151
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Frickmann H, Wiemer DF, Wassill L, Hinz R, Rojak S, Wille A, Loderstädt U, Schwarz NG, von Kalckreuth V, Im J, Jin Jeon H, Marks F, Owusu-Dabo E, Sarpong N, May J, Eibach D, Dekker D. Loop-mediated isothermal amplification-based detection of typhoid fever on an automated Genie II Mk2 system - A case-control-based approach. Acta Trop 2019; 190:293-295. [PMID: 30528158 DOI: 10.1016/j.actatropica.2018.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 12/02/2018] [Accepted: 12/03/2018] [Indexed: 12/20/2022]
Abstract
Typhoid fever, caused by the bacterium Salmonella enterica subsp. enterica serovar Typhi, is an important cause of blood stream infections in the tropics, for which easy-to-apply molecular diagnostic approaches are desirable. The diagnostic performance of a newly introduced and a previously described loop-mediated isothermal amplification (LAMP) approach using different primer sets on a Genie II Mk2 device for the identification of Salmonella enterica ssp. enterica ser. Typhi was evaluated with well-characterized residual materials from the tropics in a case control-based approach. After in-vitro confirmation of binding characteristics of both LAMP primer sets with culture isolates (n = 112), sensitivity and specificity were 100% for the newly designed new LAMP primer set 1 with incubated blood culture materials, while specificity was reduced to 97.1% for primer set 2. For 170 EDTA blood samples, sensitivity and specificity were 10% and 98.3% for primer set 1 as well as 38.0% and 83.3% for primer set 2, respectively; qPCR from EDTA blood did not score much better with 10% sensitivity and 100% specificity. LAMP using a Genie II Mk2 device is suitable for the identification of Salmonella enterica spp. enterica ser. Typhi from incubated blood culture materials. Sensitivity and specificity were insufficient for diagnosis directly from EDTA blood samples but LAMP showed similar sensitivity as qPCR.
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152
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Kroiss SJ, Ahmadzai M, Ahmed J, Alam MM, Chabot-Couture G, Famulare M, Mahamud A, McCarthy KA, Mercer LD, Muhammad S, Safdar RM, Sharif S, Shaukat S, Shukla H, Lyons H. Assessing the sensitivity of the polio environmental surveillance system. PLoS One 2018; 13:e0208336. [PMID: 30592720 PMCID: PMC6310268 DOI: 10.1371/journal.pone.0208336] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/15/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The polio environmental surveillance (ES) system has been an incredible tool for advancing polio eradication efforts because of its ability to highlight the spatial and temporal extent of poliovirus circulation. While ES often outperforms, or is more sensitive than AFP surveillance, the sensitivity of the ES system has not been well characterized. Fundamental uncertainty of ES site sensitivity makes it difficult to interpret results from ES, particularly negative results. METHODS AND FINDINGS To study ES sensitivity, we used data from Afghanistan and Pakistan to examine the probability that each ES site detected the Sabin 1, 2, or 3 components of the oral polio vaccine (OPV) as a function of virus prevalence within the same district (estimated from AFP data). Accounting for virus prevalence is essential for estimating site sensitivity because Sabin detection rates should vary with prevalence-high immediately after supplemental immunization activities (SIAs), but low in subsequent months. We found that most ES sites in Pakistan and Afghanistan are highly sensitive for detecting poliovirus relative to AFP surveillance in the same districts. For example, even when Sabin poliovirus is at low prevalence of ~0.5-3% in AFP surveillance, most ES sites have ~34-50% probability of detecting Sabin. However, there was considerable variation in ES site sensitivity and we flagged several sites for re-evaluation based on low sensitivity rankings and low wild polio virus detection rates. In these areas, adding new sites or modifying collection methods in current sites could improve sensitivity of environmental surveillance. CONCLUSIONS Relating ES detections to virus prevalence significantly improved our ability to evaluate site sensitivity compared to evaluations based solely on ES detection rates. To extend our approach to new sites and regions, we provide a preliminary framework for relating ES and AFP detection rates, and descriptions of how detection rates might relate to SIAs and natural seasonality.
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Affiliation(s)
- Steve J. Kroiss
- Institute for Disease Modeling, Bellevue, WA, United States of America
| | - Maiwand Ahmadzai
- National Emergency Operations Centre for Polio Eradication, Kabul, Afghanistan
| | - Jamal Ahmed
- World Health Organization, Geneva, Switzerland
| | - Muhammad Masroor Alam
- Department of Virology, National Institute of Health, Chak Shahzad, Islamabad, Pakistan
- World Health Organization, Islamabad, Pakistan
| | | | - Michael Famulare
- Institute for Disease Modeling, Bellevue, WA, United States of America
| | - Abdirahman Mahamud
- World Health Organization, Islamabad, Pakistan
- National Emergency Operations Centre for Polio Eradication, Islamabad, Pakistan
| | - Kevin A. McCarthy
- Institute for Disease Modeling, Bellevue, WA, United States of America
| | - Laina D. Mercer
- Institute for Disease Modeling, Bellevue, WA, United States of America
| | - Salman Muhammad
- Department of Virology, National Institute of Health, Chak Shahzad, Islamabad, Pakistan
| | - Rana M. Safdar
- National Emergency Operations Centre for Polio Eradication, Islamabad, Pakistan
| | - Salmaan Sharif
- Department of Virology, National Institute of Health, Chak Shahzad, Islamabad, Pakistan
- World Health Organization, Islamabad, Pakistan
| | - Shahzad Shaukat
- Department of Virology, National Institute of Health, Chak Shahzad, Islamabad, Pakistan
- World Health Organization, Islamabad, Pakistan
| | - Hemant Shukla
- National Emergency Operations Centre for Polio Eradication, Kabul, Afghanistan
| | - Hil Lyons
- Institute for Disease Modeling, Bellevue, WA, United States of America
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153
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Osei FB, Stein A, Nyadanu SD. Spatial and temporal heterogeneities of district-level typhoid morbidities in Ghana: A requisite insight for informed public health response. PLoS One 2018; 13:e0208006. [PMID: 30496258 PMCID: PMC6264858 DOI: 10.1371/journal.pone.0208006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 11/09/2018] [Indexed: 11/18/2022] Open
Abstract
Typhoid fever is estimated to cause between 9.9-24.2 million cases and 75,000-208,000 deaths per year globally. Low-income and middle-income countries report the majority of cases, especially those in sub-Saharan Africa. The epidemiology of typhoid fever is poorly understood, particularly in Ghana where there has been no study of the within-country variation. Our objective was to explore and analyze the spatial and temporal patterns of typhoid fever morbidities in Ghana. We used the global and local Moran's indices to uncover the existence of global and local spatial patterns, respectively. Generalized linear autoregressive moving average (glarma) models were developed to explore the overall and regional level temporal patterns of morbidities. The overall index of spatial association was 0.19 (p < 0.001). The global Moran's monthly indices of clustering ranged from ≈ 0 - 0.28, with few non-significant (p > 0.05) estimates. The yearly estimates were all significant (p < 0.001) and ranged from 0.1-0.19, suggesting spatial clustering of typhoid. The local Moran's maps indicated isolated high contributions of clustering within the Upper West and Western regions. The overall and regional level glarma models indicated significant first and second-order serial correlation as well as quarterly trends. These findings can provide relevant epidemiological insight into the spatial and temporal patterns of typhoid epidemiology and useful to complement the development of control strategies by public health managers.
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Affiliation(s)
- Frank Badu Osei
- Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede, Netherlands
| | - Alfred Stein
- Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede, Netherlands
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154
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The phylogeography and incidence of multi-drug resistant typhoid fever in sub-Saharan Africa. Nat Commun 2018; 9:5094. [PMID: 30504848 PMCID: PMC6269545 DOI: 10.1038/s41467-018-07370-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/18/2018] [Indexed: 11/18/2022] Open
Abstract
There is paucity of data regarding the geographical distribution, incidence, and phylogenetics of multi-drug resistant (MDR) Salmonella Typhi in sub-Saharan Africa. Here we present a phylogenetic reconstruction of whole genome sequenced 249 contemporaneous S. Typhi isolated between 2008-2015 in 11 sub-Saharan African countries, in context of the 2,057 global S. Typhi genomic framework. Despite the broad genetic diversity, the majority of organisms (225/249; 90%) belong to only three genotypes, 4.3.1 (H58) (99/249; 40%), 3.1.1 (97/249; 39%), and 2.3.2 (29/249; 12%). Genotypes 4.3.1 and 3.1.1 are confined within East and West Africa, respectively. MDR phenotype is found in over 50% of organisms restricted within these dominant genotypes. High incidences of MDR S. Typhi are calculated in locations with a high burden of typhoid, specifically in children aged <15 years. Antimicrobial stewardship, MDR surveillance, and the introduction of typhoid conjugate vaccines will be critical for the control of MDR typhoid in Africa. Typhoid fever is caused by the bacterium Salmonella Typhi. Here, Park et al. analyse the genomes of 249 S. Typhi isolates from 11 sub-Saharan African countries, identifying genes and plasmids associated with antibiotic resistance and showing that multi-drug resistance is highly pervasive in sub-Saharan Africa.
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155
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Marks F, Kim JH, Rakotozandrindrainy R. Madagascar should introduce typhoid conjugate vaccines now. Lancet 2018; 392:1309-1310. [PMID: 30322578 DOI: 10.1016/s0140-6736(18)31882-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/07/2018] [Indexed: 11/17/2022]
Affiliation(s)
- Florian Marks
- International Vaccine Institute, Seoul 08826, South Korea; The Department of Medicine, University of Cambridge, Cambridge, UK.
| | - Jerome H Kim
- International Vaccine Institute, Seoul 08826, South Korea
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156
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Riddle M, Chen W, Kirkwood C, MacLennan C. Update on vaccines for enteric pathogens. Clin Microbiol Infect 2018; 24:1039-1045. [DOI: 10.1016/j.cmi.2018.06.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/17/2018] [Accepted: 06/19/2018] [Indexed: 12/12/2022]
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157
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Typhoid fever in Santiago, Chile: Insights from a mathematical model utilizing venerable archived data from a successful disease control program. PLoS Negl Trop Dis 2018; 12:e0006759. [PMID: 30188904 PMCID: PMC6143279 DOI: 10.1371/journal.pntd.0006759] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 09/18/2018] [Accepted: 08/16/2018] [Indexed: 12/04/2022] Open
Abstract
Typhoid fever is endemic in many developing countries. In the early 20th century, newly industrializing countries including the United States successfully controlled typhoid as water treatment (chlorination/sand filtration) and improved sanitation became widespread. Enigmatically, typhoid remained endemic through the 1980s in Santiago, Chile, despite potable municipal water and widespread household sanitation. Data were collected across multiple stages of endemicity and control in Santiago, offering a unique resource for gaining insight into drivers of transmission in modern settings. We developed an individual-based mathematical model of typhoid transmission, with model components including distinctions between long-cycle and short-cycle transmission routes. Data used to fit the model included the prevalence of chronic carriers, seasonality, longitudinal incidence, and age-specific distributions of typhoid infection and disease. Our model captured the dynamics seen in Santiago across endemicity, vaccination, and environmental control. Both vaccination and diminished exposure to seasonal amplified long-cycle transmission contributed to the observed declines in typhoid incidence, with the vaccine estimated to elicit herd effects. Vaccines are important tools for controlling endemic typhoid, with even limited coverage eliciting herd effects in this setting. Removing the vehicles responsible for amplified long-cycle transmission and assessing the role of chronic carriers in endemic settings are additional key elements in designing programs to achieve accelerated control of endemic typhoid. Typhoid fever was successfully controlled in Santiago, Chile, after a series of interventions including vaccination with a live oral vaccine (Ty21a), and an environmental sanitation improvement, when a ban was put on the irrigation of salad vegetable crops with untreated sewage. Data collected during this period inform seasonality, age distribution and longitudinal trends of disease. We developed an individual-based, mathematical model to both simulate the dynamics of typhoid seen in Santiago, as well as to investigate relative impacts of the vaccine and sanitation interventions. We found that herd immunity resulted from field trials of the Ty21a vaccine and that chronic carriers were a likely driver of sustained transmission at low incidence levels. Modeling typhoid fever in areas that have demonstrated successful control provides insight for control strategies in modern settings.
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158
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Balasubramanian R, Im J, Lee JS, Jeon HJ, Mogeni OD, Kim JH, Rakotozandrindrainy R, Baker S, Marks F. The global burden and epidemiology of invasive non-typhoidal Salmonella infections. Hum Vaccin Immunother 2018; 15:1421-1426. [PMID: 30081708 PMCID: PMC6663144 DOI: 10.1080/21645515.2018.1504717] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Invasive non-typhoidal Salmonella (iNTS) disease has emerged as a major public health concern. Yet, understanding of the global burden is incomplete, limited particularly by the breadth of blood culture-based surveillance systems that are able to accurately diagnose the etiology of bacteremia. The accessibility of whole genome sequencing has allowed for genetic characterization of pathogens, shedding light on its evolutionary history and sounding alerts for its future progression. iNTS disease is observed to be a particular threat in sub-Saharan Africa, with a case fatality rate greatly exceeding that of typhoid fever, and commonly affecting infants, young children and immunocompromised adults. While iNTS disease might also be a threat in Asia and Latin America, its burden is not well characterized, primarily owing to the lack of comprehensive reporting in these regions. Drug-resistant Salmonella enterica (S. enterica) serovars (e.g. Typhimurium sequence type 313 (ST313)) have emerged as a potential consequence of sustained antibiotic pressure. Genetic analyses have identified distinguished iNTS disease-causing strains that are particularly virulent in certain human host populations. Effective treatment strategies, including vaccination, are necessary; iNTS vaccines targeting the most common S. enterica serovars, Typhimurium, Enteritidis and Dublin, are currently in early developmental stages. Funding and political support is needed to promote vaccine development and implementation programs to ultimately reduce the threat of iNTS disease in high risk areas.
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Affiliation(s)
| | - Justin Im
- b International Vaccine Institute , Seoul , Republic of Korea
| | - Jung-Seok Lee
- b International Vaccine Institute , Seoul , Republic of Korea
| | - Hyon Jin Jeon
- b International Vaccine Institute , Seoul , Republic of Korea
| | - Ondari D Mogeni
- b International Vaccine Institute , Seoul , Republic of Korea
| | - Jerome H Kim
- b International Vaccine Institute , Seoul , Republic of Korea
| | | | - Stephen Baker
- d The Department of Medicine , University of Cambridge , Cambridge , United Kingdom.,e Oxford University Clinical Research Unit , Ho Chi Minh City , Vietnam
| | - Florian Marks
- b International Vaccine Institute , Seoul , Republic of Korea.,d The Department of Medicine , University of Cambridge , Cambridge , United Kingdom
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159
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Andrews JR, Baker S, Marks F, Alsan M, Garrett D, Gellin BG, Saha SK, Qamar FN, Yousafzai MT, Bogoch II, Antillon M, Pitzer VE, Kim JH, John J, Gauld J, Mogasale V, Ryan ET, Luby SP, Lo NC. Typhoid conjugate vaccines: a new tool in the fight against antimicrobial resistance. THE LANCET. INFECTIOUS DISEASES 2018; 19:e26-e30. [PMID: 30170987 DOI: 10.1016/s1473-3099(18)30350-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 05/10/2018] [Accepted: 05/17/2018] [Indexed: 10/28/2022]
Abstract
Typhoid fever is an acute systemic infectious disease responsible for an estimated 12-20 million illnesses and over 150 000 deaths annually. In March, 2018, a new recommendation was issued by WHO for the programmatic use of typhoid conjugate vaccines in endemic countries. Health economic analyses of typhoid vaccines have informed funding decisions and national policies regarding vaccine rollout. However, by focusing only on averted typhoid cases and their associated costs, traditional cost-effectiveness analyses might underestimate crucial benefits of typhoid vaccination programmes, because the potential effect of typhoid vaccines on the treatment of patients with non-specific acute febrile illnesses is not considered. For every true case of typhoid fever, three to 25 patients without typhoid disease are treated with antimicrobials unnecessarily, conservatively amounting to more than 50 million prescriptions per year. Antimicrobials for suspected typhoid might therefore be an important selective pressure for the emergence and spread of antimicrobial resistance globally. We propose that large-scale, more aggressive typhoid vaccination programmes-including catch-up campaigns in children up to 15 years of age, and vaccination in lower incidence settings-have the potential to reduce the overuse of antimicrobials and thereby reduce antimicrobial resistance in many bacterial pathogens. Funding bodies and national governments must therefore consider the potential for broad reductions in antimicrobial use and resistance in decisions related to the rollout of typhoid conjugate vaccines.
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Affiliation(s)
- Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA.
| | - Stephen Baker
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Florian Marks
- Department of Medicine, University of Cambridge, Cambridge, UK; Epidemiology Unit, International Vaccine Institute, Seoul, South Korea
| | - Marcella Alsan
- Center for Health Policy and the Center for Primary Care and Outcomes Research, Stanford University, Stanford, CA, USA
| | | | | | - Samir K Saha
- Department of Microbiology, Bangladesh Institute of Child Health, Dhaka Shishu Hospital, Dhaka, Bangladesh
| | - Farah Naz Qamar
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | | | - Isaac I Bogoch
- Department of Medicine, University of Toronto, Toronto, Canada
| | - Marina Antillon
- Center for Health Economics Research and Modeling Infectious Diseases, University of Antwerp, Belgium
| | - Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Jong-Hoon Kim
- Epidemiology Unit, International Vaccine Institute, Seoul, South Korea
| | - Jacob John
- Department of Community Health, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Vittal Mogasale
- Policy and Economic Research Department, Development and Delivery Unit, International Vaccine Institute, Seoul, South Korea
| | - Edward T Ryan
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard University, Boston, MA, USA
| | - Stephen P Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Nathan C Lo
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA
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160
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Maze MJ, Bassat Q, Feasey NA, Mandomando I, Musicha P, Crump JA. The epidemiology of febrile illness in sub-Saharan Africa: implications for diagnosis and management. Clin Microbiol Infect 2018; 24:808-814. [PMID: 29454844 PMCID: PMC6057815 DOI: 10.1016/j.cmi.2018.02.011] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/08/2018] [Accepted: 02/10/2018] [Indexed: 12/18/2022]
Abstract
BACKGROUND Fever is among the most common symptoms of people living in Africa, and clinicians are challenged by the similar clinical features of a wide spectrum of potential aetiologies. AIM To summarize recent studies of fever aetiology in sub-Saharan Africa focusing on causes other than malaria. SOURCES A narrative literature review by searching the MEDLINE database, and recent conference abstracts. CONTENT Studies of multiple potential causes of fever are scarce, and for many participants the infecting organism remains unidentified, or multiple co-infecting microorganisms are identified, and establishing causation is challenging. Among ambulatory patients, self-limiting arboviral infections and viral upper respiratory infections are common, occurring in up to 60% of children attending health centres. Among hospitalized patients there is a high prevalence of potentially fatal infections requiring specific treatment. Bacterial bloodstream infection and bacterial zoonoses are major causes of fever. In recent years, the prevalence of antimicrobial resistance among bacterial isolates has increased, notably with spread of extended spectrum β-lactamase-producing Enterobacteriaceae and fluoroquinolone-resistant Salmonella enterica. Among those with human immunodeficiency virus (HIV) infection, Mycobacterium tuberculosis bacteraemia has been confirmed in up to 34.8% of patients with sepsis, and fungal infections such as cryptococcosis and histoplasmosis remain important. IMPLICATIONS Understanding the local epidemiology of fever aetiology, and the use of diagnostics including malaria and HIV rapid-diagnostic tests, guides healthcare workers in the management of patients with fever. Current challenges for clinicians include assessing which ambulatory patients require antibacterial drugs, and identifying hospitalized patients infected with organisms that are not susceptible to empiric antibacterial regimens.
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Affiliation(s)
- M J Maze
- Centre for International Health, University of Otago, New Zealand; Kilimanjaro Christian Medical Centre, Moshi, Tanzania.
| | - Q Bassat
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique; ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain; ICREA, Pg. Lluís Companys 23, Barcelona, Spain; Paediatric Infectious Diseases Unit, Paediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain
| | - N A Feasey
- Liverpool School of Tropical Medicine, Liverpool, UK; Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - I Mandomando
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique; Instituto Nacional de Saúde, Ministério da Saúde, Maputo, Mozambique
| | - P Musicha
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - J A Crump
- Centre for International Health, University of Otago, New Zealand; Kilimanjaro Christian Medical Centre, Moshi, Tanzania; Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
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161
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Radhakrishnan A, Als D, Mintz ED, Crump JA, Stanaway J, Breiman RF, Bhutta ZA. Introductory Article on Global Burden and Epidemiology of Typhoid Fever. Am J Trop Med Hyg 2018; 99:4-9. [PMID: 30047370 PMCID: PMC6128367 DOI: 10.4269/ajtmh.18-0032] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
This article is the introduction to a 12-paper supplement on global trends in typhoid fever. The Tackling Typhoid (T2) project was initiated in 2015 to synthesize the existing body of literature on typhoidal salmonellae and study national and regional typhoid fever trends. In addition to a global systematic review, eight case studies were undertaken to examine typhoid and paratyphoid fever trends in endemic countries alongside changes in relevant contextual factors. Incidence variations exist both within and between regions with large subnational differences as well, suggesting that public health changes impacting typhoid and paratyphoid fevers in one setting may not have similar impacts in another. This supplement also brings to light the lack of national typhoid fever surveillance systems, inconsistencies in diagnostics, and the lack of typhoid fever associated morbidity and mortality data in many countries, making it difficult to accurately quantify and track burden of disease. To better understand typhoid fever there is a need for more high-quality data from resource-poor settings. The implementation of typhoid surveillance systems alongside the transition to blood-culture confirmation of cases, where possible, would aid in the improvement of data quality in low-income settings. The following supplement includes the results of our global systematic review, eight-country case study articles, a qualitative article informed by semistructured interviews, and a conclusion article on potential ways forward for typhoid control.
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Affiliation(s)
| | - Daina Als
- Centre for Global Child Health, The Hospital for Sick Children, Toronto, Canada
| | - Eric D Mintz
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - John A Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Jefferey Stanaway
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
| | | | - Zulfiqar A Bhutta
- Centre for Global Child Health, The Hospital for Sick Children, Toronto, Canada.,Center of Excellence in Women and Child Health, The Aga Khan University, Karachi, Pakistan.,Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
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162
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Akinyemi KO, Oyefolu AOB, Mutiu WB, Iwalokun BA, Ayeni ES, Ajose SO, Obaro SK. Typhoid Fever: Tracking the Trend in Nigeria. Am J Trop Med Hyg 2018; 99:41-47. [PMID: 30047362 PMCID: PMC6128359 DOI: 10.4269/ajtmh.18-0045] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Typhoid fever continues to pose a serious health challenge in developing countries. A reliable database on positive blood cultures is essential for prompt interventions. To generate reliable data on Salmonella enterica serovar Typhi (S. Typhi)–positive blood culture trends in typhoidal Salmonella in Nigeria alongside changing contextual factors and antimicrobial resistance patterns, a retrospective cohort study was conducted in two hospitals in Lagos between 1993 and 2015. Medical records of typhoid patients were reviewed for positive culture and antibiogram, using standard procedures and analyzed. Additional data were retrieved from a previous study in seven facilities in Abuja and three hospitals in Kano from 2008 to 2017 and 2013 to 2017, respectively. A declining trend in percent positivity of S. Typhi was observed in Abuja with more erratic trends in Lagos and Kano. In Lagos, more than 80% of the isolates from the entire study period exhibited multiple drug resistance with a generally increasing trend. Of the chosen contextual factors, improvements were recorded in female literacy, access to improved water supply, diarrheal mortality in children younger than 5 years, gross domestic product, and poverty while access to improved sanitation facilities decreased over time nationally. Typhoid fever still poses a serious health challenge in Nigeria and in antibiotic resistance, and is a major health security issue. A combined approach that includes the use of typhoid vaccines, improvements in sanitation, and safe water supply is essential.
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Affiliation(s)
| | | | - Wasiu Bamidele Mutiu
- Department of Medical Microbiology and Parasitology, College of Medicine, Lagos State University, Lagos, Nigeria
| | - Bamidele Abiodun Iwalokun
- Biochemistry Unit and Malaria Research Laboratory, Nigerian Institute of Medical Research, Lagos, Nigeria
| | | | | | - Stephen K Obaro
- International Foundation Against Infectious Diseases in Nigeria (IFAIN), Abuja, Nigeria.,Division of Pediatric Infectious Disease, University of Nebraska Medical Centre, Omaha, Nebraska
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163
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Meiring JE, Patel P, Patel P, Gordon MA. Typhoid conjugate vaccines: making vaccine history in Africa. Expert Rev Vaccines 2018; 17:673-676. [PMID: 29972655 DOI: 10.1080/14760584.2018.1496825] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- James E Meiring
- a Oxford Vaccine Group, Department of Paediatrics , Oxford University , Oxford , UK.,b Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine , Blantyre , Malawi
| | - Pratiksha Patel
- b Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine , Blantyre , Malawi
| | - Priyanka Patel
- b Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine , Blantyre , Malawi
| | - Melita A Gordon
- b Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine , Blantyre , Malawi
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164
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Mehta PK, Rauniyar R, Gupta BP. Microfilaria persistent foci during post MDA and the risk assessment of resurgence in India. Trop Med Health 2018; 46:25. [PMID: 30026669 PMCID: PMC6050703 DOI: 10.1186/s41182-018-0107-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 06/29/2018] [Indexed: 11/10/2022] Open
Abstract
Background Pondicherry, a union territory in India, is an endemic district for bancroftian lymphatic filariasis transmitted by Culex quinquefasciatus where eight rounds of mass drug administration (MDA) were completed in 2011 (annually once from 2004 to 2011).The objectives of this study were to conduct a focal survey to assess microfilaria and antigen (Ag) prevalence among young adults and to assess vector infection and infectivity through a focal entomological survey. Methods Mosquitoes were collected using gravid traps in Sedurapet village of Pondicherry and dissected to enumerate W. bancrofti larvae stage first larval stage (L1), second larval stage (L2), and third larval stage (L3). Microfilarias (Mf) were detected using blood smears collected from inhabitants. Results A total of 360 individuals from 67 houses were enrolled in this study of which 290 (80.6%) were surveyed for the presence of Mf. Two Mf carriers were detected yielding an overall prevalence of 0.69% and two out of 85 (2.35%) were Mf antigen positive. Of the 2875 mosquitoes collected by gravid trap, Culex quinquefasciatus (93.9%) was the predominant species, followed by Anopheles subpictus (2.3%) and Culex vishnui (3.8%). The density of Cx. quinquefasciatus was 28.1 per trap-night. A total of 2429 Cx. quinquefasciatus were dissected and microscopically examined for abdominal conditions (gravid 85%, semi-gravid 9.4%, unfed 3.8%, and fully fed 1.9%) and filarial infection. One mosquito (infection rate equal to 0.04%) was found to harbor a second stage filarial larva, and none of the mosquitoes had infective stage larva. Conclusion Our results show no reappearance of infection of lymphatic filariasis in Sedurapet village of Pondicherry after MDA, and thus, no further intervention is required in that area for possible resurgence of lymphatic filariasis. However, monitoring should be continued as part of post MDA activities until the endpoint of complete elimination is achieved. We demonstrated that xenomonitoring can be used to monitor the post MDA situation for possible risk of transmission to initiate control measures.
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Affiliation(s)
- Pramod Kumar Mehta
- 1Vector Control Research Centre, Medical Complex, Indira Nagar, Pondicherry, India.,Present address: Central Regional Health Directorate Office, Ministry of Health and Population, Kathmandu, Nepal
| | - Ramanuj Rauniyar
- Kathmandu Research Institute for Biological Sciences, Kathmandu, Nepal
| | - Birendra Prasad Gupta
- Kathmandu Research Institute for Biological Sciences, Kathmandu, Nepal.,Central Diagnostic Laboratory and Research Center Pvt. Ltd, Kathmandu, Nepal
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165
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Immunogenicity and Induction of Functional Antibodies in Rabbits Immunized with a Trivalent Typhoid-Invasive Nontyphoidal Salmonella Glycoconjugate Formulation. Molecules 2018; 23:molecules23071749. [PMID: 30018230 PMCID: PMC6099966 DOI: 10.3390/molecules23071749] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/12/2018] [Accepted: 07/14/2018] [Indexed: 12/19/2022] Open
Abstract
Typhoid fever due to Salmonella Typhi and invasive nontyphoidal Salmonella (iNTS) infections caused by serovars Enteritidis (SE) and Typhimurium (STm) are major pediatric health problems in sub-Saharan Africa. Typhoid has high complication rates, and iNTS infections have high case fatality rates; moreover, emerging antimicrobial resistance is diminishing treatment options. Vi capsule-based typhoid conjugate vaccine (Typbar-TCV™), licensed in India and pre-qualified by the World Health Organization, elicits durable immunity when administered to infants, but no iNTS vaccines are licensed or imminent. We have developed monovalent SE and STm glycoconjugate vaccines based on coupling lipopolysaccharide-derived core-O polysaccharide (COPS) to phase 1 flagellin protein (FliC) from the homologous serovar. Herein, we report the immunogenicity of multivalent formulations of iNTS COPS:FliC conjugates with Typbar-TCV™. Rabbits immunized with the trivalent typhoid-iNTS glycoconjugate vaccine generated high titers of serum IgG antibody to all three polysaccharide antigens for which anti-COPS IgG antibodies were directed primarily against serogroup-specific OPS epitopes. Responses to SE and STm FliC were lower relative to anti-COPS titers. Post-vaccination rabbit sera mediated bactericidal activity in-vitro, and protected mice after passive transfer against challenge with virulent SE or STm Malian blood isolates. These results support accelerated progression to clinical trials.
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166
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Cuypers WL, Jacobs J, Wong V, Klemm EJ, Deborggraeve S, Van Puyvelde S. Fluoroquinolone resistance in Salmonella: insights by whole-genome sequencing. Microb Genom 2018; 4. [PMID: 29975627 PMCID: PMC6113872 DOI: 10.1099/mgen.0.000195] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Fluoroquinolone (FQ)-resistant Salmonella spp. were listed by the WHO in 2017 as priority pathogens for which new antibiotics were urgently needed. The overall global burden of Salmonella infections is high, but differs per region. Whereas typhoid fever is most prevalent in South and South-East Asia, non-typhoidal salmonellosis is prevalent across the globe and associated with a mild gastroenteritis. By contrast, invasive non-typhoidal Salmonella cause bloodstream infections associated with high mortality, particularly in sub-Saharan Africa. Most Salmonella strains from clinical sources are resistant to first-line antibiotics, with FQs now being the antibiotic of choice for treatment of invasive Salmonella infections. However, FQ resistance is increasingly being reported in Salmonella, and multiple molecular mechanisms are already described. Whole-genome sequencing (WGS) is becoming more frequently used to analyse bacterial genomes for antibiotic-resistance markers, and to understand the phylogeny of bacteria in relation to their antibiotic-resistance profiles. This mini-review provides an overview of FQ resistance in Salmonella, guided by WGS studies that demonstrate that WGS is a valuable tool for global surveillance.
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Affiliation(s)
- Wim L Cuypers
- 1Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium.,2Department of Mathematics and Computer Science, University of Antwerp, Antwerpen, Belgium
| | - Jan Jacobs
- 3Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium.,4Department of Microbiology and Immunology, Katholieke Universiteit Leuven (KU Leuven), Leuven, Belgium
| | - Vanessa Wong
- 5Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,6Wellcome Trust Sanger Institute, Hinxton, UK
| | | | - Stijn Deborggraeve
- 1Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Sandra Van Puyvelde
- 6Wellcome Trust Sanger Institute, Hinxton, UK.,1Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
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167
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Baliban SM, Curtis B, Toema D, Tennant SM, Levine MM, Pasetti MF, Simon R. Immunogenicity and efficacy following sequential parenterally-administered doses of Salmonella Enteritidis COPS:FliC glycoconjugates in infant and adult mice. PLoS Negl Trop Dis 2018; 12:e0006522. [PMID: 29791435 PMCID: PMC6002111 DOI: 10.1371/journal.pntd.0006522] [Citation(s) in RCA: 12] [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: 12/20/2017] [Revised: 06/14/2018] [Accepted: 05/13/2018] [Indexed: 11/18/2022] Open
Abstract
In sub-Saharan Africa, invasive nontyphoidal Salmonella (iNTS) infections with serovars S. Enteritidis, S. Typhimurium and I 4,[5],12:i:- are widespread in children < 5 years old. Development of an efficacious vaccine would provide an important public health tool to prevent iNTS disease in this population. Glycoconjugates of S. Enteritidis core and O-polysaccharide (COPS) coupled to the homologous serovar phase 1 flagellin protein (FliC) were previously shown to be immunogenic and protected adult mice against death following challenge with a virulent Malian S. Enteritidis blood isolate. This study extends these observations to immunization of mice in early life and also assesses protection with partial and full regimens. Anti-COPS and anti-FliC serum IgG titers were assessed in infant and adult mice after immunization with 1, 2 or 3 doses of S. Enteritidis COPS:FliC alone or co-formulated with aluminum hydroxide or monophosphoryl lipid A (MPL) adjuvants. S. Enteritidis COPS:FliC was immunogenic in both age groups, although the immune responses were quantitatively lower in infants. Kinetics of antibody production were similar for the native and adjuvanted formulations after three doses; conjugates formulated with MPL elicited significantly increased anti-COPS IgG titers in adult but not infant mice. Nevertheless, robust protection against S. Enteritidis challenge was seen for all three formulations when three doses were given either during infancy or as adults. We further found that significant protection could be achieved with two COPS:FliC doses, despite elicitation of modest serum anti-COPS IgG antibody titers. These findings guide potential immunization strategies that may be translated to develop a human pediatric iNTS vaccine for sub-Saharan Africa. Non-typhoidal Salmonella enterica (NTS) serovars Enteritidis and Typhimurium (including monophasic variant I 4,[5],12:i:-) are significant causes of invasive bacterial disease amongst infants and toddlers in sub-Saharan Africa, and currently, there are no approved NTS vaccines. We have demonstrated previously that immunization with S. Enteritidis core and O-polysaccharide (COPS) conjugated to the flagellin protein (FliC) from the homologous serovar protected adult mice from fatal infection with a Malian S. Enteritidis blood isolate. The target population for iNTS vaccines in sub-Saharan Africa, however, are young infants. In the current study, we evaluated S. Enteritidis COPS:FliC vaccination during murine infancy or adulthood. We found that COPS:FliC was immunogenic in both adult and infant mice and that co-formulation with adjuvant impacted the magnitude and quality of the immune response. Despite these differences, all vaccine formulations protected against experimental challenge in both age groups. Furthermore, robust efficacy was attainable after only two COPS:FliC doses, coinciding with the appearance of COPS-specific antibodies. The results from this study suggest that S. Enteritidis COPS:FliC is a promising pediatric vaccine candidate for use in sub-Saharan Africa and may help inform potential immunization strategies for iNTS COPS:FliC conjugate vaccines.
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Affiliation(s)
- Scott M. Baliban
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Brittany Curtis
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Deanna Toema
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Sharon M. Tennant
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Myron M. Levine
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Marcela F. Pasetti
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Raphael Simon
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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168
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Kim JH, Mogasale V, Im J, Ramani E, Marks F. Updated estimates of typhoid fever burden in sub-Saharan Africa. LANCET GLOBAL HEALTH 2018; 5:e969. [PMID: 28911760 DOI: 10.1016/s2214-109x(17)30328-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/12/2017] [Accepted: 07/12/2017] [Indexed: 10/18/2022]
Affiliation(s)
- Jong-Hoon Kim
- Epidemiology Unit, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Seoul 08826, South Korea
| | - Vittal Mogasale
- Development and Delivery Unit, Policy and Economic Research Department, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Seoul 08826, South Korea.
| | - Justin Im
- Epidemiology Unit, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Seoul 08826, South Korea
| | - Enusa Ramani
- Development and Delivery Unit, Policy and Economic Research Department, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Seoul 08826, South Korea
| | - Florian Marks
- Epidemiology Unit, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Seoul 08826, South Korea
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169
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Abstract
Typhoid and paratyphoid fever may follow a seasonal pattern, but this pattern is not well characterized. Moreover, the environmental drivers that influence seasonal dynamics are not fully understood, although increasing evidence suggests that rainfall and temperature may play an important role. We compiled a database of typhoid, paratyphoid, or enteric fever and their potential environmental drivers. We assessed the seasonal dynamics by region and latitude, quantifying the mean timing of peak prevalence and seasonal variability. Moreover, we investigated the potential drivers of the seasonal dynamics and compared the seasonal dynamics for typhoid and paratyphoid fever. We observed a distinct seasonal pattern for enteric and typhoid fever by latitude, with seasonal variability more pronounced further from the equator. We also found evidence of a positive association between preceding rainfall and enteric fever among settings 35°–11°N and a more consistent positive association between temperature and enteric fever incidence across most regions of the world. In conclusion, we identified varying seasonal dynamics for enteric or typhoid fever in association with environmental factors. The underlying mechanisms that drive the seasonality of enteric fever are likely dependent on the local context and should be taken into account in future control efforts.
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170
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Dougan G. Typhoid in Africa and vaccine deployment. LANCET GLOBAL HEALTH 2018; 5:e236-e237. [PMID: 28193381 DOI: 10.1016/s2214-109x(17)30045-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 01/16/2017] [Indexed: 01/21/2023]
Affiliation(s)
- Gordon Dougan
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK; Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
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171
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Parry-Hanson Kunadu A, Holmes M, Miller EL, Grant AJ. Microbiological quality and antimicrobial resistance characterization of Salmonella spp. in fresh milk value chains in Ghana. Int J Food Microbiol 2018; 277:41-49. [PMID: 29680695 DOI: 10.1016/j.ijfoodmicro.2018.04.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/08/2018] [Accepted: 04/13/2018] [Indexed: 11/16/2022]
Abstract
Consumer perception of poor hygiene of fresh milk products is a major barrier to promotion of milk consumption as an intervention to alleviate the burden of malnutrition in Ghana. Fresh milk is retailed raw, boiled, or processed into unfermented cheese and spontaneously fermented products in unlicensed outlets. In this study, we have determined microbiological quality of informally retailed fresh milk products and characterized the genomic diversity and antimicrobial resistance (AMR) patterns of non-typhoidal Salmonella (NTS) in implicated products. A total of 159 common dairy products were purchased from five traditional milk markets in Accra. Samples were analysed for concentrations of aerobic bacteria, total and fecal coliforms, Escherichia coli, staphylococci, lactic acid bacteria and yeast and moulds. The presence of Salmonella, E. coli O157:H7, Listeria monocytogenes and Staphylococcus aureus were determined. AMR of Salmonella against 18 antibiotics was experimentally determined. Genome sequencing of 19 Salmonella isolates allowed determination of serovars, antigenic profiles, prediction of AMR genes in silico and inference of phylogenetic relatedness between strains. Raw and heat-treated milk did not differ significantly in overall bacterial quality (P = 0.851). E. coli O157:H7 and Staphylococcus aureus were present in 34.3% and 12.9% of dairy products respectively. Multidrug resistant (MDR) Salmonella enterica serovars Muenster and Legon were identified in 11.8% and 5.9% of unfermented cheese samples respectively. Pan genome analysis revealed a total of 3712 core genes. All Salmonella strains were resistant to Trimethoprim/Sulfamethoxazole, Cefoxitin, Cefuroxime Axetil and Cefuroxime. Resistance to Chloramphenicol (18%) and Ciprofloxacin (100%), which are first line antibiotics used in treatment of NTS bacteremia in Ghana, was evident. AMR was attributed to presence and/or mutations in the following genes: golS, sdiA for cephalosporins, aac(6')-Iy, ant(9) for aminoglycosides, mdtK, gyrA, gyrB, parC, parE for quinolones and cat1, cat4 for phenicols. Phylogenetic analysis based on accessory genes clustered S. Legon strains separately from the S. Muenster strains. These strains were from different markets suggesting local circulation of related strains. Our study justifies consumer resistance to consumption of unripened soft cheese without further lethal heat treatment, and provides evidence that supports the Ghana Health Service recommendation for use of 3rd generation cephalosporins for the treatment of MDR NTS infections.
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Affiliation(s)
| | - Mark Holmes
- Department of Veterinary Medicine, University of Cambridge, United Kingdom
| | - Eric L Miller
- Department of Veterinary Medicine, University of Cambridge, United Kingdom
| | - Andrew J Grant
- Department of Veterinary Medicine, University of Cambridge, United Kingdom
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172
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Selection of Potential Therapeutic Bacteriophages that Lyse a CTX-M-15 Extended Spectrum β-Lactamase Producing Salmonella enterica Serovar Typhi Strain from the Democratic Republic of the Congo. Viruses 2018; 10:v10040172. [PMID: 29614013 PMCID: PMC5923466 DOI: 10.3390/v10040172] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 03/31/2018] [Accepted: 04/02/2018] [Indexed: 01/03/2023] Open
Abstract
Recently, a Salmonella Typhi isolate producing CTX-M-15 extended spectrum β-lactamase (ESBL) and with decreased ciprofloxacin susceptibility was isolated in the Democratic Republic of the Congo. We have selected bacteriophages that show strong lytic activity against this isolate and have potential for phage-based treatment of S. Typhi, and Salmonella in general.
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173
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Bos JC, Prins JM, Mistício MC, Nunguiane G, Lang CN, Beirão JC, Mathôt RAA, van Hest RM. Pharmacokinetics and pharmacodynamic target attainment of ceftriaxone in adult severely ill sub-Saharan African patients: a population pharmacokinetic modelling study. J Antimicrob Chemother 2018. [DOI: 10.1093/jac/dky071] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Jeannet C Bos
- Academic Medical Centre (AMC), University of Amsterdam, Department of Internal Medicine, Division of Infectious Diseases, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Jan M Prins
- Academic Medical Centre (AMC), University of Amsterdam, Department of Internal Medicine, Division of Infectious Diseases, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Mabor C Mistício
- Catholic University of Mozambique (UCM), Research Centre for Infectious Diseases of the Faculty of Health Sciences (CIDI), Rua Marquês do Soveral 960, CP 821, Beira, Mozambique
| | - Ginto Nunguiane
- Catholic University of Mozambique (UCM), Research Centre for Infectious Diseases of the Faculty of Health Sciences (CIDI), Rua Marquês do Soveral 960, CP 821, Beira, Mozambique
| | - Cláudia N Lang
- Catholic University of Mozambique (UCM), Research Centre for Infectious Diseases of the Faculty of Health Sciences (CIDI), Rua Marquês do Soveral 960, CP 821, Beira, Mozambique
| | - José C Beirão
- Catholic University of Mozambique (UCM), Research Centre for Infectious Diseases of the Faculty of Health Sciences (CIDI), Rua Marquês do Soveral 960, CP 821, Beira, Mozambique
| | - Ron A A Mathôt
- Academic Medical Centre (AMC), University of Amsterdam, Department of Hospital Pharmacy, Division of Clinical Pharmacology, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Reinier M van Hest
- Academic Medical Centre (AMC), University of Amsterdam, Department of Hospital Pharmacy, Division of Clinical Pharmacology, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
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174
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Tadesse G, Tessema TS, Beyene G, Aseffa A. Molecular epidemiology of fluoroquinolone resistant Salmonella in Africa: A systematic review and meta-analysis. PLoS One 2018; 13:e0192575. [PMID: 29432492 PMCID: PMC5809059 DOI: 10.1371/journal.pone.0192575] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 01/25/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Wide-ranging evidence on the occurrence of fluoroquinolone (FQ) resistance genetic determinants in African Salmonella strains is not available. The main objectives of this study were to assess the heterogeneity, estimate pooled proportions and describe the preponderance of FQ-resistance determinants in typhoidal and non-typhoidal Salmonella (NTS) isolates of Africa. METHODS Genetic and phenotypic data on 6103 Salmonella isolates were considered. Meta- and frequency analyses were performed depending on the number of studies by category, number of isolates and risks of bias. A random effects model was used to assess heterogeneity and estimate pooled proportions. Relative and cumulative frequencies were calculated to describe the overall preponderance of FQ-resistance determinants in quinolone resistant isolates. RESULTS The pooled proportion of gyrA mutants (Salmonella enterica serovar Typhi, Salmonella enterica serovar Typhimurium, and Salmonella enterica serovar Enteritidis) was estimated at 5.7% (95% Confidence interval (CI) = 2.6, 9.8; Tau squared (T2) = 0.1105), and was higher in S. Typhi than in S. Typhimurium (odds ratio (OR) = 3.3, 95%CI = 2, 5.7). The proportions of each of gyrB and parC mutants, and strains with Plasmid Mediated Quinolone Resistance genes (qnrA, qnrB and qnrS) were low (≤ 0.3%). Overall, 23 mutant serotypes were identified, and most strains had mutations at codons encoding Ser83 and Asp87 of gyrA (82%, 95%CI = 78, 86). CONCLUSIONS Mutations at gyrA appear to account for ciprofloxacin non-susceptibility in most clinical Salmonella strains in Africa. The estimates could be harnessed to develop a mismatch-amplification mutation-assay for the detection of FQ-resistant strains in Africa.
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Affiliation(s)
- Getachew Tadesse
- Department of Biomedical Sciences, College of Veterinary Medicine and Agriculture, Addis Ababa University, Debre Zeit, Ethiopia
| | - Tesfaye S. Tessema
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Getenet Beyene
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Abraham Aseffa
- Armauer Hansen Research Institute (AHRI), ALERT Campus, Addis Ababa, Ethiopia
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175
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Presence of Borrelia spp. DNA in ticks, but absence of Borrelia spp. and of Leptospira spp. DNA in blood of fever patients in Madagascar. Acta Trop 2018; 177:127-134. [PMID: 28986249 DOI: 10.1016/j.actatropica.2017.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 09/25/2017] [Accepted: 10/02/2017] [Indexed: 02/02/2023]
Abstract
The occurrence of tick-borne relapsing fever and leptospirosis in humans in Madagascar remains unclear despite the presence of their potential vectors and reservoir hosts. We screened 255 Amblyomma variegatum ticks and 148 Rhipicephalus microplus ticks from Zebu cattle in Madagascar for Borrelia-specific DNA. Borrelia spp. DNA was detected in 21 Amblyomma variegatum ticks and 2 Rhipicephalus microplus ticks. One Borrelia found in one Rhipicephalus microplus showed close relationship to Borrelia theileri based on genetic distance and phylogenetic analyses on 16S rRNA and flaB sequences. The borreliae from Amblyomma variegatum could not be identified due to very low quantities of present DNA reflected by high cycle threshold values in real-time-PCR. It is uncertain whether these low numbers of Borrelia spp. are sufficient for transmission of infection from ticks to humans. In order to determine whether spirochaete infections are relevant in humans, blood samples of 1009 patients from the highlands of Madagascar with fever of unknown origin were screened for Borrelia spp. - and in addition for Leptospira spp. - by real-time PCR. No target DNA was detected, indicating a limited relevance of these pathogens for humans in the highlands of Madagascar.
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176
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MacLennan CA, Msefula CL, Gondwe EN, Gilchrist JJ, Pensulo P, Mandala WL, Mwimaniwa G, Banda M, Kenny J, Wilson LK, Phiri A, MacLennan JM, Molyneux EM, Molyneux ME, Graham SM. Presentation of life-threatening invasive nontyphoidal Salmonella disease in Malawian children: A prospective observational study. PLoS Negl Trop Dis 2017; 11:e0006027. [PMID: 29216183 PMCID: PMC5745124 DOI: 10.1371/journal.pntd.0006027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 12/27/2017] [Accepted: 10/10/2017] [Indexed: 12/17/2022] Open
Abstract
Nontyphoidal Salmonellae commonly cause invasive disease in African children that is often fatal. The clinical diagnosis of these infections is hampered by the absence of a clear clinical syndrome. Drug resistance means that empirical antibiotic therapy is often ineffective and currently no vaccine is available. The study objective was to identify risk factors for mortality among children presenting to hospital with invasive Salmonella disease in Africa. We conducted a prospective study enrolling consecutive children with microbiologically-confirmed invasive Salmonella disease admitted to Queen Elizabeth Central Hospital, Blantyre, in 2006. Data on clinical presentation, co-morbidities and outcome were used to identify children at risk of inpatient mortality through logistic-regression modeling. Over one calendar year, 263 consecutive children presented with invasive Salmonella disease. Median age was 16 months (range 0-15 years) and 52/256 children (20%; 95%CI 15-25%) died. Nontyphoidal serovars caused 248/263 (94%) of cases. 211/259 (81%) of isolates were multi-drug resistant. 251/263 children presented with bacteremia, 6 with meningitis and 6 with both. Respiratory symptoms were present in 184/240 (77%; 95%CI 71-82%), 123/240 (51%; 95%CI 45-58%) had gastrointestinal symptoms and 101/240 (42%; 95%CI 36-49%) had an overlapping clinical syndrome. Presentation at <7 months (OR 10.0; 95%CI 2.8-35.1), dyspnea (OR 4.2; 95%CI 1.5-12.0) and HIV infection (OR 3.3; 95%CI 1.1-10.2) were independent risk factors for inpatient mortality. Invasive Salmonella disease in Malawi is characterized by high mortality and prevalence of multi-drug resistant isolates, along with non-specific presentation. Young infants, children with dyspnea and HIV-infected children bear a disproportionate burden of the Salmonella-associated mortality in Malawi. Strategies to improve prevention, diagnosis and management of invasive Salmonella disease should be targeted at these children.
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Affiliation(s)
- Calman A. MacLennan
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- * E-mail:
| | - Chisomo L. Msefula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Department of Microbiology, College of Medicine, University of Malawi, Malawi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Esther N. Gondwe
- School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Department of Biochemistry, College of Medicine, University of Malawi, Malawi
| | - James J. Gilchrist
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Department of Paediatrics, University of Oxford, United Kingdom
- Wellcome Trust Centre for Human Genetics, University of Oxford, United Kingdom
| | - Paul Pensulo
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Wilson L. Mandala
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Department of Basic Medical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi
- Academy of Medical Sciences, Malawi University of Science and Technology, Thyolo, Malawi
| | - Grace Mwimaniwa
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Meraby Banda
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Julia Kenny
- Department of Paediatrics, College of Medicine, University of Malawi, Malawi
- Infectious Diseases and Microbiology Unit, Institute of Child Health, University College London, London, United Kingdom
| | - Lorna K. Wilson
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Amos Phiri
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Jenny M. MacLennan
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Malcolm E. Molyneux
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Department of Medicine, College of Medicine, University of Malawi, Malawi
| | - Stephen M. Graham
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
- Department of Paediatrics, College of Medicine, University of Malawi, Malawi
- Centre for International Child Health, University of Melbourne and Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, Australia
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Saha S, Islam M, Uddin MJ, Saha S, Das RC, Baqui AH, Santosham M, Black RE, Luby SP, Saha SK. Integration of enteric fever surveillance into the WHO-coordinated Invasive Bacterial-Vaccine Preventable Diseases (IB-VPD) platform: A low cost approach to track an increasingly important disease. PLoS Negl Trop Dis 2017; 11:e0005999. [PMID: 29073137 PMCID: PMC5658195 DOI: 10.1371/journal.pntd.0005999] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/28/2017] [Indexed: 01/07/2023] Open
Abstract
Background Lack of surveillance systems and accurate data impede evidence-based decisions on treatment and prevention of enteric fever, caused by Salmonella Typhi/Paratyphi. The WHO coordinates a global Invasive Bacterial–Vaccine Preventable Diseases (IB-VPD) surveillance network but does not monitor enteric fever. We evaluated the feasibility and sustainability of integrating enteric fever surveillance into the ongoing IB-VPD platform. Methodologies The IB-VPD surveillance system uses WHO definitions to enroll 2–59 month children hospitalized with possible pneumonia, sepsis or meningitis. We expanded this surveillance system to additionally capture suspect enteric fever cases during 2012–2016, in two WHO sentinel hospitals of Bangladesh, by adding inclusion criteria of fever ≥102°F for ≥3 days, irrespective of other manifestations. Culture-positive enteric fever cases from in-patient departments (IPD) detected in the hospital laboratories but missed by the expanded surveillance, were also enrolled to assess completion. Costs for this integration were calculated for the additional personnel and resources required. Principal findings In the IB-VPD surveillance, 5,185 cases were enrolled; 3% (N = 171/5185) were positive for microbiological growth, of which 55% (94/171) were culture-confirmed cases of enteric fever (85 Typhi and 9 Paratyphi A). The added inclusion criteria for enteric fever enrolled an additional 1,699 cases; 22% (358/1699) were positive, of which 85% (349/358) were enteric fever cases (305 Typhi and 44 Paratyphi A). Laboratory surveillance of in-patients of all ages enrolled 311 additional enteric fever cases (263 Typhi and 48 Paratyphi A); 9% (28/311) were 2–59 m and 91% (283/311) >59 m. Altogether, 754 (94+349+311) culture-confirmed enteric fever cases were found, of which 471 were 2–59 m. Of these 471 cases, 94% (443/471) were identified through the hospital surveillances and 6% (28/471) through laboratory results. Twenty-three percent (170/754) of all cases were children <2 years. Additional cost for the integration was USD 44,974/year, a 27% increase to the IB-VPD annual expenditure. Conclusion In a setting where enteric disease is a substantial public health problem, we could integrate enteric fever surveillance into the standard IB-VPD surveillance platform at a modest cost. Typhoid/paratyphoid fever imposes a major global burden, specifically in low-and-middle-income countries (LMICs). However, it is challenging to implement evidence-based decisions for treatment and prevention because of lack of data from comprehensive surveillance systems, which are often expensive and difficult to sustain. The WHO has established a global surveillance program called “Invasive Bacterial–Vaccine Preventable Diseases (IB-VPD) Surveillance” to capture sepsis, meningitis and pneumonia in under-five children in many LMICs. Data generated by this program have facilitated introduction of live-saving vaccines and development of treatment strategies. However, the program does not include typhoid/paratyphoid surveillance. We tested the feasibility and sustainability of integrating typhoid/paratyphoid surveillance into this program in two leading children’s hospitals in Bangladesh. By monitoring all patients with signs of typhoid/paratyphoid, we captured 471 laboratory-confirmed episodes in under-five children between Jan 2012 and Dec 2016. Blood culture results from all in-patients revealed that the proposed expanded surveillance captures 94% of hospitalized typhoid/paratyphoid cases. Thirty-six percent (170/471) of 2–59 m cases were in children <2 years. Overall, age distribution and antibiotic resistance patterns were consistent with data generated from larger, expensive and typhoid-specific surveillance programs in the region, adding credence to the proposed integration. Adding typhoid/paratyphoid surveillance to an established invasive disease surveillance platform took advantage of existing infrastructure and resources and as such was easy and cost-effective to implement. We recommend that WHO considers similar integration in other countries; data generated from such surveillances will help countries make evidence-based decisions on introduction of upcoming vaccines and prepare for impact studies.
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Affiliation(s)
- Senjuti Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh
| | - Maksuda Islam
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh
| | - Mohammad J. Uddin
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh
| | - Shampa Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh
| | - Rajib C. Das
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh
| | - Abdullah H. Baqui
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Mathuram Santosham
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Robert E. Black
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Stephen P. Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, United States of America
| | - Samir K. Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh
- Bangladesh Institute of Child Health, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh
- * E-mail:
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Haselbeck AH, Panzner U, Im J, Baker S, Meyer CG, Marks F. Current perspectives on invasive nontyphoidal Salmonella disease. Curr Opin Infect Dis 2017; 30:498-503. [PMID: 28731899 PMCID: PMC7680934 DOI: 10.1097/qco.0000000000000398] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW We searched PubMed for scientific literature published in the past 2 years for relevant information regarding the burden of invasive nontyphoidal Salmonella disease and host factors associated with nontyphoidal Salmonella infection and discuss current knowledge on vaccine development. The following search terms were used: Salmonella, non typhoidal/nontyphoidal, NTS, disease, bloodstream infection, invasive, sepsis/septicaemia/septicemia, bacteraemia/bacteremia, gastroenteritis, incidence, prevalence, morbidity, mortality, case fatality, host/risk factor, vaccination, and prevention/control. RECENT FINDINGS Estimates of the global invasive nontyphoidal Salmonella disease burden have been recently updated; additional data from Africa, Asia, and Latin America are now available. New data bridge various knowledge gaps, particularly with respect to host risk factors and the geographical distribution of iNTS serovars. It has also been observed that Salmonella Typhimurium sequence type 313 is emergent in several African countries. Available data suggest that genetic variation in the sequence type 313 strain has led to increased pathogenicity and human host adaptation. A bivalent efficacious vaccine, targeting Salmonella serovars Typhimurium and Enteritidis, would significantly lower the disease burden in high-risk populations. SUMMARY The mobilization of surveillance networks, especially in Asia and Latin America, may provide missing data regarding the invasive nontyphoidal Salmonella disease burden and their corresponding antimicrobial susceptibility profiles. Efforts and resources should be directed toward invasive nontyphoidal Salmonella disease vaccine development.
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Affiliation(s)
- Andrea H. Haselbeck
- International Vaccine Institute, Epidemiology Unit, Seoul, Republic of Korea
| | - Ursula Panzner
- International Vaccine Institute, Epidemiology Unit, Seoul, Republic of Korea
| | - Justin Im
- International Vaccine Institute, Epidemiology Unit, Seoul, Republic of Korea
| | - Stephen Baker
- Hospital for Tropical Diseases,Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City,Vietnam
- Department of Medicine, University of Cambridge, Cambridge,United Kingdom
| | - Christian G. Meyer
- Institute of Tropical Medicine, Eberhard-Karls University T€ubingen, T€ubingen, Germany and
- Duy Tan University, Da Nang, Vietnam
| | - Florian Marks
- International Vaccine Institute, Epidemiology Unit, Seoul, Republic of Korea
- Department of Medicine, University of Cambridge, Cambridge,United Kingdom
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179
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Meiring JE, Gibani M. The Typhoid Vaccine Acceleration Consortium (TyVAC): Vaccine effectiveness study designs: Accelerating the introduction of typhoid conjugate vaccines and reducing the global burden of enteric fever. Report from a meeting held on 26-27 October 2016, Oxford, UK. Vaccine 2017; 35:5081-5088. [PMID: 28802757 DOI: 10.1016/j.vaccine.2017.08.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 07/31/2017] [Accepted: 08/01/2017] [Indexed: 11/26/2022]
Abstract
Typhoid fever is estimated to cause between 11.9-26.9 million infections globally each year with 129,000-216,510 deaths. Access to improved water sources have reduced disease incidence in parts of the world but the use of efficacious vaccines is seen as an important public health tool for countries with a high disease burden. A new generation of Vi typhoid conjugate vaccines (TCVs), licensed for use in young children and expected to provide longer lasting protection than previous vaccines, are now available. The WHO Strategic Advisory Group of Experts on Immunization (SAGE) has convened a working group to review the evidence on TCVs and produce an updated WHO position paper for all typhoid vaccines in 2018 that will inform Gavi, the Vaccine Alliance's future vaccine investment strategies for TCVs. The Typhoid Vaccine Acceleration Consortium (TyVAC) has been formed through a $36.9 million funding program from the Bill & Melinda Gates Foundation to accelerate the introduction of TCVs into Gavi-eligible countries. In October 2016, a meeting was held to initiate planning of TCV effectiveness studies that will provide the data required by policy makers and stakeholders to support decisions on TCV use in countries with a high typhoid burden. Discussion topics included (1) the latest evidence and data gaps in typhoid epidemiology; (2) WHO and Gavi methods and data requirements; (3) data on TCV efficacy; (4) cost effectiveness analysis for TCVs from mathematical models; (5) TCV delivery and effectiveness study design. Specifically, participants were asked to comment on study design in 3 sites for which population-based typhoid surveillance is underway. The conclusion of the meeting was that country-level decision making would best be informed by the respective selected sites in Africa and Asia vaccinating children aged from 9-months to 15-years-old, employing either an individual or cluster randomized design with design influenced by population characteristics, transmission dynamics, and statistical considerations.
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Affiliation(s)
- James E Meiring
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.
| | - Malick Gibani
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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180
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Population-based incidence, seasonality and serotype distribution of invasive salmonellosis among children in Nanoro, rural Burkina Faso. PLoS One 2017; 12:e0178577. [PMID: 28692655 PMCID: PMC5503169 DOI: 10.1371/journal.pone.0178577] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/15/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Bloodstream infections (BSI) caused by Salmonella Typhi and invasive non-Typhoidal Salmonella (iNTS) frequently affect children living in rural sub-Saharan Africa but data about incidence and serotype distribution are rare. OBJECTIVE The present study assessed the population-based incidence of Salmonella BSI and severe malaria in a Health and Demographic Surveillance System in a rural area with seasonal malaria transmission in Nanoro, Burkina Faso. METHODS Children between 2 months-15 years old with severe febrile illness were enrolled during a one-year surveillance period (May 2013-May 2014). Thick blood films and blood cultures were sampled and processed upon admission. Population-based incidences were corrected for non-referral, health seeking behavior, non-inclusion and blood culture sensitivity. Adjusted incidence rates were expressed per 100,000 person-years of observations (PYO). RESULTS Among children < 5 years old, incidence rates for iNTS, Salmonella Typhi and severe malaria per 100,000 PYO were 4,138 (95% Confidence Interval (CI): 3,740-4,572), 224 (95% CI: 138-340) and 2,866 (95% CI: 2,538-3,233) respectively. Among those aged 5-15 years, corresponding incidence rates were 25 (95% CI: 8-60), 273 (95% CI: 203-355) and 135 (95% CI: 87-195) respectively. Most iNTS occurred during the peak of the rainy season and in parallel with the increase of Plasmodium falciparum malaria; for Salmonella Typhi no clear seasonal pattern was observed. Salmonella Typhi and iNTS accounted for 13.3% and 55.8% of all 118 BSI episodes; 71.6% of iNTS (48/67) isolates were Salmonella enterica serovar Typhimurium and 25.4% (17/67) Salmonella enterica serovar Enteritidis; there was no apparent geographical clustering. CONCLUSION The present findings from rural West-Africa confirm high incidences of Salmonella Typhi and iNTS, the latter with a seasonal and Plasmodium falciparum-related pattern. It urges prioritization of the development and implementation of Salmonella Typhi as well as iNTS vaccines in this setting.
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181
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Antillón M, Bilcke J, Paltiel AD, Pitzer VE. Cost-effectiveness analysis of typhoid conjugate vaccines in five endemic low- and middle-income settings. Vaccine 2017; 35:3506-3514. [PMID: 28527687 PMCID: PMC5462484 DOI: 10.1016/j.vaccine.2017.05.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 04/28/2017] [Accepted: 05/01/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND Typhoid fever remains endemic in low- and middle-income countries. Programmatic use of existing vaccines is limited, but upcoming typhoid conjugate vaccines (TCVs) could warrant wider use. We evaluated the cost-effectiveness of five TCV delivery strategies in three urban areas (Delhi and Kolkata, India and Nairobi, Kenya) and two rural settings (Lwak, Kenya and Dong Thap, Vietnam) with varying incidence. METHODS AND FINDINGS We evaluated routine infant vaccination with and without catch-up campaigns among older individuals. We used a dynamic model of typhoid transmission to simulate cases, hospitalizations, deaths, disability-adjusted life-years (DALY) lost, treatment and intervention costs. We estimated cost-effectiveness (in terms of cost in international dollars (I$) per DALY averted) from the healthcare payer perspective, and assessed how it was influenced by uncertain model parameters. Compared to no vaccination, routine infant vaccination at I$1/dose was cost-saving in Delhi and Dong Thap, "very cost-effective" in Kolkata and Nairobi, and "cost-effective" in Lwak according to World Health Organization thresholds. However, routine vaccination was not the optimal strategy compared to strategies that included a catch-up campaign, which yielded the highest probability of being cost-saving in Delhi and Dong Thap and were most likely to provide a return on investment above a willingness-to-pay threshold of I$1440 in Kolkata, I$2300 in Nairobi, and I$5360 in Lwak. Vaccine price impacted the optimal strategy, and the number of doses required and rate of hospitalization were the primary sources of uncertainty. CONCLUSION Routine vaccination with TCV would be cost-effective in most settings, and additional one-time catch-up campaigns would also be economically justified.
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Affiliation(s)
- Marina Antillón
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520-8034, USA.
| | - Joke Bilcke
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520-8034, USA; Center for Health Economics Research and Modeling Infectious Diseases, University of Antwerp, Belgium
| | - A David Paltiel
- Department of Health Policy and Management, Yale School of Public Health, New Haven, CT 06520-8034, USA
| | - Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520-8034, USA.
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182
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Näsström E, Parry CM, Vu Thieu NT, Maude RR, de Jong HK, Fukushima M, Rzhepishevska O, Marks F, Panzner U, Im J, Jeon H, Park S, Chaudhury Z, Ghose A, Samad R, Van TT, Johansson A, Dondorp AM, Thwaites GE, Faiz A, Antti H, Baker S. Reproducible diagnostic metabolites in plasma from typhoid fever patients in Asia and Africa. eLife 2017; 6. [PMID: 28483042 PMCID: PMC5423768 DOI: 10.7554/elife.15651] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/17/2017] [Indexed: 11/13/2022] Open
Abstract
Salmonella Typhi is the causative agent of typhoid. Typhoid is diagnosed by blood culture, a method that lacks sensitivity, portability and speed. We have previously shown that specific metabolomic profiles can be detected in the blood of typhoid patients from Nepal (Näsström et al., 2014). Here, we performed mass spectrometry on plasma from Bangladeshi and Senegalese patients with culture confirmed typhoid fever, clinically suspected typhoid, and other febrile diseases including malaria. After applying supervised pattern recognition modelling, we could significantly distinguish metabolite profiles in plasma from the culture confirmed typhoid patients. After comparing the direction of change and degree of multivariate significance, we identified 24 metabolites that were consistently up- or down regulated in a further Bangladeshi/Senegalese validation cohort, and the Nepali cohort from our previous work. We have identified and validated a metabolite panel that can distinguish typhoid from other febrile diseases, providing a new approach for typhoid diagnostics.
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Affiliation(s)
- Elin Näsström
- Department of Chemistry, Computational Life Science Cluster, Umeå University, Umeå, Sweden
| | - Christopher M Parry
- Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Nga Tran Vu Thieu
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University, Oxford, United Kingdom.,Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Rapeephan R Maude
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Hanna K de Jong
- Department of Internal Medicine, Division of Infectious Diseases and Center for Infection and Immunity Amsterdam (CINIMA), University of Amsterdam, Amsterdam, the Netherlands.,Center for Experimental Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Masako Fukushima
- Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Olena Rzhepishevska
- Department of Chemistry, Computational Life Science Cluster, Umeå University, Umeå, Sweden
| | - Florian Marks
- The International Vaccine Institute, Seoul, South Korea
| | | | - Justin Im
- The International Vaccine Institute, Seoul, South Korea
| | - Hyonjin Jeon
- The International Vaccine Institute, Seoul, South Korea
| | - Seeun Park
- The International Vaccine Institute, Seoul, South Korea
| | | | | | - Rasheda Samad
- Chittagong Medical College Hospital, Chittagong, Bangladesh
| | - Tan Trinh Van
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University, Oxford, United Kingdom
| | - Anders Johansson
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Guy E Thwaites
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University, Oxford, United Kingdom.,Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom
| | - Abul Faiz
- Malaria Research Group and Dev Care Foundation, Dhaka, Bangladesh
| | - Henrik Antti
- Department of Chemistry, Computational Life Science Cluster, Umeå University, Umeå, Sweden
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University, Oxford, United Kingdom.,Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom.,Department of Medicine, The University of Cambridge, Cambridge, United Kingdom
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183
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Antillón M, Warren JL, Crawford FW, Weinberger DM, Kürüm E, Pak GD, Marks F, Pitzer VE. The burden of typhoid fever in low- and middle-income countries: A meta-regression approach. PLoS Negl Trop Dis 2017; 11:e0005376. [PMID: 28241011 PMCID: PMC5344533 DOI: 10.1371/journal.pntd.0005376] [Citation(s) in RCA: 170] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/09/2017] [Accepted: 01/31/2017] [Indexed: 11/26/2022] Open
Abstract
Background Upcoming vaccination efforts against typhoid fever require an assessment of the baseline burden of disease in countries at risk. There are no typhoid incidence data from most low- and middle-income countries (LMICs), so model-based estimates offer insights for decision-makers in the absence of readily available data. Methods We developed a mixed-effects model fit to data from 32 population-based studies of typhoid incidence in 22 locations in 14 countries. We tested the contribution of economic and environmental indices for predicting typhoid incidence using a stochastic search variable selection algorithm. We performed out-of-sample validation to assess the predictive performance of the model. Results We estimated that 17.8 million cases of typhoid fever occur each year in LMICs (95% credible interval: 6.9–48.4 million). Central Africa was predicted to experience the highest incidence of typhoid, followed by select countries in Central, South, and Southeast Asia. Incidence typically peaked in the 2–4 year old age group. Models incorporating widely available economic and environmental indicators were found to describe incidence better than null models. Conclusions Recent estimates of typhoid burden may under-estimate the number of cases and magnitude of uncertainty in typhoid incidence. Our analysis permits prediction of overall as well as age-specific incidence of typhoid fever in LMICs, and incorporates uncertainty around the model structure and estimates of the predictors. Future studies are needed to further validate and refine model predictions and better understand year-to-year variation in cases. Typhoid fever is a bacterial enteric infection that continues to pose a considerable burden to the 5.5 billion people living in low- and middle-income countries (LMICs). We developed and validated a model incorporating widely available indicators of economic and social development and the environment to estimate the burden of typhoid fever across LMICs. Our analysis uses all available data to estimate the incidence of typhoid in key age groups, which is important for the design and implementation of optimal vaccination strategies, and it identifies regions of the world that have the most uncertainty in typhoid incidence. Across all LMICs, we estimated that the expected number of typhoid fever cases per year is 17.8 million (95% CI: 6.9–48.4 million). We also present the probability that incidence surpasses the criteria for low, medium, high, and very high incidence in each country, which could help guide policy in the face of uncertainty.
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Affiliation(s)
- Marina Antillón
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- * E-mail:
| | - Joshua L. Warren
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Forrest W. Crawford
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Daniel M. Weinberger
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Esra Kürüm
- Department of Statistics, University of California Riverside, Riverside, California, United States of America
| | - Gi Deok Pak
- International Vaccine Institute, Seoul, Republic of Korea
| | - Florian Marks
- International Vaccine Institute, Seoul, Republic of Korea
| | - Virginia E. Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
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Steele AD, Hay Burgess DC, Diaz Z, Carey ME, Zaidi AKM. Challenges and Opportunities for Typhoid Fever Control: A Call for Coordinated Action. Clin Infect Dis 2016; 62 Suppl 1:S4-8. [PMID: 26933019 PMCID: PMC4772836 DOI: 10.1093/cid/civ976] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The burden of enteric fever caused by Salmonella enterica serovars Typhi and Paratyphi is substantial and has high impact in toddlers and young children. This burden is relatively well documented in Asia, and this supplement provides new data on the substantial burden in several sub-Saharan African countries. Challenges in standardized surveillance and imperfect diagnostic tools have resulted in patchy local disease data, which are not well acknowledged or integrated into local country evidence and health awareness for decision making. There is a need to strengthen diagnostics for the generation of burden data in country. Furthermore, the guidelines and training for treatment of enteric fever cases in Africa are sorely needed to help mitigate the inappropriate use of antimicrobial treatment. Classic water safety and access to sanitation development remain powerful tools for the control of typhoid fever, yet the huge economic costs and long timelines are unlikely to provide a short- to middle-term solution. Emerging threats, including multidrug resistance and increasing urbanization in regions such as sub-Saharan Africa, warrant focused attention to shorter-term interventions including immunization, and must include vaccine strategies with the new typhoid conjugate vaccines.
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Affiliation(s)
- A Duncan Steele
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Deborah C Hay Burgess
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Zoey Diaz
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Megan E Carey
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Anita K M Zaidi
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington
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