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Mukhopadhyay K, Sengupta M, Misra SC, Majee K. Trends in emerging vector-borne viral infections and their outcome in children over two decades. Pediatr Res 2024; 95:464-479. [PMID: 37880334 DOI: 10.1038/s41390-023-02866-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/27/2023] [Accepted: 10/02/2023] [Indexed: 10/27/2023]
Abstract
This review utilizes quatitative methods and bibliometric data to analyse the trends of emerging and re-emerging vector-borne diseases, with a focus on their impact on pediatric population. To conduct this analysis, a systematic search of PubMed articles from the past two decades was performed, specifically looking at 26 different vector-borne viruses listed in WHO and CDC list of vector-borne viruses. The review found that diseases like Dengue, Zika, West Nile, and Chikungunya were frequently discussed in the literature. On the other hand, diseases such as Tick-borne encephalitis, Rift Valley fever, Venezuelan equine encephalitis, Sindbis fever, Venezuelan equine encephalitis, Ross River virus, and Eastern equine encephalitis showed an upward trend in publications, indicating potential resurgence. In addition to discussing trends and patterns, the review delves into the clinical manifestations and long-term effects of the top 10 viruses in children. It highlights various factors including deforestation, urbanization, global travel, and immunosuppression that contribute to disease emergence and resurgence. To effectively combat these vector-borne diseases, continuous surveillance is crucial. The review also emphasizes the importance of increased vaccination efforts and targeted research to address the health challenges they pose. IMPACT: This review employs quantitative analysis of publications to elucidate trends in emerging pediatric vector-borne viral diseases over two decades. Dengue, the most prevalent of these diseases, has spread to new regions. New strains of Japanese Encephalitis have caused outbreaks. Resurgence of Tick-borne Encephalitis, West Nile, and Yellow Fever due to vaccine hesitancy has also transpired. Continuous global surveillance, increased vaccination, and research into novel therapeutics are imperative to combat the substantial morbidity and mortality burden these diseases pose for children worldwide.
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Affiliation(s)
| | - Mallika Sengupta
- Microbiology, AIIMS Kalyani, Basantapur, Saguna, West Bengal, India
| | | | - Kiranmay Majee
- Student, AIIMS Kalyani, Basantapur, Saguna, West Bengal, India
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2
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Kayange N, Hau DK, Pain K, Mshana SE, Peck R, Gehring S, Groendahl B, Koliopoulos P, Revocatus B, Msaki EB, Malande O. Seroprevalence of Dengue and Chikungunya Virus Infections in Children Living in Sub-Saharan Africa: Systematic Review and Meta-Analysis. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1662. [PMID: 37892325 PMCID: PMC10605353 DOI: 10.3390/children10101662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 09/23/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023]
Abstract
Dengue and chikungunya viruses are frequent causes of malarial-like febrile illness in children. The rapid increase in virus transmission by mosquitoes is a global health concern. This is the first systematic review and meta-analysis of the childhood prevalence of dengue and chikungunya in Sub-Saharan Africa (SSA). A comprehensive search of the MEDLINE (Ovid), Embase (Ovid), and Cochrane Library (Wiley) databases was conducted on 28 June 2019, and updated on 12 February 2022. The search strategy was designed to retrieve all articles pertaining to arboviruses in SSA children using both controlled vocabulary and keywords. The pooled (weighted) proportion of dengue and chikungunya was estimated using a random effect model. The overall pooled prevalence of dengue and chikungunya in SSA children was estimated to be 16% and 7%, respectively. Prevalence was slightly lower during the period 2010-2020 compared to 2000-2009. The study design varied depending on the healthcare facility reporting the disease outbreak. Importantly, laboratory methods used to detect arbovirus infections differed. The present review documents the prevalence of dengue and chikungunya in pediatric patients throughout SSA. The results provide unprecedented insight into the transmission of dengue and chikungunya viruses among these children and highlight the need for enhanced surveillance and controlled methodology.
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Affiliation(s)
- Neema Kayange
- Department of Pediatrics, Bugando Medical Centre, Weill Bugando School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania;
| | - Duncan K Hau
- Department of Pediatrics, Weill Cornell Medical College, New York, NY 10065, USA;
| | - Kevin Pain
- Samuel J. Wood Library and C.V. Starr Biomedical Information Center, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA;
| | - Stephen E Mshana
- Department of Microbiology and Immunology, Weill Bugando School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania;
| | - Robert Peck
- Department of Pediatrics, Bugando Medical Centre, Weill Bugando School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania;
- Department of Pediatrics, Weill Cornell Medical College, New York, NY 10065, USA;
- Center for Global Health, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Stephan Gehring
- Department of Pediatrics, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany; (S.G.); (B.G.); (P.K.)
| | - Britta Groendahl
- Department of Pediatrics, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany; (S.G.); (B.G.); (P.K.)
| | - Philip Koliopoulos
- Department of Pediatrics, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany; (S.G.); (B.G.); (P.K.)
| | - Baraka Revocatus
- Department of Data and Statistics, Bugando Medical Centre, Mwanza P.O. Box 1370, Tanzania;
| | - Evarist B Msaki
- Department of Epidemiology and Biostatistics, Bugando Medical Centre, Mwanza P.O. Box 1370, Tanzania;
| | - Ombeva Malande
- East Africa Centre for Vaccines and Immunization (ECAVI), Kampala P.O. Box 3040, Uganda;
- Department of Public Health Phamarmacy, Sefako Makgatho Health Sciences University, Pretoria P.O. Box 60, South Africa
- Department of Paediatrics & Child Health, Makerere University, Kampala P.O. Box 7072, Uganda
- Department of Public Health, UNICAF University, Lusaka P.O. Box 20842, Zambia
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3
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Vu DM, Krystosik AR, Ndenga BA, Mutuku FM, Ripp K, Liu E, Bosire CM, Heath C, Chebii P, Maina PW, Jembe Z, Malumbo SL, Amugongo JS, Ronga C, Okuta V, Mutai N, Makenzi NG, Litunda KA, Mukoko D, King CH, LaBeaud AD. Detection of acute dengue virus infection, with and without concurrent malaria infection, in a cohort of febrile children in Kenya, 2014-2019, by clinicians or machine learning algorithms. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0001950. [PMID: 37494331 PMCID: PMC10370704 DOI: 10.1371/journal.pgph.0001950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 06/29/2023] [Indexed: 07/28/2023]
Abstract
Poor access to diagnostic testing in resource limited settings restricts surveillance for emerging infections, such as dengue virus (DENV), to clinician suspicion, based on history and exam observations alone. We investigated the ability of machine learning to detect DENV based solely on data available at the clinic visit. We extracted symptom and physical exam data from 6,208 pediatric febrile illness visits to Kenyan public health clinics from 2014-2019 and created a dataset with 113 clinical features. Malaria testing was available at the clinic site. DENV testing was performed afterwards. We randomly sampled 70% of the dataset to develop DENV and malaria prediction models using boosted logistic regression, decision trees and random forests, support vector machines, naïve Bayes, and neural networks with 10-fold cross validation, tuned to maximize accuracy. 30% of the dataset was reserved to validate the models. 485 subjects (7.8%) had DENV, and 3,145 subjects (50.7%) had malaria. 220 (3.5%) subjects had co-infection with both DENV and malaria. In the validation dataset, clinician accuracy for diagnosis of malaria was high (82% accuracy, 85% sensitivity, 80% specificity). Accuracy of the models for predicting malaria diagnosis ranged from 53-69% (35-94% sensitivity, 11-80% specificity). In contrast, clinicians detected only 21 of 145 cases of DENV (80% accuracy, 14% sensitivity, 85% specificity). Of the six models, only logistic regression identified any DENV case (8 cases, 91% accuracy, 5.5% sensitivity, 98% specificity). Without diagnostic testing, interpretation of clinical findings by humans or machines cannot detect DENV at 8% prevalence. Access to point-of-care diagnostic tests must be prioritized to address global inequities in emerging infections surveillance.
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Affiliation(s)
- David M Vu
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, California, United States of America
| | - Amy R Krystosik
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, California, United States of America
| | - Bryson A Ndenga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Francis M Mutuku
- Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Kelsey Ripp
- University of Global Health Equity, Butaro, Rwanda
| | - Elizabeth Liu
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, California, United States of America
| | - Carren M Bosire
- Department of Pure and Applied Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Claire Heath
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, California, United States of America
| | - Philip Chebii
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | | | - Zainab Jembe
- Vector-Borne Diseases Unit, Diani Health Center, Ukunda, Kwale, Kenya
| | - Said Lipi Malumbo
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | - Jael Sagina Amugongo
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | - Charles Ronga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Victoria Okuta
- Paediatric Department, Obama Children's Hospital, Jaramogi Oginga Odinga Referral Hospital, Kisumu, Kenya
| | - Noah Mutai
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Nzaro G Makenzi
- Department of Pure and Applied Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Kennedy A Litunda
- Department of Pure and Applied Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Dunstan Mukoko
- Vector-Borne Diseases Unit, Ministry of Health, Nairobi, Kenya
| | - Charles H King
- Department of Pathology, Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - A Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, California, United States of America
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Peña-García VH, Mutuku FM, Ndenga BA, Mbakaya JO, Ndire SO, Agola GA, Mutuku PS, Malumbo SL, Ng'ang'a CM, Andrews JR, Mordecai EA, LaBeaud AD. The Importance of Including Non-Household Environments in Dengue Vector Control Activities. Viruses 2023; 15:1550. [PMID: 37515236 PMCID: PMC10384488 DOI: 10.3390/v15071550] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 06/29/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023] Open
Abstract
Most vector control activities in urban areas are focused on household environments; however, information relating to infection risks in spaces other than households is poor, and the relative risk that these spaces represent has not yet been fully understood. We used data-driven simulations to investigate the importance of household and non-household environments for dengue entomological risk in two Kenyan cities where dengue circulation has been reported. Fieldwork was performed using four strategies that targeted different stages of mosquitoes: ovitraps, larval collections, Prokopack aspiration, and BG-sentinel traps. Data were analyzed separately between household and non-household environments to assess mosquito presence, the number of vectors collected, and the risk factors for vector presence. With these data, we simulated vector and human populations to estimate the parameter m and mosquito-to-human density in both household and non-household environments. Among the analyzed variables, the main difference was found in mosquito abundance, which was consistently higher in non-household environments in Kisumu but was similar in Ukunda. Risk factor analysis suggests that small, clean water-related containers serve as mosquito breeding places in households as opposed to the trash- and rainfall-related containers found in non-household structures. We found that the density of vectors (m) was higher in non-household than household environments in Kisumu and was also similar or slightly lower between both environments in Ukunda. These results suggest that because vectors are abundant, there is a potential risk of transmission in non-household environments; hence, vector control activities should take these spaces into account.
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Affiliation(s)
- Víctor Hugo Peña-García
- Department of Biology, Stanford University, Stanford, CA 94305, USA
- School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Francis M Mutuku
- Department of Environmental and Health Sciences, Technical University of Mombasa, Mombasa 80110, Kenya
| | | | | | | | | | - Paul S Mutuku
- Vector Borne Disease Control Unit, Msambweni County Referral Hospital, Msambweni, Kwale County 80404, Kenya
| | - Said L Malumbo
- Vector Borne Disease Control Unit, Msambweni County Referral Hospital, Msambweni, Kwale County 80404, Kenya
| | - Charles M Ng'ang'a
- Vector Borne Disease Control Unit, Msambweni County Referral Hospital, Msambweni, Kwale County 80404, Kenya
| | - Jason R Andrews
- School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Erin A Mordecai
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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Musunzaji PS, Ndenga BA, Mzee S, Abubakar LU, Kitron UD, Labeaud AD, Mutuku FM. Oviposition Preferences of Aedes aegypti in Msambweni, Kwale County, Kenya. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2023; 39:85-95. [PMID: 37270926 PMCID: PMC10885850 DOI: 10.2987/22-7103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aedes aegypti is the primary vector of dengue fever virus (DENV) worldwide. Infusions made from organic materials have been shown to act as oviposition attractants for Ae. aegypti; however, studies on locally suitable infusion materials are lacking. The current study assessed the suitability of 4 locally available materials as oviposition infusions for use in surveillance and control of Ae. aegypti in Kwale County, Kenya. Oviposition infusion preferences were assessed in laboratory, semifield, and field conditions, using 4 infusions made from banana, grass, neem, and coconut. In addition, ovitrapping in wall, grass, bush, and banana microhabitats was done in 10 houses each in urban and rural coastal households to determine suitable oviposition microhabitats. Overall, the highest oviposition responses were observed for banana infusion, followed by neem and grass infusions, which were comparable. Coconut infusion resulted in the lowest oviposition response. Although female Ae. aegypti did not show preference for any microhabitat, the oviposition activity across all the microhabitats was highly enhanced by use of the organic infusions. Banana, neem, and grass infusions could be used to attract gravid mosquitoes to oviposition sites laced with insecticide to kill eggs. Additionally, banana plantings could be important targets for integrated vector control programs.
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A Retrospective Study of the Seroprevalence of Dengue Virus and Chikungunya Virus Exposures in Nigeria, 2010–2018. Pathogens 2022; 11:pathogens11070762. [PMID: 35890007 PMCID: PMC9318586 DOI: 10.3390/pathogens11070762] [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: 05/10/2022] [Revised: 06/25/2022] [Accepted: 06/30/2022] [Indexed: 02/01/2023] Open
Abstract
Arboviruses are important public health threats in many regions of the world. Nigeria has experienced outbreaks of arboviruses over the past decades, leading to concerns of widespread endemicity, which are frequently misdiagnosed. This study aimed to determine the seroprevalence of dengue virus (DENV) (a flavivirus) and chikungunya virus (CHIKV) (an alphavirus) infections in three major population centers of Nigeria. A convenience sample of 701 sera was collected from both healthy and febrile participants between August 2010 and March 2018. Sera were tested for prior exposure to CHIKV virus and DENV using indirect IgG ELISA. Results showed that 54.1% (379/701) of participants were seropositive for anti-DENV antibodies, 41.3% (290/701) were seropositive for anti-CHIKV antibodies, and 20.1% (141/701) had previous exposure to both. The seropositivity for prior CHIKV exposure and prior exposure to DENV and CHIKV was significantly associated with age (CHIKV: OR = 2.7 (95% CI: 1.7–4.3); DENV and CHIKV: OR = 2.2 (95% CI: 1.2–4.0) for adults compared to participants under 18 years old). Overall, the high seropositivity across all age groups suggests that arboviral infections are prevalent in Nigeria and indicates that surveillance and further epidemiological studies are required to determine the true burden of these infections and the spectrum of diseases associated with these exposures.
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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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Khan A, Ndenga B, Mutuku F, Bosire CM, Okuta V, Ronga CO, Mutai NK, Musaki SK, Chebii PK, Maina PW, Jembe Z, Amugongo JS, Malumbo SL, Ng'ang'a CM, LaBeaud D. Majority of pediatric dengue virus infections in Kenya do not meet 2009 WHO criteria for dengue diagnosis. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000175. [PMID: 36962138 PMCID: PMC10021889 DOI: 10.1371/journal.pgph.0000175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 03/09/2022] [Indexed: 11/19/2022]
Abstract
From 1975-2009, the WHO guidelines classified symptomatic dengue virus infections as dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. In 2009 the case definition was changed to a clinical classification after concern the original criteria was challenging to apply in resource-limited settings and not inclusive of a substantial proportion of severe dengue cases. Our goal was to examine how well the current WHO definition identified new dengue cases at our febrile surveillance sites in Kenya. Between 2014 and 2019 as part of a child cohort study of febrile illness in our four clinical study sites (Ukunda, Kisumu, Msambweni, Chulaimbo) we identified 369 dengue PCR positive symptomatic cases and characterized whether they met the 2009 revised WHO diagnostic criteria for dengue with and without warning signs and severe dengue. We found 62% of our PCR-confirmed dengue cases did not meet criteria per the guidelines. Our findings also correlate with our experience that dengue disease in children in Kenya is less severe as reported in other parts of the world. Although the 2009 clinical classification has recently been criticized for being overly inclusive and non-specific, our findings suggest the 2009 WHO dengue case definition may miss more than 50% of symptomatic infections in Kenya and may require further modification to include the African experience.
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Affiliation(s)
- Aslam Khan
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, California, United States of America
| | - Bryson Ndenga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Francis Mutuku
- Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Carren M Bosire
- Department of Pure and Applied Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Victoria Okuta
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Charles O Ronga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Noah K Mutai
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Sandra K Musaki
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Philip K Chebii
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | - Priscilla W Maina
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | - Zainab Jembe
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | - Jael S Amugongo
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | - Said L Malumbo
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | - Charles M Ng'ang'a
- Vector-Borne Diseases Unit, Msambweni County Referral Hospital, Msambweni, Kwale, Kenya
| | - Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, California, United States of America
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Hooft AM, Ndenga B, Mutuku F, Otuka V, Ronga C, Chebii PK, Maina PW, Jembe Z, Lee J, Vu DM, Mukoko D, LaBeaud AD. High Frequency of Antibiotic Prescription in Children With Undifferentiated Febrile Illness in Kenya. Clin Infect Dis 2021; 73:e2399-e2406. [PMID: 32882032 PMCID: PMC8492150 DOI: 10.1093/cid/ciaa1305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 09/01/2020] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In low-resource, malaria-endemic settings, accurate diagnosis of febrile illness in children is challenging. The World Health Organization (WHO) currently recommends laboratory-confirmed diagnosis of malaria prior to starting treatment in stable children. Factors guiding management of children with undifferentiated febrile illness outside of malaria are not well understood. METHODS This study examined clinical presentation and management of a cohort of febrile Kenyan children at 5 hospital/clinic sites from January 2014 to December 2017. Chi-squared and multivariate regression analyses were used to compare frequencies and correlate demographic, environmental, and clinical factors with patient diagnosis and prescription of antibiotics. RESULTS Of 5735 total participants, 68% were prescribed antibiotic treatment (n = 3902), despite only 28% given a diagnosis of bacterial illness (n = 1589). Factors associated with prescription of antibiotic therapy included: negative malaria testing, reporting head, ears, eyes, nose and throat (HEENT) symptoms (ie, cough, runny nose), HEENT findings on exam (ie, nasal discharge, red throat), and having a flush toilet in the home (likely a surrogate for higher socioeconomic status). CONCLUSION In a cohort of acutely ill Kenyan children, prescription of antimalarial therapy and malaria test results were well correlated, whereas antibiotic treatment was prescribed empirically to most of those who tested malaria negative. Clinical management of febrile children in these settings is difficult, given the lack of diagnostic testing. Providers may benefit from improved clinical education and implementation of enhanced guidelines in this era of malaria testing, as their management strategies must rely primarily on critical thinking and decision-making skills.
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Affiliation(s)
- Anneka M Hooft
- Department of Pediatrics, UCSF Benioff Children’s Hospital Oakland, Oakland, California, USA
- Department of Emergency Medicine, Pediatric Emergency Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Bryson Ndenga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Francis Mutuku
- Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Victoria Otuka
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Charles Ronga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Philip K Chebii
- Department of Pediatrics, Msambweni County Referral Hospital, Msambweni, Kenya
| | - Priscillah W Maina
- Department of Pediatrics, Msambweni County Referral Hospital, Msambweni, Kenya
| | - Zainab Jembe
- Department of Pediatrics, Diani Health Center, Ukunda, Kenya
| | - Justin Lee
- Quantitative Sciences Unit, Department of Medicine, Stanford University, Stanford, California, USA
| | - David M Vu
- Department of Pediatrics, Division of Infectious Disease, Stanford University, Stanford, California, USA
| | | | - A Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Disease, Stanford University, Stanford, California, USA
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10
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Nosrat C, Altamirano J, Anyamba A, Caldwell JM, Damoah R, Mutuku F, Ndenga B, LaBeaud AD. Impact of recent climate extremes on mosquito-borne disease transmission in Kenya. PLoS Negl Trop Dis 2021; 15:e0009182. [PMID: 33735293 PMCID: PMC7971569 DOI: 10.1371/journal.pntd.0009182] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 01/26/2021] [Indexed: 01/12/2023] Open
Abstract
Climate change and variability influence temperature and rainfall, which impact vector abundance and the dynamics of vector-borne disease transmission. Climate change is projected to increase the frequency and intensity of extreme climate events. Mosquito-borne diseases, such as dengue fever, are primarily transmitted by Aedes aegypti mosquitoes. Freshwater availability and temperature affect dengue vector populations via a variety of biological processes and thus influence the ability of mosquitoes to effectively transmit disease. However, the effect of droughts, floods, heat waves, and cold waves is not well understood. Using vector, climate, and dengue disease data collected between 2013 and 2019 in Kenya, this retrospective cohort study aims to elucidate the impact of extreme rainfall and temperature on mosquito abundance and the risk of arboviral infections. To define extreme periods of rainfall and land surface temperature (LST), we calculated monthly anomalies as deviations from long-term means (1983–2019 for rainfall, 2000–2019 for LST) across four study locations in Kenya. We classified extreme climate events as the upper and lower 10% of these calculated LST or rainfall deviations. Monthly Ae. aegypti abundance was recorded in Kenya using four trapping methods. Blood samples were also collected from children with febrile illness presenting to four field sites and tested for dengue virus using an IgG enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). We found that mosquito eggs and adults were significantly more abundant one month following an abnormally wet month. The relationship between mosquito abundance and dengue risk follows a non-linear association. Our findings suggest that early warnings and targeted interventions during periods of abnormal rainfall and temperature, especially flooding, can potentially contribute to reductions in risk of viral transmission. Dengue is a rapidly spreading mosquito-borne disease transmitted primarily by Aedes aegypti mosquitoes. As climate change leads to extremes in rainfall and temperature, the abundance and populations of these vectors will be affected, thus influencing transmission of dengue. Using satellite-derived climate data for Kenya, we classified months that experienced highly abnormal rainfall and temperature as extreme climate events (floods, droughts, heat waves, or cold waves). We compared the average monthly Ae. aegypti abundance and confirmed dengue counts following extreme climate months using lag periods of one month and two months, respectively. This study utilized several statistical models to account for differences among study sites and time. Floods resulted in significantly increased egg and adult abundance. Our results contributed to a better understanding of the effect of climate variability and change on dengue. As suggested by our observed increase in vector counts yet a relatively unchanged dengue infection risk, human behavior can help reduce viral transmission. Targeted interventions should be focused on both reducing vector populations and limiting human-vector contact, especially during these climate anomalies.
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Affiliation(s)
- Cameron Nosrat
- Program in Human Biology, Stanford University, Stanford, California, United States of America
- * E-mail:
| | - Jonathan Altamirano
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Assaf Anyamba
- Universities Space Research Association & NASA Goddard Space Flight Center, Greenbelt, Maryland, United States of America
| | - Jamie M. Caldwell
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Richard Damoah
- Morgan State University & NASA Goddard Space Flight Center, Greenbelt, Maryland, United States of America
| | | | - Bryson Ndenga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - A. Desiree LaBeaud
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
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11
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Koliopoulos P, Kayange NM, Daniel T, Huth F, Gröndahl B, Medina-Montaño GC, Pretsch L, Klüber J, Schmidt C, Züchner A, Ulbert S, Mshana SE, Addo M, Gehring S. Multiplex-RT-PCR-ELISA panel for detecting mosquito-borne pathogens: Plasmodium sp. preserved and eluted from dried blood spots on sample cards. Malar J 2021; 20:66. [PMID: 33526038 PMCID: PMC7851927 DOI: 10.1186/s12936-021-03595-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/15/2021] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Children are the most vulnerable group affected by malaria and other tropical, vector-borne diseases in low-resource countries. Infants presenting with acute onset fever represent a major sector of outpatient care in the Lake Victoria region. Misclassification and overuse of antibiotics and anti-malarial medications are consistent problems. Identifying the prevalent mosquito-borne pathogens in the region will reduce the prescription of non-indicated medicines. METHODS The literature was reviewed focusing on the mosquito-borne pathogens most prevalent in sub-Saharan Africa. Accordingly, an assay comprised of a multiplex-reverse transcriptase-polymerase chain reaction and an enzyme-linked immunosorbent assay (multiplex-RT-PCR-ELISA) was designed and validated in its ability to identify and differentiate nine human mosquito-borne pathogens including eight arboviruses and Plasmodium sp., the aetiologic agents of malaria. Blood samples obtained from 132 children suspected of having malaria were spotted and preserved on Whatman® 903 protein sample cards. Multiplex-RT-PCR-ELISA analysis was assessed and compared to results obtained by blood smear microscopy and the malaria rapid diagnostic test (RDT). RESULTS Nine out of nine pathogens were amplified specifically by the multiplex-RT-PCR-ELISA panel. Twenty-seven out of 132 paediatric patients presenting with acute fever were infected with Plasmodium sp., confirmed by multiplex-RT-PCR. The results of blood smear microscopy were only 40% sensitive and 92.8% specific. The malaria RDT, on the other hand, detected acute Plasmodium infections with 96.3% sensitivity and 98.1% specificity. The preservation of Plasmodium sp. in clinical sera and whole blood samples spotted on sample cards was evaluated. The duration of successful, sample card storage was 186 to 312 days. CONCLUSIONS Reliable, easy-to-use point of care diagnostic tests are a powerful alternative to laboratory-dependent gold standard tests. The multiplex-RT-PCR-ELISA amplified and identified nine vector-borne pathogens including Plasmodium sp. with great accuracy. Translation of improved diagnostic approaches, i.e., multiplex-RT-PCR-ELISA, into effective treatment options promises to reduce childhood mortality and non-indicated prescriptions.
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Affiliation(s)
- Philip Koliopoulos
- Center of Pediatric and Adolescent Medicine, University Medical Center, Mainz, Germany
| | - Neema Mathias Kayange
- Department of Pediatric and Adolescent Medicine, Bugando Medical Centre, Mwanza, Tanzania
| | - Tim Daniel
- Center of Pediatric and Adolescent Medicine, University Medical Center, Mainz, Germany
| | - Florian Huth
- Department of Infectiology and Tropical Medicine, University Medical Center Hamburg-Eppendorf, Eppendorf, Germany
| | - Britta Gröndahl
- Center of Pediatric and Adolescent Medicine, University Medical Center, Mainz, Germany.
| | | | - Leah Pretsch
- Center of Pediatric and Adolescent Medicine, University Medical Center, Mainz, Germany
| | - Julia Klüber
- Center of Pediatric and Adolescent Medicine, University Medical Center, Mainz, Germany.,Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Luxembourg
| | - Christian Schmidt
- Department of Pediatric and Adolescent Medicine, St. Vinzenz-Hospital, Dinslaken, Germany
| | - Antke Züchner
- Department of Pediatric and Adolescent Medicine, Bugando Medical Centre, Mwanza, Tanzania
| | - Sebastian Ulbert
- Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany
| | - Steven E Mshana
- Department of Microbiology and Immunology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Marylyn Addo
- Department of Infectiology and Tropical Medicine, University Medical Center Hamburg-Eppendorf, Eppendorf, Germany
| | - Stephan Gehring
- Center of Pediatric and Adolescent Medicine, University Medical Center, Mainz, Germany
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12
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Watts DM, Rodriguez CM, Palermo PM, Suarez V, Wong SJ, Orbegozo J, Dupuis AP, Kramer LD, Gonzalez FJ, Handel GA. Serosurvey for dengue virus infection among pregnant women in the West Nile virus enzootic community of El Paso Texas. PLoS One 2020; 15:e0242889. [PMID: 33253280 PMCID: PMC7703982 DOI: 10.1371/journal.pone.0242889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/10/2020] [Indexed: 01/14/2023] Open
Abstract
All 4 dengue viruses (DENV) cause sporadic outbreaks of human disease in the Rio Grande Valley along the US-Mexico border. In addition, West Nile virus (WNV) is enzootic in most border communities, and is the only arbovirus known to cause human disease in the El Paso, Texas community. In an effort to determine if DENV were also endemic in the El Paso community, a serosurvey was conducted among mothers at the time of delivery of their babies in selected hospitals. Cord-blood plasma samples obtained from mothers were tested for DENV antibody by an enzyme-linked immuno-sorbent assay (ELISA), plaque reduction neutralization test (PRNT) and a multiplex microsphere immunoassay. All DENV antibody positive plasma samples were also tested for WNV antibody by the same assays to consider the possibility that DENV antibody positive samples reflected WNV cross reactive antibody. The results indicated that 0.74% (11/1,472) of the mothers had a previous DENV infection and that 3.3% (48/1,472) had a previous WNV infection. Of these mothers, 0.20% (3/1,472) had antibody to both DENV and WNV as evidence of infection by both viruses. The results indicated that 0.2% (3/1472) of the mothers were positive for antibody to only WNV envelope, thus suggesting an undetermined flavivirus infection. Although 6 of the 11 DENV antibody positive mothers did not have a history of travel to a DENV endemic country, the findings of this survey provided further evidence of local transmission of WNV and suggested the possibility of focal autochthonous transmission of DENV in the El Paso community.
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Affiliation(s)
- Douglas M. Watts
- Department of Biological Science, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Cynthia M. Rodriguez
- Department of Biological Science, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Pedro M. Palermo
- Department of Biological Science, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Veronica Suarez
- Department of Biological Science, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Susan J. Wong
- Diagnostic Immunology Laboratory, Wadsworth Center, New York State Department of Health, Albany, NY, United States of America
| | - Jeanette Orbegozo
- Department of Biological Science, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Alan P. Dupuis
- Arbovirus Laboratory, Wadsworth Center, New York State Department of Health, Slingerlands, NY, United States of America
| | - Laura D. Kramer
- Arbovirus Laboratory, Wadsworth Center, New York State Department of Health, Slingerlands, NY, United States of America
| | | | - Gilbert A. Handel
- Paul L. Foster School of Medicine, El Paso, Texas, United States of America
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13
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Pollett S, Gathii K, Figueroa K, Rutvisuttinunt W, Srikanth A, Nyataya J, Mutai BK, Awinda G, Jarman RG, Berry IM, Waitumbi JN. The evolution of dengue-2 viruses in Malindi, Kenya and greater East Africa: Epidemiological and immunological implications. INFECTION GENETICS AND EVOLUTION 2020; 90:104617. [PMID: 33161179 DOI: 10.1016/j.meegid.2020.104617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 10/15/2020] [Accepted: 11/01/2020] [Indexed: 01/17/2023]
Abstract
Kenya experiences a substantial burden of dengue, yet there are very few DENV-2 sequence data available from this country and indeed the entire continent of Africa. We therefore undertook whole genome sequencing and evolutionary analysis of fourteen dengue virus (DENV)-2 strains sampled from Malindi sub-County Hospital during the 2017 DENV-2 outbreak in the Kenyan coast. We further performed an extended East African phylogenetic analysis, which leveraged 26 complete African env genes. Maximum likelihood analysis showed that the 2017 outbreak was due to the Cosmopolitan genotype, indicating that this has been the only confirmed human DENV-2 genotype circulating in Africa to date. Phylogeographic analyses indicated transmission of DENV-2 viruses between East Africa and South/South-West Asia. Time-scaled genealogies show that DENV-2 viruses shows spatial structure at the country level in Kenya, with a time-to-most-common-recent ancestor analysis indicating that these DENV-2 strains were circulating for up to 5.38 years in Kenya before detection in the 2017 Malindi outbreak. Selection pressure analyses indicated sampled Kenyan DENV strains uniquely being under positive selection at 6 sites, predominantly across the non-structural genes, and epitope prediction analyses showed that one of these sites corresponds to a putative predicted MHC-I CD8+ DENV-2 Cosmopolitan virus epitope only evident in a sampled Kenyan virus. Taken together, our findings indicate that the 2017 Malindi DENV-2 outbreak arose from a strain which had circulated for several years in Kenya before recent detection, has experienced diversifying selection pressure, and may contain new putative immunogens relevant to vaccine design. These findings prompt further genomic epidemiology studies in this and other Kenyan locations to further elucidate the transmission dynamics of DENV in this region.
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Affiliation(s)
- Simon Pollett
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Kimita Gathii
- Basic Science Laboratory, US Army Medical Research Directorate - Africa (USAMRD-A), Kisumu, Kenya
| | - Katherine Figueroa
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Wiriya Rutvisuttinunt
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Abhi Srikanth
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Josphat Nyataya
- Basic Science Laboratory, US Army Medical Research Directorate - Africa (USAMRD-A), Kisumu, Kenya
| | - Beth K Mutai
- Basic Science Laboratory, US Army Medical Research Directorate - Africa (USAMRD-A), Kisumu, Kenya
| | - George Awinda
- Basic Science Laboratory, US Army Medical Research Directorate - Africa (USAMRD-A), Kisumu, Kenya
| | - Richard G Jarman
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Irina Maljkovic Berry
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States of America.
| | - J N Waitumbi
- Basic Science Laboratory, US Army Medical Research Directorate - Africa (USAMRD-A), Kisumu, Kenya
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14
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Ngugi HN, Nyathi S, Krystosik A, Ndenga B, Mbakaya JO, Aswani P, Musunzaji PS, Irungu LW, Bisanzio D, Kitron U, Desiree LaBeaud A, Mutuku F. Risk factors for Aedes aegypti household pupal persistence in longitudinal entomological household surveys in urban and rural Kenya. Parasit Vectors 2020; 13:499. [PMID: 33004074 PMCID: PMC7528257 DOI: 10.1186/s13071-020-04378-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/23/2020] [Indexed: 12/31/2022] Open
Abstract
Background Aedes aegypti is an efficient vector of several arboviruses of public health importance, including Zika and dengue. Currently vector management is the only available avenue for disease control. Development of efficient vector control strategies requires a thorough understanding of vector ecology. In this study, we identified households that are consistently productive for Ae. aegypti pupae and determined the ecological and socio-demographic factors associated with the persistence and abundance of pupae in households in rural and urban Kenya. Methods We collected socio-demographic, environmental and entomological data monthly from July 2014 to June 2018 from 80 households across four sites in Kenya. Pupae count data were collected via entomological surveillance of households and paired with socio-demographic and environmental data. We calculated pupal persistence within a household as the number of months of pupal presence within a year. We used spatially explicit generalized additive mixed models (GAMMs) to identify the risk factors for pupal abundance, and a logistic regression to identify the risk factors for pupal persistence in households. Results The median number of months of pupal presence observed in households was 4 and ranged from 0 to 35 months. We identified pupal persistence in 85 house-years. The strongest risk factors for high pupal abundance were the presence of bushes or tall grass in the peri-domicile area (OR: 1.60, 95% CI: 1.13–2.28), open eaves (OR: 2.57, 95% CI: 1.33–4.95) and high habitat counts (OR: 1.42, 95% CI: 1.21–1.66). The main risk factors for pupal persistence were the presence of bushes or tall grass in the peri-domicile (OR: 4.20, 95% CI: 1.42–12.46) and high number of breeding sites (OR: 2.17, 95% CI: 1.03–4.58). Conclusions We observed Ae. aegypti pupal persistence at the household level in urban and rural and in coastal and inland Kenya. High counts of potential breeding containers, vegetation in the peri-domicile area and the presence of eaves were strongly associated with increased risk of pupal persistence and abundance. Targeting households that exhibit pupal persistence alongside the risk factors for pupal abundance in vector control interventions may result in more efficient use of limited resources.![]()
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Affiliation(s)
- Harun N Ngugi
- School of Biological Sciences, Department of Zoology, University of Nairobi, Nairobi, Kenya.,Department of Biological Sciences, Chuka University, Chuka, Kenya
| | - Sindiso Nyathi
- Department of Epidemiology and Population Health, School of Medicine, Stanford University, Stanford, CA, USA
| | - Amy Krystosik
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Stanford University, Stanford, CA, USA
| | - Bryson Ndenga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Joel O Mbakaya
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Peter Aswani
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - Lucy W Irungu
- School of Biological Sciences, Department of Zoology, University of Nairobi, Nairobi, Kenya
| | - Donal Bisanzio
- RTI International, Washington, DC, USA.,Epidemiology and Public Health Division, School of Medicine, University of Nottingham, Nottingham, UK
| | - Uriel Kitron
- Department of Environmental Sciences, Emory University, Atlanta, GA, USA
| | - A Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Diseases, School of Medicine, Stanford University, Stanford, CA, USA
| | - Francis Mutuku
- Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa, Kenya.
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15
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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: 107] [Impact Index Per Article: 26.8] [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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16
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Mordecai EA, Ryan SJ, Caldwell JM, Shah MM, LaBeaud AD. Climate change could shift disease burden from malaria to arboviruses in Africa. Lancet Planet Health 2020; 4:e416-e423. [PMID: 32918887 PMCID: PMC7490804 DOI: 10.1016/s2542-5196(20)30178-9] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 05/28/2023]
Abstract
Malaria is a long-standing public health problem in sub-Saharan Africa, whereas arthropod-borne viruses (arboviruses) such as dengue and chikungunya cause an under-recognised burden of disease. Many human and environmental drivers affect the dynamics of vector-borne diseases. In this Personal View, we argue that the direct effects of warming temperatures are likely to promote greater environmental suitability for dengue and other arbovirus transmission by Aedes aegypti and reduce suitability for malaria transmission by Anopheles gambiae. Environmentally driven changes in disease dynamics will be complex and multifaceted, but given that current public efforts are targeted to malaria control, we highlight Ae aegypti and dengue, chikungunya, and other arboviruses as potential emerging public health threats in sub-Saharan Africa.
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Affiliation(s)
- Erin A. Mordecai
- Biology Department, Stanford University, 371 Serra Mall, Stanford, CA, United States
| | - Sadie J. Ryan
- Department of Geography, University of Florida, Gainesville, FL, United States; Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States; School of Life Sciences, College of Agriculture, Engineering, and Science, University of KwaZulu Natal, KwaZulu Natal, South Africa
| | - Jamie M. Caldwell
- Biology Department, Stanford University, 371 Serra Mall, Stanford, CA, United States
| | - Melisa M. Shah
- Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - A. Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Disease, School of Medicine, Stanford University, Stanford, CA, United States
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17
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High Seroprevalence of Dengue Virus Infection in Sudan: Systematic Review and Meta-Analysis. Trop Med Infect Dis 2020; 5:tropicalmed5030120. [PMID: 32708492 PMCID: PMC7559303 DOI: 10.3390/tropicalmed5030120] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 12/15/2022] Open
Abstract
The goal of this study was to systematically review the published data on dengue virus (DENV) seroprevalence in Sudan and to estimate disease burden through meta-analysis. We searched, reviewed, and extracted online available reports on DENV in Sudan. Among 168 identified records, 19 were selected. Dengue infections were documented in 11/18 states. The overall seroprevalence of DENV in Sudan was estimated to be 27%, while the prevalence of dengue IgM was 22% and IgG was 38%. The prevalence of dengue estimated from community and hospital-based cross-sectional studies were 26% and 30% respectively. Additionally, one cohort study and a single PCR-based study reported a prevalence of 1% and 4%, respectively. Regional analysis revealed that the variation in seroprevalence in East, North, West, and Central Sudan was 23%, 24%, 36% and 43%, respectively. Interestingly, we found that DENV is circulating countrywide with a significant spatiotemporal variation in the disease seroprevalence. Furthermore, publications on dengue prevalence are temporally and geographically fragmented, perhaps due to limited resources. However, this gap in data and knowledge highlights the urgent need for a country-wide surveillance system and continued study of dengue burden in Sudan to accurately estimate the disease prevalence and determine the associated risk factors.
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18
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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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19
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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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20
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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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21
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Sanou AS, Dirlikov E, Sondo KA, Kagoné TS, Yameogo I, Sow HE, Adjami AG, Traore SM, Dicko A, Tinto B, Diendere EA, Ouedraogo-Konate SMWK, Kiemtore T, Kangoye DT, Sangare L, Dama ETH, Fuller JA, Major CG, Tosado-Acevedo R, Sharp TM, Koné RG, Bicaba BW. Building Laboratory-Based Arbovirus Sentinel Surveillance Capacity During an Ongoing Dengue Outbreak, Burkina Faso, 2017. Health Secur 2019; 16:S103-S110. [PMID: 30480496 DOI: 10.1089/hs.2018.0048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In West Africa, identification of nonmalarial acute febrile illness (AFI) etiologic pathogens is challenging, given limited epidemiologic surveillance and laboratory testing, including for AFI caused by arboviruses. Consequently, public health action to prevent, detect, and respond to outbreaks is constrained, as experienced during dengue outbreaks in several African countries. We describe the successful implementation of laboratory-based arbovirus sentinel surveillance during a dengue outbreak in Burkina Faso during fall 2017. We describe implementation, surveillance methods, and associated costs of enhanced surveillance during an outbreak response as an effort to build capacity to better understand the burden of disease caused by arboviruses in Burkina Faso. The system improved on existing routine surveillance through an improved case report form, systematic testing of specimens, and linking patient information with laboratory results through a data management system. Lessons learned will improve arbovirus surveillance in Burkina Faso and will contribute to enhancing global health security in the region. Elements critical to the success of this intervention include responding to a specific and urgent request by the government of Burkina Faso and building on existing systems and infrastructure already supported by CDC's global health security program.
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Affiliation(s)
- Anselme Simeon Sanou
- Anselme Simeon Sanou, MD, is Senior Surveillance Advisor, the Division for Global Health Protection/Burkina Faso Country Office, US Centers for Disease Control and Prevention , Ouagadougou, Burkina Faso
| | - Emilio Dirlikov
- Emilio Dirlikov, PhD, is Emergency Public Health Epidemiologist, Division for Global Health Protection/Emergency Recovery and Response Branch/Global Rapid Response Team, the US Centers for Disease Control and Prevention , Atlanta, Georgia
| | - Kongnimissom Apoline Sondo
- Kongnimissom Apoline Sondo, MD, is Head of the Service, Service of Infectious Diseases, the Centre Hospitalier Universitaire Yalgado Ouedraogo , Ouagadougou, Burkina Faso
| | - Thérèse Samdapawindé Kagoné
- Thérèse Samdapawindé Kagoné, PhD, is Head of the Viral Hemorrhagic Fever laboratory, the Laboratoire National de Référence des Fièvres Hémorragiques Virales , Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Issaka Yameogo
- Issaka Yameogo, MD, is a Medical Epidemiologist, the Direction de la Protection de la Santé de la Population, Ministère de la Sante, Ouagadougou, Burkina Faso
| | - Hyacinthe Euvrard Sow
- Hyacinthe Euvrard Sow, MD, is a Medical Epidemiologist, the Direction de la Protection de la Santé de la Population, Ministère de la Sante, Ouagadougou, Burkina Faso
| | - Aimé Gilles Adjami
- Aimé Gilles Adjami, PhD, is a Biologist and Executive Director, DAVYCAS International , Ouagadougou, Burkina Faso
| | - Siriky Martin Traore
- Siriky Martin Traore, PharmD, is a Medical Biologist, the Direction de la Protection de la Santé de la Population, Ministère de la Sante, Ouagadougou, Burkina Faso
| | - Amadou Dicko
- Amadou Dicko, DVM, is a Researcher, the Laboratoire National de Référence des Fièvres Hémorragiques Virales , Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Bachirou Tinto
- Bachirou Tinto, PharmD, is a Researcher, the Laboratoire National de Référence des Fièvres Hémorragiques Virales , Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Eric Arnaud Diendere
- Eric Arnaud Diendere, MD, is Infectiologist, Service of Infectious Diseases, the Centre Hospitalier Universitaire Yalgado Ouedraogo , Ouagadougou, Burkina Faso
| | - Sonia Marie W K Ouedraogo-Konate
- Sonia Marie W. K. Ouedraogo-Konate, MD, is a Medical Epidemiologist, the Direction de la Protection de la Santé de la Population, Ministère de la Sante, Ouagadougou, Burkina Faso
| | - Tanga Kiemtore
- Tanga Kiemtore, is Data Manager, the Direction de la Protection de la Santé de la Population, Ministère de la Sante, Ouagadougou, Burkina Faso
| | - David Tiga Kangoye
- David Tiga Kangoye, MD, is an Immuno Epidemiologist, Head of the Department of Public Health, the Centre Hospitalier Universitaire Yalgado Ouedraogo , Ouagadougou, Burkina Faso
| | - Lassana Sangare
- Lassana Sangare, PhD, is Virologist, Head of the Department of laboratories, the Centre Hospitalier Universitaire Yalgado Ouedraogo , Ouagadougou, Burkina Faso
| | - Emilie T H Dama
- Emilie T. H. Dama, PhD, is Senior Laboratory Advisor, the Division for Global Health Protection/Burkina Faso Country Office, US Centers for Disease Control and Prevention , Ouagadougou, Burkina Faso
| | - James A Fuller
- James A. Fuller, PhD, is an Epidemiologist, Division for Global Health Protection/Global Disease Detection Operations Center, the US Centers for Disease Control and Prevention , Atlanta, Georgia
| | - Chelsea G Major
- Chelsea G. Major, MPH, is a Public Health Advisor, the National Center for Emerging and Zoonotic Infectious Diseases/Division of Vector-Borne Diseases/Dengue Branch, US Centers for Disease Control and Prevention , San Juan, Puerto Rico
| | - Rafael Tosado-Acevedo
- Rafael Tosado-Acevedo, PhD, is a Microbiologist, the National Center for Emerging and Zoonotic Infectious Diseases/Division of Vector-Borne Diseases/Dengue Branch, US Centers for Disease Control and Prevention , San Juan, Puerto Rico
| | - Tyler M Sharp
- Tyler M. Sharp, PhD, is an Epidemiologist, the National Center for Emerging and Zoonotic Infectious Diseases/Division of Vector-Borne Diseases/Dengue Branch, US Centers for Disease Control and Prevention , San Juan, Puerto Rico
| | - Rebecca Greco Koné
- Rebecca Greco Koné, MPH, is Country Director, the Division for Global Health Protection/Burkina Faso Country Office, US Centers for Disease Control and Prevention , Ouagadougou, Burkina Faso
| | - Brice Wilfried Bicaba
- Brice Wilfried Bicaba, MD, is Director, the Direction de la Protection de la Santé de la Population, Ministère de la Sante, Ouagadougou, Burkina Faso
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22
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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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23
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Ndenga BA, Mutuku FM, Ngugi HN, Mbakaya JO, Aswani P, Musunzaji PS, Vulule J, Mukoko D, Kitron U, LaBeaud AD. Characteristics of Aedes aegypti adult mosquitoes in rural and urban areas of western and coastal Kenya. PLoS One 2017; 12:e0189971. [PMID: 29261766 PMCID: PMC5736227 DOI: 10.1371/journal.pone.0189971] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 12/05/2017] [Indexed: 01/26/2023] Open
Abstract
Aedes aegypti is the main vector for yellow fever, dengue, chikungunya and Zika viruses. Recent outbreaks of dengue and chikungunya have been reported in Kenya. Presence and abundance of this vector is associated with the risk for the occurrence and transmission of these diseases. This study aimed to characterize the presence and abundance of Ae. aegypti adult mosquitoes from rural and urban sites in western and coastal regions of Kenya. Presence and abundance of Ae. aegypti adult mosquitoes were determined indoors and outdoors in two western (urban Kisumu and rural Chulaimbo) and two coastal (urban Ukunda and rural Msambweni) sites in Kenya. Sampling was performed using quarterly human landing catches, monthly Prokopack automated aspirators and monthly Biogents-sentinel traps. A total of 2,229 adult Ae. aegypti mosquitoes were collected: 785 (35.2%) by human landing catches, 459 (20.6%) by Prokopack aspiration and 985 (44.2%) by Biogents-sentinel traps. About three times as many Ae. aegypti mosquitoes were collected in urban than rural sites (1,650 versus 579). Comparable numbers were collected in western (1,196) and coastal (1,033) sites. Over 80% were collected outdoors through human landing catches and Prokopack aspiration. The probability of collecting Ae. aegypti mosquitoes by human landing catches was significantly higher in the afternoon than morning hours (P<0.001), outdoors than indoors (P<0.001) and in urban than rural sites (P = 0.008). Significantly more Ae. aegypti mosquitoes were collected using Prokopack aspiration outdoors than indoors (P<0.001) and in urban than rural areas (P<0.001). Significantly more mosquitoes were collected using Biogents-sentinel traps in urban than rural areas (P = 0.008) and in western than coastal sites (P = 0.006). The probability of exposure to Ae. aegypti bites was highest in urban areas, outdoors and in the afternoon hours. These characteristics have major implications for the possible transmission of arboviral diseases and for the planning of surveillance and control programs.
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Affiliation(s)
| | - Francis Maluki Mutuku
- Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Harun Njenga Ngugi
- Department of Biological Sciences, Chuka University, Chuka, Kenya
- Department of Zoology, University of Nairobi, Nairobi, Kenya
| | - Joel Omari Mbakaya
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Peter Aswani
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - John Vulule
- Centre for Infectious and Parasitic Diseases Control Research, Kenya Medical Research Institute, Busia, Kenya
| | - Dunstan Mukoko
- Vector Borne Disease Control Unit, Ministry of Health, Nairobi, Kenya
| | - Uriel Kitron
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Angelle Desiree LaBeaud
- Department of Pediatrics, Stanford University, Stanford, California, United States of America
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24
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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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