fleming, Saint-Martin, France
| | - Sylvie Abel
- Department of Infectious Diseases, Centre Hospitalier Universitaire de Martinique, Fort-de-France, Martinique France
| | - Fatiha Najioullah
- Laboratoire de Virologie, Centre Hospitalier Universitaire de Martinique, Fort-de-France, Martinique France
| | - Laurence Fagour
- Virology Laboratory, University Hospital of Martinique, Fort de France, France
| | | | - Marcus Lacerda
- Fundação de Medicina Tropical Dr. Heitor Viera Dourado, Manaus, Amazonas Brazil
| | - Raymond Cézaire
- Laboratoire de Virologie, Centre Hospitalier Universitaire de Martinique, Fort-de-France, Martinique France
| | - Narcisse Elenga
- Service de Médecine et Chirurgie Pédiatrique, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | - Moustapha Dramé
- Department of Clinical Research and Innovation, University Hospital of Martinique, Fort-de-France, Martinique France
| | - Bruno Hoen
- Service de Maladies Infectieuses et Tropicales, Dermatologie, Médecine Interne, Centre Hospitalier Universitaire de Pointe-à-Pitre/Abymes, Pointe-à-Pitre, France
| | - André Cabié
- Department of Infectious Diseases, Centre Hospitalier Universitaire de Martinique, Fort-de-France, Martinique France
| | - Félix Djossou
- Service des Maladies Infectieuses et Tropicales, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | - Loïc Epelboin
- Service des Maladies Infectieuses et Tropicales, Centre Hospitalier de Cayenne, Cayenne, French Guiana
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15
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Chiuya T, Masiga DK, Falzon LC, Bastos ADS, Fèvre EM, Villinger J. A survey of mosquito-borne and insect-specific viruses in hospitals and livestock markets in western Kenya. PLoS One 2021; 16:e0252369. [PMID: 34048473 PMCID: PMC8162702 DOI: 10.1371/journal.pone.0252369] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/15/2021] [Indexed: 11/18/2022] Open
Abstract
Aedes aegypti and Culex pipiens complex mosquitoes are prolific vectors of arboviruses that are a global threat to human and animal health. Increased globalization and ease of travel have facilitated the worldwide dissemination of these mosquitoes and the viruses they transmit. To assess disease risk, we determined the frequency of arboviruses in western Kenyan counties bordering an area of high arboviral activity. In addition to pathogenic viruses, insect-specific flaviviruses (ISFs), some of which are thought to impair the transmission of specific pathogenic arboviruses, were also evaluated. We trapped mosquitoes in the short and long rainy seasons in 2018 and 2019 at livestock markets and hospitals. Mosquitoes were screened for dengue, chikungunya and other human pathogenic arboviruses, ISFs, and their blood-meal sources as determined by high-resolution melting analysis of (RT-)PCR products. Of 6,848 mosquitoes collected, 89% were trapped during the long rainy season, with A. aegypti (59%) and Cx. pipiens sensu lato (40%) being the most abundant. Most blood-fed mosquitoes were Cx. pipiens s.l. with blood-meals from humans, chicken, and sparrow (Passer sp.). We did not detect dengue or chikungunya viruses. However, one Culex poicilipes female was positive for Sindbis virus, 30 pools of Ae. aegypti had cell fusing agent virus (CFAV; infection rate (IR) = 1.27%, 95% CI = 0.87%-1.78%); 11 pools of Ae. aegypti had Aedes flavivirus (AeFV; IR = 0.43%, 95% CI = 0.23%-0.74%); and seven pools of Cx. pipiens s.l. (IR = 0.23%, 95% CI = 0.1%-0.45%) and one pool of Culex annulioris had Culex flavivirus. Sindbis virus, which causes febrile illness in humans, can complicate the diagnosis and prognosis of patients with fever. The presence of Sindbis virus in a single mosquito from a population of mosquitoes with ISFs calls for further investigation into the role ISFs may play in blocking transmission of other arboviruses in this region.
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Affiliation(s)
- Tatenda Chiuya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- * E-mail: , (TC); (JV)
| | - Daniel K. Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Laura C. Falzon
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, United Kingdom
- International Livestock Research Institute, Nairobi, Kenya
| | - Armanda D. S. Bastos
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Eric M. Fèvre
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, United Kingdom
- International Livestock Research Institute, Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- * E-mail: , (TC); (JV)
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16
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Elaagip A, Alsedig K, Altahir O, Ageep T, Ahmed A, Siam HA, Samy AM, Mohamed W, Khalid F, Gumaa S, Mboera L, Sindato C, Elton L, Zumla A, Haider N, Kock R, Abdel Hamid MM. Seroprevalence and associated risk factors of Dengue fever in Kassala state, eastern Sudan. PLoS Negl Trop Dis 2020; 14:e0008918. [PMID: 33296362 PMCID: PMC7752093 DOI: 10.1371/journal.pntd.0008918] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 12/21/2020] [Accepted: 10/25/2020] [Indexed: 12/14/2022] Open
Abstract
Dengue is a rapidly growing public health threat in Kassala state, eastern Sudan. The objective of this study was to determine the seroprevalence, entomological transmission indices, and socioeconomic risk factors associated with dengue in this region. A cross-sectional community-based study was conducted in four dengue-endemic sites; Khatmia, West Gash, Thoriba, and Shokriya between March 2016 to March 2017. Enzyme-linked immunosorbent assay (ELISA) of immunoglobulin G (IgG) was used to determine the prevalence of dengue virus among the study participants. An entomological survey was conducted using pyrethrum spray catch and dipping for the collection of adults and aquatic stages of Aedes aegypti, respectively. Ribonucleic acid was extracted from the buffy coat of participants as well as from adult female Ae. aegypti to assess the possible circulation of dengue virus using Reverse Transcription Polymerase Chain Reaction (RT-PCR). Multiple logistic regression model was used to estimate the association between potential risk factors and dengue seropositivity. A total of 409 persons were recruited to the study: 45.5% were in the 20–39 years’ age category; 57.9% were living in houses with 6–10 persons; and 29.1% had at most secondary school education. In the majority (65.8%) of the households, the socioeconomic status was low (P<0.001). Long-lasting insecticide-treated bed nets were used in 56.5% of the households. Over three-quarters (77.8%) claimed not to have experienced febrile illness in the last three months. Routine entomological survey across Kassala state identified a total of 3,304 larvae and 390 pupae Ae. aegypti, respectively. The overall house index was 32.8% and Breteau Index was 35.96% (146/406). The overall pupal demographic index was 13.31%, and the pupal children index was 97.26%. Antibodies against IgG were detected from 66 (42.04%) out of a total of 157 sera. Twenty-two positive sera (75.9%) were collected from Khatmia. A total of 329 adults Ae. aegypti were identified but only one (0.3%) was positive for DENV in Khatmia. Finally, four independent risk factors were identified to derive dengue circulation in Kassala: elder age (> 60 years) (OR 6.31, CI 1.09–36.36); type of bathroom (OR 3.52, CI 1.35–9.20); using water-based air conditioner (OR 6.90, CI 1.78–26.85) and previous infection of any household member with dengue (OR 28.73, CI 3.31–249.63). Our findings suggest that Kassala state is facing an increasing occurrence of dengue and emphasizes the need for developing appropriate interventions to address the identified risk factors, and place control programs into actions. Establishment of routine dengue epidemiological and entomological surveillance, and climate warning systems will contribute to early warning and timely detection and response to emerging outbreaks. Dengue is a rapidly growing public health threat in Sudan. Kassala state is facing a major outbreak of the mosquito-borne dengue virus. This recent outbreak alarmed the local health authorities to establish a successful control program. However, lack of data obstructs their roles to achieve this goal. Here, we provided a detailed picture on the seroprevalence of dengue virus, entomological indices, and natural mosquito infection across Kassala state, Sudan. The study also identified key factors associated with the recent dengue outbreaks in Sudan. All these findings marked the importance to establish successful routine vector and dengue surveillance. These active surveillances should consider sensitive early warning systems providing early anticipation and timely detection and response to the future outbreaks in Sudan.
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Affiliation(s)
- Arwa Elaagip
- Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences, University of Khartoum, Khartoum, Sudan
- Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
- * E-mail: (AE); (MMAH)
| | - Khider Alsedig
- Department of Medical Entomology, National Public Health Laboratory, Federal Ministry of Health, Khartoum, Sudan
| | - Omnia Altahir
- Department of Epidemiology, Tropical Medicine Research Institute, National Center for Research, Khartoum, Sudan
| | - Tellal Ageep
- Department of Epidemiology, Tropical Medicine Research Institute, National Center for Research, Khartoum, Sudan
| | - Ayman Ahmed
- Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Hanaa Adli Siam
- Department of Medical Entomology, National Public Health Laboratory, Federal Ministry of Health, Khartoum, Sudan
| | - Abdallah M. Samy
- Entomology Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt
| | - Waleed Mohamed
- Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Fatima Khalid
- Department of Biochemistry, Faculty of Medicine and Health Sciences, University of Kassala, Kassala, Sudan
| | - Suhaib Gumaa
- Department of Immunology and Biotechnology, Tropical Medicine Research Institute, National Center for Research, Khartoum, Sudan
| | - Leonard Mboera
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Calvin Sindato
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
- National Institute for Medical Research, Tabora, Tanzania
| | - Linzy Elton
- Centre for Clinical Microbiology, Department of Infection, Division of Infection and Immunity, Royal Free Campus, University College London, London, United Kingdom
| | - Alimuddin Zumla
- Centre for Clinical Microbiology, Department of Infection, Division of Infection and Immunity, Royal Free Campus, University College London, London, United Kingdom
| | - Najmul Haider
- Royal Veterinary College (RVC), London, United Kingdom
| | - Richard Kock
- Royal Veterinary College (RVC), London, United Kingdom
| | - Muzamil Mahdi Abdel Hamid
- Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
- * E-mail: (AE); (MMAH)
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17
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Chiuya T, Masiga DK, Falzon LC, Bastos ADS, Fèvre EM, Villinger J. Tick-borne pathogens, including Crimean-Congo haemorrhagic fever virus, at livestock markets and slaughterhouses in western Kenya. Transbound Emerg Dis 2020; 68:2429-2445. [PMID: 33142046 PMCID: PMC8359211 DOI: 10.1111/tbed.13911] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/26/2020] [Accepted: 10/31/2020] [Indexed: 12/14/2022]
Abstract
Vectors of emerging infectious diseases have expanded their distributional ranges in recent decades due to increased global travel, trade connectivity and climate change. Transboundary range shifts, arising from the continuous movement of humans and livestock across borders, are of particular disease control concern. Several tick-borne diseases are known to circulate between eastern Uganda and the western counties of Kenya, with one fatal case of Crimean-Congo haemorrhagic fever (CCHF) reported in 2000 in western Kenya. Recent reports of CCHF in Uganda have highlighted the risk of cross-border disease translocation and the importance of establishing inter-epidemic, early warning systems to detect possible outbreaks. We therefore carried out surveillance of tick-borne zoonotic pathogens at livestock markets and slaughterhouses in three counties of western Kenya that neighbour Uganda. Ticks and other ectoparasites were collected from livestock and identified using morphological keys. The two most frequently sampled tick species were Rhipicephalus decoloratus (35%) and Amblyomma variegatum (30%); Ctenocephalides felis fleas and Haematopinus suis lice were also present. In total, 486 ticks, lice and fleas were screened for pathogen presence using established molecular workflows incorporating high-resolution melting analysis and identified through sequencing of PCR products. We detected CCHF virus in Rh. decoloratus and Rhipicephalus sp. cattle ticks, and 82 of 96 pools of Am. variegatum were positive for Rickettsia africae. Apicomplexan protozoa and bacteria of veterinary importance, such as Theileria parva, Babesia bigemina and Anaplasma marginale, were primarily detected in rhipicephaline ticks. Our findings show the presence of several pathogens of public health and veterinary importance in ticks from livestock at livestock markets and slaughterhouses in western Kenya. Confirmation of CCHF virus, a Nairovirus that causes haemorrhagic fever with a high case fatality rate in humans, highlights the risk of under-diagnosed zoonotic diseases and calls for continuous surveillance and the development of preventative measures.
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Affiliation(s)
- Tatenda Chiuya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.,Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Laura C Falzon
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, UK.,International Livestock Research Institute, Nairobi, Kenya
| | - Armanda D S Bastos
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Eric M Fèvre
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, UK.,International Livestock Research Institute, Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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18
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Cattarino L, Rodriguez-Barraquer I, Imai N, Cummings DAT, Ferguson NM. Mapping global variation in dengue transmission intensity. Sci Transl Med 2020; 12:12/528/eaax4144. [PMID: 31996463 DOI: 10.1126/scitranslmed.aax4144] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 09/12/2019] [Accepted: 01/02/2020] [Indexed: 12/28/2022]
Abstract
Intervention planning for dengue requires reliable estimates of dengue transmission intensity. However, current maps of dengue risk provide estimates of disease burden or the boundaries of endemicity rather than transmission intensity. We therefore developed a global high-resolution map of dengue transmission intensity by fitting environmentally driven geospatial models to geolocated force of infection estimates derived from cross-sectional serological surveys and routine case surveillance data. We assessed the impact of interventions on dengue transmission and disease using Wolbachia-infected mosquitoes and the Sanofi-Pasteur vaccine as specific examples. We predicted high transmission intensity in all continents straddling the tropics, with hot spots in South America (Colombia, Venezuela, and Brazil), Africa (western and central African countries), and Southeast Asia (Thailand, Indonesia, and the Philippines). We estimated that 105 [95% confidence interval (CI), 95 to 114] million dengue infections occur each year with 51 (95% CI, 32 to 66) million febrile disease cases. Our analysis suggests that transmission-blocking interventions such as Wolbachia, even at intermediate efficacy (50% transmission reduction), might reduce global annual disease incidence by up to 90%. The Sanofi-Pasteur vaccine, targeting only seropositive recipients, might reduce global annual disease incidence by 20 to 30%, with the greatest impact in high-transmission settings. The transmission intensity map presented here, and made available for download, may help further assessment of the impact of dengue control interventions and prioritization of global public health efforts.
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Affiliation(s)
- Lorenzo Cattarino
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK.
| | | | - Natsuko Imai
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK
| | - Derek A T Cummings
- Department of Biology and Emerging Pathogens Institute, University of Florida, P. O. Box 100009, Gainesville, FL 32610, USA
| | - Neil M Ferguson
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, UK
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19
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Endale A, Michlmayr D, Abegaz WE, Asebe G, Larrick JW, Medhin G, Legesse M. Community-based sero-prevalence of chikungunya and yellow fever in the South Omo Valley of Southern Ethiopia. PLoS Negl Trop Dis 2020; 14:e0008549. [PMID: 32881913 PMCID: PMC7470273 DOI: 10.1371/journal.pntd.0008549] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 07/01/2020] [Indexed: 12/31/2022] Open
Abstract
Background Chikungunya (CHIK) and yellow fever (YF) are becoming major public health threats in East African countries including Ethiopia. In Ethiopia, there is no reliable information about the epidemiology of CHIK. This study aimed to assess a community-based sero-prevalence of CHIK and YF in the South Omo Valley, an endemic area for YF. Methods Between February and June 2018, blood samples were collected from study participants and screened for IgG antibody against CHIK virus (CHIKV) and YF virus (YFV) infections using ELISA. Data were computerized using Epi Data Software v.3.1 and analyzed using SPSS. Results A total of 360 participants (51.7% males, age range from 6 to 80, mean age ± SD = 31.95 ± 14.05 years) participated in this study. The overall sero-prevalence of IgG antibody was 43.6% (157/360) against CHIKV, while it was 49.5% (155/313) against YFV. Out of 155 samples which were positive for IgG antibody to YFV, 93 (60.0%) were positive for IgG antibody to CHIKV. Out of 158 samples which were negative for IgG antibody to YFV, 64(40.5%) were positive for IgG antibody to CHIKV. There was a significant positive correlation between IgG antibodies to CHIKV and YFV (sr = 0.82; P<0.01). Residency in the Debub Ari district (AOR = 8.47; 95% CI: 1.50, 47.74) and travel history to sylvatic areas (AOR = 2.21; 95% CI: 1.02, 4.81) were significantly and positively associated with high sero-prevalence of IgG antibody to CHIKV and YFV, respectively. Conclusion High sero-prevalence of IgG antibody to CHIKV shows the circulation of the virus in the present study area. A low sero-prevalence of IgG antibody to YFV in YF vaccine received individuals is highly concerning from a public health point of view as waning of immune response to YFV infection could result in a periodic outbreaks of YF in endemic areas.Nevertheless, the present study has not investigated for possible cross-reactivity of antibody to CHIKV with other alphaviruses like O’nyong-nyong virus and antibody to YFV with other flaviviruses like Dengue fever virus and this warrants further studies in the present study area. Mosquito-borne viral diseases including yellow fever and chikungunya are becoming major public health problem in Africa. Community-based sero-epidemiological studies of mosquito-borne viral infections are important to known the occurrence of these diseases and to design appropriate prevention and control strategies. In this study, we assessed the sero-prevalence of IgG antibody against Chikungunya virus and Yellow fever virus in 360 study participants and associated risk factors among the community members of South Omo, Southern Ethiopia. Our study showed a sero-prevalence of IgG antibody; 43.6%, (157 out of 360) to Chikungunya virus, and 49.5% (155 out of 313) against Yellow fever virus in the study participants.Further studies on active case detection of chikungunya and raising awareness, advocating policies to mitigate the risk of arboviral infections have paramount importance in the present study area.
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Affiliation(s)
- Adugna Endale
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
- School of Medicine, College of Medicine and Health Sciences, Dire Dawa University, Dire Dawa, Ethiopia
| | - Daniela Michlmayr
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California Berkeley, Berkeley, California, United States of America
| | - Woldaregay Erku Abegaz
- Department of Microbiology, Immunology & Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Getahun Asebe
- Department of Veterinary Microbiology, Immunology and Public Health, College of Veterinary Medicine, Addis Ababa University, Bishoftu, Ethiopia
- College of Agriculture and Natural Resources, Gambella University, Gambella, Ethiopia
| | - James W. Larrick
- Panorama Research Institute, Sunnyvale, California, United States of America
| | - Girmay Medhin
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Mengistu Legesse
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
- * E-mail:
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20
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Matheson AI, Mogeni OD, Lacsina JR, Ochieng M, Audi A, Bigogo G, Neatherlin J, Margolis HS, Fields B, Ahenda P, Walson JL, Montgomery JM. No Evidence of Acute Dengue Virus Infections at a Rural Site in Western Kenya, 2011 and 2013. Am J Trop Med Hyg 2020; 103:2054-2058. [PMID: 32876014 DOI: 10.4269/ajtmh.20-0132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The incidence and spread of dengue virus (DENV) have increased rapidly in recent decades. Dengue is underreported in Africa, but recent outbreaks and seroprevalence data suggest that DENV is widespread there. A lack of ongoing surveillance limits knowledge about its spatial reach and hinders disease control planning. We sought to add data on dengue distribution in Kenya through diagnostic testing of serum specimens from persons with an acute febrile illness (AFI) attending an outpatient clinic in rural western Kenya (Asembo) during rainy seasons. Patients with symptoms not likely to be misclassified as dengue (e.g., diarrhea and anemia), those with a positive diagnostic laboratory results which explained their febrile illness, or those with serum collected more than 5 days after fever onset were excluded. However, febrile patients with a positive malaria smear were included in the study. We used reverse transcription polymerase chain reaction (RT-PCR) to test for DENV and IgM anti-DENV to test for recent infection. Of the 615 serum specimens available for testing, none were dengue positive by either RT-PCR or IgM anti-DENV testing. Dengue did not appear to be a cause of febrile illness in this area of western Kenya, although our relatively small sample size may not have identified DENV infections occurring at low incidence. A more widespread AFI surveillance system that includes dengue diagnostic testing by RT-PCR and antibody-based methods is required to more definitively gauge the size and geographic distribution of DENV infection in western Kenya.
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Affiliation(s)
- Alastair I Matheson
- Department of Global Health, University of Washington, Seattle, Washington.,Department of Epidemiology, University of Washington, Seattle, Washington
| | - Ondari D Mogeni
- Centre for Global Health Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Joshua R Lacsina
- Department of Medicine, University of Washington, Seattle, Washington
| | - Melvin Ochieng
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Allan Audi
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Godfrey Bigogo
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - John Neatherlin
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Harold S Margolis
- Dengue Branch, Division of Vectorborne Diseases, Centers for Disease Control and Prevention, San Juan, Puerto Rico
| | - Barry Fields
- Division of Global Health Protection, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Petronella Ahenda
- School of Public Health, Texas A&M University, College Station, Texas
| | - Judd L Walson
- Department of Medicine, University of Washington, Seattle, Washington.,Department of Global Health, University of Washington, Seattle, Washington.,Department of Epidemiology, University of Washington, Seattle, Washington
| | - Joel M Montgomery
- Division of Global Health Protection, Centers for Disease Control and Prevention, Atlanta, Georgia
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21
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Kimata Y, Borus P, Nzunza R, Ofula V, Chepkorir E, Waihenya R, Sang R. Serological Evidence of Chikungunya Virus Infection Among Suspected Measles Cases in Selected Regions of Kenya: 2008-2014. Vector Borne Zoonotic Dis 2020; 20:903-909. [PMID: 32845826 DOI: 10.1089/vbz.2019.2593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Chikungunya virus (family Togavirdae and genus Alphavirus) is an emerging and reemerging virus of public health importance both regionally and globally. In Kenya, about 50-60% of the suspected measles cases remain undiagnosed once measles and rubella is ruled out by immunoglobulin M (IgM) ELISA thus prompted the need to do differential diagnosis on the measles/rubella negative samples. Nothing is known about the role played by chikungunya infection among these suspected measles cases. Febrile rash illness is a common clinical presentation of arboviruses, including chikungunya. In this study, we conducted a serosurvey to explore the possible role of chikungunya infections among suspected measles cases in Kenya that had tested negative for measles and rubella. Sera were tested by commercially available ELISA for the presence of IgG and IgM antibodies against the chikungunya virus. All positive samples for chikungunya by ELISA were confirmed by plaque reduction neutralization test (PRNT), and to rule out cross-reactivity with other alphaviruses a panel of viruses was used, namely o' nyong' nyong, Semliki Forest, and Sindbis viruses. Of the 392 serum samples screened, 0.3% (n = 1) tested positive for IgM antibodies, while 4.6% (n = 18) tested positive for IgG antibodies against the chikungunya virus. PRNT results indicated 2 (11%) chikungunya positives and 7 (38.9%) o' nyong' nyong positives. We recommend awareness among health care providers and improved surveillance for these arboviruses by both serology and molecular testing. Testing for other pathogens should also be done to improve disease detection and diagnosis.
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Affiliation(s)
- Yvonne Kimata
- School of Biomedical Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Peter Borus
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Rosemary Nzunza
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Victor Ofula
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Edith Chepkorir
- Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Rebecca Waihenya
- School of Biomedical Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Rosemary Sang
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
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22
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Evidence of transovarial transmission of Chikungunya and Dengue viruses in field-caught mosquitoes in Kenya. PLoS Negl Trop Dis 2020; 14:e0008362. [PMID: 32559197 PMCID: PMC7329127 DOI: 10.1371/journal.pntd.0008362] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 07/01/2020] [Accepted: 05/04/2020] [Indexed: 01/14/2023] Open
Abstract
Arboviruses are among the most important emerging pathogens due to their increasing public health impact. In Kenya, continued population growth and associated urbanization are conducive to vector spread in both urban and rural environments, yet mechanisms of viral amplification in vector populations is often overlooked when assessing risks for outbreaks. Thus, the characterization of local arbovirus circulation in mosquito populations is imperative to better inform risk assessments and vector control practices. Aedes species mosquitoes were captured at varying stages of their life cycle during different seasons between January 2014 and May 2016 at four distinct sites in Kenya, and tested for chikungunya (CHIKV), dengue (DENV) and Zika (ZIKV) viruses by RT-PCR. CHIKV was detected in 45 (5.9%) and DENV in 3 (0.4%) mosquito pools. No ZIKV was detected. Significant regional variation in prevalence was observed, with greater frequency of CHIKV on the coast. DENV was detected exclusively on the coast. Both viruses were detected in immature mosquitoes of both sexes, providing evidence of transovarial transmission of these arboviruses in local mosquitoes. This phenomenon may be driving underlying viral maintenance that may largely contribute to periodic re-emergence among humans in Kenya. Transovarial transmission, or vertical transmission, is the spread of a pathogen from parent to offspring. It has been observed that some mosquito-borne viruses can be transmitted from female mosquitoes to their offspring during follicle development or during oviposition. The occurrence of transovarial transmission is evident in the presence of virally infected male mosquitoes, which typically do not take bloodmeals, and the presence of virus in immature mosquitoes of any sex. Transovarial transmission aids in the amplification of mosquito-borne viruses in the environment by increasing the number of infected mosquitoes in a given region, thus expanding the possibility of viral transmission to humans. The combination of transovarial transmission and the preservation of viable eggs during dry seasons may trigger sudden amplification of the virus after rainy periods, resulting in an outbreak. This study provides some of the first evidence of transovarial transmission of chikungunya and dengue viruses in Aedes aegypti mosquitoes in Africa during interepidemic periods, which has important implications for local virus persistence and epidemic patterns.
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23
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Langat SK, Eyase FL, Berry IM, Nyunja A, Bulimo W, Owaka S, Ofula V, Limbaso S, Lutomiah J, Jarman R, Distelhorst J, Sang RC. Origin and evolution of dengue virus type 2 causing outbreaks in Kenya: Evidence of circulation of two cosmopolitan genotype lineages. Virus Evol 2020; 6:veaa026. [PMID: 32523778 PMCID: PMC7266482 DOI: 10.1093/ve/veaa026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Dengue fever (DF) is an arboviral disease caused by dengue virus serotypes 1-4 (DENV 1-4). Globally, DF incidence and disease burden have increased in the recent past. Initially implicated in a 1982 outbreak, DENV-2 recently reemerged in Kenya causing outbreaks between 2011 and 2014 and more recently 2017–8. The origin and the evolutionary patterns that may explain the epidemiological expansion and increasing impact of DENV-2 in Kenya remain poorly understood. Using whole-genome sequencing, samples collected during the 2011–4 and 2017–8 dengue outbreaks were analyzed. Additional DENV-2 genomes were downloaded and pooled together with the fourteen genomes generated in this study. Bioinformatic methods were used to analyze phylogenetic relationships and evolutionary patterns of DENV-2 causing outbreaks in Kenya. The findings from this study have shown the first evidence of circulation of two different Cosmopolitan genotype lineages of DENV-2; Cosmopolitan-I (C-I) and Cosmopolitan-II (C-II), in Kenya. Our results put the origin location of C-I lineage in India in 2011, and C-II lineage in Burkina Faso between 1979 and 2013. C-I lineage was the most isolated during recent outbreaks, thus showing the contribution of this newly emerged strain to the increased DENV epidemics in the region. Our findings, backed by evidence of recent local epidemics that have been associated with C-I in Kenya and C-II in Burkina Faso, add to the growing evidence of expanding circulation and the impact of multiple strains of DENV in the region as well as globally. Thus, continued surveillance efforts on DENV activity and its evolutionary trends in the region, would contribute toward effective control and the current vaccine development efforts.
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Affiliation(s)
- Solomon K Langat
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Fredrick Lunyagi Eyase
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology
| | | | - Albert Nyunja
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Wallace Bulimo
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Department of Biochemistry, University of Nairobi
| | - Samuel Owaka
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Victor Ofula
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Samson Limbaso
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Center for Virus Research, Kenya Medical Research Institute
| | - Joel Lutomiah
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Center for Virus Research, Kenya Medical Research Institute
| | - Richard Jarman
- Viral Diseases Branch, Walter Reed Army Institute of Research
| | - John Distelhorst
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Rosemary C Sang
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Center for Virus Research, Kenya Medical Research Institute
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24
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Futami K, Iwashita H, Higa Y, Lutiali PA, Sonye GO, Mwatele C, Njenga SM, Minakawa N. Geographical Distribution of Aedes aegypti aegypti and Aedes aegypti formosus (Diptera: Culicidae) in Kenya and Environmental Factors Related to Their Relative Abundance. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:772-779. [PMID: 31815285 DOI: 10.1093/jme/tjz233] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Indexed: 06/10/2023]
Abstract
The mosquito Aedes aegypti (L.) is the primary vector of various infectious viruses and is typified by a polymorphic color and abundance of white scales on the body. It has been conventionally separated into two subspecies, Ae. aeg. formosus (Walker) (Aaf) and Ae. aeg. aegypti (L.) (Aaa), with Aaf considered a 'sylvan' form and Aaa a 'domestic' form. Because the two subspecies show different susceptibilities to dengue viruses it is important to understand their distribution. In this study, we collected larvae from artificial and natural habitats in southern Kenya and reared them to adults to morphologically identify subspecies. We describe the geographical distribution and relative abundance of Aaa and Aaf in Kenya, and estimate the environmental factors associated with their distributions by GIS using climate and environment data. A total of 5,243 Ae. aegypti adults were collected from 249 sites, with Aaa accounting for 22% of the specimens. The relative abundance of Aaa was higher in coastal areas versus sites in western Kenya. Aaa abundance was also higher in urbanized than forested areas, which is consistent with known ecology. In contrast and inconsistent with previous studies, both Aaa and Aaf were sympatric in artificial and natural habitats. The high relative abundance of Aaa in coastal areas might derive from old populated cities, climate, and/or introduction from abroad.
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Affiliation(s)
- K Futami
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - H Iwashita
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- Department of Bacteriology, Graduate School of Medicine, University of the Ryukyus, Nishiharacho, Okinawa, Japan
| | - Y Higa
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | - P A Lutiali
- Center for Research in Tropical Medicine and Community Development (CRTMCD), Nairobi, Kenya
| | - G O Sonye
- ASK Community Based Organization located in Mbita, Homabay, Kenya
| | - C Mwatele
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute, Nairobi, Kenya
| | - S M Njenga
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute, Nairobi, Kenya
| | - N Minakawa
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
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25
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Abdullahi IN, Akande AO, Muhammed Y, Rogo LD, Oderinde BS. Prevalence Pattern of Chikungunya Virus Infection in Nigeria: A Four Decade Systematic Review and Meta-analysis. Pathog Glob Health 2020; 114:111-116. [PMID: 32191166 DOI: 10.1080/20477724.2020.1743087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Chikungunya (CHIK) is a re-emerging and myo-arthritogenic arboviral infection that has affected significant global population. However, CHIK is a neglected disease in Nigeria. This study aimed to estimate the pooled prevalence pattern of CHIK virus infection in Nigeria. A systematic review of eligible articles was conducted from "PubMed", "Scopus", "Google Scholar" and "Web of Science", between January 1980 to February 2020. Peer-reviewed articles describing CHIKV infection in cross-sectional studies were systematically reviewed. Random-effect model was used to pool the prevalence of CHIKV infection and associated sociodemographic data reported from eligible studies. In total, there were 10 published articles on CHIKV infection. Of these, 7 were cross-sectional studies, which comprised of 1347 pooled participants. The pooled anti-CHIKV IgM and IgG seroprevalence were 26.7% (95% CI: 23.2 - 30.4) and 29.3% (95% CI: 26.2 -32.6), respectively. Of the pooled studies, there were 3.8% (95% CI: 2.0-6.4) CHIKV RNA positive cases and 46.1% prevalence of CHIKV neutralizing antibodies. Of the 6 geopolitical zones in Nigeria, Northeast had the highest serological evidence of CHIKV infection. There was a significance association between the prevalence of anti-CHIKV and geopolitical zones of Nigeria (χ²= 70.04; p˂0.0001). Sex (p ˂0.0001; OR= 1.87 [1.47 - 2.38]) and level of education (p ˂0.0001; OR= 2.74 [1.89 - 3.95]) were significant risk factors for pooled anti-CHIKV IgM seropositivity. However, no significant association was found with other sociodemographic variables (p ˃0.05). Although there was paucity of data on CHIKV research in Nigeria, this meta-analysis revealed a high prevalence of CHIKV infection in the country.
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Affiliation(s)
- Idris Nasir Abdullahi
- Department of Medical Microbiology and Parasitology, Faculty of Clinical Sciences, Bayero University, Kano, Nigeria.,Department of Medical Laboratory Science, Faculty of Allied Health Sciences, Ahmadu Bello University, Zaria, Nigeria
| | - Azeez Oyebanji Akande
- Department of Medical Microbiology and Parasitology, Faculty of Clinical Sciences, Bayero University, Kano, Nigeria
| | - Yusuf Muhammed
- Department of Medical Microbiology and Parasitology, Faculty of Clinical Sciences, Bayero University, Kano, Nigeria
| | - Lawal Dahiru Rogo
- Department of Medical Laboratory Science, Faculty of Allied Health Sciences, Bayero University, Kano, Nigeria
| | - Bamidele Soji Oderinde
- Department of Medical Laboratory Science, Faculty of Allied Health Sciences, University of Maiduguri, Maiduguri, Nigeria
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26
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Barsosio HC, Gitonga JN, Karanja HK, Nyamwaya DK, Omuoyo DO, Kamau E, Hamaluba MM, Nyiro JU, Kitsao BS, Nyaguara A, Mwakio S, Newton CR, Sang R, Wright D, Sanders EJ, Seale AC, Agoti CN, Berkley JA, Bejon P, Warimwe GM. Congenital microcephaly unrelated to flavivirus exposure in coastal Kenya. Wellcome Open Res 2020; 4:179. [PMID: 32175480 PMCID: PMC7059837 DOI: 10.12688/wellcomeopenres.15568.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2019] [Indexed: 11/20/2022] Open
Abstract
Background: Zika virus (ZIKV) was first discovered in East Africa in 1947. ZIKV has caused microcephaly in the Americas, but it is not known whether ZIKV is a cause of microcephaly in East Africa. Methods: We used surveillance data from 11,061 live births at Kilifi County Hospital in coastal Kenya between January 2012 and October 2016 to identify microcephaly cases and conducted a nested case-control study to determine risk factors for microcephaly. Gestational age at birth was estimated based on antenatal ultrasound scanning ('Scanned cohort') or last menstrual period ('LMP cohort', including births ≥37 weeks' gestation only). Controls were newborns with head circumference Z scores between >-2 and ≤2 SD that were compared to microcephaly cases in relation to ZIKV exposure and other maternal and newborn factors. Results: Of the 11,061 newborns, 214 (1.9%, 95%CI 1.69, 2.21) had microcephaly. Microcephaly prevalence was 1.0% (95%CI 0.64, 1.70, n=1529) and 2.1% (95%CI 1.81, 2.38, n=9532) in the scanned and LMP cohorts, respectively. After excluding babies <2500 g (n=1199) in the LMP cohort the prevalence was 1.1% (95%CI 0.93, 1.39). Microcephaly showed an association with being born small for gestational age (p<0.001) but not with ZIKV neutralising antibodies (p=0.6) or anti-ZIKV NS1 IgM response (p=0.9). No samples had a ZIKV neutralising antibody titre that was at least fourfold higher than the corresponding dengue virus (DENV) titre. No ZIKV or other flavivirus RNA was detected in cord blood from cases or controls. Conclusions: Microcephaly was prevalent in coastal Kenya, but does not appear to be related to ZIKV exposure; the ZIKV response observed in our study population was largely due to cross-reactive responses to DENV or other related flaviviruses. Further research into potential causes and the clinical consequences of microcephaly in this population is urgently needed.
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Affiliation(s)
- Hellen C Barsosio
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Liverpool School of Tropical Medicine, Liverpool, UK
| | | | | | | | | | - Everlyn Kamau
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Joyce U Nyiro
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Amek Nyaguara
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Stella Mwakio
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Charles R Newton
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Daniel Wright
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,The Jenner Institute, University of Oxford, Oxford, UK
| | | | - Anna C Seale
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,London School of Hygiene & Tropical Medicine, London, UK
| | | | - James A Berkley
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | - George M Warimwe
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
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27
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Masika MM, Korhonen EM, Smura T, Uusitalo R, Vapalahti K, Mwaengo D, Jääskeläinen AJ, Anzala O, Vapalahti O, Huhtamo E. Detection of dengue virus type 2 of Indian origin in acute febrile patients in rural Kenya. PLoS Negl Trop Dis 2020; 14:e0008099. [PMID: 32126086 PMCID: PMC7069648 DOI: 10.1371/journal.pntd.0008099] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 03/13/2020] [Accepted: 01/29/2020] [Indexed: 01/25/2023] Open
Abstract
Dengue virus (DENV) has caused recent outbreaks in coastal cities of Kenya, but the epidemiological situation in other areas of Kenya is largely unknown. We investigated the role of DENV infection as a cause of acute febrile disease in non-epidemic settings in rural and urban study areas in Kenya. Altogether, 560 patients were sampled in 2016–2017 in rural Taita–Taveta County (n = 327) and urban slums of Kibera, Nairobi (n = 233). The samples were studied for DENV IgM, IgG, NS1 antigen and flaviviral RNA. IgG seroprevalence was found to be higher in Taita–Taveta (14%) than in Nairobi (3%). Five Taita–Taveta patients were positive for flaviviral RNA, all identified as DENV-2, cosmopolitan genotype. Local transmission in Taita–Taveta was suspected in a patient without travel history. The sequence analysis suggested that DENV-2 strains circulating in coastal and southern Kenya likely arose from a single introduction from India. The molecular clock analyses dated the most recent ancestor to the Kenyan strains a year before the large 2013 outbreak in Mombasa. After this, the virus has been detected in Kilifi in 2014, from our patients in Taita–Taveta in 2016, and in an outbreak in Malindi in 2017. The results highlight that silent transmission occurs between epidemics and also affects rural areas. More information is needed to understand the local epidemiological characteristics and future risks of dengue in Kenya. Dengue virus (DENV) is an emerging mosquito-borne global health threat in the tropics and subtropics. The majority of the world’s population live in areas at risk of dengue that can cause a wide variety of symptoms from febrile illness to haemorrhagic fever. Information of DENV in Africa is limited and fragmented. In Kenya, dengue is a recognized disease in coastal cities that have experienced recent outbreaks. We investigated the role of DENV infection as a cause of acute febrile disease in non-epidemic settings in rural and urban study areas in Kenya. We found DENV-2 in five febrile patients from rural Taita–Taveta, where no dengue has been reported before. Genetic analysis of the virus suggests it to be most likely of Indian origin. This Indian origin DENV-2 was detected in the Mombasa outbreak in 2013, in Kilifi in 2014, in Taita–Taveta in 2016 (our study samples) and again in the Malindi outbreak in 2017. The results suggest that dengue is unrecognized in rural Kenya and more studies are needed for local risk assessment. Our findings of virus transmission between epidemics contribute to better understanding of the epidemiological situation and origins of DENV in Kenya.
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Affiliation(s)
- Moses Muia Masika
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
- KAVI Institute of Clinical Research, University of Nairobi, Nairobi, Kenya
| | - Essi M. Korhonen
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Teemu Smura
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
| | - Ruut Uusitalo
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
| | - Katariina Vapalahti
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Dufton Mwaengo
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
- Institute of Tropical and Infectious Diseases, University of Nairobi, Nairobi, Kenya
| | - Anne J. Jääskeläinen
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Virology and Immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Omu Anzala
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
- KAVI Institute of Clinical Research, University of Nairobi, Nairobi, Kenya
| | - Olli Vapalahti
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- Department of Virology and Immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Eili Huhtamo
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
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28
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Shoemaker TR, Nyakarahuka L, Balinandi S, Ojwang J, Tumusiime A, Mulei S, Kyondo J, Lubwama B, Sekamatte M, Namutebi A, Tusiime P, Monje F, Mayanja M, Ssendagire S, Dahlke M, Kyazze S, Wetaka M, Makumbi I, Borchert J, Zufan S, Patel K, Whitmer S, Brown S, Davis WG, Klena JD, Nichol ST, Rollin PE, Lutwama J. First Laboratory-Confirmed Outbreak of Human and Animal Rift Valley Fever Virus in Uganda in 48 Years. Am J Trop Med Hyg 2020; 100:659-671. [PMID: 30675833 PMCID: PMC6402942 DOI: 10.4269/ajtmh.18-0732] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In March 2016, an outbreak of Rift Valley fever (RVF) was identified in Kabale district, southwestern Uganda. A comprehensive outbreak investigation was initiated, including human, livestock, and mosquito vector investigations. Overall, four cases of acute, nonfatal human disease were identified, three by RVF virus (RVFV) reverse transcriptase polymerase chain reaction (RT-PCR), and one by IgM and IgG serology. Investigations of cattle, sheep, and goat samples from homes and villages of confirmed and probable RVF cases and the Kabale central abattoir found that eight of 83 (10%) animals were positive for RVFV by IgG serology; one goat from the home of a confirmed case tested positive by RT-PCR. Whole genome sequencing from three clinical specimens was performed and phylogenetic analysis inferred the relatedness of 2016 RVFV with the 2006–2007 Kenya-2 clade, suggesting previous introduction of RVFV into southwestern Uganda. An entomological survey identified three of 298 pools (1%) of Aedes and Coquillettidia species that were RVFV positive by RT-PCR. This was the first identification of RVFV in Uganda in 48 years and the 10th independent viral hemorrhagic fever outbreak to be confirmed in Uganda since 2010.
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Affiliation(s)
- Trevor R Shoemaker
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia.,Viral Special Pathogens Branch, Centers for Disease Control and Prevention-Uganda, Entebbe, Uganda
| | - Luke Nyakarahuka
- Department of Biosecurity, Ecosystems and Veterinary Public Health, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda.,Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Stephen Balinandi
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention-Uganda, Entebbe, Uganda
| | - Joseph Ojwang
- Global Health Security Unit, Centers for Disease Control and Prevention-Uganda, Kampala, Uganda
| | - Alex Tumusiime
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention-Uganda, Entebbe, Uganda
| | - Sophia Mulei
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Jackson Kyondo
- Department of Biosecurity, Ecosystems and Veterinary Public Health, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | | | | | | | | | - Fred Monje
- Ministry of Agriculture, Animal Industry and Fisheries, Kampala, Uganda
| | - Martin Mayanja
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | | | - Melissa Dahlke
- Public Health Emergency Operations Centre, Ministry of Health, Kampala, Uganda
| | - Simon Kyazze
- Public Health Emergency Operations Centre, Ministry of Health, Kampala, Uganda
| | - Milton Wetaka
- Public Health Emergency Operations Centre, Ministry of Health, Kampala, Uganda
| | - Issa Makumbi
- Public Health Emergency Operations Centre, Ministry of Health, Kampala, Uganda
| | - Jeff Borchert
- Global Health Security Unit, Centers for Disease Control and Prevention-Uganda, Kampala, Uganda
| | - Sara Zufan
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Ketan Patel
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Shannon Whitmer
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Shelley Brown
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - William G Davis
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - John D Klena
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stuart T Nichol
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Pierre E Rollin
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Julius Lutwama
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
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29
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Inziani M, Adungo F, Awando J, Kihoro R, Inoue S, Morita K, Obimbo E, Onyango F, Mwau M. Seroprevalence of yellow fever, dengue, West Nile and chikungunya viruses in children in Teso South Sub-County, Western Kenya. Int J Infect Dis 2019; 91:104-110. [PMID: 31712089 DOI: 10.1016/j.ijid.2019.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/01/2019] [Accepted: 11/03/2019] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND Arboviruses often cause widespread morbidity in children in endemic regions. Data on the burden of arboviruses in Kenyan children are limited. OBJECTIVES This study was performed to determine the seroprevalence of yellow fever (YFV), dengue (DENV), West Nile (WNV), and chikungunya (CHIKV) viruses among children 1-12 years of age at two health facilities in Teso South Sub-County in Western Kenya. METHODS In a hospital-based cross-sectional survey, a questionnaire was used to collect socio-demographic information. Serum drawn from the children was tested for IgA/IgM/IgG serocomplex antibodies to selected arboviruses using indirect ELISA and plaque reduction neutralization tests. RESULTS A total of 182 (27.7%) of the 656 participants tested were positive for any arbovirus antibody. Of these, 4.4% (29/656) tested positive for YFV, 9.6% (62/649) for WNV, 5.6% (36/649) for CHIKV, 1.4% (5/368) for DENV1, 9% (59/656) for DENV2, and 19.7% (40/203) for DENV3. Neutralizing antibodies to CHIKV were found in 77.8% (42/54) of participants, to YFV in 15.8% (3/19), to DENV2 in 58% (29/50), and to WNV in 8% (1/55). Sex, age, urban residence, schooling, and lack of vaccination were associated with arbovirus exposure. CONCLUSIONS This study confirmed that children under 12 years of age in Teso South Sub-County are exposed to ongoing arbovirus infections early in life.
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Affiliation(s)
- Mary Inziani
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya.
| | - Ferdinard Adungo
- Centre for Infectious and Parasitic Diseases Control Research (CIPDCR), Kenya Medical Research Institute, Busia, Kenya
| | - Janet Awando
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Richelle Kihoro
- Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Shingo Inoue
- Nagasaki University Africa Research Station, Nairobi, Kenya
| | - Kouichi Morita
- Nagasaki University Institute of Tropical Medicine, Nagasaki, Japan
| | - Elizabeth Obimbo
- Department of Paediatrics and Child Health, University of Nairobi, Nairobi, Kenya
| | - Francis Onyango
- Department of Paediatrics and Child Health, University of Nairobi, Nairobi, Kenya
| | - Matilu Mwau
- Centre for Infectious and Parasitic Diseases Control Research (CIPDCR), Kenya Medical Research Institute, Busia, Kenya
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30
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Hortion J, Mutuku FM, Eyherabide AL, Vu DM, Boothroyd DB, Grossi-Soyster EN, King CH, Ndenga BA, LaBeaud AD. Acute Flavivirus and Alphavirus Infections among Children in Two Different Areas of Kenya, 2015. Am J Trop Med Hyg 2019; 100:170-173. [PMID: 30457092 DOI: 10.4269/ajtmh.18-0297] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Alphaviruses and flaviviruses are known to be endemic in Eastern Africa, but few data are available to evaluate the prevalence of these infections. This leads to missed opportunities for prevention against future outbreaks. This cohort study investigated the frequency of alphavirus and flavivirus incident infections in two regions of Kenya and identified potential risk factors. Seroconversions for alphavirus and flavivirus infections were identified by immunoglobulin G enzyme-linked immunosorbent assay (IgG-ELISA) in a cohort of 1,604 acutely ill children over the year 2015. The annual incidence was 0.5% (0.2-1.2%) for alphaviruses and 1.2% (0.7-2.2%) for flaviviruses. Overall, seroprevalence was significantly higher for alphaviruses in western Kenya than on the coast (P = 0.014), whereas flavivirus seroprevalence was higher on the coast (P = 0.044). Poverty indicators did not emerge as risk factors, but reliance on household water storage was associated with increased exposure to both alphaviruses and flaviviruses (odds ratio = 2.3).
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Affiliation(s)
- Jimmy Hortion
- Division of Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California.,Département de Biologie, Ecole Normale Supérieure de Lyon, Lyon, France
| | - Francis M Mutuku
- Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Ana L Eyherabide
- Departamento de Pediatría, Sanatorio de Niños, Rosario, Argentina
| | - David M Vu
- Division of Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Derek B Boothroyd
- Quantitative Science Unit, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | | | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Bryson A Ndenga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
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31
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Chepkorir E, Tchouassi DP, Konongoi SL, Lutomiah J, Tigoi C, Irura Z, Eyase F, Venter M, Sang R. Serological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016-2017. Virol J 2019; 16:65. [PMID: 31101058 PMCID: PMC6525424 DOI: 10.1186/s12985-019-1176-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/06/2019] [Indexed: 01/05/2023] Open
Abstract
Background Yellow fever, Dengue, West Nile and Zika viruses are re-emerging mosquito-borne Flaviviruses of public health concern. However, the extent of human exposure to these viruses and associated disease burden in Kenya and Africa at large remains unknown. We assessed the seroprevalence of Yellow fever and other Flaviviruses in human populations in West Pokot and Turkana Counties of Kenya. These areas border Uganda, South Sudan and Ethiopia where recent outbreaks of Yellow fever and Dengue have been reported, with possibility of spillover to Kenya. Methodology Human serum samples collected through a cross-sectional survey in West Pokot and Turkana Counties were screened for neutralizing antibodies to Yellow fever, Dengue-2, West Nile and Zika virus using the Plaque Reduction Neutralization Test (PRNT). Seroprevalence was compared by county, site and important human demographic characteristics. Adjusted odds ratios (aOR) were estimated using Firth logistic regression model. Results Of 877 samples tested, 127 neutralized with at least one of the four flaviviruses (14.5, 95% CI 12.3–17.0%), with a higher proportion in Turkana (21.1%, n = 87/413) than in West Pokot (8.6%, n = 40/464). Zika virus seroprevalence was significantly higher in West Pokot (7.11%) than in Turkana County (0.24%; χ2P < 0.0001). A significantly higher Yellow fever virus seroprevalence was also observed in Turkana (10.7%) compared to West Pokot (1.29%; χ2 P < 0.0001). A high prevalence of West Nile virus was detected in Turkana County only (10.2%) while Dengue was only detected in one sample, from West Pokot. The odds of infection with West Nile virus was significantly higher in males than in females (aOR = 2.55, 95% CI 1.22–5.34). Similarly, the risk of Zika virus infection in West Pokot was twice higher in males than females (aOR = 2.01, 95% CI 0.91–4.41). Conclusion Evidence of neutralizing antibodies to West Nile and Zika viruses indicates that they have been circulating undetected in human populations in these areas. While the observed Yellow Fever prevalence in Turkana and West Pokot Counties may imply virus activity, we speculate that this could also be as a result of vaccination following the Yellow Fever outbreak in the Omo river valley, South Sudan and Uganda across the border. Electronic supplementary material The online version of this article (10.1186/s12985-019-1176-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- E Chepkorir
- International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya. .,Center for Viral Zoonoses, Department of Medical Virology, University of Pretoria, P. O. Box 323, Arcadia, 0007, South Africa.
| | - D P Tchouassi
- International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya
| | - S L Konongoi
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54628-00200, Nairobi, Kenya
| | - J Lutomiah
- Center for Virus Research, Kenya Medical Research Institute, P. O. Box 54628-00200, Nairobi, Kenya
| | - C Tigoi
- International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya
| | - Z Irura
- Division of Disease Surveillance and Response, Ministry of Health, P. O. Box 20781-00202, Nairobi, Kenya
| | - F Eyase
- Jomo Kenyatta University of Agriculture and Technology, P.O. Box 606, Village Market, Nairobi, Kenya
| | - M Venter
- Center for Viral Zoonoses, Department of Medical Virology, University of Pretoria, P. O. Box 323, Arcadia, 0007, South Africa
| | - R Sang
- International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya
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32
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Nemg Simo FB, Sado Yousseu FB, Evouna Mbarga A, Bigna JJ, Melong A, Ntoude A, Kamgang B, Bouyne R, Moundipa Fewou P, Demanou M. Investigation of an Outbreak of Dengue Virus Serotype 1 in a Rural Area of Kribi, South Cameroon: A Cross-Sectional Study. Intervirology 2019; 61:265-271. [PMID: 31048588 DOI: 10.1159/000499465] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 03/08/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND On May 2017, a case of dengue serotype 1 was detected and confirmed through routine surveillance in a traveler returning from Kribi, a seaside town of Southern Cameroon. This study aimed at confirming the circulation of dengue virus (DENV) in Southern Cameroon. METHODS A cross sectional study was carried out in Londji near Kribi from June 21-25, 2017, by a joint team of Centre Pasteur of Cameroon and the Department of Diseases, Epidemics and Pandemics Control. Blood samples of consented participants were collected and tested for anti-D ENV IgM using an IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA), and for the detection of Zika, dengue, or chikungunya viruses using Trioplex real-time reverse transcription-polymerase chain reaction (RT-PCR). DENV RNA-positive samples were serotyped using an end-point nested RT-PCR. RESULTS Ninety-one participants were enrolled, 50.55% (46/91) of them males. The mean age of the population was 30.71 years (±18.89). In total, 14.28% (13/91) of the participants had DENV infection (3 anti-DENV IgM positive and 10 DENV serotype 1 RT-PCR positive). CONCLUSION The detection of DENV serotype 1 in an autochthonous population during this survey is a confirmation that the seaside city of Kribi is a risk area for contracting dengue infection in Cameroon.
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Affiliation(s)
- Fredy Brice Nemg Simo
- National Reference Laboratory for Chikungunya and Dengue, Department of Virology, Centre Pasteur of Cameroon, Yaoundé, Cameroon.,Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Francine Berlange Sado Yousseu
- National Reference Laboratory for Chikungunya and Dengue, Department of Virology, Centre Pasteur of Cameroon, Yaoundé, Cameroon
| | - Armel Evouna Mbarga
- Cameroon Field Epidemiology Training Program, Ministry of Public Health, Yaoundé, Cameroon
| | - Jean Joel Bigna
- School of Public Health, Faculty of Medicine, University of Paris Sud, Kremlin Bicêtre, Paris, France
| | - Armel Melong
- Cameroon Field Epidemiology Training Program, Ministry of Public Health, Yaoundé, Cameroon
| | - Anicet Ntoude
- Délégation régionale de la santé publique du Sud Cameroun, Ebolowa, Cameroon
| | - Basile Kamgang
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Raphael Bouyne
- Centre Médico-Social de l'Ambassade de France, Yaoundé, Cameroon
| | - Paul Moundipa Fewou
- Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Maurice Demanou
- National Reference Laboratory for Chikungunya and Dengue, Department of Virology, Centre Pasteur of Cameroon, Yaoundé, Cameroon,
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33
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Kolawole OM, Adelaiye G, Ogah JI. Emergence and Associated Risk Factors of Vector Borne West Nile Virus Infection in Ilorin, Nigeria. J Arthropod Borne Dis 2018; 12:341-350. [PMID: 30918903 PMCID: PMC6423457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 08/05/2018] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND West Nile Virus (WNV) is a mosquito-borne viral pathogen that is the causative agent of West Nile fever and encephalitis. Diagnostic tools for WNV infection in Nigeria are not well established hence the current prevalence rate of WNV infection in Nigeria is unknown. We aimed to establish the serological prevalence of WNV infection in febrile patients in Ilorin, Nigeria in 2016, and to assess the risk factors associated with the acquisition of the virus. METHODS This was a cross-sectional study involving the screening of subjects presenting with febrile illnesses. While specific IgM ELISA was used to determine the seroprevalence, a closed-ended questionnaire was used to ascertain the risk factors associated with this viral infection. RESULTS Fifteen (7.5%) of the respondents were positive for WNV infection. Subjects living in areas in close proximity to trees and bushes (P= 0.011) and stagnant water (P= 0.001) were at a higher risk of having WNV infection. Other risk factors associated with WNV among the respondents include the none use of insecticide (P= 0.001), sitting out at night (P= 0.044), HIV positivity (P= 0.003) and having an organ transplant (P= 0.002). CONCLUSION This study clearly shows a considerable WNV infection in Ilorin, with the presence of factors that can promulgate an outbreak, hence a need for further surveillance in the study area.
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Chikungunya virus infection prevalence in Africa: a contemporaneous systematic review and meta-analysis. Public Health 2018; 166:79-88. [PMID: 30468973 DOI: 10.1016/j.puhe.2018.09.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 09/20/2018] [Accepted: 09/27/2018] [Indexed: 02/05/2023]
Abstract
OBJECTIVES The (re)emergence of chikungunya virus (CHIKV) in Africa requires better knowledge on the epidemiology of CHIKV infection in the continent for efficient public health strategies. We aimed to describe the epidemiology of CHIKV infection in Africa, a neglected tropical disease (NTD). STUDY DESIGN This was a systematic review with meta-analysis of studies reporting CHIKV infection prevalence. We searched Embase, PubMed, Africa Journal Online and Global Index Medicus to identify observational studies published from January 2000 to September 2017. METHODS We used a random-effect model to pool the prevalence of CHIKV infections reported with their 95% confidence interval (CI). Heterogeneity was assessed via the Chi-squared test on Cochran's Q statistic. Review registration is in PROSPERO CRD42017080395. RESULTS A total of 39 studies (37,881 participants; 18 countries) were included. No study was reported from Southern Africa. Thirty-two (82.0%), seven (18.0%) and no studies had low, moderate and high risk of bias, respectively. Outside outbreak periods, the pooled immunoglobulin M (IgM) and immunoglobulin G (IgG) seroprevalence was 9.7% (95% CI 3.0-19.6; 16 studies) and 16.4% (95% CI 9.1-25.2; 23 studies), respectively. The IgM seroprevalence was lower in Northern Africa, and there was no difference for IgG prevalence across regions in Africa. The IgM and IgG seroprevalences were not different between acute and non-acute febrile participants. The seroprevalence was not associated with GPS coordinates (latitude, longitude and altitude). CONCLUSIONS Although considered a NTD, we find high prevalence of CHIKV infection in Africa. As such, chikungunya fever should deserve more attention from healthcare providers, researchers, policymakers and stakeholders from many sectors.
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Ajamma YU, Onchuru TO, Ouso DO, Omondi D, Masiga DK, Villinger J. Vertical transmission of naturally occurring Bunyamwera and insect-specific flavivirus infections in mosquitoes from islands and mainland shores of Lakes Victoria and Baringo in Kenya. PLoS Negl Trop Dis 2018; 12:e0006949. [PMID: 30452443 PMCID: PMC6287884 DOI: 10.1371/journal.pntd.0006949] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 12/10/2018] [Accepted: 10/26/2018] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Many arboviruses transmitted by mosquitoes have been implicated as causative agents of both human and animal illnesses in East Africa. Although epidemics of arboviral emerging infectious diseases have risen in frequency in recent years, the extent to which mosquitoes maintain pathogens in circulation during inter-epidemic periods is still poorly understood. This study aimed to investigate whether arboviruses may be maintained by vertical transmission via immature life stages of different mosquito vector species. METHODOLOGY We collected immature mosquitoes (egg, larva, pupa) on the shores and islands of Lake Baringo and Lake Victoria in western Kenya and reared them to adults. Mosquito pools (≤25 specimens/pool) of each species were screened for mosquito-borne viruses by high-resolution melting analysis and sequencing of multiplex PCR products of genus-specific primers (alphaviruses, flaviviruses, phleboviruses and Bunyamwera-group orthobunyaviruses). We further confirmed positive samples by culturing in baby hamster kidney and Aedes mosquito cell lines and re-sequencing. PRINCIPAL FINDINGS Culex univittatus (2/31pools) and Anopheles gambiae (1/77 pools) from the Lake Victoria region were positive for Bunyamwera virus, a pathogenic virus that is of public health concern. In addition, Aedes aegypti (3/50), Aedes luteocephalus (3/13), Aedes spp. (2/15), and Culex pipiens (1/140) pools were positive for Aedes flaviviruses at Lake Victoria, whereas at Lake Baringo, three pools of An. gambiae mosquitoes were positive for Anopheles flavivirus. These insect-specific flaviviruses (ISFVs), which are presumably non-pathogenic to vertebrates, were found in known medically important arbovirus and malaria vectors. CONCLUSIONS Our results suggest that not only ISFVs, but also a pathogenic arbovirus, are naturally maintained within mosquito populations by vertical transmission, even in the absence of vertebrate hosts. Therefore, virus and vector surveillance, even during inter-epidemics, and the study of vector-arbovirus-ISFV interactions, may aid in identifying arbovirus transmission risks, with the potential to inform control strategies that lead to disease prevention.
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Affiliation(s)
| | - Thomas Ogao Onchuru
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany
| | - Daniel O. Ouso
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - David Omondi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Biochemistry and Molecular Biology Department, Egerton University, Egerton, Kenya
| | - Daniel K. Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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Vector competence of Aedes bromeliae and Aedes vitattus mosquito populations from Kenya for chikungunya virus. PLoS Negl Trop Dis 2018; 12:e0006746. [PMID: 30321181 PMCID: PMC6207330 DOI: 10.1371/journal.pntd.0006746] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 10/30/2018] [Accepted: 08/10/2018] [Indexed: 11/19/2022] Open
Abstract
Background Kenya has experienced outbreaks of chikungunya in the past years with the most recent outbreak occurring in Mandera in the northern region in May 2016 and in Mombasa in the coastal region from November 2017 to February 2018. Despite the outbreaks in Kenya, studies on vector competence have only been conducted on Aedes aegypti. However, the role played by other mosquito species in transmission and maintenance of the virus in endemic areas remains unclear. This study sought to determine the possible role of rural Aedes bromeliae and Aedes vittatus in the transmission of chikungunya virus, focusing on Kilifi and West Pokot regions of Kenya. Methods Four day old female mosquitoes were orally fed on chikungunya virus-infected blood at a dilution of 1:1 of the viral isolate and blood (106.4 plaque-forming units [PFU]/ml) using artificial membrane feeder (Hemotek system) for 45 minutes. The engorged mosquitoes were picked and incubated at 29–30°C ambient temperature and 70–80% humidity in the insectary. At days 5, 7 and 10 post-infection, the mosquitoes were carefully dissected to separate the legs and wings from the body and their proboscis individually inserted in the capillary tube containing minimum essential media (MEM) to collect salivary expectorate. The resultant homogenates and the salivary expectorates were tested by plaque assay to determine virus infection, dissemination and transmission potential of the mosquitoes. Results A total of 515 female mosquitoes (311 Ae. bromeliae and 204 Ae. vittatus) were exposed to the East/Central/South Africa (ECSA) lineage of chikungunya virus. Aedes vittatus showed high susceptibility to the virus ranging between 75–90% and moderate dissemination and transmission rates ranging from 35–50%. Aedes bromeliae had moderate susceptibility ranging between 26–40% with moderate dissemination and transmission rates ranging from 27–55%. Conclusion This study demonstrates that both Ae. vittatus and Ae. bromeliae populations from West Pokot and Kilifi counties in Kenya are competent vectors of chikungunya virus. Based on these results, the two areas are at risk of virus transmission in the event of an outbreak. This study underscores the need to institute vector competence studies for populations of potential vector species as a means of evaluating risk of transmission of the emerging and re-emerging arboviruses in diverse regions of Kenya. Kenya experienced its first chikungunya outbreak in 2004/2005 along the coastal area, followed by sporadic outbreaks in Mandera in 2016, and subsequently in Mombasa city in late 2017 and early 2018. Despite the rising risk of transmission of the virus in the country based on evidence of outbreaks in Kenya, vector competence studies have only been limited to Ae. aegypti, while the role played by other Aedes species largely remain unknown. This study demonstrated the ability of Ae. bromeliae and Ae. vittatus to transmit chikungunya virus under controlled laboratory conditions. Vector competence remains the most important approach in disease risk assessment that provides knowledge to the public health sector in developing vector control guideline.
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Konongoi SL, Nyunja A, Ofula V, Owaka S, Koka H, Koskei E, Eyase F, Langat D, Mancuso J, Lutomiah J, Sang R. Human and entomologic investigations of chikungunya outbreak in Mandera, Northeastern Kenya, 2016. PLoS One 2018; 13:e0205058. [PMID: 30308064 PMCID: PMC6181335 DOI: 10.1371/journal.pone.0205058] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/19/2018] [Indexed: 01/14/2023] Open
Abstract
Chikungunya is a reemerging vector borne pathogen associated with severe morbidity in affected populations. Lamu, along the Kenyan coast was affected by a major chikungunya outbreak in 2004. Twelve years later, we report on entomologic investigations and laboratory confirmed chikungunya cases in northeastern Kenya. Patient blood samples were received at the Kenya Medical Research Institute (KEMRI) viral hemorrhagic fever laboratory and the immunoglobulin M enzyme linked immunosorbent assay (IgM ELISA) was used to test for the presence of IgM antibodies against chikungunya and dengue. Reverse transcription polymerase chain reaction (RT-PCR) utilizing flavivirus, alphavirus and chikungunya specific primers were used to detect acute infections and representative PCR positive samples sequenced to confirm the circulating strain. Immature mosquitoes were collected from water-holding containers indoors and outdoors in the affected areas in northeastern Kenya. A total of 189 human samples were tested; 126 from Kenya and 63 from Somalia. 52.9% (100/189) tested positive for Chikungunya virus (CHIKV) by either IgM ELISA or RT-PCR. Sequence analysis of selected samples revealed that the virus was closely related to that from China (2010). 29% (55/189) of the samples, almost all from northeastern Kenya or with a history of travel to northern Kenya, tested positive for dengue IgM antibodies. Entomologic risk assessment revealed high house, container and Breteau indices of, 14.5, 41.9 and 17.1% respectively. Underground water storage tanks were the most abundant, 30.1%, of which 77.4% were infested with Aedes aegypti mosquitoes. These findings confirm the presence of active chikungunya infections in the northeastern parts of Kenya. The detection of dengue IgM antibodies concurrently with chikungunya virus circulation emphasizes on the need for improved surveillance systems and diagnostic algorithms with the capacity to capture multiple causes of arbovirus infections as these two viruses share common vectors and eco-systems. In addition sustained entomological surveillance and vector control programs targeting most productive containers are needed to monitor changes in vector densities, for early detection of the viruses and initiate vector control efforts to prevent possible outbreaks.
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Affiliation(s)
- Samson Limbaso Konongoi
- Kenya Medical Research Institute, Nairobi, Kenya
- United States Army Medical Research Directorate, Nairobi, Kenya
| | - Albert Nyunja
- United States Army Medical Research Directorate, Nairobi, Kenya
| | - Victor Ofula
- United States Army Medical Research Directorate, Nairobi, Kenya
| | - Samuel Owaka
- United States Army Medical Research Directorate, Nairobi, Kenya
| | - Hellen Koka
- United States Army Medical Research Directorate, Nairobi, Kenya
| | - Edith Koskei
- United States Army Medical Research Directorate, Nairobi, Kenya
| | - Fredrick Eyase
- United States Army Medical Research Directorate, Nairobi, Kenya
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Daniel Langat
- Kenya Ministry of Health -Division of Disease Surveillance and Response, Nairobi, Kenya
| | - James Mancuso
- United States Army Medical Research Directorate, Nairobi, Kenya
| | - Joel Lutomiah
- Kenya Medical Research Institute, Nairobi, Kenya
- United States Army Medical Research Directorate, Nairobi, Kenya
| | - Rosemary Sang
- Kenya Medical Research Institute, Nairobi, Kenya
- United States Army Medical Research Directorate, Nairobi, Kenya
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Mengesha Tsegaye M, Beyene B, Ayele W, Abebe A, Tareke I, Sall A, Yactayo S, Shibeshi ME, Staples E, Belay D, Lilay A, Alemu A, Alemu E, Kume A, H/Mariam A, Ronveaux O, Tefera M, Kassa W, Bekele Weyessa A, Jima D, Kebede A, Tayachew A. Sero-prevalence of yellow fever and related Flavi viruses in Ethiopia: a public health perspective. BMC Public Health 2018; 18:1011. [PMID: 30107830 PMCID: PMC6092792 DOI: 10.1186/s12889-018-5726-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 06/19/2018] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Yellow fever (YF) is a viral hemorrhagic fever, endemic in the tropical forests of Africa and Central and South America. The disease is transmitted by mosquitoes infected with the yellow fever virus (YFV). Ethiopia was affected by the largest YF outbreak since the vaccination era during 1960-1962. The recent YF outbreak occurred in 2013 in Southern part of the country. The current survey of was carried out to determine the YF seroprevalence so as to make recommendations from YF prevention and control in Ethiopia. METHODOLOGY A multistage cluster design was utilized. Consequently, the country was divided into 5 ecological zones and two sampling towns were picked per zone randomly. A total of 1643 serum samples were collected from human participants. The serum samples were tested for IgG antibody against YFV using ELISA. Any serum sample testing positive by ELISA was confirmed by plaque reduction neutralization test (PRNT). In addition, differential testing was performed for other flaviviruses, namely dengue, Zika and West Nile viruses. RESULT Of the total samples tested, 10 (0.61%) were confirmed to be IgG positive against YFV and confirmed with PRNT. Nine (0.5%) samples were antibody positive for dengue virus, 15(0.9%) forWest Nile virus and 7 (0.4%) for Zika virus by PRNT. Three out of the five ecological zones namely zones 1, 3 and 5 showed low levels (< 2%) of IgG positivity against YFV. A total of 41(2.5%) cases were confirmed to be positive for one of flaviviruses tested. CONCLUSION Based on the seroprevalence data, the level of YFV activity and the risk of a YF epidemic in Ethiopia are low. However additional factors that could impact the likelihood of such an epidemic occurring should be considered before making final recommendations for YF prevention and control in Ethiopia. Based on the results of the serosurvey and other YF epidemic risk factors considered, a preventive mass vaccination campaign is not recommended, however the introduction of YF vaccine in routine EPI is proposed nationwide, along with strong laboratory based YF surveillance.
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Affiliation(s)
| | - Berhane Beyene
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Almaz Abebe
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Israel Tareke
- World Health Organizations, Country Office, Addis Ababa, Ethiopia
| | | | | | | | - Erin Staples
- Centers for Disease Control and Prevention, Atlanta, USA
| | - Desalegn Belay
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Abrham Lilay
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Abebe Alemu
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Emana Alemu
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Adugna Kume
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | | | - Mesfin Tefera
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | | | - Daddi Jima
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Amha Kebede
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Adamu Tayachew
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
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Clark MHA, Warimwe GM, Di Nardo A, Lyons NA, Gubbins S. Systematic literature review of Rift Valley fever virus seroprevalence in livestock, wildlife and humans in Africa from 1968 to 2016. PLoS Negl Trop Dis 2018; 12:e0006627. [PMID: 30036382 PMCID: PMC6072204 DOI: 10.1371/journal.pntd.0006627] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 08/02/2018] [Accepted: 06/22/2018] [Indexed: 02/03/2023] Open
Abstract
Background Rift Valley fever virus (RVFV) is a zoonotic arbovirus that causes severe disease in livestock and humans. The virus has caused recurrent outbreaks in Africa and the Arabian Peninsula since its discovery in 1931. This review sought to evaluate RVFV seroprevalence across the African continent in livestock, wildlife and humans in order to understand the spatio-temporal distribution of RVFV seroprevalence and to identify knowledge gaps and areas requiring further research. Risk factors associated with seropositivity were identified and study designs evaluated to understand the validity of their results. Methodology The Preferred Reporting of Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to produce a protocol to systematically search for RVFV seroprevalence studies in PubMed and Web of Science databases. The Strengthening the Reporting of Observational studies in Epidemiology (STROBE) statement guided the evaluation of study design and analyses. Principal findings A total of 174 RVFV seroprevalence studies in 126 articles fulfilled the inclusion criteria. RVFV seroprevalence was recorded in 31 African countries from 1968 to 2016 and varied by time, species and country. RVFV seroprevalence articles including either livestock and humans or livestock and wildlife seroprevalence records were limited in number (8/126). No articles considered wildlife, livestock and human seroprevalence concurrently, nor wildlife and humans alone. Many studies did not account for study design bias or the sensitivity and specificity of diagnostic tests. Conclusions Future research should focus on conducting seroprevalence studies at the wildlife, livestock and human interface to better understand the nature of cross-species transmission of RVFV. Reporting should be more transparent and biases accounted for in future seroprevalence research to understand the true burden of disease on the African continent. Rift Valley fever virus (RVFV) is a vector-borne virus that infects wildlife and livestock, and can subsequently spread to humans. Due to the nature of the disease it has the potential to cause substantial economic and public health impacts. Rift Valley Fever (RVF) has been identified in Africa and the Arabian Peninsula, but has the potential to spread more widely. This systematic review assessed the distribution of RVF in livestock and humans in Africa by collating all the relevant studies we could find, extracting the data and critically evaluating them. Understanding when and where RVF has occurred in Africa and why some animals and humans get disease helps target control strategies and, in particular, those that reduce spread from livestock to humans. Furthermore, by evaluating past studies we can ensure that future ones are more robust and reproducible, so they can help us better understand the disease.
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Affiliation(s)
- Madeleine H. A. Clark
- Transmission Biology Group, The Pirbright Institute, Pirbright, Woking, United Kingdom
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - George M. Warimwe
- Biosciences Department, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Antonello Di Nardo
- Vesicular Disease Reference Laboratories, The Pirbright Institute, Pirbright, Woking, United Kingdom
| | - Nicholas A. Lyons
- Vesicular Disease Reference Laboratories, The Pirbright Institute, Pirbright, Woking, United Kingdom
| | - Simon Gubbins
- Transmission Biology Group, The Pirbright Institute, Pirbright, Woking, United Kingdom
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Fritzell C, Rousset D, Adde A, Kazanji M, Van Kerkhove MD, Flamand C. Current challenges and implications for dengue, chikungunya and Zika seroprevalence studies worldwide: A scoping review. PLoS Negl Trop Dis 2018; 12:e0006533. [PMID: 30011271 PMCID: PMC6062120 DOI: 10.1371/journal.pntd.0006533] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 07/26/2018] [Accepted: 05/16/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Arboviral infections are a public health concern and an escalating problem worldwide. Estimating the burden of these diseases represents a major challenge that is complicated by the large number of unapparent infections, especially those of dengue fever. Serological surveys are thus required to identify the distribution of these diseases and measure their impact. Therefore, we undertook a scoping review of the literature to describe and summarize epidemiological practices, findings and insights related to seroprevalence studies of dengue, chikungunya and Zika virus, which have rapidly expanded across the globe in recent years. METHODOLOGY/PRINCIPAL FINDINGS Relevant studies were retrieved through a literature search of MEDLINE, WHOLIS, Lilacs, SciELO and Scopus (2000 to 2018). In total, 1389 publications were identified. Studies addressing the seroprevalence of dengue, chikungunya and/or Zika written in English or French and meeting the inclusion and exclusion criteria were included. In total, 147 studies were included, from which 185 data points were retrieved, as some studies used several different samples. Most of the studies were exclusively conducted on dengue (66.5%), but 16% were exclusively conducted on chikungunya, and 7 were exclusively conducted on Zika; the remainder were conducted on multiple arboviruses. A wide range of designs were applied, but most studies were conducted in the general population (39%) and in households (41%). Although several assays were used, enzyme-linked immunosorbent assays (ELISAs) were the predominant test used (77%). The temporal distribution of chikungunya studies followed the virus during its rapid expansion since 2004. The results revealed heterogeneity of arboviruses seroprevalence between continents and within a given country for dengue, chikungunya and Zika viruses, ranging from 0 to 100%, 76% and 73% respectively. CONCLUSIONS/SIGNIFICANCE Serological surveys provide the most direct measurement for defining the immunity landscape for infectious diseases, but the methodology remains difficult to implement. Overall, dengue, chikungunya and Zika serosurveys followed the expansion of these arboviruses, but there remain gaps in their geographic distribution. This review addresses the challenges for researchers regarding study design biases. Moreover, the development of reliable, rapid and affordable diagnosis tools represents a significant issue concerning the ability of seroprevalence surveys to differentiate infections when multiple viruses co-circulate.
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Affiliation(s)
- Camille Fritzell
- Epidemiology Unit, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | - Dominique Rousset
- National Reference Laboratory for Arboviruses, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | - Antoine Adde
- Epidemiology Unit, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | - Mirdad Kazanji
- Epidemiology Unit, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | | | - Claude Flamand
- Epidemiology Unit, Institut Pasteur de la Guyane, Cayenne, French Guiana
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Vu DM, Mutai N, Heath CJ, Vulule JM, Mutuku FM, Ndenga BA, LaBeaud AD. Unrecognized Dengue Virus Infections in Children, Western Kenya, 2014-2015. Emerg Infect Dis 2018; 23:1915-1917. [PMID: 29048283 PMCID: PMC5652413 DOI: 10.3201/eid2311.170807] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We detected a cluster of dengue virus infections in children in Kenya during July 2014-June 2015. Most cases were serotype 1, but we detected all 4 serotypes, including co-infections with 2 serotypes. Our findings implicate dengue as a cause of febrile illness in this population and highlight a need for robust arbovirus surveillance.
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Obonyo M, Fidhow A, Ofula V. Investigation of laboratory confirmed Dengue outbreak in North-eastern Kenya, 2011. PLoS One 2018; 13:e0198556. [PMID: 29879159 PMCID: PMC5991696 DOI: 10.1371/journal.pone.0198556] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 05/21/2018] [Indexed: 01/24/2023] Open
Abstract
The first laboratory confirmed dengue outbreak in Kenya was reported in coastal towns of Malindi and Kilifi in 1982. Since then, no other outbreak had been confirmed in Kenya. Dengue outbreak was confirmed among African Mission soldiers in Somalia (AMISOM) between May to October 2011. From September 2011, an upsurge of febrile patients who were negative for malaria on microscopy were reported in several health facilities in Mandera town, an adjacent area to Somalia in northern Kenya. We investigated a suspected dengue outbreak in Mandera town from 26th September 2011 to 5th October 2011. A suspected case was defined as acute onset of fever with two or more of the following: headache, arthralgia, myalgia, rash and hemorrhages and negative malaria microscopy results in a person presenting to a health facility in Mandera town from 1st August to 2nd October 2011. We prospectively identified new cases meeting the suspect case definition from 2nd October to 5th October 2011 and we collected blood samples from consenting patients. Blood was collected into plastic vacutainers and stored in dry shipper at -80oc to laboratory for dengue virus testing using real time reverse transcriptase polymerase chain reaction (rRT-PCR). We administered a standardized form to obtain clinical information. We calculated descriptive statistics to describe the outbreak. A total of 1,332 patients had been line listed by the district surveillance team, of which 381 (29%) met our suspect case definition of dengue. Cases peaked between 10th September and 1st October 2011 and thereafter declined. We prospectively identified 33 cases meeting the suspect case definition, of whom 30 (91%) were positive for dengue virus serotype 3 by PCR. Among the 30 laboratory confirmed patients, 20 (67%) required hospitalization (Median hospitalization period, two days with a range: 1-4 days)). And of these, 26 (86%) patients reported aches and pain, 16 (53%) reported vomiting, and four (13%) gingival bleeding. Twenty-three (77%) received anti-malarial therapy. Among laboratory-confirmed dengue patients, seven (23%) had malaria co-infection. This was the second confirmed Dengue outbreak in Kenya, and highlighted the need for improved surveillance to better define disease burden and continuous education to medical personnel to improve detection and clinical management. We also recommended enhanced community education for disease prevention.
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Affiliation(s)
- Mark Obonyo
- Kenya Field Epidemiology and Laboratory Training Program, Ministry of Public Health and Sanitation, Nairobi, Kenya
- * E-mail:
| | - Ahmed Fidhow
- Kenya Field Epidemiology and Laboratory Training Program, Ministry of Public Health and Sanitation, Nairobi, Kenya
| | - Victor Ofula
- Arbovirology/Viral Hemorrhagic Fever Laboratory, Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
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Iwashita H, Higa Y, Futami K, Lutiali PA, Njenga SM, Nabeshima T, Minakawa N. Mosquito arbovirus survey in selected areas of Kenya: detection of insect-specific virus. Trop Med Health 2018; 46:19. [PMID: 29991925 PMCID: PMC5987586 DOI: 10.1186/s41182-018-0095-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/04/2018] [Indexed: 11/29/2022] Open
Abstract
Background Many arboviral outbreaks have occurred in various locations in Kenya. Entomological surveys are suitable methods for revealing information about circulating arboviruses before human outbreaks are recognized. Therefore, mosquitoes were collected in Kenya to determine the distribution of arboviruses. Methods Various species of mosquitoes were sampled from January to July 2012 using several collection methods. Mosquito homogenates were directly tested by reverse transcription-polymerase chain reaction (RT-PCR) using various arbovirus-targeted primer pairs. Results We collected 12,569 mosquitoes. Although no human-related arboviruses were detected, Culex flavivirus (CxFV), an insect-specific arbovirus, was detected in 54 pools of 324 Culex quinquefasciatus individuals collected during the rainy season. Of these 54 positive pools, 96.3% (52/54) of the mosquitoes were collected in Busia, on the border of western Kenya and Uganda. The remaining two CxFV-positive pools were collected in Mombasa and Kakamega, far from Busia. Phylogenetic analysis revealed minimal genetic diversity among the CxFVs collected in Mombasa, Kakamega, and Busia, even though these cities are in geographically different regions. Additionally, CxFV was detected in one mosquito pool collected in Mombasa during the dry season. In addition to Culex mosquitoes, Aedes (Stegomyia) and Anopheles mosquitoes were also positive for the Flavivirus genus. Cell fusing agent virus was detected in one pool of Aedes aegypti. Mosquito flavivirus was detected in three pools of Anopheles gambiae s.l. collected in the dry and rainy seasons. Conclusions Although no mosquitoes were positive for human-related arbovirus, insect-specific viruses were detected in various species of mosquitoes. The heterogeneity observed in the number of CxFVs in Culex mosquitoes in different locations in Kenya suggests that the abundance of human-related viruses might differ depending on the abundance of insect-specific viruses. We may have underestimated the circulation of any human-related arbovirus in Kenya, and the collection of larger samples may allow for determination of the presence of human-related arboviruses.
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Affiliation(s)
- Hanako Iwashita
- 1Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523 Japan.,2Department of Bacteriology, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishiharacho, Okinawa, 903-0125 Japan
| | - Yukiko Higa
- 1Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523 Japan
| | - Kyoko Futami
- 1Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523 Japan
| | - Peter A Lutiali
- 3NUITM-KEMRI Project, Kenya Medical Research Institute, Nairobi, Kenya
| | - Sammy M Njenga
- 4Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute, Nairobi, Kenya
| | - Takeshi Nabeshima
- 5Department of Virology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Noboru Minakawa
- 1Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523 Japan
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Lim JK, Carabali M, Lee JS, Lee KS, Namkung S, Lim SK, Ridde V, Fernandes J, Lell B, Matendechero SH, Esen M, Andia E, Oyembo N, Barro A, Bonnet E, Njenga SM, Agnandji ST, Yaro S, Alexander N, Yoon IK. Evaluating dengue burden in Africa in passive fever surveillance and seroprevalence studies: protocol of field studies of the Dengue Vaccine Initiative. BMJ Open 2018; 8:e017673. [PMID: 29358421 PMCID: PMC5780679 DOI: 10.1136/bmjopen-2017-017673] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 09/25/2017] [Accepted: 10/18/2017] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Dengue is an important and well-documented public health problem in the Asia-Pacific and Latin American regions. However, in Africa, information on disease burden is limited to case reports and reports of sporadic outbreaks, thus hindering the implementation of public health actions for disease control. To gather evidence on the undocumented burden of dengue in Africa, epidemiological studies with standardised methods were launched in three locations in Africa. METHODS AND ANALYSIS In 2014-2017, the Dengue Vaccine Initiative initiated field studies at three sites in Ouagadougou, Burkina Faso; Lambaréné, Gabon and Mombasa, Kenya to obtain comparable incidence data on dengue and assess its burden through standardised hospital-based surveillance and community-based serological methods. Multidisciplinary measurements of the burden of dengue were obtained through field studies that included passive facility-based fever surveillance, cost-of-illness surveys, serological surveys and healthcare utilisation surveys. All three sites conducted case detection using standardised procedures with uniform laboratory assays to diagnose dengue. Healthcare utilisation surveys were conducted to adjust population denominators in incidence calculations for differing healthcare seeking patterns. The fever surveillance data will allow calculation of age-specific incidence rates and comparison of symptomatic presentation between patients with dengue and non-dengue using multivariable logistic regression. Serological surveys assessed changes in immune status of cohorts of approximately 3000 randomly selected residents at each site at 6-month intervals. The age-stratified serosurvey data will allow calculation of seroprevalence and force of infection of dengue. Cost-of-illness evaluations were conducted among patients with acute dengue by Rapid Diagnostic Test. ETHICS AND DISSEMINATION By standardising methods to evaluate dengue burden across several sites in Africa, these studies will generate evidence for dengue burden in Africa and data will be disseminated as publication in peer-review journals in 2018.
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Affiliation(s)
- Jacqueline Kyungah Lim
- Global Dengue and Aedes-transmitted Diseases Consortium, International Vaccine Institute, Gwanak-gu, The Republic of Korea
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Mabel Carabali
- Global Dengue and Aedes-transmitted Diseases Consortium, International Vaccine Institute, Gwanak-gu, The Republic of Korea
- Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada
| | - Jung-Seok Lee
- Development and Delivery, International Vaccine Institute, Gwanak-gu, The Republic of Korea
| | - Kang-Sung Lee
- Development and Delivery, International Vaccine Institute, Gwanak-gu, The Republic of Korea
| | - Suk Namkung
- Global Dengue and Aedes-transmitted Diseases Consortium, International Vaccine Institute, Gwanak-gu, The Republic of Korea
| | - Sl-Ki Lim
- Global Dengue and Aedes-transmitted Diseases Consortium, International Vaccine Institute, Gwanak-gu, The Republic of Korea
| | - Valéry Ridde
- School of Public Health, University of Montreal, Montreal, Quebec, Canada
| | - Jose Fernandes
- Centre de Recherches Médicales de Lambaréné, Fondation Internationale de l'Hôpital Albert Schweitzer, Lambaréné, Gabon
| | - Bertrand Lell
- Centre de Recherches Médicales de Lambaréné, Fondation Internationale de l'Hôpital Albert Schweitzer, Lambaréné, Gabon
| | | | - Meral Esen
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Esther Andia
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute, Nairobi, Kenya
| | - Noah Oyembo
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute, Nairobi, Kenya
| | - Ahmed Barro
- Program Equité, Action-Gouvernance-Integration-Reinforcement, Ouagadougou, Burkina Faso
| | - Emmanuel Bonnet
- UMI Résiliences, Institut de recherche pour le developpement (IRD), Paris, France
| | - Sammy M Njenga
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute, Nairobi, Kenya
| | - Selidji Todagbe Agnandji
- Centre de Recherches Médicales de Lambaréné, Fondation Internationale de l'Hôpital Albert Schweitzer, Lambaréné, Gabon
| | - Seydou Yaro
- Centre Muraz, Bobo Dioulasso, Hauts Bassins, Burkina Faso
| | - Neal Alexander
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - In-Kyu Yoon
- Global Dengue and Aedes-transmitted Diseases Consortium, International Vaccine Institute, Gwanak-gu, The Republic of Korea
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Toda M, Zurovac D, Njeru I, Kareko D, Mwau M, Morita K. Health worker knowledge of Integrated Disease Surveillance and Response standard case definitions: a cross-sectional survey at rural health facilities in Kenya. BMC Public Health 2018; 18:146. [PMID: 29343225 PMCID: PMC5772726 DOI: 10.1186/s12889-018-5028-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 01/03/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The correct knowledge of standard case definition is necessary for frontline health workers to diagnose suspected diseases across Africa. However, surveillance evaluations commonly assume this prerequisite. This study assessed the knowledge of case definitions for health workers and their supervisors for disease surveillance activities in rural Kenya. METHODS A cross-sectional survey including 131 health workers and their 11 supervisors was undertaken in two counties in Kenya. Descriptive analysis was conducted to classify the correctness of knowledge into four categories for three tracer diseases (dysentery, measles, and dengue). We conducted a univariate and multivariable logistic regression analyses to explore factors influencing knowledge of the case definition for dysentery. RESULTS Among supervisors, 81.8% knew the correct definition for dysentery, 27.3% for measles, and no correct responses were provided for dengue. Correct knowledge was observed for 50.4% of the health workers for dysentery, only 12.2% for measles, and none for dengue. Of 10 examined factors, the following were significantly associated with health workers' correct knowledge of the case definition for dysentery: health workers' cadre (aOR 2.71; 95% CI 1.20-6.12; p = 0.017), and display of case definition poster (aOR 2.24; 95% CI 1.01-4.98; p = 0.048). Health workers' exposure to the surveillance refresher training, supportive supervision and guidelines were not significantly associated with the knowledge. CONCLUSION The correct knowledge of standard case definitions was sub-optimal among health workers and their supervisors, which is likely to impact the reliability of routine surveillance reports generated from health facilities.
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Affiliation(s)
- Mitsuru Toda
- Nagasaki University Institute of Tropical Medicine, KEMRI-NUITM, Kenyatta Hospital Grounds, Nairobi, Kenya.
| | - Dejan Zurovac
- Oxford University, Oxford, UK.,Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Ian Njeru
- Kenya Ministry of Health Disease Surveillance and Response Unit, Nairobi, Kenya
| | - David Kareko
- Kenya Ministry of Health Disease Surveillance and Response Unit, Nairobi, Kenya
| | - Matilu Mwau
- Kenya Medical Research Institute, Nairobi, Kenya
| | - Kouichi Morita
- Nagasaki University Institute of Tropical Medicine, Nagasaki, Japan
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46
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Ang LW, Kam YW, Lin C, Krishnan PU, Tay J, Ng LC, James L, Lee VJM, Goh KT, Ng LFP, Lin RTP. Seroprevalence of antibodies against chikungunya virus in Singapore resident adult population. PLoS Negl Trop Dis 2017; 11:e0006163. [PMID: 29281644 PMCID: PMC5760101 DOI: 10.1371/journal.pntd.0006163] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 01/09/2018] [Accepted: 12/12/2017] [Indexed: 11/24/2022] Open
Abstract
Objectives We determined the seroprevalence of chikungunya virus (CHIKV) infection in the adult resident population in Singapore following local outbreaks of chikungunya fever (CHIKF) in 2008–2009. Methods Our cross-sectional study involved residual sera from 3,293 adults aged 18–79 years who had participated in the National Health Survey in 2010. Sera were tested for IgG antibodies against CHIKV and dengue virus (DENV) and neutralizing antibodies against CHIKV. Results The prevalence of CHIKV-neutralizing antibodies among Singapore residents aged 18–79 years was 1.9% (95% confidence interval: 1.4%– 2.3%). The CHIKV seroprevalence was highest in the elderly aged 70–79 years at 11.5%, followed by those aged 30–39 years at 3.1%. Men had significantly higher CHIKV seroprevalence than women (2.5% versus 1.3%, p = 0.01). Among the three main ethnic groups, Indians had the highest seroprevalence (3.5%) compared to Chinese (1.6%) and Malays (0.7%) (p = 0.02 and p = 0.01, respectively). Multivariable logistic regression identified adults aged 30–39 years and 70–79 years, men, those of Indian ethnicity and ethnic minority groups, and residence on ground floor of public and private housing apartments as factors that were significantly associated with a higher likelihood of exposure to CHIKV. The overall prevalence of anti-DENV IgG antibodies was 56.8% (95% CI: 55.1%– 58.5%), while 1.5% (95% CI: 1.1%– 2.0%) of adults possessed both neutralizing antibodies against CHIKV and IgG antibodies against DENV. Conclusions Singapore remains highly susceptible to CHIKV infection. There is a need to maintain a high degree of vigilance through disease surveillance and vector control. Findings from such serological study, when conducted on a regular periodic basis, could supplement surveillance to provide insights on CHIKV circulation in at-risk population. The prevalence of neutralizing antibodies against chikungunya virus (CHIKV) was low at 1.9% among resident adults in Singapore after local outbreaks in 2008–2009. Adults aged 30–39 years and 70–79 years, men, those of Indian ethnicity and ethnic minority groups, and residence on ground floor of public and private housing apartments were significantly associated with a higher likelihood of exposure to CHIKV.
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Affiliation(s)
- Li Wei Ang
- Public Health Group, Ministry of Health, Singapore
- * E-mail:
| | - Yiu Wing Kam
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Cui Lin
- Public Health Group, Ministry of Health, Singapore
| | - Prabha Unny Krishnan
- Public Health Group, Ministry of Health, Singapore
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
| | - Joanne Tay
- Public Health Group, Ministry of Health, Singapore
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore
| | - Lyn James
- Public Health Group, Ministry of Health, Singapore
| | | | - Kee Tai Goh
- Public Health Group, Ministry of Health, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Lisa F. P. Ng
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Singapore
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Grossi-Soyster EN, Cook EAJ, de Glanville WA, Thomas LF, Krystosik AR, Lee J, Wamae CN, Kariuki S, Fèvre EM, LaBeaud AD. Serological and spatial analysis of alphavirus and flavivirus prevalence and risk factors in a rural community in western Kenya. PLoS Negl Trop Dis 2017; 11:e0005998. [PMID: 29040262 PMCID: PMC5659799 DOI: 10.1371/journal.pntd.0005998] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/27/2017] [Accepted: 09/27/2017] [Indexed: 01/29/2023] Open
Abstract
Alphaviruses, such as chikungunya virus, and flaviviruses, such as dengue virus, are (re)-emerging arboviruses that are endemic in tropical environments. In Africa, arbovirus infections are often undiagnosed and unreported, with febrile illnesses often assumed to be malaria. This cross-sectional study aimed to characterize the seroprevalence of alphaviruses and flaviviruses among children (ages 5-14, n = 250) and adults (ages 15 ≥ 75, n = 250) in western Kenya. Risk factors for seropositivity were explored using Lasso regression. Overall, 67% of participants showed alphavirus seropositivity (CI95 63%-70%), and 1.6% of participants showed flavivirus seropositivity (CI95 0.7%-3%). Children aged 10-14 were more likely to be seropositive to an alphavirus than adults (p < 0.001), suggesting a recent transmission period. Alphavirus and flavivirus seropositivity was detected in the youngest participants (age 5-9), providing evidence of inter-epidemic transmission. Demographic variables that were significantly different amongst those with previous infection versus those without infection included age, education level, and occupation. Behavioral and environmental variables significantly different amongst those in with previous infection to those without infection included taking animals for grazing, fishing, and recent village flooding. Experience of recent fever was also found to be a significant indicator of infection (p = 0.027). These results confirm alphavirus and flavivirus exposure in western Kenya, while illustrating significantly higher alphavirus transmission compared to previous studies.
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Affiliation(s)
- Elysse N. Grossi-Soyster
- Departments of Pediatrics, Infectious Disease Division, Stanford University School of Medicine, Stanford, California, United States of America
| | - Elizabeth A. J. Cook
- Zoonotic and Emerging Diseases Group, International Livestock Research Institute, Nairobi, Kenya
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Edinburgh, United Kingdom
| | - William A. de Glanville
- Zoonotic and Emerging Diseases Group, International Livestock Research Institute, Nairobi, Kenya
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Edinburgh, United Kingdom
| | - Lian F. Thomas
- Zoonotic and Emerging Diseases Group, International Livestock Research Institute, Nairobi, Kenya
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Edinburgh, United Kingdom
| | - Amy R. Krystosik
- Departments of Pediatrics, Infectious Disease Division, Stanford University School of Medicine, Stanford, California, United States of America
| | - Justin Lee
- Quantitative Sciences Unit, Stanford University School of Medicine, Stanford, California, United States of America
| | - C. Njeri Wamae
- Department of Microbiology, School of Medicine, Mount Kenya University, Thika, Kenya
| | - Samuel Kariuki
- Centre for Microbiology Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Eric M. Fèvre
- Zoonotic and Emerging Diseases Group, International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Neston, United Kingdom
| | - A. Desiree LaBeaud
- Departments of Pediatrics, Infectious Disease Division, Stanford University School of Medicine, Stanford, California, United States of America
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Homenauth E, Kajeguka D, Kulkarni MA. Principal component analysis of socioeconomic factors and their association with malaria and arbovirus risk in Tanzania: a sensitivity analysis. J Epidemiol Community Health 2017; 71:1046-1051. [PMID: 28822980 DOI: 10.1136/jech-2017-209119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 08/01/2017] [Accepted: 08/07/2017] [Indexed: 11/03/2022]
Abstract
Principal component analysis (PCA) is frequently adopted for creating socioeconomic proxies in order to investigate the independent effects of wealth on disease status. The guidelines and methods for the creation of these proxies are well described and validated. The Demographic and Health Survey, World Health Survey and the Living Standards Measurement Survey are examples of large data sets that use PCA to create wealth indices particularly in low and middle-income countries (LMIC), where quantifying wealth-disease associations is problematic due to the unavailability of reliable income and expenditure data. However, the application of this method to smaller survey data sets, especially in rural LMIC settings, is less rigorously studied.In this paper, we aimed to highlight some of these issues by investigating the association of derived wealth indices using PCA on risk of vector-borne disease infection in Tanzania focusing on malaria and key arboviruses (ie, dengue and chikungunya). We demonstrated that indices consisting of subsets of socioeconomic indicators provided the least methodologically flawed representations of household wealth compared with an index that combined all socioeconomic variables. These results suggest that the choice of the socioeconomic indicators included in a wealth proxy can influence the relative position of households in the overall wealth hierarchy, and subsequently the strength of disease associations. This can, therefore, influence future resource planning activities and should be considered among investigators who use a PCA-derived wealth index based on community-level survey data to influence programme or policy decisions in rural LMIC settings.
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Affiliation(s)
- Esha Homenauth
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada
| | - Debora Kajeguka
- Department of Microbiology and Immunology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Manisha A Kulkarni
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada
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49
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de Glanville WA, Conde-Álvarez R, Moriyón I, Njeru J, Díaz R, Cook EAJ, Morin M, Bronsvoort BMDC, Thomas LF, Kariuki S, Fèvre EM. Poor performance of the rapid test for human brucellosis in health facilities in Kenya. PLoS Negl Trop Dis 2017; 11:e0005508. [PMID: 28388625 PMCID: PMC5413359 DOI: 10.1371/journal.pntd.0005508] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 05/02/2017] [Accepted: 03/20/2017] [Indexed: 02/07/2023] Open
Abstract
Human brucellosis is considered to be an important but typically under-diagnosed cause of febrile illness in many low and middle-income countries. In Kenya, and throughout East Africa, laboratory diagnosis for the disease is based primarily on the febrile antigen Brucella agglutination test (FBAT), yet few studies of the diagnostic accuracy of this test exist. Assessment of the performance of the FBAT is essential for its appropriate clinical use, as well as for evaluating surveillance data reported by public health systems. To assess FBAT performance, we collected sera from people with symptoms compatible with brucellosis attending two health facilities in Busia County, Kenya. Sera were tested using the FBAT and results compared with those from the Rose Bengal Test (RBT), an assay with well-known performance characteristics. Positives on either test were confirmed using the classical serum agglutination test (SAT)-Coombs test combination and a rapid IgM/IgG lateral flow immunochromatography assay (LFA). A questionnaire focussing on known risk factors for exposure to Brucella spp. was also conducted, and relationships with FBAT positivity examined using logistic regression. Out of 825 recruited individuals, 162 (19.6%) were classified as positive using the FBAT. In contrast, only eight (1.0%) were positive using the RBT. Of the 162 FBAT positives, one (0.62%) had an atypical agglutination in SAT and three (1.9%) showed low Coombs titres. Out of 148 FBAT positive individuals tested using the LFA, five (3.4%) were IgM positive and none were IgG positive. Poor or no correlation was observed between FBAT results and most established risk factors for Brucella infection. We observed substantial disagreement between the FBAT and a number of well-known serological tests, with the majority of reactive FBAT results appearing to be false positives. Poor FBAT specificity, combined with a lack of confirmatory testing, strongly suggests overdiagnosis of brucellosis is common in this low prevalence setting. This is expected to have important economic impacts on affected patients subjected to the long and likely unnecessary courses of multiple antibiotics required for treatment of the disease. Brucellosis is a debilitating disease of people caused by infection with one of a number of different Brucella species. In almost all cases, people acquire the infection through exposure to infected animals or contaminated animal products. Human brucellosis is well known for its wide range of symptoms, and is often clinically indistinguishable from other infectious diseases, such as malaria or typhoid. Diagnosing the disease therefore typically relies on laboratory tests. A wide range of tests are available, but little is known about the accuracy of the principal test used in Government health facilities in Kenya, the febrile Brucella agglutination test (FBAT). In this study, we identified people with symptoms compatible with brucellosis attending health centres in Kenya. By comparing results from the FBAT performed on samples collected from these individuals with the results from a range of well-established diagnostic tests, we were able to show that the FBAT produces large numbers of false positive results. We expect that this leads to a high levels of overdiagnosis of brucellosis in some parts of Kenya. Treatment of the disease involves multiple weeks of multiple antibiotics, and these incorrect diagnoses may have important and unnecessary negative impacts on affected patients.
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Affiliation(s)
- William A de Glanville
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.,International Livestock Research Institute, Nairobi, Kenya
| | - Raquel Conde-Álvarez
- Institute for Tropical Health, Navarra Institute for Sanitary Research and Department of Microbiology and Parasitology, Medical School, University of Navarra, Pamplona, Spain
| | - Ignacio Moriyón
- Institute for Tropical Health, Navarra Institute for Sanitary Research and Department of Microbiology and Parasitology, Medical School, University of Navarra, Pamplona, Spain
| | - John Njeru
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya.,Institute for Bacterial Infections and Zoonoses, Friedrich Loeffler Institute, Berlin, Germany
| | - Ramón Díaz
- Institute for Tropical Health, Navarra Institute for Sanitary Research and Department of Microbiology and Parasitology, Medical School, University of Navarra, Pamplona, Spain
| | - Elizabeth A J Cook
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.,International Livestock Research Institute, Nairobi, Kenya
| | - Matilda Morin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Barend M de C Bronsvoort
- Epidemiology, Economics and Risk Assessment Group, The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Lian F Thomas
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.,International Livestock Research Institute, Nairobi, Kenya
| | - Samuel Kariuki
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Eric M Fèvre
- International Livestock Research Institute, Nairobi, Kenya.,Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
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50
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Ngoi CN, Price MA, Fields B, Bonventure J, Ochieng C, Mwashigadi G, Hassan AS, Thiong’o AN, Micheni M, Mugo P, Graham S, Sanders EJ. Dengue and Chikungunya Virus Infections among Young Febrile Adults Evaluated for Acute HIV-1 Infection in Coastal Kenya. PLoS One 2016; 11:e0167508. [PMID: 27942016 PMCID: PMC5152832 DOI: 10.1371/journal.pone.0167508] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 11/15/2016] [Indexed: 01/24/2023] Open
Abstract
Background Fever is common among patients seeking care in sub-Saharan Africa (sSA), but causes other than malaria are rarely diagnosed. We assessed dengue and chikungunya virus infections among young febrile adults evaluated for acute HIV infection (AHI) and malaria in coastal Kenya. Methods We tested plasma samples obtained in a cross-sectional study from febrile adult patients aged 18–35 years evaluated for AHI and malaria at urgent care seeking at seven health facilities in coastal Kenya in 2014–2015. Dengue virus (DENV) and chikungunya virus (CHIKV) were amplified using quantitative real-time reverse-transcription polymerase chain reaction. We conducted logistic regression analyses to determine independent predictors of dengue virus infection. Results 489 samples that were negative for both AHI and malaria were tested, of which 43 (8.8%, 95% confidence interval [CI]: 6.4–11.7) were positive for DENV infection. No participant was positive for CHIKV infection. DENV infections were associated with clinic visits in the rainy season (adjusted odds ratio (AOR) = 3.0, 95% CI: 1.3–6.5) and evaluation at a private health facility (AOR 5.2, 95% CI: 2.0–13.1) or research health facility (AOR = 25.6, 95% CI: 8.9–73.2) instead of a public health facility. Conclusion A high prevalence of DENV infections was found in febrile young adult patients evaluated for AHI. Our data suggests that DENV, along with AHI and malaria, should be considered in the differential diagnosis of the adult patient seeking care for fever in coastal Kenya.
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Affiliation(s)
- Carolyne N. Ngoi
- Centre for Geographic Medicine Research – Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
- * E-mail:
| | - Matt A. Price
- International AIDS Vaccine Initiative (IAVI) New York, New York, United States of America
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, United States of America
| | - Barry Fields
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya
| | - Juma Bonventure
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya
| | | | - Grace Mwashigadi
- Centre for Geographic Medicine Research – Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
| | - Amin S. Hassan
- Centre for Geographic Medicine Research – Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
| | - Alexander N. Thiong’o
- Centre for Geographic Medicine Research – Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
| | - Murugi Micheni
- Centre for Geographic Medicine Research – Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
| | - Peter Mugo
- Centre for Geographic Medicine Research – Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
| | - Susan Graham
- Centre for Geographic Medicine Research – Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
- Departments of Medicine, Global Health, and Epidemiology, University of Washington, Seattle, United States of America
| | - Eduard J. Sanders
- Centre for Geographic Medicine Research – Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya
- Nuffield Department of Medicine, University of Oxford, Headington, United Kingdom
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