@article{b3ddb06ad6f84080a65c88fcd29722a3,
title = "Estimating typhoid incidence from community-based serosurveys: a multicohort study",
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.",
author = "Kristen Aiemjoy and Seidman, {Jessica C.} and Senjuti Saha and Munira, {Sira Jam} and {Islam Sajib}, {Mohammad Saiful} and Sium, {Syed Muktadir Al} and Anik Sarkar and Nusrat Alam and Zahan, {Farha Nusrat} and Kabir, {Md Shakiul} and Dipesh Tamrakar and Krista Vaidya and Rajeev Shrestha and Jivan Shakya and Nishan Katuwal and Sony Shrestha and Yousafzai, {Mohammad Tahir} and Junaid Iqbal and Dehraj, {Irum Fatima} and Yasmin Ladak and Noshi Maria and Mehreen Adnan and Sadaf Pervaiz and Carter, {Alice S.} and Longley, {Ashley T.} and Clare Fraser and Ryan, {Edward T.} and Ariana Nodoushani and Alessio Fasano and Leonard, {Maureen M.} and Victoria Kenyon and Bogoch, {Isaac I.} and Jeon, {Hyon Jin} and Andrea Haselbeck and Park, {Se Eun} and Zellweger, {Rapha{\"e}l M.} and Florian Marks and Ellis Owusu-Dabo and Yaw Adu-Sarkodie and Michael Owusu and Peter Teunis and Luby, {Stephen P.} and Garrett, {Denise O.} and Qamar, {Farah Naz} and Saha, {Samir K.} and Charles, {Richelle C.} and Andrews, {Jason R.}",
note = "Funding Information: 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. Funding Information: 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. Publisher Copyright: {\textcopyright} 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license",
year = "2022",
month = aug,
day = "1",
doi = "https://doi.org/10.1016/S2666-5247(22)00114-8",
language = "English",
volume = "3",
pages = "e578--e587",
journal = "The Lancet. Microbe",
issn = "2666-5247",
publisher = "Elsevier Ltd",
number = "8",
}