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Extensively drug-resistant typhoid fever in Pakistan. THE LANCET. INFECTIOUS DISEASES 2020; 19:242-243. [PMID: 30833059 DOI: 10.1016/s1473-3099(19)30051-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 01/18/2019] [Indexed: 11/24/2022]
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A prospective study of bloodstream infections among febrile adolescents and adults attending Yangon General Hospital, Yangon, Myanmar. PLoS Negl Trop Dis 2020; 14:e0008268. [PMID: 32352959 PMCID: PMC7217485 DOI: 10.1371/journal.pntd.0008268] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 05/12/2020] [Accepted: 04/03/2020] [Indexed: 11/20/2022] Open
Abstract
Data on causes of community-onset bloodstream infection in Myanmar are scarce. We aimed to identify etiological agents of bloodstream infections and patterns of antimicrobial resistance among febrile adolescents and adults attending Yangon General Hospital (YGH), Yangon, Myanmar. We recruited patients ≥12 years old with fever ≥38°C who attended YGH from 5 October 2015 through 4 October 2016. A standardized clinical history and physical examination was performed. Provisional diagnoses and vital status at discharge was recorded. Blood was collected for culture, bloodstream isolates were identified, and antimicrobial susceptibility testing was performed. Using whole-genome sequencing, we identified antimicrobial resistance mechanisms of Enterobacteriaceae and sequence types of Enterobacteriaceae and Streptococcus agalactiae. Among 947 participants, 90 (9.5%) had bloodstream infections (BSI) of which 82 (91.1%) were of community-onset. Of 91 pathogens isolated from 90 positive blood cultures, we identified 43 (47.3%) Salmonella enterica including 33 (76.7%) serovar Typhi and 10 (23.3%) serovar Paratyphi A; 20 (22.0%) Escherichia coli; 7 (7.7%) Klebsiella pneumoniae; 6 (6.6%), Staphylococcus aureus; 4 (4.4%) yeasts; and 1 (1.1%) each of Burkholderia pseudomallei and Streptococcus agalactiae. Of 70 Enterobacteriaceae, 62 (88.6%) were fluoroquinolone-resistant. Among 27 E. coli and K. pneumoniae, 18 (66.6%) were extended-spectrum beta-lactamase (ESBL)-producers, and 1 (3.7%) each were AmpC beta-lactamase- and carbapenemase-producers. Fluoroquinolone resistance was associated predominantly with mutations in the quinolone resistance-determining region. blaCTX-M-15 expression was common among ESBL-producers. Methicillin-resistant S. aureus was not detected. Fluoroquinolone-resistant, but not multiple drug-resistant, typhoidal S. enterica was the leading cause of community-onset BSI at a tertiary hospital in Yangon, Myanmar. Fluoroquinolone and extended-spectrum cephalosporin resistance was common among other Enterobactericeae. Our findings inform empiric management of severe febrile illness in Yangon and indicate that measures to prevent and control enteric fever are warranted. We suggest ongoing monitoring and efforts to mitigate antimicrobial resistance among community-onset pathogens.
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Thindwa D, Farooq YG, Shakya M, Saha N, Tonks S, Anokwa Y, Gordon MA, Hartung C, Meiring JE, Pollard AJ, Heyderman RS. Electronic data capture for large scale typhoid surveillance, household contact tracing, and health utilisation survey: Strategic Typhoid Alliance across Africa and Asia. Wellcome Open Res 2020; 5:66. [DOI: 10.12688/wellcomeopenres.15811.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2020] [Indexed: 12/25/2022] Open
Abstract
Electronic data capture systems (EDCs) have the potential to achieve efficiency and quality in collection of multisite data. We quantify the volume, time, accuracy and costs of an EDC using large-scale census data from the STRATAA consortium, a comprehensive programme assessing population dynamics and epidemiology of typhoid fever in Malawi, Nepal and Bangladesh to inform vaccine and public health interventions. A census form was developed through a structured iterative process and implemented using Open Data Kit Collect running on Android-based tablets. Data were uploaded to Open Data Kit Aggregate, then auto-synced to MySQL-defined database nightly. Data were backed-up daily from three sites centrally, and auto-reported weekly. Pre-census materials’ costs were estimated. Demographics of 308,348 individuals from 80,851 households were recorded within an average of 14.7 weeks range (13-16) using 65 fieldworkers. Overall, 21.7 errors (95% confidence interval: 21.4, 22.0) per 10,000 data points were found: 13.0 (95% confidence interval: 12.6, 13.5) and 24.5 (95% confidence interval: 24.1, 24.9) errors on numeric and text fields respectively. These values meet standard quality threshold of 50 errors per 10,000 data points. The EDC’s total variable cost was estimated at US$13,791.82 per site. In conclusion, the EDC is robust, allowing for timely and high-volume accurate data collection, and could be adopted in similar epidemiological settings.
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Dash D, Das P, Bhargava A, Gaikwad UN, Negi SS, Wankhede A. Estimating the burden of enteric fever in Chhattisgarh: A single-center study on culture-positive cases from a newly built tertiary care hospital. J Lab Physicians 2020; 11:234-239. [PMID: 31579242 PMCID: PMC6771319 DOI: 10.4103/jlp.jlp_154_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Enteric fever is the most common cause of community acquired blood stream infections in under developed and developing countries. The enteric fever is exclusive to humans and transmitted through the faeco-oral route. Though India is an endemic zone for enteric fever, the data is very scarce from Central India. The present study was undertaken to determine the prevalence of enteric fever in this region and to know the antimicrobial susceptibility pattern of the isolated typhoidal Salmonellae. MATERIAL AND METHOD We conducted a retrospective analysis of blood culture positive cases of enteric fever over a period of two years (December 2015 to December 2017). All blood cultures submitted for suspected enteric fever and associated symptoms were included in the study. Relevant demographic, clinical and laboratory data were analyzed. RESULT A total of 51 cases (3.56%) were of typhoidal Salmonella from a total of 1430 blood culture submission. Salmonella Typhi were 70.5% while Salmonella Paratyphi A were 29.5% of the total isolated Salmonellae. The most vulnerable age group was 10-19years (41.2%). The mean minimum inhibitory concentration of ciprofloxacin for Salmonella Typhi and Salmonella Paratyphi A are 1.20 and 1.97 μg/ml respectively. All the isolates were susceptible to ceftriaxone. Highest isolation was in the July - September quarter (35.3%). CONCLUSION There is a high prevalence of the disease which needs urgent focus on safe water, sanitation services and also to establish guidelines for empiric therapy for enteric fever.
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Affiliation(s)
- Debabrata Dash
- Department of Microbiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India
| | - Padma Das
- Department of Microbiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India
| | - Anudita Bhargava
- Department of Microbiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India
| | - Ujjwala Nitin Gaikwad
- Department of Microbiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India
| | - Sanjay Singh Negi
- Department of Microbiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India
| | - Archana Wankhede
- Department of Microbiology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India
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O'Reilly PJ, Pant D, Shakya M, Basnyat B, Pollard AJ. Progress in the overall understanding of typhoid fever: implications for vaccine development. Expert Rev Vaccines 2020; 19:367-382. [PMID: 32238006 DOI: 10.1080/14760584.2020.1750375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Typhoid fever continues to have a substantial impact on human health, especially in Asia and sub-Saharan Africa. Access to safe water, and adequate sanitation and hygiene remain the cornerstone of prevention, but these are not widely available in many impoverished settings. The emergence of antibiotic resistance affects typhoid treatment and adds urgency to typhoid control efforts. Vaccines provide opportunities to prevent and control typhoid fever in endemic settings. AREAS COVERED Literature search was performed looking for evidence concerning the global burden of typhoid and strategies for the prevention and treatment of typhoid fever. Cost of illness, available typhoid and paratyphoid vaccines and cost-effectiveness were also reviewed. The objective was to provide a critical overview of typhoid fever, in order to assess the current understanding and potential future directions for typhoid treatment and control. EXPERT COMMENTARY Our understanding of typhoid burden and methods of prevention has grown over recent years. However, typhoid fever still has a significant impact on health in low and middle-income countries. Introduction of typhoid conjugate vaccines to the immunization schedule is expected to make a major contribution to control of typhoid fever in endemic countries, although vaccination alone is unlikely to eliminate the disease.
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Affiliation(s)
- Peter J O'Reilly
- Oxford Vaccine Group, Department of Pediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre , Oxford, UK
| | - Dikshya Pant
- Department of Paediatrics, Patan Academy of Health Sciences, Patan Hospital , Kathmandu, Nepal
| | - Mila Shakya
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences , Kathmandu, Nepal
| | - Buddha Basnyat
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences , Kathmandu, Nepal
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Pediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre , Oxford, UK
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Verma S, Senger S, Cherayil BJ, Faherty CS. Spheres of Influence: Insights into Salmonella Pathogenesis from Intestinal Organoids. Microorganisms 2020; 8:microorganisms8040504. [PMID: 32244707 PMCID: PMC7232497 DOI: 10.3390/microorganisms8040504] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/27/2020] [Accepted: 03/28/2020] [Indexed: 12/19/2022] Open
Abstract
The molecular complexity of host-pathogen interactions remains poorly understood in many infectious diseases, particularly in humans due to the limited availability of reliable and specific experimental models. To bridge the gap between classical two-dimensional culture systems, which often involve transformed cell lines that may not have all the physiologic properties of primary cells, and in vivo animal studies, researchers have developed the organoid model system. Organoids are complex three-dimensional structures that are generated in vitro from primary cells and can recapitulate key in vivo properties of an organ such as structural organization, multicellularity, and function. In this review, we discuss how organoids have been deployed in exploring Salmonella infection in mice and humans. In addition, we summarize the recent advancements that hold promise to elevate our understanding of the interactions and crosstalk between multiple cell types and the microbiota with Salmonella. These models have the potential for improving clinical outcomes and future prophylactic and therapeutic intervention strategies.
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Affiliation(s)
- Smriti Verma
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Charlestown Navy Yard, Boston, 02129 MA, USA; (S.S.); (B.J.C.); (C.S.F.)
- Harvard Medical School, Boston, 02115 MA, USA
- Correspondence: ; Tel.: +1-617-726-7991
| | - Stefania Senger
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Charlestown Navy Yard, Boston, 02129 MA, USA; (S.S.); (B.J.C.); (C.S.F.)
- Harvard Medical School, Boston, 02115 MA, USA
| | - Bobby J. Cherayil
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Charlestown Navy Yard, Boston, 02129 MA, USA; (S.S.); (B.J.C.); (C.S.F.)
- Harvard Medical School, Boston, 02115 MA, USA
| | - Christina S. Faherty
- Mucosal Immunology and Biology Research Center, Division of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Charlestown Navy Yard, Boston, 02129 MA, USA; (S.S.); (B.J.C.); (C.S.F.)
- Harvard Medical School, Boston, 02115 MA, USA
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107
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Ohanu ME, Iroezindu MO, Maduakor U, Onodugo OD, Gugnani HC. Typhoid fever among febrile Nigerian patients: Prevalence, diagnostic performance of the Widal test and antibiotic multi-drug resistance. Malawi Med J 2020; 31:184-192. [PMID: 31839887 PMCID: PMC6895380 DOI: 10.4314/mmj.v31i3.4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background Over-dependence on clinical presentation and/or the Widal agglutination test for the diagnosis of typhoid fever in developing countries can lead to antibiotic abuse. In Nigeria, the antibiotic resistance of typhoid organisms is poorly characterized. In this study, we determined the prevalence of culture positivity among patients suspected of having typhoid fever, evaluated the diagnostic value of the Widal test and the burden created by the multi-drug resistance of typhoid organisms in South-East Nigeria. Methodology This was a prospective and case-controlled study carried out between 2013 and 2016. We acquired samples of blood/stool/urine cultures, and data relating to the Widal agglutination test and malaria parasites from 810 febrile patients (suspected of having typhoid) and 288 apparently healthy controls. Individuals with a history of antibiotic use within the previous 14 days were excluded. We then carried out antibiotic susceptibility tests on all isolates. Multi-drug resistance was defined as a resistance to ≥3 of the antibiotics tested. We determined the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Widal test for typhoid laboratory diagnosis compared to bacterial culture which is the gold standard. A P-value <0.05 was considered to be statistically significant. Results The mean age of typhoid suspects was 33.1±6.5 years and 50.7% were women. Of the 810 typhoid suspects tested, 114 (14.1%) had positive cultures for the typhoid organisms Salmonella enterica serovar paratyphi (72) and S. enterica serovar Typhi (42). Sample-specific rates of culture positivity were as follows: stool (72; 8.9%), blood (21; 2.6%) and urine (21; 2.6%), P<0.001. None of the controls had typhoid isolates. The sensitivity, specificity, PPV and NPV of the Widal test were 49.1%, 90.7%, 46.2% and 91.6%, respectively. Malaria parasitaemia was detected in 180 (22.2%) febrile patients, out of whom 115 (63.9%) had a positive Widal test for O/H antigens vs. 1% (6/630) in those with negative malaria parasite test results (P<0.001). The rate of false-positive Widal titres was 48%. Antibiotic multi-drug resistance was detected in 52.6% of patients. The antibiotics with the highest susceptibility were ciprofloxacin, levofloxacin and meropenem (all 100% susceptibility) and ceftriaxone (95.6% susceptibility). Conclusion Our data showed that while typhoid fever is common in Nigeria, malaria is more prevalent. Our analysis showed that the Widal test performed poorly as a diagnostic test and that the burden created by multi-drug resistance was high. Our data indicate that periodic surveillance of antibiotic susceptibility is critical for optimal typhoid therapy.
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Affiliation(s)
- Martin E Ohanu
- Department of Medical Microbiology, College of Medicine, University of Nigeria, Ituku/Ozalla, Enugu, Nigeria
| | - Michael O Iroezindu
- Department of Medicine, College of Medicine, University of Nigeria, Ituku/Ozalla, Enugu, Nigeria
| | - Uzoamaka Maduakor
- Department of Medical Laboratory Sciences, Faculty of Health Sciences and Technology, University of Nigeria, Enugu Campus, Enugu, Nigeria
| | - Obinna D Onodugo
- Department of Medicine, College of Medicine, University of Nigeria, Ituku/Ozalla, Enugu, Nigeria
| | - Harish C Gugnani
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
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Phillips MT, Owers KA, Grenfell BT, Pitzer VE. Changes in historical typhoid transmission across 16 U.S. cities, 1889-1931: Quantifying the impact of investments in water and sewer infrastructures. PLoS Negl Trop Dis 2020; 14:e0008048. [PMID: 32187188 PMCID: PMC7105137 DOI: 10.1371/journal.pntd.0008048] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 03/30/2020] [Accepted: 01/10/2020] [Indexed: 12/25/2022] Open
Abstract
Investments in water and sanitation systems are believed to have led to the decline in typhoid fever in developed countries, such that most cases now occur in regions lacking adequate clean water and sanitation. Exploring seasonal and long-term patterns in historical typhoid mortality in the United States can offer deeper understanding of disease drivers. We fit modified Time-series Susceptible-Infectious-Recovered models to city-level weekly mortality counts to estimate seasonal and long-term typhoid transmission. We examined seasonal transmission separately by city and aggregated by water source. Typhoid transmission peaked in late summer/early fall. Seasonality varied by water source, with the greatest variation occurring in cities with reservoirs. We then fit hierarchical regression models to measure associations between long-term transmission and annual financial investments in water and sewer systems. Overall historical $1 per capita ($16.13 in 2017) investments in the water supply were associated with approximately 5% (95% confidence interval: 3-6%) decreases in typhoid transmission, while $1 increases in the overall sewer system investments were associated with estimated 6% (95% confidence interval: 4-9%) decreases. Our findings aid in the understanding of typhoid transmission dynamics and potential impacts of water and sanitation improvements, and can inform cost-effectiveness analyses of interventions to reduce the typhoid burden.
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Affiliation(s)
- Maile T. Phillips
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Katharine A. Owers
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Bryan T. Grenfell
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - 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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109
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Rudolph ME, McArthur MA, Magder LS, Barnes RS, Chen WH, Sztein MB. Diversity of Salmonella Typhi-responsive CD4 and CD8 T cells before and after Ty21a typhoid vaccination in children and adults. Int Immunol 2020; 31:315-333. [PMID: 30951606 DOI: 10.1093/intimm/dxz011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/18/2019] [Indexed: 11/13/2022] Open
Abstract
Typhoid fever is a life-threatening disease caused by the human-restricted pathogen Salmonella enterica serovar Typhi (S. Typhi). The oral live attenuated Ty21a typhoid vaccine protects against this severe disease by eliciting robust, multifunctional cell-mediated immunity (CMI), shown to be associated with protection in wild-type S. Typhi challenge studies. Ty21a induces S. Typhi-responsive CD8+ and CD4+ T cells but little is known about the response to this vaccine in children. To address this important gap in knowledge, we have used mass cytometry to analyze pediatric and adult pre- and post-Ty21a vaccination CMI in an autologous S. Typhi antigen presentation model. Here, using conventional supervised analytical tools, we show adult T cells are more multifunctional at baseline than those obtained from children. Moreover, pediatric and adult T cells respond similarly to Ty21a vaccination, but adult responders remain more multifunctional. The use of the unsupervised dimensionality reduction tool tSNE (t-distributed Stochastic Neighbor Embedding) allowed us to confirm these findings, as well as to identify increases and decreases in well-defined specific CD4+ and CD8+ T-cell populations that were not possible to uncover using the conventional gating strategies. These findings evidenced age-associated maturation of multifunctional S. Typhi-responsive T-cell populations, including those which we have previously shown to be associated with protection from, and/or delayed onset of, typhoid disease. These findings are likely to play an important role in improving pediatric vaccination strategies against S. Typhi and other enteric pathogens.
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Affiliation(s)
- Mark E Rudolph
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Molecular Microbiology and Immunology Department, University of Maryland Graduate Program in Life Sciences, Baltimore, MD, USA
| | - Monica A McArthur
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Laurence S Magder
- Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Robin S Barnes
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Wilbur H Chen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Marcelo B Sztein
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA
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110
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Ngogo FA, Joachim A, Abade AM, Rumisha SF, Mizinduko MM, Majigo MV. Factors associated with Salmonella infection in patients with gastrointestinal complaints seeking health care at Regional Hospital in Southern Highland of Tanzania. BMC Infect Dis 2020; 20:135. [PMID: 32050928 PMCID: PMC7017463 DOI: 10.1186/s12879-020-4849-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 02/06/2020] [Indexed: 11/10/2022] Open
Abstract
Background Salmonellosis remains an important public health problem globally. The disease is among the leading causes of morbidity and mortality in developing countries that experience poor hygiene and lack of access to clean and safe water. There was an increase in reported cases of Salmonellosis in Njombe Region, Southern Highland of Tanzania between 2015 and 2016 based on clinical diagnosis. Nevertheless, little is known about the factors contributing to the transmission of this disease in the region. This study was conducted to determine the prevalence, antimicrobial susceptibility, and factors associated with Salmonella infection among patients who report gastrointestinal complaints. Methods A cross-sectional study was conducted from December 2017 to February 2018 among patients with gastrointestinal complaints at Kibena Regional Hospital. Stool samples were submitted for isolation of Salmonella spp. Identification was based on conventional biochemical tests and serotyping to differentiate typhoid and non-typhoid Salmonella (NTS). Antimicrobial susceptibility was performed using the Kirby-Bauer disc diffusion method. Multivariable logistic regression analysis was performed to examine the factors independently associated with Salmonella infection. Results The prevalence of Salmonella infection among participants with gastrointestinal complaints was 16.5% (95% CI: 12.7–21.1) of them, 83.7, 95% CI: 70.9–91.5 were NTS while 16.3, 95% CI: 8.5–29.0 were Typhoid Salmonella species. All isolates were sensitive to ceftriaxone and ciprofloxacin, whereas 27.8 and 100% were resistant to co-trimoxazole and ampicillin respectively. The odd of Salmonella infection was fourfold higher among participants with formal employment (AOR 3.8, 95% CI, 1.53–9.40). Use of water from wells/rivers (AOR 2.2, 95% CI, 1.07–4.45), drinking untreated water (AOR 2.6, 95% CI, 1.21–5.48) and often eating at a restaurant (AOR 3.4, 95% CI, 1.28–8.93) had increased odds of Salmonella infection. Likewise, having abdominal pain (AOR 8.5, 95% CI, 1.81–39.78) and diarrhea (AOR 2.3, 95% CI, 1.12–4.68) were independent symptoms that predict Salmonella infection. Conclusion There is a high prevalence of Salmonella infection among people who report gastrointestinal complaints and it is clinically predicated by diarhoea and abdominal pain. Employed participants and those eating at restaurant and drinking unsafe water had higher risk of infection. Salmonella spp. causing gastroenteritis has developed resistance to commonly used antibiotics.
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Affiliation(s)
- Fadhili A Ngogo
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.,Field Epidemiology and Laboratory Training Programme, Dar es Salaam, Tanzania
| | - Agricola Joachim
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Ahmed M Abade
- Field Epidemiology and Laboratory Training Programme, Dar es Salaam, Tanzania
| | - Susan F Rumisha
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Mucho M Mizinduko
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Mtebe V Majigo
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
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111
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Neuzil KM, Pollard AJ, Marfin AA. Introduction of Typhoid Conjugate Vaccines in Africa and Asia. Clin Infect Dis 2020; 68:S27-S30. [PMID: 30767005 PMCID: PMC6376078 DOI: 10.1093/cid/ciy878] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Typhoid fever continues to be a major public health concern, particularly in many low- and middle-income countries. The current threats of increasing antimicrobial resistance, urbanization, and climate change elevate the urgency for better prevention and control efforts for typhoid fever. In 2017, the results of ground-breaking research on typhoid conjugate vaccines (TCVs), the World Health Organization prequalification of a TCV, and global policy and financing decisions have set the stage for the introduction of TCVs into routine immunization programs in endemic countries. Country-level decision-making and program planning are critical for local uptake and sustainability.
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Affiliation(s)
- Kathleen M Neuzil
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, United Kingdom
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112
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Bhutta ZA. Integrating Typhoid Fever Within the Sustainable Development Goals: Pragmatism or Utopia? Clin Infect Dis 2020; 68:S34-S41. [PMID: 30767006 PMCID: PMC6376087 DOI: 10.1093/cid/ciy957] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Several decades following the first estimates of the global burden of typhoidal salmonellosis (infections caused by Salmonella Typhi and Salmonella Paratyphi), this disorder remains a major cause of morbidity worldwide with an estimated 17 million cases annually. The risk factors for typhoid include poverty, poor living conditions with unsafe water and lack of adequate sanitation, and unsafe foods-all reasons for the disease burden being highest among such populations including urban slums. A recent review of typhoid trends globally and in specific countries suggests that the relative contributions of these risk factors to disease burden reduction as well as persistence have varied. There is also the risk of periodic outbreaks related to introduction of relatively virulent drug-resistant strains or movements of vulnerable populations, including those in conflict zones. Most countries of the world are now aligning their health and multisectoral strategies to address the Sustainable Development Goals (SDGs) and targets, which were agreed upon by all countries of the world in September 2015. Though neglected so far, there are huge opportunities for mainstreaming typhoid prevention and control strategies within the SDGs. This article reviews some of the approaches that may help elevate typhoid to a higher level of awareness in public health programs and policy and to ensure that investments in major public health preventive measures are made part of the universal health coverage agenda.
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Affiliation(s)
- Zulfiqar A Bhutta
- Centre for Global Child Health, The Hospital for Sick Children, Toronto, Ontario, Canada
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113
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Carey ME, Diaz ZI, Zaidi AKM, Steele AD. A Global Agenda for Typhoid Control-A Perspective from the Bill & Melinda Gates Foundation. Clin Infect Dis 2020; 68:S42-S45. [PMID: 30766999 PMCID: PMC6376097 DOI: 10.1093/cid/ciy928] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recognizing that enteric fever disproportionately affects the poorest and the most vulnerable communities that have limited access to improved sanitation, safe water sources, and optimal medical care, the Bill & Melinda Gates Foundation has funded efforts to augment global understanding of the disease since the foundation’s inception. At the turn of the century, early efforts focused on characterizing the burden of disease in Asia and evaluating use of the available Vi-polysaccharide vaccines through the Diseases of the Most Impoverished projects at the International Vaccine Institute (IVI). More recent efforts have centered on supporting development of typhoid conjugate vaccines and expanding disease surveillance efforts into Africa, as well as generating a greater understanding of the clinical severity and sequelae of enteric fever in Africa, Asia, and India. The Typhoid Vaccine Accelerator Consortium is playing a critical role in coordinating these and other global efforts for the control of typhoid fever. Here, we outline the scope of support and strategic view of the foundation and describe how, by working through strong partnerships, we can realize a radical reduction of the significance of enteric fever as a global public health problem in the next 10 to 15 years.
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Affiliation(s)
- Megan E Carey
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Zoey I Diaz
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - Anita K M Zaidi
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
| | - A Duncan Steele
- Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington
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114
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Cost-effectiveness of using environmental surveillance to target the roll-out typhoid conjugate vaccine. Vaccine 2020; 38:1661-1670. [PMID: 31917040 DOI: 10.1016/j.vaccine.2019.12.061] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 12/26/2019] [Accepted: 12/27/2019] [Indexed: 01/15/2023]
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115
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Thindwa D, Chipeta MG, Henrion MYR, Gordon MA. Distinct climate influences on the risk of typhoid compared to invasive non-typhoid Salmonella disease in Blantyre, Malawi. Sci Rep 2019; 9:20310. [PMID: 31889080 PMCID: PMC6937328 DOI: 10.1038/s41598-019-56688-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/02/2019] [Indexed: 12/04/2022] Open
Abstract
Invasive Salmonella diseases, both typhoid and invasive non-typhoidal Salmonella (iNTS), are seasonal bloodstream infections causing important morbidity and mortality globally in Africa. The reservoirs and transmission of both are not fully understood. We hypothesised that differences in the time-lagged relationships of rainfall or temperature with typhoid and iNTS incidence might infer differences in epidemiology. We assessed the dynamics of invasive Salmonella incidence over a 16-year period of surveillance, quantifying incidence peaks, seasonal variations, and nonlinear effects of rainfall and temperature exposures on the relative risks of typhoid and iNTS, using monthly lags. An increased relative risk of iNTS incidence was short-lasting but immediate after the onset of the rains, whereas that of typhoid was long-lasting but with a two months delayed start, implying a possible difference in transmission. The relative-risk function of temperature for typhoid was bimodal, with higher risk at both lower (with a 1 month lag) and higher (with a ≥4 months lag) temperatures, possibly reflecting the known patterns of short and long cycle typhoid transmission. In contrast, the relative-risk of iNTS was only increased at lower temperatures, suggesting distinct transmission mechanisms. Environmental and sanitation control strategies may be different for iNTS compared to typhoid disease.
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Affiliation(s)
- Deus Thindwa
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
- Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
| | - Michael G Chipeta
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Nuffield Department of Medicine, Big Data Institute, Oxford University, Oxford, United Kingdom
- Malawi College of Medicine, University of Malawi, Blantyre, Malawi
| | - Marc Y R Henrion
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Melita A Gordon
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
- Malawi College of Medicine, University of Malawi, Blantyre, Malawi
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116
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Raymond M, Gibani MM, Day NPJ, Cheah PY. Typhoidal Salmonella human challenge studies: ethical and practical challenges and considerations for low-resource settings. Trials 2019; 20:704. [PMID: 31852488 PMCID: PMC6921376 DOI: 10.1186/s13063-019-3844-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Typhoidal Salmonella is a major global problem affecting more than 12 million people annually. Controlled human infection models (CHIMs) in high-resource settings have had an important role in accelerating the development of conjugate vaccines against Salmonella Typhi. The typhoidal Salmonella model has an established safety profile in over 2000 volunteers in high-income settings, and trial protocols, with modification, could be readily transferred to new study sites. To date, a typhoidal Salmonella CHIM has not been conducted in a low-resource setting, although it is being considered. Our article describes the challenges posed by a typhoidal Salmonella CHIM in the high-resource setting of Oxford and explores considerations for an endemic setting. Development of CHIMs in endemic settings is scientifically justifiable as it remains unclear whether findings from challenge studies performed in high-resource non-endemic settings can be extrapolated to endemic settings, where the burden of invasive Salmonella is highest. Volunteers are likely to differ across a range of important variables such as previous Salmonella exposure, diet, intestinal microbiota, and genetic profile. CHIMs in endemic settings arguably are ethically justifiable as affected communities are more likely to gain benefit from the study. Local training and research capacity may be bolstered. Safety was of primary importance in the Oxford model. Risk of harm to the individual was mitigated by careful inclusion and exclusion criteria; close monitoring with online diary and daily visits; 24/7 on-call staffing; and access to appropriate hospital facilities with capacity for in-patient admission. Risk of harm to the community was mitigated by exclusion of participants with contact with vulnerable persons; stringent hygiene and sanitation precautions; and demonstration of clearance of Salmonella infection from stool following antibiotic treatment. Safety measures should be more stringent in settings where health systems, transport networks, and sanitation are less robust. We compare the following issues between high- and low-resource settings: scientific justification, risk of harm to the individual and community, benefits to the individual and community, participant understanding, compensation, and regulatory requirements. We conclude that, with careful consideration of country-specific ethical and practical issues, a typhoidal Salmonella CHIM in an endemic setting is possible.
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Affiliation(s)
- Meriel Raymond
- Oxford Vaccine Group Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Churchill Hospital, Old Road, Headington, Oxford, OX3 7LE, UK
| | - Malick M Gibani
- Oxford Vaccine Group Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Churchill Hospital, Old Road, Headington, Oxford, OX3 7LE, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Phaik Yeong Cheah
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand. .,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK. .,Nuffield Departmemt of Population Health, The Ethox Centere, University of Oxford, Old Road, Oxford, OX3 7LF, UK.
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117
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Shakya M, Colin-Jones R, Theiss-Nyland K, Voysey M, Pant D, Smith N, Liu X, Tonks S, Mazur O, Farooq YG, Clarke J, Hill J, Adhikari A, Dongol S, Karkey A, Bajracharya B, Kelly S, Gurung M, Baker S, Neuzil KM, Shrestha S, Basnyat B, Pollard AJ. Phase 3 Efficacy Analysis of a Typhoid Conjugate Vaccine Trial in Nepal. N Engl J Med 2019; 381:2209-2218. [PMID: 31800986 PMCID: PMC6785806 DOI: 10.1056/nejmoa1905047] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Salmonella Typhi is a major cause of fever in children in low- and middle-income countries. A typhoid conjugate vaccine (TCV) that was recently prequalified by the World Health Organization was shown to be efficacious in a human challenge model, but data from efficacy trials in areas where typhoid is endemic are lacking. METHODS In this phase 3, randomized, controlled trial in Lalitpur, Nepal, in which both the participants and observers were unaware of the trial-group assignments, we randomly assigned children who were between 9 months and 16 years of age, in a 1:1 ratio, to receive either a TCV or a capsular group A meningococcal conjugate vaccine (MenA) as a control. The primary outcome was typhoid fever confirmed by blood culture. We present the prespecified analysis of the primary and main secondary outcomes (including an immunogenicity subgroup); the 2-year trial follow-up is ongoing. RESULTS A total of 10,005 participants received the TCV and 10,014 received the MenA vaccine. Blood culture-confirmed typhoid fever occurred in 7 participants who received TCV (79 cases per 100,000 person-years) and in 38 who received MenA vaccine (428 cases per 100,000 person-years) (vaccine efficacy, 81.6%; 95% confidence interval, 58.8 to 91.8; P<0.001). A total of 132 serious adverse events (61 in the TCV group and 71 in the MenA vaccine group) occurred in the first 6 months, and 1 event (pyrexia) was identified as being vaccine-related; the participant remained unaware of the trial-group assignment. Similar rates of adverse events were noted in the two trial groups; fever developed in 5.0% of participants in the TCV group and 5.4% in the MenA vaccine group in the first week after vaccination. In the immunogenicity subgroup, seroconversion (a Vi IgG level that at least quadrupled 28 days after vaccination) was 99% in the TCV group (677 of 683 participants) and 2% in the MenA vaccine group (8 of 380 participants). CONCLUSIONS A single dose of TCV was immunogenic and effective in reducing S. Typhi bacteremia in children 9 months to 16 years of age. (Funded by the Bill and Melinda Gates Foundation; Current Controlled Trials number, ISRCTN43385161.).
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Affiliation(s)
- Mila Shakya
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Rachel Colin-Jones
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Katherine Theiss-Nyland
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Merryn Voysey
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Dikshya Pant
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Nicola Smith
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Xinxue Liu
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Susan Tonks
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Olga Mazur
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Yama G Farooq
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Jenny Clarke
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Jennifer Hill
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Anup Adhikari
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Sabina Dongol
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Abhilasha Karkey
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Binod Bajracharya
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Sarah Kelly
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Meeru Gurung
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Stephen Baker
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Kathleen M Neuzil
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Shrijana Shrestha
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Buddha Basnyat
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
| | - Andrew J Pollard
- From the Oxford University Clinical Research Unit (M.S., S.D., A.K., B. Basnyat), Patan Academy of Health Sciences, Patan Hospital (D.P., M.G., S.S.), the Nepal Family Development Foundation (A.A.), and Wasa Pasa Polyclinics Private, Lalitpur (B. Bajracharya) - all in Kathmandu; the Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford (R.C.-J., K.T.-N., M.V., N.S., X.L., S.T., O.M., Y.G.F., J.C., J.H., S.K., A.J.P.), and the Department of Medicine, University of Cambridge, Cambridge (S.B.) - all in the United Kingdom; the Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam (S.B.); and the University of Maryland School of Medicine, Baltimore (K.M.N.)
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118
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AMICIZIA D, MICALE R, PENNATI B, ZANGRILLO F, IOVINE M, LECINI E, MARCHINI F, LAI P, PANATTO D. Burden of typhoid fever and cholera: similarities and differences. Prevention strategies for European travelers to endemic/epidemic areas. JOURNAL OF PREVENTIVE MEDICINE AND HYGIENE 2019; 60:E271-E285. [PMID: 31967084 PMCID: PMC6953460 DOI: 10.15167/2421-4248/jpmh2019.60.4.1333] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 09/04/2019] [Indexed: 11/16/2022]
Abstract
The burden of diarrheal diseases is very high, accounting for 1.7 to 5 billion cases per year worldwide. Typhoid fever (TF) and cholera are potentially life-threatening infectious diseases, and are mainly transmitted through the consumption of food, drink or water that have been contaminated by the feces or urine of subjects excreting the pathogen. TF is mainly caused by Salmonella typhi, whereas cholera is caused by intestinal infection by the toxin-producing bacterium Vibrio cholerae. These diseases typically affect low- and middle-income countries where housing is overcrowded and water and sanitation are poor, or where conflicts or natural disasters have led to the collapse of the water, sanitation and healthcare systems. Mortality is higher in children under 5 years of age. Regarding their geographical distribution, TF has a high incidence in sub-Saharan Africa, India and south-east Asia, while cholera has a high incidence in a few African countries, particularly in the Horn of Africa and the Arabian Peninsula. In the fight against these diseases, preventive measures are fundamental. With modern air travel, transmissible diseases can spread across continents and oceans in a few days, constituting a threat to global public health. Nowadays, people travel for many reasons, such as tourism and business. Several surveys have shown that a high proportion of travelers lack adequate information on safety issues, such as timely vaccination and prophylactic medications. The main objective of this overview is to provide information to help European travelers to stay healthy while abroad, and thus also to reduce the potential importation of these diseases and their consequent implications for public health and society. The preventive measures to be implemented in the case of travel to countries where these diseases are still endemic are well known: the adoption of safe practices and vaccinations. It is important to stress that an effective preventive strategy should be based both on vaccinations and on hygiene travel guidelines. Furthermore, the emergence of multidrug-resistant strains is becoming a serious problem in the clinical treatment of these diseases. For this reason, vaccination is the main solution.
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Affiliation(s)
| | | | | | | | | | | | | | | | - D. PANATTO
- Department of Health Sciences, University of Genoa, Italy
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119
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Jeon HJ, Pak GD, Im J, Owusu-Dabo E, Adu-Sarkodie Y, Gassama Sow A, Bassiahi Soura A, Gasmelseed N, Keddy KH, Bjerregaard-Andersen M, Konings F, Aseffa A, Crump JA, Chon Y, Breiman RF, Park SE, Cruz Espinoza LM, Seo HJ, May J, Meyer CG, Andrews JR, Panzner U, von Kalckreuth V, Wierzba TF, Rakotozandrindrainy R, Dougan G, Levine MM, Hombach J, Kim JH, Clemens JD, Baker S, Marks F. Determining the Best Immunization Strategy for Protecting African Children Against Invasive Salmonella Disease. Clin Infect Dis 2019; 67:1824-1830. [PMID: 29746615 PMCID: PMC6260167 DOI: 10.1093/cid/ciy386] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 04/27/2018] [Indexed: 12/26/2022] Open
Abstract
Background The World Health Organization recently prequalified a typhoid conjugate vaccine (TCV), recommending its use in persons ≥6 months to 45 years residing in typhoid fever (TF)-endemic areas. We now need to consider how TCVs can have the greatest impact in the most vulnerable populations. Methods The Typhoid Fever Surveillance in Africa Program (TSAP) was a blood culture-based surveillance of febrile patients from defined populations presenting at healthcare facilities in 10 African countries. TF and invasive non-typhoidal Salmonella (iNTS) disease incidences were estimated for 0-10 year-olds in one-year age increments. Results Salmonella Typhi and iNTS were the most frequently isolated pathogens; 135 and 94 cases were identified, respectively. Analysis from three countries was excluded (incomplete person-years of observation (PYO) data). Thirty-seven of 123 TF cases (30.1%) and 71/90 iNTS disease cases (78.9%) occurred in children aged <5 years. No TF and 8/90 iNTS infections (8.9%) were observed in infants aged <9 months. The TF incidences (/100 000 PYO) for children aged <1 year and 1 to <2 years were 5 and 39, respectively; the highest incidence was 304 per 100 000 PYO in 4 to <5 year-olds. The iNTS disease incidence in the defined age groups ranged between 81 and 233 per 100 000 PYO, highest in 1 to <2 year-olds. TF and iNTS disease incidences were higher in West Africa. Conclusions High burden of TF detected in young children strengthens the need for TCV introduction. Given the concurrent iNTS disease burden, development of a trivalent vaccine against S. Typhi, S. Typhimurium, and S. Enteritidis may be timely in this region.
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Affiliation(s)
- Hyon Jin Jeon
- International Vaccine Institute, Seoul, Republic of Korea
| | - Gi Deok Pak
- International Vaccine Institute, Seoul, Republic of Korea
| | - Justin Im
- International Vaccine Institute, Seoul, Republic of Korea
| | - Ellis Owusu-Dabo
- Kumasi Center for Collaborative Research in Tropical Medicine, Kumasi, Ghana.,Departments of Global and International Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Yaw Adu-Sarkodie
- Departments of Clinical Microbiology, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Amy Gassama Sow
- Institute Pasteur de Dakar.,Université Cheikh Anta Diop de Dakar, Senegal
| | | | - Nagla Gasmelseed
- Faculty of Medicine, University of Gezira, Wad Medani, Sudan.,Faculty of Science, University of Hafr Al Batin, Saudi Arabia
| | - Karen H Keddy
- National Institute for Communicable Diseases, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Morten Bjerregaard-Andersen
- Bandim Health Project, Bissau, Guinea-Bissau.,Research Center for Vitamins and Vaccines, Copenhagen, Denmark
| | - Frank Konings
- International Vaccine Institute, Seoul, Republic of Korea
| | - Abraham Aseffa
- Armauer Hansen Research Institute, ALERT Campus, Addis Ababa, Ethiopia
| | - John A Crump
- Kilimanjaro Christian Medical Centre, Moshi, Tanzania.,Division of Infectious Diseases and International Health, Duke University Medical Center.,Duke Global Health Institute, Duke University, Durham, North Carolina.,Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Yun Chon
- International Vaccine Institute, Seoul, Republic of Korea
| | | | - Se Eun Park
- International Vaccine Institute, Seoul, Republic of Korea.,Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Hye Jin Seo
- International Vaccine Institute, Seoul, Republic of Korea
| | - Jürgen May
- Bernhard Nocht Institute for Tropical Medicine, Hamburg
| | - Christian G Meyer
- Institute of Tropical Medicine, Eberhard-Karls University Tübingen, Germany.,Duy Tan University, Da Nang, Vietnam
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University, California
| | - Ursula Panzner
- International Vaccine Institute, Seoul, Republic of Korea
| | | | | | | | - Gordon Dougan
- Department of Medicine, University of Cambridge, United Kingdom
| | - Myron M Levine
- Department of Medicine, University of Maryland School of Medicine, Baltimore
| | | | - Jerome H Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | - John D Clemens
- International Centre for Diarrheal Disease Research, Bangladesh, Dhaka.,Fielding School of Public Health, University of California, Los Angeles.,Korea University School of Medicine, Seoul, Republic of Korea
| | - Stephen Baker
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Department of Medicine, University of Cambridge, United Kingdom
| | - Florian Marks
- International Vaccine Institute, Seoul, Republic of Korea.,Department of Medicine, University of Cambridge, United Kingdom
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120
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Dahora LC, Jin C, Spreng RL, Feely F, Mathura R, Seaton KE, Zhang L, Hill J, Jones E, Alam SM, Dennison SM, Pollard AJ, Tomaras GD. IgA and IgG1 Specific to Vi Polysaccharide of Salmonella Typhi Correlate With Protection Status in a Typhoid Fever Controlled Human Infection Model. Front Immunol 2019; 10:2582. [PMID: 31781100 PMCID: PMC6852708 DOI: 10.3389/fimmu.2019.02582] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/17/2019] [Indexed: 01/09/2023] Open
Abstract
Vaccination against Salmonella Typhi using the Vi capsular polysaccharide, a T-cell independent antigen, can protect from the development of typhoid fever. This implies that antibodies to Vi alone can protect in the absence of a T cell-mediated immune response; however, protective Vi antibodies have not been well-characterized. We hypothesized that variability in the biophysical properties of vaccine-elicited antibodies, including subclass distribution and avidity, may impact protective outcomes. To interrogate the relationship between antibody properties and protection against typhoid fever, we analyzed humoral responses from participants in a vaccine efficacy (VE) trial using a controlled human infection model (CHIM) who received either a purified Vi polysaccharide (Vi-PS) or Vi tetanus toxoid conjugate (Vi-TT) vaccine followed by oral challenge with live S. Typhi. We determined the avidity, overall magnitude, and vaccine-induced fold-change in magnitude from before immunization to day of challenge of Vi IgA and IgG subclass antibodies. Amongst those who received the Vi-PS vaccine, Vi IgA magnitude (FDR p = 0.01) and fold-change (FDR p = 0.02) were significantly higher in protected individuals compared with those individuals who developed disease ("diagnosed"). In the Vi-TT vaccine group, the responses of protected individuals had higher fold-change in Vi IgA (FDR p = 0.06) and higher Vi IgG1 avidity (FDR p = 0.058) than the diagnosed Vi-TT vaccinees, though these findings were not significant at p < 0.05. Overall, protective antibody signatures differed between the Vi-PS and Vi-TT vaccines, thus, we conclude that although the Vi-PS and Vi-TT vaccines were observed to have similar efficacies, these vaccines may protect through different mechanisms. These data will inform studies on mechanisms of protection against typhoid fever, including identification of antibody effector functions, as well as informing future vaccination strategies.
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Affiliation(s)
- Lindsay C Dahora
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Immunology, Duke University, Durham, NC, United States
| | - Celina Jin
- Oxford Vaccine Group, Department of Paediatrics, The NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Rachel L Spreng
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Medicine, Duke University, Durham, NC, United States
| | - Frederick Feely
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Surgery, Duke University, Durham, NC, United States
| | - Ryan Mathura
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Surgery, Duke University, Durham, NC, United States
| | - Kelly E Seaton
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Surgery, Duke University, Durham, NC, United States
| | - Lu Zhang
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Surgery, Duke University, Durham, NC, United States
| | - Jennifer Hill
- Oxford Vaccine Group, Department of Paediatrics, The NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Elizabeth Jones
- Oxford Vaccine Group, Department of Paediatrics, The NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - S Munir Alam
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Medicine, Duke University, Durham, NC, United States.,Department of Pathology, Duke University, Durham, NC, United States
| | - S Moses Dennison
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Surgery, Duke University, Durham, NC, United States
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, The NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Georgia D Tomaras
- Duke Human Vaccine Institute, Duke University, Durham, NC, United States.,Department of Immunology, Duke University, Durham, NC, United States.,Department of Surgery, Duke University, Durham, NC, United States.,Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
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121
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Park SE, Toy T, Cruz Espinoza LM, Panzner U, Mogeni OD, Im J, Poudyal N, Pak GD, Seo H, Chon Y, Schütt-Gerowitt H, Mogasale V, Ramani E, Dey A, Park JY, Kim JH, Seo HJ, Jeon HJ, Haselbeck A, Conway Roy K, MacWright W, Adu-Sarkodie Y, Owusu-Dabo E, Osei I, Owusu M, Rakotozandrindrainy R, Soura AB, Kabore LP, Teferi M, Okeke IN, Kehinde A, Popoola O, Jacobs J, Lunguya Metila O, Meyer CG, Crump JA, Elias S, Maclennan CA, Parry CM, Baker S, Mintz ED, Breiman RF, Clemens JD, Marks F. The Severe Typhoid Fever in Africa Program: Study Design and Methodology to Assess Disease Severity, Host Immunity, and Carriage Associated With Invasive Salmonellosis. Clin Infect Dis 2019; 69:S422-S434. [PMID: 31665779 PMCID: PMC6821161 DOI: 10.1093/cid/ciz715] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Invasive salmonellosis is a common community-acquired bacteremia in persons residing in sub-Saharan Africa. However, there is a paucity of data on severe typhoid fever and its associated acute and chronic host immune response and carriage. The Severe Typhoid Fever in Africa (SETA) program, a multicountry surveillance study, aimed to address these research gaps and contribute to the control and prevention of invasive salmonellosis. METHODS A prospective healthcare facility-based surveillance with active screening of enteric fever and clinically suspected severe typhoid fever with complications was performed using a standardized protocol across the study sites in Burkina Faso, the Democratic Republic of Congo (DRC), Ethiopia, Ghana, Madagascar, and Nigeria. Defined inclusion criteria were used for screening of eligible patients for enrollment into the study. Enrolled patients with confirmed invasive salmonellosis by blood culture or patients with clinically suspected severe typhoid fever with perforation were eligible for clinical follow-up. Asymptomatic neighborhood controls and immediate household contacts of each case were enrolled as a comparison group to assess the level of Salmonella-specific antibodies and shedding patterns. Healthcare utilization surveys were performed to permit adjustment of incidence estimations. Postmortem questionnaires were conducted in medically underserved areas to assess death attributed to invasive Salmonella infections in selected sites. RESULTS Research data generated through SETA aimed to address scientific knowledge gaps concerning the severe typhoid fever and mortality, long-term host immune responses, and bacterial shedding and carriage associated with natural infection by invasive salmonellae. CONCLUSIONS SETA supports public health policy on typhoid immunization strategy in Africa.
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Affiliation(s)
- Se Eun Park
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Trevor Toy
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | | | - Ursula Panzner
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Ondari D Mogeni
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Justin Im
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Nimesh Poudyal
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
- Department of Microbiology and Infectious Disease, B. P. Koirala Institute of Health Sciences, Dharan, Nepal
| | - Gi Deok Pak
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Hyeongwon Seo
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Yun Chon
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Heidi Schütt-Gerowitt
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
- Institute of Medical Microbiology, University of Cologne, Germany
| | - Vittal Mogasale
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Enusa Ramani
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Ayan Dey
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Ju Yeong Park
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Jong-Hoon Kim
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Hye Jin Seo
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | - Hyon Jin Jeon
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
- Department of Medicine, Cambridge University, United Kingdom
| | - Andrea Haselbeck
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
| | | | | | - Yaw Adu-Sarkodie
- School of Public Health, and, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Ellis Owusu-Dabo
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Isaac Osei
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Michael Owusu
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Abdramane Bassiahi Soura
- Institut Supérieur des Sciences de la Population, University of Ouagadougou, Ouagadougou, Burkina Faso
| | | | - Mekonnen Teferi
- Armauer Hansen Research Institute, ALERT Campus, Addis Ababa, Ethiopia
| | | | - Aderemi Kehinde
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Ibadan
- Department of Medical Microbiology and Parasitology, University College Hospital
| | - Oluwafemi Popoola
- Department of Community Medicine, College of Medicine, University of Ibadan
- Department of Community Medicine, University College Hospital, Ibadan, Nigeria
| | - Jan Jacobs
- Department of Microbiology and Immunology, KU Leuven
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Octavie Lunguya Metila
- Institut National de Recherche Biomedicales, Kinshasa
- Service de Microbiologie, Cliniques Universitaires de Kinshasa, Democratic Republic of Congo
| | - Christian G Meyer
- Institute of Tropical Medicine, Eberhard-Karls University of Tübingen, Germany
- Duy Tan University, Da Nang, Vietnam
| | - John A Crump
- Kilimanjaro Christian Medical Centre, Moshi, Tanzania
- Division of Infectious Diseases and International Health, Duke University Medical Center
- Duke Global Health Institute, Duke University, Durham, North Carolina
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Sean Elias
- Jenner Institute, University of Oxford, United Kingdom
| | | | | | - Stephen Baker
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Department of Medicine, Cambridge University, United Kingdom
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Eric D Mintz
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - John D Clemens
- icddr,b, Dhaka, Bangladesh
- Fielding School of Public Health, University of California, Los Angeles
| | - Florian Marks
- International Vaccine Institute, Seoul National University Research Park, Republic of Korea
- Department of Medicine, Cambridge University, United Kingdom
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122
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Marchello CS, Dale AP, Pisharody S, Crump JA. Using hospital-based studies of community-onset bloodstream infections to make inferences about typhoid fever incidence. Trop Med Int Health 2019; 24:1369-1383. [PMID: 31633858 PMCID: PMC6916262 DOI: 10.1111/tmi.13319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Objectives Hospital-based studies of community-onset bloodstream infections (CO-BSI) are less resource-intensive to carry out than population-based incidence studies. We examined several metrics capturing the potential role of Salmonella Typhi as a cause of CO-BSI for making inferences about incidence. Methods We systematically reviewed three databases for hospital-based studies of CO-BSI. We determined, by study, the prevalence and rank order of Salmonella among pathogenic bloodstream isolates, and the prevalence ratio of Salmonella Typhi to Escherichia coli (S:E ratio). We then describe these hospital-based study metrics in relation to population-based typhoid fever incidence data from a separate systematic review. Results Forty-four studies met the inclusion criteria, of which 23 (52.3%) isolated Salmonella Typhi at least once. Among studies isolating Salmonella Typhi, the median (interquartile range) prevalence and rank order of Salmonella Typhi compared to other pathogens isolated in BSI was 8.3% (3.2–37.9%) and 3 (1–6), respectively. The median (interquartile range) S:E ratio was 1.0 (0.4–3.0). With respect to incidence, in Pemba Island, Tanzania, prevalence, rank order, S:E ratio, and incidence was 64.8%, 1, 9.2 and 110 cases per 100 000, respectively, and in Boulkiemdé, Burkina Faso, was 13.3%, 3, 2.3 and 249 cases per 100 000. Conclusions We describe considerable variation in place and time for Salmonella Typhi prevalence, rank order, and S:E ratio among hospital-based studies of CO-BSI. Data from simultaneous typhoid prevalence and incidence studies are limited. We propose that hospital-based study metrics warrant evaluation for making inference about typhoid incidence and as covariates in typhoid incidence models.
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Affiliation(s)
| | - Ariella P Dale
- Colorado Department of Public Health and Environment, Denver, CO, USA
| | | | - John A Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
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123
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Pitzer VE, Meiring J, Martineau FP, Watson CH, Kang G, Basnyat B, Baker S. The Invisible Burden: Diagnosing and Combatting Typhoid Fever in Asia and Africa. Clin Infect Dis 2019; 69:S395-S401. [PMID: 31612938 PMCID: PMC6792124 DOI: 10.1093/cid/ciz611] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Measuring the burden of typhoid fever and developing effective strategies to reduce it require a surveillance infrastructure that is currently lacking in many endemic countries. Recent efforts and partnerships between local and international researchers have helped to provide new data on the incidence and control of typhoid in parts of Asia and Africa. Here, we highlight examples from India, Nepal, Vietnam, Fiji, Sierra Leone, and Malawi that summarize past and present experiences with the diagnosis, treatment, and prevention of typhoid fever in different locations with endemic disease. While there is no validated road map for the elimination of typhoid, the lessons learned in studying the epidemiology and control of typhoid in these settings can provide insights to guide future disease control efforts.
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Affiliation(s)
- Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut
| | - James Meiring
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, United Kingdom
| | | | - Conall H Watson
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Gagandeep Kang
- Translational Health Sciences Technology Institute, Faridabad, Haryana, India
| | - Buddha Basnyat
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - 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, United Kingdom
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124
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Meiring JE, Giubilini A, Savulescu J, Pitzer VE, Pollard AJ. Generating the Evidence for Typhoid Vaccine Introduction: Considerations for Global Disease Burden Estimates and Vaccine Testing Through Human Challenge. Clin Infect Dis 2019; 69:S402-S407. [PMID: 31612941 PMCID: PMC6792111 DOI: 10.1093/cid/ciz630] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Typhoid fever has had a major impact on human populations, with the causative pathogen Salmonella enterica serovar Typhi implicated in many outbreaks through history. The current burden of disease is estimated at 11-18 million infections annually, with the majority of infections located in Africa and South Asia. Data that have been used to estimate burden are limited to a small number of blood-culture surveillance studies, largely from densely populated urban centers. Extrapolating these data to estimate disease burden within and across countries highlights the lack of precision in global figures. A number of approaches have been developed, characterizing different geographical areas by water-based risk factors for typhoid infection or broader measures of health and development to more accurately extrapolate incidence. Recognition of the substantial disease burden is essential for policy-makers considering vaccine introduction. Typhoid vaccines have been in development for >100 years. The Vi polysaccharide (ViPS) and Ty21a vaccines have had a World Health Organization (WHO) recommendation for programmatic use in countries with high burden for 10 years, with 1 ViPS vaccine also having WHO prequalification. Despite this, uptake and introduction of these vaccines has been minimal. The development of a controlled human infection model (CHIM) enabled the accelerated testing of the newly WHO-prequalified ViPS-tetanus toxoid protein conjugate vaccine, providing efficacy estimates for the vaccine, prior to larger field trials. There is an urgency to the global control of enteric fever due to the escalating problem of antimicrobial resistance. With more accurate burden of disease estimates and a vaccine showing efficacy in CHIM, that control is now a possibility.
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Affiliation(s)
- James E Meiring
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, United Kingdom
- National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford, United Kingdom
| | - Alberto Giubilini
- Oxford Uehiro Centre for Practical Ethics, University of Oxford, United Kingdom
| | - Julian Savulescu
- Oxford Uehiro Centre for Practical Ethics, University of Oxford, United Kingdom
| | - Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, United Kingdom
- National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford, United Kingdom
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125
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Saha S, Islam M, Saha S, Uddin MJ, Rahman H, Das RC, Hasan M, Amin MR, Hanif M, Shahidullah M, Hussain M, Saha SK. Designing Comprehensive Public Health Surveillance for Enteric Fever in Endemic Countries: Importance of Including Different Healthcare Facilities. J Infect Dis 2019; 218:S227-S231. [PMID: 30060199 PMCID: PMC6226780 DOI: 10.1093/infdis/jiy191] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Indexed: 12/22/2022] Open
Abstract
Background Designing comprehensive surveillance to generate credible burden estimates of enteric fever in an endemic country can be challenging because care-seeking behavior is complex and surveillance in different healthcare facilities may lead to documentation of different epidemiological characteristics. Methods We conducted retrospective surveillance in 3 healthcare facilities to identify culture-confirmed enteric fever cases in Dhaka, Bangladesh, from January 2012 through December 2016. The study settings included (1) hospital in-patient department (IPD), (2) hospital out-patient department (OPD), and (3) private consultation center OPD. We analyzed the cases to understand their distribution, age ranges, and antibiotic susceptibility patterns across the settings. Results Of the 1837 culture-confirmed enteric fever cases, 59% (1079 of 1837) were OPD cases. Children with enteric fever hospitalized in the IPDs were younger than children seeking care at the hospital OPD (median age: 45 vs 60 months) or private OPD (median age: 45 vs 72 months). Multidrug resistance rates were slightly higher in hospital IPD cases than in private OPD cases (26% vs 24%). Conclusions In each facility, we identified different epidemiological characteristics, and lack of consideration of any of these may result in misinterpretation of disease burden, identification of different age groups, and/or antibiotic susceptibility patterns.
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Affiliation(s)
- Senjuti Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh
| | - Maksuda Islam
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh
| | - Shampa Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh
| | - Mohammad Jamal Uddin
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh
| | - Hafizur Rahman
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh
| | - Rajib Chandra Das
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh
| | - Md Hasan
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh
| | - Md Ruhul Amin
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh.,Bangladesh Institute of Child Health, Dhaka Shishu (Children) Hospital, Bangladesh
| | - Mohammed Hanif
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh.,Bangladesh Institute of Child Health, Dhaka Shishu (Children) Hospital, Bangladesh
| | | | - Manzoor Hussain
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh.,Bangladesh Institute of Child Health, Dhaka Shishu (Children) Hospital, Bangladesh
| | - Samir K Saha
- Child Health Research Foundation, Department of Microbiology, Dhaka Shishu Hospital, Bangladesh.,Bangladesh Institute of Child Health, Dhaka Shishu (Children) Hospital, Bangladesh.,Popular Diagnostic Center, Bangladesh
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126
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Kingsley RA, Langridge G, Smith SE, Makendi C, Fookes M, Wileman TM, El Ghany MA, Keith Turner A, Dyson ZA, Sridhar S, Pickard D, Kay S, Feasey N, Wong V, Barquist L, Dougan G. Functional analysis of Salmonella Typhi adaptation to survival in water. Environ Microbiol 2019; 20:4079-4090. [PMID: 30450829 PMCID: PMC6282856 DOI: 10.1111/1462-2920.14458] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 10/16/2018] [Accepted: 10/21/2018] [Indexed: 11/28/2022]
Abstract
Contaminated water is a major risk factor associated with the transmission of Salmonella enterica serovar Typhi (S. Typhi), the aetiological agent of human typhoid. However, little is known about how this pathogen adapts to living in the aqueous environment. We used transcriptome analysis (RNA‐seq) and transposon mutagenesis (TraDIS) to characterize these adaptive changes and identify multiple genes that contribute to survival. Over half of the genes in the S. Typhi genome altered expression level within the first 24 h following transfer from broth culture to water, although relatively few did so in the first 30 min. Genes linked to central metabolism, stress associated with arrested proton motive force and respiratory chain factors changed expression levels. Additionally, motility and chemotaxis genes increased expression, consistent with a scavenging lifestyle. The viaB‐associated gene tviC encoding a glcNAc epimerase that is required for Vi polysaccharide biosynthesis was, along with several other genes, shown to contribute to survival in water. Thus, we define regulatory adaptation operating in S. Typhi that facilitates survival in water.
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Affiliation(s)
| | - Gemma Langridge
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Sarah E Smith
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Carine Makendi
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Maria Fookes
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Tom M Wileman
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Moataz Abd El Ghany
- The Westmead Institute for Medical Research, The University of Sydney, Sydney, Australia and Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia
| | - A Keith Turner
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Zoe A Dyson
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, UK
| | - Sushmita Sridhar
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, UK
| | - Derek Pickard
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Sally Kay
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | | | - Vanessa Wong
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, UK
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research, Würzburg, Germany.,Faculty of Medicine, University of Würzburg, Würzburg, Germany
| | - Gordon Dougan
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, UK
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127
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Wang KY, Lee DJ, Shie SS, Chen CJ. Population structure and transmission modes of indigenous typhoid in Taiwan. BMC Med Genomics 2019; 12:126. [PMID: 31481113 PMCID: PMC6724314 DOI: 10.1186/s12920-019-0576-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 08/29/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Indigenous typhoid fever was continuing to be identified in Taiwan which has not been endemic for the enteric fever for more than 20 years. The source and transmission by which the local patients acquired typhoid and the population structure of the indigenous typhoid strains remain not well characterized. METHODS During 2001 and 2014, non-duplicated clinical Salmonella enterica serovar Typhi isolates in a hospital were analyzed by whole-genome sequencing (WGS) and determined for pulsotypes. Maximum likelihood phylogeny was constructed by nucleotide alterations in core genomes and compared to the framework of global typhoid strains. Potential source and transmission were traced by correlating the phylogeny and the temporal relationship between isolates. RESULTS A total of 43 S. Typhi isolates from indigenous cases were analyzed and a majority (39, 90.7%) of them were belonged to six WGS-defined genotypes prevailing mainly in Southeast Asia. Genotype 3.4.0 and a multidrug-resistant type 4.3.1 (also known as pandemic H58 haplotype) were associated respectively with two solitary small-scale outbreaks, implying a transmission mode of importation followed by outbreak. Twelve isolates with nearly identical core genomes were belonged to genotype 3.2.1 but were categorized into three different pulsotypes. The 3.2.1 isolates were identified across 13 years and involved in three clusters and a sporadic case, indicating sustained local transmission of the same strain. The remaining indigenous isolates belonging to three genotypes (2.1, 3.1.2, and 3.0.0) were of substantial genetic diversity and isolated at different time points, indicating independent event of each case. CONCLUSIONS Indigenous typhoid in Taiwan occurred mainly with the forms of small-scale outbreaks or sporadic events likely by contracting imported strains which prevailed in Southeast Asia. Sustained local transmission of certain strain was also evident by WGS analysis, but not by conventional pulsotyping, highlighting the importance of continuing molecular surveillance of typhoid fever with adequate tools in the non-endemic region.
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Affiliation(s)
- Kai-Yu Wang
- School of medicine, College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan
| | - De-Jen Lee
- Physical Education Office, Chang Gung University, 333, Taoyuan, Taiwan
| | - Shian-Sen Shie
- School of medicine, College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan.,Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, 333, Taoyuan, Taiwan
| | - Chih-Jung Chen
- School of medicine, College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan. .,Division of Pediatric Infectious Diseases, Department of Paediatrics, Chang Gung Memorial Hospital, Linkou, No. 5, Fu-Shin Street, Kweishan, 333, Taoyuan, Taiwan. .,Department of Pediatrics, Xiamen Chang Gung Hospital, Xiamen, Fujian, China.
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128
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Salerno-Goncalves R, Kayastha D, Fasano A, Levine MM, Sztein MB. Crosstalk between leukocytes triggers differential immune responses against Salmonella enterica serovars Typhi and Paratyphi. PLoS Negl Trop Dis 2019; 13:e0007650. [PMID: 31412039 PMCID: PMC6709971 DOI: 10.1371/journal.pntd.0007650] [Citation(s) in RCA: 10] [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: 02/05/2019] [Revised: 08/26/2019] [Accepted: 07/23/2019] [Indexed: 12/30/2022] Open
Abstract
Enteric fevers, caused by the Salmonella enterica serovars Typhi (ST), Paratyphi A (PA) and Paratyphi B (PB), are life-threatening illnesses exhibiting very similar clinical symptoms but with distinct epidemiologies, geographical distributions and susceptibilities to antimicrobial treatment. Nevertheless, the mechanisms by which the host recognizes pathogens with high levels of homology, such as these bacterial serovars, remain poorly understood. Using a three-dimensional organotypic model of the human intestinal mucosa and PA, PB, and ST, we observed significant differences in the secretion patterns of pro-inflammatory cytokines and chemokines elicited by these serovars. These cytokines/chemokines were likely to be co-regulated and influenced the function of epithelial cells, such as the production of IL-8. We also found differing levels of polymorphonuclear leukocyte (PMN) migration among various infection conditions that either included or excluded lymphocytes and macrophages (Mϕ), strongly suggesting feedback mechanisms among these cells. Blocking experiments showed that IL-1β, IL-6, IL-8, TNF-α and CCL3 cytokines were involved in the differential regulation of migration patterns. We conclude that the crosstalk among the lymphocytes, Mϕ, PMN and epithelial cells is cytokine/chemokine-dependent and bacterial-serotype specific, and plays a pivotal role in orchestrating the functional efficiency of the innate cells and migratory characteristics of the leukocytes.
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Affiliation(s)
- Rosangela Salerno-Goncalves
- Center for Vaccine Development and Global Health, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Darpan Kayastha
- Center for Vaccine Development and Global Health, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Alessio Fasano
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Boston, MA, United States of America
| | - Myron M. Levine
- Center for Vaccine Development and Global Health, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Marcelo B. Sztein
- Center for Vaccine Development and Global Health, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States of America
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130
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Abstract
Purpose of review Enteric fever remains a major global-health concern, estimated to be responsible for between 11.9 and 26.9 million cases annually. Long-term prevention of enteric fever will require improved access to safe drinking water combined with investment in sanitation and hygiene interventions. In the short-to-medium term, new control strategies for typhoid fever have arrived in the form of typhoid Vi-conjugate vaccines (TCVs), offering hope that disease control can be achieved in the near future. Recent findings The diagnosis of enteric fever is complicated by its nonspecific clinical presentation, coupled with the low sensitivity of commonly used diagnostics. Investment in diagnostics has the potential to improve management, to refine estimates of disease burden and to facilitate vaccine impact studies. A new generation of reliable, diagnostic tests is needed that are simultaneously accessible, cost-effective, sensitive, and specific. The emergence and global dissemination of multidrug-resistant, fluoroquinolone-resistant, and extensively drug-resistant (XDR) strains of Salmonella Typhi emphasizes the importance of continued surveillance and appropriate antibiotic stewardship, integrated into a global strategy to address antimicrobial resistance (AMR). Current empirical treatment guidelines are out of date and should be updated to respond to local trends in AMR, so as to guide treatment choices in the absence of robust diagnostics and laboratory facilities. In September 2017, the WHO Strategic Advisory Group of Experts (SAGE) immunization recommended the programmatic use of TCVs in high burden countries. Ongoing and future studies should aim to study the impact of these vaccines in a diverse range of setting and to support the deployment of TCVs in high-burden countries. Summary The advent of new generation TCVs offers us a practical and affordable public-health tool that – for the first time – can be integrated into routine childhood immunization programmes. In this review, we advocate for the deployment of TCVs in line with WHO recommendations, to improve child health and limit the spread of antibiotic-resistant S. Typhi.
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131
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Msefula CL, Olgemoeller F, Jambo N, Segula D, Van Tan T, Nyirenda TS, Nedi W, Kennedy N, Graham M, Henrion MYR, Baker S, Feasey N, Gordon M, Heyderman RS. Ascertaining the burden of invasive Salmonella disease in hospitalised febrile children aged under four years in Blantyre, Malawi. PLoS Negl Trop Dis 2019; 13:e0007539. [PMID: 31314752 PMCID: PMC6663031 DOI: 10.1371/journal.pntd.0007539] [Citation(s) in RCA: 8] [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: 01/24/2019] [Revised: 07/29/2019] [Accepted: 06/10/2019] [Indexed: 11/19/2022] Open
Abstract
Typhoid fever is endemic across sub-Saharan Africa. However, estimates of the burden of typhoid are undermined by insufficient blood volumes and lack of sensitivity of blood culture. Here, we aimed to address this limitation by exploiting pre-enrichment culture followed by PCR, alongside routine blood culture to improve typhoid case detection. We carried out a prospective diagnostic cohort study and enrolled children (aged 0-4 years) with non-specific febrile disease admitted to a tertiary hospital in Blantyre, Malawi from August 2014 to July 2016. Blood was collected for culture (BC) and real-time PCR after a pre-enrichment culture in tryptone soy broth and ox-bile. DNA was subjected to PCR for invA (Pan-Salmonella), staG (S. Typhi), and fliC (S. Typhimurium) genes. A positive PCR was defined as invA plus either staG or fliC (CT<29). IgM and IgG ELISA against four S. Typhi antigens was also performed. In total, 643 children (median age 1.3 years) with nonspecific febrile disease were enrolled; 31 (4.8%) were BC positive for Salmonella (n = 13 S. Typhi, n = 16 S. Typhimurium, and n = 2 S. Enteritidis). Pre-enrichment culture of blood followed by PCR identified a further 8 S. Typhi and 15 S. Typhimurium positive children. IgM and IgG titres to the S. Typhi antigen STY1498 (haemolysin) were significantly higher in children that were PCR positive but blood culture negative compared to febrile children with all other non-typhoid illnesses. The addition of pre-enrichment culture and PCR increased the case ascertainment of invasive Salmonella disease in children by 62-94%. These data support recent burden estimates that highlight the insensitivity of blood cultures and support the targeting of pre-school children for typhoid vaccine prevention in Africa. Blood culture with real-time PCR following pre-enrichment should be used to further refine estimates of vaccine effectiveness in typhoid vaccine trials.
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Affiliation(s)
- Chisomo L. Msefula
- Pathology Department, College of Medicine, University of Malawi, Blantyre, Malawi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- * E-mail:
| | - Franziska Olgemoeller
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Department of Paediatrics, Queen Elizabeth Central Hospital, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Ndaru Jambo
- Pathology Department, College of Medicine, University of Malawi, Blantyre, Malawi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- University of Liverpool, Liverpool, United Kingdom
| | - Dalitso Segula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Department of Internal Medicine, Queen Elizabeth Central Hospital, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Trinh Van Tan
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tonney S. Nyirenda
- Pathology Department, College of Medicine, University of Malawi, Blantyre, Malawi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Wilfred Nedi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Neil Kennedy
- Department of Paediatrics, Queen Elizabeth Central Hospital, College of Medicine, University of Malawi, Blantyre, Malawi
- Centre for Medical Education, Queens University, Belfast, United Kingdom
| | - Matthew Graham
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Marc Y. R. Henrion
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Stephen Baker
- The Department of Medicine, The University of Cambridge, Cambridge, United Kingdom
| | - Nicholas Feasey
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Melita Gordon
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- University of Liverpool, Liverpool, United Kingdom
| | - Robert S. Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- Division of Infection & Immunity, University College London, London, England, United Kingdom
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132
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Jo Y, Dowdy DW. The economic case for typhoid conjugate vaccines in countries with medium and high incidence of infection. THE LANCET. INFECTIOUS DISEASES 2019; 19:675-676. [PMID: 31130328 DOI: 10.1016/s1473-3099(19)30054-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Affiliation(s)
- Youngji Jo
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - David W Dowdy
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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Bilcke J, Antillón M, Pieters Z, Kuylen E, Abboud L, Neuzil KM, Pollard AJ, Paltiel AD, Pitzer VE. Cost-effectiveness of routine and campaign use of typhoid Vi-conjugate vaccine in Gavi-eligible countries: a modelling study. THE LANCET. INFECTIOUS DISEASES 2019; 19:728-739. [PMID: 31130329 PMCID: PMC6595249 DOI: 10.1016/s1473-3099(18)30804-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 12/10/2018] [Accepted: 12/14/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND Typhoid fever is a major cause of morbidity and mortality in low-income and middle-income countries. In 2017, WHO recommended the programmatic use of typhoid Vi-conjugate vaccine (TCV) in endemic settings, and Gavi, The Vaccine Alliance, has pledged support for vaccine introduction in these countries. Country-level health economic evaluations are now needed to inform decision-making. METHODS In this modelling study, we compared four strategies: no vaccination, routine immunisation at 9 months, and routine immunisation at 9 months with catch-up campaigns to either age 5 years or 15 years. For each of the 54 countries eligible for Gavi support, output from an age-structured transmission-dynamic model was combined with country-specific treatment and vaccine-related costs, treatment outcomes, and disability weights to estimate the reduction in typhoid burden, identify the strategy that maximised average net benefit (ie, the optimal strategy) across a range of country-specific willingness-to-pay (WTP) values, estimate and investigate the uncertainties surrounding our findings, and identify the epidemiological conditions under which vaccination is optimal. FINDINGS The optimal strategy was either no vaccination or TCV immunisation including a catch-up campaign. Routine vaccination with a catch-up campaign to 15 years of age was optimal in 38 countries, assuming a WTP value of at least US$200 per disability-adjusted life-year (DALY) averted, or assuming a WTP value of at least 25% of each country's gross domestic product (GDP) per capita per DALY averted, at a vaccine price of $1·50 per dose (but excluding Gavi's contribution according to each country's transition phase). This vaccination strategy was also optimal in 48 countries assuming a WTP of at least $500 per DALY averted, in 51 with assumed WTP values of at least $1000, in 47 countries assuming a WTP value of at least 50% of GDP per capita per DALY averted, and in 49 assuming a minimum of 100%. Vaccination was likely to be cost-effective in countries with 300 or more typhoid cases per 100 000 person-years. Uncertainty about the probability of hospital admission (and typhoid incidence and mortality) had the greatest influence on the optimal strategy. INTERPRETATION Countries should establish their own WTP threshold and consider routine TCV introduction, including a catch-up campaign when vaccination is optimal on the basis of this threshold. Obtaining improved estimates of the probability of hospital admission would be valuable whenever the optimal strategy is uncertain. FUNDING Bill & Melinda Gates Foundation, Research Foundation-Flanders, and the Belgian-American Education Foundation.
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Affiliation(s)
- Joke Bilcke
- Centre for Health Economics Research and Modeling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium.
| | - Marina Antillón
- Centre for Health Economics Research and Modeling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT, USA
| | - Zoë Pieters
- Centre for Health Economics Research and Modeling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium; Center for Statistics, I-Biostat, Hasselt University, Diepenbeek, Belgium
| | - Elise Kuylen
- Centre for Health Economics Research and Modeling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | - Linda Abboud
- Centre for Health Economics Research and Modeling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | - Kathleen M Neuzil
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the National Institute for Health Research Oxford Biomedical Research Centre, Oxford, UK
| | - A David Paltiel
- Department of Health Policy and Management, Yale School of Public Health, Yale University, New Haven, CT, USA
| | - Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT, USA.
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McDowell MA, Byrne AM, Mylona E, Johnson R, Sagfors A, Crepin VF, Lea S, Frankel G. The S. Typhi effector StoD is an E3/E4 ubiquitin ligase which binds K48- and K63-linked diubiquitin. Life Sci Alliance 2019; 2:2/3/e201800272. [PMID: 31142637 PMCID: PMC6545606 DOI: 10.26508/lsa.201800272] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/03/2019] [Accepted: 05/07/2019] [Indexed: 11/24/2022] Open
Abstract
Salmonella Typhi is estimated to cause 100,000–200,000 deaths annually, yet its infection strategy remains elusive. This article reports of the first Typhi-specific effector, which has an E3/E4 ubiquitin ligase activity and can uniquely bind K48- and K63-linked diubiquitin. Salmonella enterica (e.g., serovars Typhi and Typhimurium) relies on translocation of effectors via type III secretion systems (T3SS). Specialization of typhoidal serovars is thought to be mediated via pseudogenesis. Here, we show that the Salmonella Typhi STY1076/t1865 protein, named StoD, a homologue of the enteropathogenic Escherichia coli/enterohemorrhagic E. coli/Citrobacter rodentium NleG, is a T3SS effector. The StoD C terminus (StoD-C) is a U-box E3 ubiquitin ligase, capable of autoubiquitination in the presence of multiple E2s. The crystal structure of the StoD N terminus (StoD-N) at 2.5 Å resolution revealed a ubiquitin-like fold. In HeLa cells expressing StoD, ubiquitin is redistributed into puncta that colocalize with StoD. Binding assays showed that StoD-N and StoD-C bind the same exposed surface of the β-sheet of ubiquitin, suggesting that StoD could simultaneously interact with two ubiquitin molecules. Consistently, StoD interacted with both K63- (KD = 5.6 ± 1 μM) and K48-linked diubiquitin (KD = 15 ± 4 μM). Accordingly, we report the first S. Typhi–specific T3SS effector. We suggest that StoD recognizes and ubiquitinates pre-ubiquitinated targets, thus subverting intracellular signaling by functioning as an E4 enzyme.
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Affiliation(s)
| | - Alexander Mp Byrne
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Elli Mylona
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Rebecca Johnson
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Agnes Sagfors
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Valerie F Crepin
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Susan Lea
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
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Dasgupta S, Das S, Biswas A, Bhadra RK, Das S. Small alarmones (p)ppGpp regulate virulence associated traits and pathogenesis of Salmonella enterica serovar Typhi. Cell Microbiol 2019; 21:e13034. [PMID: 31013389 DOI: 10.1111/cmi.13034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/29/2019] [Accepted: 04/17/2019] [Indexed: 12/13/2022]
Abstract
How Salmonella enterica serovar Typhi (S. Typhi), an important human pathogen, survives the stressful microenvironments inside the gastrointestinal tract and within macrophages remains poorly understood. We report here that S. Typhi has a bonafide stringent response (SR) system, which is mediated by (p)ppGpp and regulates multiple virulence-associated traits and the pathogenicity of the S. Typhi Ty2 strain. In an iron overload mouse model of S. Typhi infection, the (p)ppGpp0 (Ty2ΔRelAΔSpoT) strain showed minimal systemic spread and no mortality, as opposed to 100% death of the mice challenged with the isogenic wild-type strain. Ty2ΔRelAΔSpoT had markedly elongated morphology with incomplete septa formation and demonstrated severely attenuated motility and chemotaxis due to the loss of flagella. Absence of the Vi-polysaccharide capsule rendered the mutant strain highly susceptible to complement-mediated lysis. The phenotypes of Ty2ΔRelAΔSpoT was contributed by transcriptional repression of several genes, including fliC, tviA, and ftsZ, as found by reverse transcriptase quantitative polymerase chain reaction and gene complementation studies. Finally, Ty2ΔRelAΔSpoT had markedly reduced invasion into intestinal epithelial cells and significantly attenuated survival within macrophages. To the best of our knowledge, this was the first study that addressed SR in S. Typhi and showed that (p)ppGpp was essential for optimal pathogenic fitness of the organism.
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Affiliation(s)
- Shreya Dasgupta
- Division of Clinical Medicine, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Sayan Das
- Division of Clinical Medicine, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Asim Biswas
- Division of Clinical Medicine, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Rupak K Bhadra
- Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Santasabuj Das
- Division of Clinical Medicine, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
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Arora P, Thorlund K, Brenner DR, Andrews JR. Comparative accuracy of typhoid diagnostic tools: A Bayesian latent-class network analysis. PLoS Negl Trop Dis 2019; 13:e0007303. [PMID: 31067228 PMCID: PMC6527309 DOI: 10.1371/journal.pntd.0007303] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 05/20/2019] [Accepted: 03/13/2019] [Indexed: 11/19/2022] Open
Abstract
Background Typhoid fevers are infections caused by the bacteria Salmonella enterica serovar Typhi (Salmonella Typhi) and Paratyphi A, B and C (Salmonella Paratyphi). Approximately 17.8 million incident cases of typhoid fever occur annually, and incidence is highest in children. The accuracy of current diagnostic tests of typhoid fever is poorly understood. We aimed to determine the comparative accuracy of available tests for the pediatric population. Methods We first conducted a systematic literature review to identify studies that compared diagnostic tests for typhoid fever in children (aged ≤15 years) to blood culture results. We applied a Bayesian latent-class extension to a network meta-analysis model. We modelled known diagnostic properties of bone marrow culture and the relationship between bone marrow and blood culture as informative priors in a Bayesian framework. We tested sensitivities for the proportion of negative blood samples that were false as well as bone marrow sensitivity and specificity. Results We found 510 comparisons from 196 studies and 57 specific to the pediatric population. IgM-based tests outperformed their IgG-based counterparts for ELISA and Typhidot tests. The lateral flow IgG test performed comparatively well with 92% sensitivity (72% to 98% across scenario analyses) and 94% specificity. The most sensitive test of those investigated for the South Asian pediatric population was the Reverse Passive Hemagglutination Assay with 99% sensitivity (98% - 100% across scenario analyses). Adding a Widal slide test to other typhoid diagnostics did not substantially improve diagnostic performance beyond the single test alone, however, a lateral flow-based IgG rapid test combined with the typhoid/paratyphoid (TPT) assay yielded improvements in sensitivity without substantial declines in specificity and was the best performing combination test in this setting. Conclusion In the pediatric population, lateral-flow IgG, TPT and Reverse Passive Hemagglutination tests had high diagnostic accuracy compared to other diagnostics. Combinations of tests may provide a feasible option to increase diagnostic sensitivity. South Asia has the most informed set of data on typhoid diagnostic testing accuracy, and the evidence base in other important regions needs to be expanded. Typhoid fever is an infection caused by the bacterium Salmonella Typhi. Typhoid fever is rare in developed countries but remains high in the developing world. Effective treatment is available but accurate diagnosis of typhoid fever is challenging as typhoid fever can be difficult to distinguish from other infections. Bone marrow culture is the most accurate diagnostic test for typhoid fever however is invasive and not feasible in many settings. New vaccines for typhoid and the need for improved estimates of burden increases the demand for improved understanding of diagnostic accuracy. Comparing the diagnostic accuracy of tests for typhoid fever is challenging as head-to-head studies are few. We applied newly developed methods for comparative evaluation of diagnostic tests for typhoid fever in children using statistical approaches that allowed for the proper incorporation of uncertainty and comparison of tests that had not been compared directly. The lateral-flow IgG, TPT and Reverse Passive Hemagglutination tests all had good diagnostic accuracy compared to other diagnostics. Combinations of tests may provide a feasible option to increase diagnostic sensitivity. Finally, while South Asia has the most informed set of data on typhoid diagnostic testing accuracy, the evidence base in other important regions needs to be expanded.
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Affiliation(s)
- Paul Arora
- Dalla Lana School of Public Health, Division of Epidemiology, University of Toronto, Ontario, Canada
- * E-mail:
| | - Kristian Thorlund
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Darren R. Brenner
- Departments of Oncology and Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jason R. Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, United States of America
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Temporal, spatial and household dynamics of Typhoid fever in Kasese district, Uganda. PLoS One 2019; 14:e0214650. [PMID: 31009473 PMCID: PMC6476469 DOI: 10.1371/journal.pone.0214650] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 03/18/2019] [Indexed: 11/19/2022] Open
Abstract
Typhoid fever affects 21 million people globally, 1% of whom succumb to the disease. The social, economic and public health consequences of this disease disproportionately affect people in Africa and Asia. In order to design context specific prevention strategies, we need to holistically characterise outbreaks in these settings. In this study, we used retrospective data (2013–2016) at national and district level to characterise temporal and spatial dynamics of Typhoid fever outbreaks using time series and spatial analysis. We then selected cases matched with controls to investigate household socio-economic drivers using a conditional logistic regression model, and also developed a Typhoid fever outbreak-forecasting framework. The incidence rate of Typhoid fever at national and district level was ~ 160 and 60 cases per 100,000 persons per year, respectively, predominantly in urban areas. In Kasese district, Bwera sub-county registered the highest incidence rate, followed by Kisinga, Kitholhu and Nyakiyumbu sub-counties. The male-female case ratio at district level was at 1.68 and outbreaks occurred between the 20th and 40th week (May and October) each year following by seven weeks of precipitation. Our forecasting framework predicted outbreaks better at the district level rather than national. We identified a temporal window associated with Typhoid fever outbreaks in Kasese district, which is preceded by precipitation, flooding and displacement of people. We also observed that areas with high incidence of Typhoid fever also had high environmental contamination with limited water treatment. Taken together with the forecasting framework, this knowledge can inform the development of specific control and preparedness strategies at district and national level.
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Characteristics of regulatory T-cell populations before and after Ty21a typhoid vaccination in children and adults. Clin Immunol 2019; 203:14-22. [PMID: 30953793 DOI: 10.1016/j.clim.2019.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 03/10/2019] [Accepted: 04/02/2019] [Indexed: 11/23/2022]
Abstract
Typhoid fever, caused by the pathogen Salmonella enterica serovar Typhi (S. Typhi), is a serious global health concern. Challenge studies with wild type S. Typhi identified associations between gut-homing regulatory T cells (Treg) and development of typhoid disease. Whether oral live-attenuated Ty21a vaccination induces gut-homing Treg remains unclear. Here, we analyze pediatric and adult Treg pre- and post-Ty21a vaccination in an autologous S. Typhi-antigen presentation model to address this knowledge gap. We show that peripheral memory Treg populations change from childhood to adulthood, but not following Ty21a vaccination. Unsupervised dimensionality reduction with t-distributed stochastic neighbor embedding (tSNE) identifies homing, memory, and functional features which evidence age-associated maturation of multifunctional S. Typhi-responsive Treg, which were not impacted by Ty21a vaccination. These findings improve understanding of pediatric regulatory T cells, while identifying age-related differences in S. Typhi-responsive Treg, which may aid in the development of improved pediatric vaccination strategies against S. Typhi.
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139
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Stanaway JD, Reiner RC, Blacker BF, Goldberg EM, Khalil IA, Troeger CE, Andrews JR, Bhutta ZA, Crump JA, Im J, Marks F, Mintz E, Park SE, Zaidi AKM, Abebe Z, Abejie AN, Adedeji IA, Ali BA, Amare AT, Atalay HT, Avokpaho EFGA, Bacha U, Barac A, Bedi N, Berhane A, Browne AJ, Chirinos JL, Chitheer A, Dolecek C, El Sayed Zaki M, Eshrati B, Foreman KJ, Gemechu A, Gupta R, Hailu GB, Henok A, Hibstu DT, Hoang CL, Ilesanmi OS, Iyer VJ, Kahsay A, Kasaeian A, Kassa TD, Khan EA, Khang YH, Magdy Abd El Razek H, Melku M, Mengistu DT, Mohammad KA, Mohammed S, Mokdad AH, Nachega JB, Naheed A, Nguyen CT, Nguyen HLT, Nguyen LH, Nguyen NB, Nguyen TH, Nirayo YL, Pangestu T, Patton GC, Qorbani M, Rai RK, Rana SM, Ranabhat CL, Roba KT, Roberts NLS, Rubino S, Safiri S, Sartorius B, Sawhney M, Shiferaw MS, Smith DL, Sykes BL, Tran BX, Tran TT, Ukwaja KN, Vu GT, Vu LG, Weldegebreal F, Yenit MK, Murray CJL, Hay SI. The global burden of typhoid and paratyphoid fevers: a systematic analysis for the Global Burden of Disease Study 2017. THE LANCET. INFECTIOUS DISEASES 2019; 19:369-381. [PMID: 30792131 PMCID: PMC6437314 DOI: 10.1016/s1473-3099(18)30685-6] [Citation(s) in RCA: 384] [Impact Index Per Article: 76.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 10/17/2018] [Accepted: 11/01/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Efforts to quantify the global burden of enteric fever are valuable for understanding the health lost and the large-scale spatial distribution of the disease. We present the estimates of typhoid and paratyphoid fever burden from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, and the approach taken to produce them. METHODS For this systematic analysis we broke down the relative contributions of typhoid and paratyphoid fevers by country, year, and age, and analysed trends in incidence and mortality. We modelled the combined incidence of typhoid and paratyphoid fevers and split these total cases proportionally between typhoid and paratyphoid fevers using aetiological proportion models. We estimated deaths using vital registration data for countries with sufficiently high data completeness and using a natural history approach for other locations. We also estimated disability-adjusted life-years (DALYs) for typhoid and paratyphoid fevers. FINDINGS Globally, 14·3 million (95% uncertainty interval [UI] 12·5-16·3) cases of typhoid and paratyphoid fevers occurred in 2017, a 44·6% (42·2-47·0) decline from 25·9 million (22·0-29·9) in 1990. Age-standardised incidence rates declined by 54·9% (53·4-56·5), from 439·2 (376·7-507·7) per 100 000 person-years in 1990, to 197·8 (172·0-226·2) per 100 000 person-years in 2017. In 2017, Salmonella enterica serotype Typhi caused 76·3% (71·8-80·5) of cases of enteric fever. We estimated a global case fatality of 0·95% (0·54-1·53) in 2017, with higher case fatality estimates among children and older adults, and among those living in lower-income countries. We therefore estimated 135·9 thousand (76·9-218·9) deaths from typhoid and paratyphoid fever globally in 2017, a 41·0% (33·6-48·3) decline from 230·5 thousand (131·2-372·6) in 1990. Overall, typhoid and paratyphoid fevers were responsible for 9·8 million (5·6-15·8) DALYs in 2017, down 43·0% (35·5-50·6) from 17·2 million (9·9-27·8) DALYs in 1990. INTERPRETATION Despite notable progress, typhoid and paratyphoid fevers remain major causes of disability and death, with billions of people likely to be exposed to the pathogens. Although improvements in water and sanitation remain essential, increased vaccine use (including with typhoid conjugate vaccines that are effective in infants and young children and protective for longer periods) and improved data and surveillance to inform vaccine rollout are likely to drive the greatest improvements in the global burden of the disease. FUNDING Bill & Melinda Gates Foundation.
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Kumar Y, Mani KR, Tahlan AK. Analysis of Salmonella enterica Serovar Typhi by Outer Membrane Protein (OMP) Profiling, Random Amplification of Polymorphic DNA (RAPD) and Pulsed Field Gel Electrophoresis (PFGE). Trop Life Sci Res 2019; 30:57-71. [PMID: 30847033 PMCID: PMC6396889 DOI: 10.21315/tlsr2019.30.1.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A number of countries, including developed countries, still have typhoid fever as a major problem resulting in frequent outbreaks. The importance of controlling spread of typhoid fever is well known and necessitates periodic studies to delineate epidemiological relationships. Although phage typing remains to be the preferred conventional method for characterisation of typhoid bacilli, it is of limited use due to prevalence of few predominant phage types in the country like India. Therefore, an effort has been made to assess three molecular methods [Outer Membrane Protein (OMP) Profiling, Random Amplification of Polymorphic DNA (RAPD) and Pulsed Field Gel Electrophoresis (PFGE)] for typing of Salmonella enterica serovar Typhi. 128 Salmonella enterica serovar Typhi isolates were identified using biotyping and serotyping followed by antimicrobial susceptibility testing. These isolates were further subjected to OMP analysis, RAPD and PFGE. PFGE (114 unique clusters) was found to be the most discriminatory method followed by RAPD (94 unique clusters) and OMP profiling (50 unique clusters). Multidrug resistant strains were well discriminated by all three methods used in the study. PFGE still remains the most preferred method for detailed epidemiological investigations. However, random amplification of polymorphic DNA and outer membrane protein profiling can also be considered for molecular discrimination of the isolates in the laboratories lacking high-end facilities.
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Affiliation(s)
- Yashwant Kumar
- National Salmonella and Escherichia Centre, Central Research Institute, Kasauli-173204, Himachal Pradesh, India
| | - Kavaratty Raju Mani
- National Salmonella and Escherichia Centre, Central Research Institute, Kasauli-173204, Himachal Pradesh, India
| | - Ajay Kumar Tahlan
- National Salmonella and Escherichia Centre, Central Research Institute, Kasauli-173204, Himachal Pradesh, India
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141
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Affiliation(s)
- Andrew J Pollard
- Oxford Vaccine Group, University of Oxford, and the National Institute for Health Research Oxford Biomedical Research Centre, United Kingdom
| | - Anthony A Marfin
- Center for Vaccine Innovation and Access, PATH, Seattle, Washington
| | - Kathleen M Neuzil
- Center for Vaccine Development and Global Health at the University of Maryland School of Medicine, Baltimore, MD
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142
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Abstract
BACKGROUND Contemporary incidence estimates of typhoid fever are needed to guide policy decisions and control measures and to improve future epidemiological studies. METHODS We systematically reviewed 3 databases (Ovid Medline, PubMed, and Scopus) without restriction on age, country, language, or time for studies reporting the incidence of blood culture-confirmed typhoid fever. Outbreak, travel-associated, and passive government surveillance reports were excluded. We performed a meta-analysis using a random-effects model to calculate estimates of pooled incidence, stratifying by studies that reported the incidence of typhoid fever and those that estimated incidence by using multipliers. RESULTS Thirty-three studies were included in the analysis. There were 26 study sites from 16 countries reporting typhoid cases from population-based incidence studies, and 17 sites in 9 countries used multipliers to account for underascertainment in sentinel surveillance data. We identified Africa and Asia as regions with studies showing high typhoid incidence while noting considerable variation of typhoid incidence in time and place, including in consecutive years at the same location. Overall, more recent studies reported lower typhoid incidence compared to years prior to 2000. We identified variation in the criteria for collecting a blood culture, and among multiplier studies we identified a lack of a standardization for the types of multipliers being used to estimate incidence. CONCLUSIONS Typhoid fever incidence remains high at many sites. Additional and more accurate typhoid incidence studies are needed to support country decisions about typhoid conjugate vaccine adoption. Standardization of multiplier types applied in multiplier studies is recommended.
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Affiliation(s)
| | - Chuen Yen Hong
- Centre for International Health, University of Otago, New Zealand
| | - John A Crump
- Centre for International Health, University of Otago, New Zealand
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143
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Rudolph ME, McArthur MA, Magder LS, Barnes RS, Chen WH, Sztein MB. Age-Associated Heterogeneity of Ty21a-Induced T Cell Responses to HLA-E Restricted Salmonella Typhi Antigen Presentation. Front Immunol 2019; 10:257. [PMID: 30886613 PMCID: PMC6409365 DOI: 10.3389/fimmu.2019.00257] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 01/29/2019] [Indexed: 01/15/2023] Open
Abstract
Human-restricted Salmonella enterica serovar Typhi (S. Typhi) is the causative agent of typhoid fever—a life-threatening disease of great global health significance, particularly in the developing world. Ty21a is an oral live-attenuated vaccine that protects against the development of typhoid disease in part by inducing robust T cell responses, among which multifunctional CD8+ cytotoxic T lymphocytes (CTL) play an important role. Following Ty21a vaccination, a significant component of adult CTL have shown to be targeted to S. Typhi antigen presented by the conserved major histocompatibility complex (MHC) class Ib molecule, human leukocyte antigen-E (HLA-E). S. Typhi challenge studies have shown that baseline, multifunctional HLA-E responsive T cells are associated with protection from, and delayed onset of, typhoid disease. However, despite the overwhelming burden of typhoid fever in school-aged children, and due to limited availability of pediatric samples, incomplete information is available regarding these important HLA-E-restricted responses in children, even though studies have shown that younger children may be less likely to develop protective cell mediated immune (CMI) responses than adults following vaccination. To address this gap, we have studied this phenomenon in depth by using mass cytometry to analyze pediatric and adult T cell responses to HLA-E-restricted S. Typhi antigen presentation, before and after Ty21a vaccination. Herein, we show variable responses in all age strata following vaccination among T effector memory (TEM) and T effector memory CD45RA+ (TEMRA) cells based on conventional gating analysis. However, by utilizing the dimensionality reduction tool tSNE (t-distributed Stochastic Neighbor Embedding), we are able to identify diverse, highly multifunctional gut-homing- TEM and TEMRA clusters of cells which are more abundant in adult and older pediatric participants than in younger children. These findings highlight a potential age-associated maturation of otherwise conserved HLA-E restricted T cell responses. Such insights, coupled with the marked importance of multifunctional T cell responses to combat infection, may better inform future pediatric vaccination strategies against S. Typhi and other infectious diseases.
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Affiliation(s)
- Mark E Rudolph
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States.,Molecular Microbiology and Immunology Department, University of Maryland Graduate Program in Life Sciences, Baltimore, MD, United States
| | - Monica A McArthur
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Laurence S Magder
- Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Robin S Barnes
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Wilbur H Chen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Marcelo B Sztein
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States.,Molecular Microbiology and Immunology Department, University of Maryland Graduate Program in Life Sciences, Baltimore, MD, United States.,Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
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Abstract
Salmonella enterica subspecies enterica serovar Typhi (Salmonella Typhi) is the cause of typhoid fever and a human host-restricted organism. Our understanding of the global burden of typhoid fever has improved in recent decades, with both an increase in the number and geographic representation of high-quality typhoid fever incidence studies, and greater sophistication of modeling approaches. The 2017 World Health Organization Strategic Advisory Group of Experts on Immunization recommendation for the introduction of typhoid conjugate vaccines for infants and children aged >6 months in typhoid-endemic countries is likely to require further improvements in our understanding of typhoid burden at the global and national levels. Furthermore, the recognition of the critical and synergistic role of water and sanitation improvements in concert with vaccine introduction emphasize the importance of improving our understanding of the sources, patterns, and modes of transmission of Salmonella Typhi in diverse settings.
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Affiliation(s)
- John A Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
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146
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In silico epitope identification of unique multidrug resistance proteins from Salmonella Typhi for vaccine development. Comput Biol Chem 2019; 78:74-80. [DOI: 10.1016/j.compbiolchem.2018.11.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 10/14/2018] [Accepted: 11/20/2018] [Indexed: 12/12/2022]
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147
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von Asmuth EGJ, Brockhoff HJ, Wallinga J, Visser LG. S. typhi Vi capsular polysaccharide vaccine-induced humoral immunity in travellers with immunosuppressive therapy for rheumatoid disease. J Travel Med 2019; 26:5077767. [PMID: 30137469 DOI: 10.1093/jtm/tay073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/18/2018] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Typhoid fever is a global health problem, causing significant morbidity and mortality. Currently, the most widely used vaccine is the typhoid Vi capsular polysaccharide (Vi-PS) vaccine. While epidemiological studies on its efficacy have been performed in children in endemic countries, there are no efficacy studies evaluating its use in travel medicine. Response to vaccination may differ in travellers receiving immunosuppressive therapy. This study investigates the humoral response to Vi-PS vaccination in travellers receiving immunosuppressive therapy for rheumatoid disease. METHODS We recruited patients from the LUMC rheumatology outpatient clinic and travellers from the travel clinic who had previously received Vi-PS vaccination and also immunosuppressive therapy for rheumatoid disease. We analysed blood samples acquired from 42 patients over a period of 3 years. We estimated the length of persistence of protective titres using the survival analysis using multiple cut-off values for protection and measured titre half-life and the influence of immunosuppressive medication on titre half-life using mixed models. RESULTS Anti-Vi-PS antibody levels stayed above 10 EU/ml for a mean of 13.3 years, above 15 EU/ml for a mean of 10.1 years and above 20 EU/ml for a mean of 8.6 years after Vi-PS vaccination. Titre half-life was 7.5 years (95% CI 5.0-14.7 years, P < 0.001). No significant influence of medication on titre half-life was found. CONCLUSION Both persistence of protective antibody titres and titre half-life are longer than expected based on other studies. This warrants further study in adult volunteers, both in healthy individuals and patients suffering from rheumatoid disease.
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Affiliation(s)
- E G J von Asmuth
- Department of Infectious Diseases, LUMC, Leiden, The Netherlands
| | | | - J Wallinga
- Department of Medical Statistics and Bio-informatics, LUMC, Leiden, The Netherlands
| | - L G Visser
- Department of Infectious Diseases, LUMC, Leiden, The Netherlands
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148
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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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Chowdhury R, Das S, Ta A, Das S. Epithelial invasion by Salmonella Typhi using STIV-Met interaction. Cell Microbiol 2018; 21:e12982. [PMID: 30426648 DOI: 10.1111/cmi.12982] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 11/01/2018] [Accepted: 11/09/2018] [Indexed: 12/20/2022]
Abstract
Typhoid is a life-threatening febrile illness that affects ~24.2 million people worldwide and is caused by the intracellular bacteria Salmonella Typhi (S. Typhi). Intestinal epithelial invasion by S. Typhi is essential for the establishment of successful infection and is traditionally believed to depend on Salmonella pathogenicity island 1-encoded type 3 secretion system 1 (T3SS-1). We had previously reported that bacterial outer membrane protein T2942/STIV functions as a standalone invasin and contributes to the pathogenesis of S. Typhi by promoting epithelial invasion independent of T3SS-1 (Cell Microbiol, 2015). Here, we show that STIV, by using its 20-amino-acid extracellular loop, interacts with receptor tyrosine kinase, Met, of host intestinal epithelial cells. This interaction leads to Met phosphorylation and activation of a downstream signalling cascade, involving Src, phosphatidylinositol 3-kinase/Akt, and Rac1, which culminates into localized actin polymerisation and bacterial engulfment by the cell. Inhibition of Met tyrosine kinase activity severely limited intestinal invasion and systemic infection by S. Typhi in vivo, highlighting the importance of this invasion pathway in disease progression. This is the first report elucidating the mechanism of T3SS-1-independent epithelial invasion of S. Typhi, and this crucial host-pathogen interaction may be targeted therapeutically to restrict pathogenesis.
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Affiliation(s)
- Rimi Chowdhury
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Sayan Das
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Atri Ta
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Santasabuj Das
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, India
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150
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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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