{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T07:55:14Z","timestamp":1768463714145,"version":"3.49.0"},"posted":{"date-parts":[[2026,1,13]]},"group-title":"Infectious Diseases (except HIV\/AIDS)","reference-count":40,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,1,13]],"date-time":"2026-01-13T00:00:00Z","timestamp":1768262400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,1,13]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>\n                    Enteric fever, caused by\n                    <jats:italic>Salmonella<\/jats:italic>\n                    Typhi or Paratyphi, is a major public health issue in low-and middle-income countries. Accurate burden estimation is hampered by limited microbiological facilities and low sensitivity of blood culture tests. Serosurveillance offers a scalable alternative to address these challenges. This study estimated the seroincidence of enteric fever in Bangladesh using cross-sectional rapid serosurveys.\n                  <\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>School-based surveys (January-June 2022) were conducted in Chattogram, Dinajpur, Sylhet, Satkhira, and Faridpur, and community-based surveys (July 2019-November 2021) were conducted in Dhaka and Mirzapur. Blood samples (dried blood spots or venous blood) were collected and tested for anti-Hemolysin E IgG responses using a kinetic Enzyme-linked Immunosorbent Assay. Seroincidence was estimated using a maximum likelihood approach based on peak antibody titers and decay rates, modelled from blood-culture confirmed enteric fever cases in Bangladesh.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Findings<\/jats:title>\n                  <jats:p>A total of 2,969 participants aged 0-22 years were enrolled, with 75.5% aged 5-15 years. Seroincidence rates (per 100 person-years) were highest in Dhaka (33.1; 95% confidence interval [CI], 29.0-37.9), followed by Mirzapur (19.5; 95%CI, 17.4-21.7) and Chattogram (17.1; 95% CI, 15.0-19.4), and the lowest in Faridpur (11.1; 95%CI, 9.6-12.7). The under 5 age group exhibited higher rates in Dhaka (40.3; 95%CI, 32.1-50.7) and Mirzapur (26.1; 95%CI, 21.0-32.4) compared to older age groups. Seroincidence was elevated in areas with higher population density.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>This study highlights a substantial burden of enteric fever infections across Bangladesh. These provide important evidence to guide post-introduction monitoring and optimization of the typhoid conjugate vaccine program in the national immunization schedule.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Key points<\/jats:title>\n                  <jats:p>This study provides the first multi-site, rapid seroincidence estimates of typhoid and paratyphoid fever across diverse urban and rural settings in Bangladesh, revealing a substantial and previously under-recognized burden, particularly among young children. By measuring antibody responses using a targeted serologic blood test and applying a novel analytical approach based on Bangladesh-specific antibody kinetics to cross-sectional school- and community-based surveys, it addresses critical gaps left by blood culture\u2013based surveillance, which is limited in coverage and sensitivity. Our findings demonstrate that scalable serosurveillance can reliably capture population-level transmission intensity where routine diagnostics are unavailable. These results directly inform post-introduction monitoring and optimization of the typhoid conjugate vaccine program and provide a practical framework for burden estimation and vaccine policy decision-making in other low-resource settings.<\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.01.11.26343883","type":"posted-content","created":{"date-parts":[[2026,1,13]],"date-time":"2026-01-13T18:10:20Z","timestamp":1768327820000},"source":"Crossref","is-referenced-by-count":0,"title":["Estimating enteric fever seroincidence in Bangladesh using rapid serosurveys"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4067-5331","authenticated-orcid":false,"given":"Sira Jam","family":"Munira","sequence":"first","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Naito","family":"Kanon","sequence":"additional","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nahidul","family":"Islam","sequence":"additional","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Md. Shakiul","family":"Kabir","sequence":"additional","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anik","family":"Sarkar","sequence":"additional","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shamsul Alam","family":"Polash","sequence":"additional","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hafizur","family":"Rahman","sequence":"additional","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alice S.","family":"Carter","sequence":"additional","affiliation":[{"name":"Sabin Vaccine Institute, Washington, DC, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Richelle C.","family":"Charles","sequence":"additional","affiliation":[{"name":"Massachusetts General Hospital, Harvard Medical School, Harvard T.H. Chan School of Public Health, Boston, MA, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jason R.","family":"Andrews","sequence":"additional","affiliation":[{"name":"Stanford University, Stanford, CA, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stephen P.","family":"Luby","sequence":"additional","affiliation":[{"name":"Stanford University, Stanford, CA, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1886-2699","authenticated-orcid":false,"given":"Kristen","family":"Aiemjoy","sequence":"additional","affiliation":[{"name":"University of California Davis School of Medicine, Department of Public Health Sciences, Davis, CA, USA; Mahidol University Faculty of Tropical Medicine, Department of Microbiology and Immunology, Bangkok, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Denise O.","family":"Garrett","sequence":"additional","affiliation":[{"name":"Sabin Vaccine Institute, Washington, DC, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Samir K","family":"Saha","sequence":"additional","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jessica C.","family":"Seidman","sequence":"additional","affiliation":[{"name":"Sabin Vaccine Institute, Washington, DC, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Senjuti","family":"Saha","sequence":"additional","affiliation":[{"name":"Child Health Research Foundation, Dhaka, Bangladesh"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"54368","reference":[{"key":"2026011411350850000_2026.01.11.26343883v1.1","doi-asserted-by":"publisher","DOI":"10.1016\/s1473-3099(18)30685-6"},{"key":"2026011411350850000_2026.01.11.26343883v1.2","doi-asserted-by":"publisher","DOI":"10.1016\/j.eclinm.2024.102883"},{"key":"2026011411350850000_2026.01.11.26343883v1.3","doi-asserted-by":"publisher","DOI":"10.1016\/S2214-109X(22)00119-X"},{"key":"2026011411350850000_2026.01.11.26343883v1.4","doi-asserted-by":"crossref","first-page":"S196","DOI":"10.1093\/cid\/ciaa1356","article-title":"Hospitalization of Pediatric Enteric Fever Cases, Dhaka, Bangladesh, 2017-2019: Incidence and Risk Factors","volume":"71","year":"2020","journal-title":"Clinical Infectious Diseases"},{"key":"2026011411350850000_2026.01.11.26343883v1.5","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijid.2009.11.023"},{"key":"2026011411350850000_2026.01.11.26343883v1.6","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiy471"},{"key":"2026011411350850000_2026.01.11.26343883v1.7","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0008275"},{"key":"2026011411350850000_2026.01.11.26343883v1.8","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0252617"},{"key":"2026011411350850000_2026.01.11.26343883v1.9","doi-asserted-by":"crossref","unstructured":"Arnold BF , Martin DL , Juma J , et al. Enteropathogen antibody dynamics and force of infection among children in low-resource settings. Elife 2019; 8.","DOI":"10.7554\/eLife.45594"},{"key":"2026011411350850000_2026.01.11.26343883v1.10","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-018-0157-4"},{"key":"2026011411350850000_2026.01.11.26343883v1.11","doi-asserted-by":"publisher","DOI":"10.1017\/S0950268821000972"},{"key":"2026011411350850000_2026.01.11.26343883v1.12","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0005785"},{"key":"2026011411350850000_2026.01.11.26343883v1.13","doi-asserted-by":"publisher","DOI":"10.1016\/S2214-109X(21)00370-3"},{"key":"2026011411350850000_2026.01.11.26343883v1.14","doi-asserted-by":"crossref","first-page":"1413","DOI":"10.1128\/CVI.00245-09","article-title":"Kinetics of the natural, humoral immune response to Salmonella enterica serovar Typhi in Kathmandu, Nepal","volume":"16","year":"2009","journal-title":"Clinical and Vaccine Immunology"},{"key":"2026011411350850000_2026.01.11.26343883v1.15","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1128\/CVI.00661-13","article-title":"Immunoproteomic analysis of antibody in lymphocyte supernatant in patients with typhoid fever in Bangladesh","volume":"21","year":"2014","journal-title":"Clinical and Vaccine Immunology"},{"key":"2026011411350850000_2026.01.11.26343883v1.16","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciy578"},{"key":"2026011411350850000_2026.01.11.26343883v1.17","doi-asserted-by":"crossref","unstructured":"Aiemjoy K , Seidman JC , Saha S , et al. Estimating typhoid incidence from community-based serosurveys: a multicohort study. Lancet Microbe 2022;","DOI":"10.1016\/S2666-5247(22)00114-8"},{"key":"2026011411350850000_2026.01.11.26343883v1.18","first-page":"2316","article-title":"Seroincidence of Enteric Fever, Juba, South Sudan","volume":"28","year":"2022","journal-title":"Emerg Infect Dis"},{"key":"2026011411350850000_2026.01.11.26343883v1.19","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0012373"},{"key":"2026011411350850000_2026.01.11.26343883v1.20","unstructured":"Khan A , Kamenskaya P , Rezende I , et al. Seroincidence rate of typhoidal Salmonella in children in Kenya. medRxiv 2025; :2025.06.24.25330223. Available at: http:\/\/medrxiv.org\/content\/early\/2025\/06\/25\/2025.06.24.25330223.abstract."},{"key":"2026011411350850000_2026.01.11.26343883v1.21","doi-asserted-by":"crossref","unstructured":"Andrews JR , Vaidya K , Saha S , et al. Healthcare Utilization Patterns for Acute Febrile Illness in Bangladesh, Nepal, and Pakistani]: Results from the Surveillance for Enteric Fever in Asia Project. 2020; 71.","DOI":"10.1093\/cid\/ciaa1321"},{"key":"2026011411350850000_2026.01.11.26343883v1.22","unstructured":"Saha S , Kanon N , Islam MS , et al. Cohort Profile: Health and Demographic Surveillance System in Mirzapur, Tangail, Bangladesh. medRxiv 2025; :2025.07.21.25331957. Available at: http:\/\/medrxiv.org\/content\/early\/2025\/07\/22\/2025.07.21.25331957.abstract."},{"key":"2026011411350850000_2026.01.11.26343883v1.23","unstructured":"Weyant C , Hooda Y , Munira SJ , et al. Cost-effectiveness and public health impact of typhoid conjugate vaccine introduction strategies in Bangladesh. Vaccine 2024; Available at: https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/S0264410X24003220. Accessed 29 March 2024."},{"key":"2026011411350850000_2026.01.11.26343883v1.24","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0002148"},{"key":"2026011411350850000_2026.01.11.26343883v1.25","doi-asserted-by":"publisher","DOI":"10.1002\/sim.8578"},{"key":"2026011411350850000_2026.01.11.26343883v1.26","unstructured":"Kristen Aiemjoy , Ezra Morrison , Kristina Lai , Jessica Siedman . Serocalculator Data Repository. 2025. Available at: https:\/\/osf.io\/ne8pc\/overview. Accessed 16 December 2025."},{"key":"2026011411350850000_2026.01.11.26343883v1.27","unstructured":"Lai KW , Orwa C , Seidman JC , et al. serocalculator, an R package for estimating seroincidence from cross-sectional serological data. medRxiv 2025; :2025.06.04.25328941. Available at: http:\/\/medrxiv.org\/content\/early\/2025\/06\/06\/2025.06.04.25328941.abstract."},{"key":"2026011411350850000_2026.01.11.26343883v1.28","unstructured":"Walker J , Russell P , Kermack L , et al. Leveraging paired serology to estimate the incidence of typhoidal Salmonella; infection in the STRATAA study. medRxiv 2025; :2025.03.15.25324021. Available at: http:\/\/medrxiv.org\/content\/early\/2025\/03\/17\/2025.03.15.25324021.abstract."},{"key":"2026011411350850000_2026.01.11.26343883v1.29","doi-asserted-by":"publisher","DOI":"10.15585\/MMWR.MM7207A2"},{"key":"2026011411350850000_2026.01.11.26343883v1.30","doi-asserted-by":"publisher","DOI":"10.4269\/ajtmh.18-0428"},{"key":"2026011411350850000_2026.01.11.26343883v1.31","doi-asserted-by":"crossref","unstructured":"Maude RR , Ghose A , Samad R , et al. A prospective study of the importance of enteric fever as a cause of non-malarial febrile illness in patients admitted to Chittagong Medical College Hospital, Bangladesh. BMC Infect Dis 2016; 16.","DOI":"10.1186\/s12879-016-1886-3"},{"key":"2026011411350850000_2026.01.11.26343883v1.32","unstructured":"Crump JA , Luby SP , Mintz ED . The global burden of typhoid fever. 2004; 002295."},{"key":"2026011411350850000_2026.01.11.26343883v1.33","doi-asserted-by":"crossref","unstructured":"Aiemjoy K , Seidman JC , Saha S , et al. Estimating typhoid incidence from community-based serosurveys: a multicohort study. Lancet Microbe 2022;","DOI":"10.1016\/S2666-5247(22)00114-8"},{"key":"2026011411350850000_2026.01.11.26343883v1.34","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciy578"},{"key":"2026011411350850000_2026.01.11.26343883v1.35","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0002148"},{"key":"2026011411350850000_2026.01.11.26343883v1.36","doi-asserted-by":"crossref","unstructured":"Harris JB , LaRocque RC , Chowdhury F , et al. Susceptibility to Vibrio cholerae infection in a cohort of household contacts of patients with cholera in Bangladesh. PLoS Negl Trop Dis 2008; 2.","DOI":"10.1371\/journal.pntd.0000221"},{"key":"2026011411350850000_2026.01.11.26343883v1.37","doi-asserted-by":"publisher","DOI":"10.1002\/sim.8578"},{"key":"2026011411350850000_2026.01.11.26343883v1.38","doi-asserted-by":"publisher","DOI":"10.3390\/nu7115470"},{"key":"2026011411350850000_2026.01.11.26343883v1.39","unstructured":"James F. Pierson-Perry , Jeffrey E. Vaks , A. Paul Durham , et al. EP17 _ Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures. 2012: 80. Available at: https:\/\/clsi.org\/standards\/products\/method-evaluation\/documents\/ep17\/. Accessed 23 July 2025."},{"key":"2026011411350850000_2026.01.11.26343883v1.40","unstructured":"Weyant C , Hooda Y , Munira SJ , et al. Cost-effectiveness and public health impact of typhoid conjugate vaccine introduction strategies in Bangladesh. Vaccine 2024; Available at: https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/S0264410X24003220. Accessed 29 March 2024."}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.01.11.26343883","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T19:35:28Z","timestamp":1768419328000},"score":1,"resource":{"primary":{"URL":"http:\/\/medrxiv.org\/lookup\/doi\/10.64898\/2026.01.11.26343883"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,13]]},"references-count":40,"URL":"https:\/\/doi.org\/10.64898\/2026.01.11.26343883","relation":{},"subject":[],"published":{"date-parts":[[2026,1,13]]},"subtype":"preprint"}}