The Severe Typhoid Fever in Africa Program: Study Design and Methodology to Assess Disease Severity, Host Immunity, and Carriage Associated With Invasive Salmonellosis

• Type of Material: Article
• Authors: Se Eun Park, International Vaccine Institute; Trevor Toy, International Vaccine Institute; Ligia Maria Cruz Espinoza, International Vaccine Institute; Ursula Panzner, International Vaccine Institute; Ondari D Mogeni, International Vaccine Institute; Justin Im, International Vaccine Institute; Nimesh Poudyal, International Vaccine Institute; Gi Deok Pak, International Vaccine Institute; Hyeongwon Seo, International Vaccine Institute; Yun Chon, International Vaccine Institute; Heidi Schutt-Gerowitt, International Vaccine Institute; Vittal Mogasale, International Vaccine Institute; Enusa Ramani, International Vaccine Institute; Ayan Dey, International Vaccine Institute; Ju Yeong Park, International Vaccine Institute; Jong-Hoon Kim, International Vaccine Institute; Hye Jin Seo, International Vaccine Institute; Hyon Jin Jeon, International Vaccine Institute; Robert F Breiman, Emory University; Eric Mintz, Emory University
• Language: English
• Date: 2019-11-15
• Publisher: Oxford University Press (OUP): Policy B - Oxford Open Option C
• Publication Version: Final Published Version
• Copyright Statement: © 2019 The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1093/cid/ciz715
• Title of Journal or Parent Work: Clinical Infectious Diseases
• ISSN: 1058-4838
• Volume: 69
• Issue: Supplement_6
• Start Page: S422
• End Page: S434
• Grant/Funding Information: The International Vaccine Institute acknowledges its donors including the Republic of Korea and the Swedish International Development Cooperation Agency.; This research was funded by the Bill & Melinda Gates Foundation [OPP1127988].; This article was published as part of the supplement “Severe Typhoid Fever in Africa (SETA) Program” sponsored by the International Vaccine Institute.; This publication was made possible through a grant from the Bill & Melinda Gates Foundation [OPP1201031].
• Keywords: Severe typhoid fever; sub-Saharan Africa; GLOBAL BURDEN; Immunology; invasive Salmonellosis; Life Sciences & Biomedicine; Infectious Diseases; Microbiology; surveillance protocol; SURVEILLANCE; DRUG-RESISTANCE; Science & Technology; host immunity and carriage
• Research Categories: Health Sciences, Public Health; Health Sciences, Medicine and Surgery

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.