About this item:

69 Views | 24 Downloads

Author Notes:

Dr Kristen Aiemjoy, Division of Epidemiology, Department of Public Health Sciences, University of California Davis School of Medicine, Davis, CA 95616, USA. Email: kaiemjoy@ucdavis.edu

KA, JCS, SKS, FNQ, SPL, DOG, and JRA conceptualised the study. KA, JCS, PT, SKS, FNQ, SPL, DOG, RCC, and JRA developed the methodology. All authors did the investigation. KA and JCS did the data analysis and data visualisation. AF, MML, VK, AH, SEP, RMZ, FM, EO-D, YA-S, and MO supervised enrolment and data collection for SETA-Ghana study. JCS, ASC, MSK, MSIS, SMAS, NA, KV, NK, YL, NM, and MA curated the data. SPL, DOG, FNQ, SKS, RCC, and JRA acquired the funding. KA, JCS, ASC, KV, RS, DT, SSa, SJM, IFD, DOG, SKS, FNQ, and JRA did the project administration. SSa, SKS, DT, SPL, DOG, FNQ, RCC, and JRA supervised data collection and laboratory work. KA, JCS, RCC, and JRA wrote the original draft of the manuscript. All authors reviewed and edited the manuscript. KA and JCS accessed and verified the data. All authors had full access to all the data in the study and had final responsibility for the decision to submit for publication.

This study was supported by a grant from Bill & Melinda Gates Foundation (INV-000572). Research on Vi antibody responses in Nepal was supported by a grant from the National Institutes of Health National Institute of Allergy and Infectious Diseases (R01AI134814). We would like to acknowledge the essential contributions of field and laboratory teams in Bangladesh: Sultana Aflatun Rubana, Raktim Das, Khairun Naher, Kanis Fatema, Shamima Sultana, Masrufa Akhter, Jarin Sultana, Sathi Akter, Kristina Bain, Lima Akter, Shaswati Gain, Rehana Akter, Morium Akter, Aklima Akter, Khandokar Rehana, Rasheda Khan; Nepal: Sudan Maharjan, Lok Raj Bhatt, Natasha Shrestha, Shishir Ranjit, Anil Khanal, Bipin Khadka, Suman Shrestha, Pusp Raj Bhatt; and Pakistan teams: Kosar Riaz, Shazia Maqsood, Hira Asghar, Naik Banu, Afshan Piyar Ali, Hasina Wajid, Khalida Gul, Salima Shah, Samrina Karim, Faisal Hussain; as well as Caryn Bern and Alexander Yu. We are extremely grateful to all the study participants for their interest and valuable time. Finally, we would like to acknowledge the foundational contributions of Jan van Eijkeren to developing the seroincidence models and advancing methods to incorporate biological and measurement noise. The findings and conclusions of this report are those of the authors and do not necessarily represent the official position, policies, or views of the US Centers for Disease Control and Prevention and the Agency for Toxic Substances and Disease Registry.

We declare no competing interests.

Subjects:

Keywords:

  • Bangladesh
  • Bayes Theorem
  • Child
  • Cross-Sectional Studies
  • Humans
  • Incidence
  • Salmonella
  • Typhoid Fever

Estimating typhoid incidence from community-based serosurveys: a multicohort study

Show all authors Show less authors

Tools:

Journal Title:

The Lancet Microbe

Volume:

Volume 3, Number 8

Publisher:

, Pages e578-e587

Type of Work:

Article | Final Publisher PDF

Abstract:

Background: The incidence of enteric fever, an invasive bacterial infection caused by typhoidal Salmonellae (Salmonella enterica serovars Typhi and Paratyphi), is largely unknown in regions without blood culture surveillance. The aim of this study was to evaluate whether new diagnostic serological markers for typhoidal Salmonella can reliably estimate population-level incidence. Methods: We collected longitudinal blood samples from patients with blood culture-confirmed enteric fever enrolled from surveillance studies in Bangladesh, Nepal, Pakistan, and Ghana between 2016 and 2021 and conducted cross-sectional serosurveys in the catchment areas of each surveillance site. We used ELISAs to measure quantitative IgA and IgG antibody responses to hemolysin E and S Typhi lipopolysaccharide. We used Bayesian hierarchical models to fit two-phase power-function decay models to the longitudinal antibody responses among enteric fever cases and used the joint distributions of the peak antibody titres and decay rate to estimate population-level incidence rates from cross-sectional serosurveys. Findings: The longitudinal antibody kinetics for all antigen-isotypes were similar across countries and did not vary by clinical severity. The seroincidence of typhoidal Salmonella infection among children younger than 5 years ranged between 58·5 per 100 person-years (95% CI 42·1–81·4) in Dhaka, Bangladesh, to 6·6 per 100 person-years (4·3–9·9) in Kavrepalanchok, Nepal, and followed the same rank order as clinical incidence estimates. Interpretation: The approach described here has the potential to expand the geographical scope of typhoidal Salmonella surveillance and generate incidence estimates that are comparable across geographical regions and time. Funding: Bill & Melinda Gates Foundation. Translations: For the Nepali, Bengali and Urdu translations of the abstract see Supplementary Materials section.

Copyright information:

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license

This is an Open Access work distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
Export to EndNote