{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T21:41:09Z","timestamp":1790372469509,"version":"4.1.0"},"reference-count":32,"publisher":"Public Library of Science (PLoS)","issue":"6","license":[{"start":{"date-parts":[[2024,6,12]],"date-time":"2024-06-12T00:00:00Z","timestamp":1718150400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100004107","name":"Albert B. Sabin Vaccine Institute","doi-asserted-by":"publisher","award":["041896-00"],"award-info":[{"award-number":["041896-00"]}],"id":[{"id":"10.13039\/100004107","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosntds.org"],"crossmark-restriction":false},"short-container-title":["PLoS Negl Trop Dis"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Background<\/jats:title>\n<jats:p>Enteric fever is caused by <jats:italic>Salmonella<\/jats:italic> enterica serovars Typhi (<jats:italic>S<\/jats:italic>. Typhi) and Paratyphi A, B, and C. It continues to be a significant cause of morbidity and mortality worldwide. In highly endemic areas, children are disproportionately affected, and antimicrobial resistance reduces therapeutic options. It is estimated that 2\u20135% of enteric fever patients develop chronic asymptomatic infection. These carriers may act as reservoirs of infection; therefore, the prospective identification and treatment of carriers are critical for long-term disease control. We aimed to find the frequency of <jats:italic>Salmonella<\/jats:italic> Typhi carriers in patients undergoing cholecystectomy. We also compared the detection limit of culturing versus qPCR in detecting <jats:italic>S<\/jats:italic>. Typhi, performed a geospatial analysis of the carriers identified using this study, and evaluated the accuracy of anti-Vi and anti-YncE in identifying chronic typhoid carriage.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>We performed a cross-sectional study in two centers in Pakistan. Gallbladder specimens were subjected to quantitative PCR (qPCR) and serum samples were analyzed for IgG against YncE and Vi by ELISA. We also mapped the residential location of those with a positive qPCR result.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Findings<\/jats:title>\n<jats:p>Out of 988 participants, 3.4% had qPCR-positive gallbladder samples (23 <jats:italic>S<\/jats:italic>. Typhi and 11 <jats:italic>S<\/jats:italic>. Paratyphi). Gallstones were more likely to be qPCR positive than bile and gallbladder tissue. Anti-Vi and YncE were significantly correlated (r = 0.78 p&lt;0.0001) and elevated among carriers as compared to qPCR negative controls, except for anti-Vi response in Paratyphi A. But the discriminatory values of these antigens in identifying carriers from qPCR negative controls were low.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusion<\/jats:title>\n<jats:p>The high prevalence of typhoid carriers observed in this study suggests that further studies are required to gain information that will help in controlling future typhoid outbreaks in a superior manner than they are currently being managed.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pntd.0011775","type":"journal-article","created":{"date-parts":[[2024,6,12]],"date-time":"2024-06-12T17:22:51Z","timestamp":1718212971000},"page":"e0011775","update-policy":"https:\/\/doi.org\/10.1371\/journal.pntd.corrections_policy","source":"Crossref","is-referenced-by-count":7,"title":["The frequency and associated factors of typhoid carriage in patients undergoing cholecystectomy for gallbladder disease in Pakistan: A cross-sectional study"],"prefix":"10.1371","volume":"18","author":[{"given":"Sonia","family":"Qureshi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Noshi","family":"Maria","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tabish","family":"Chawla","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junaid","family":"Iqbal","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abdul Momin","family":"Kazi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-7655-1163","authenticated-orcid":true,"given":"Mehreen","family":"Adnan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aneeta","family":"Hotwani","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Najeeb","family":"Rahman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Muhammed Wahhaab","family":"Sadiq","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Richelle","family":"Charles","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stephen","family":"Baker","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4173-680X","authenticated-orcid":true,"given":"Farah Naz","family":"Qamar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2024,6,12]]},"reference":[{"issue":"2","key":"pntd.0011775.ref001","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1086\/649541","article-title":"Global trends in typhoid and paratyphoid Fever","volume":"50","author":"J.A. Crump","year":"2010","journal-title":"Clin Infect Dis"},{"issue":"6","key":"pntd.0011775.ref002","first-page":"49","article-title":"Typhoid vaccines: WHO position paper.","volume":"83","year":"2008","journal-title":"Wkly Epidemiol Rec"},{"issue":"8","key":"pntd.0011775.ref003","doi-asserted-by":"crossref","first-page":"567","DOI":"10.7326\/0003-4819-150-8-200904210-00017","article-title":"Gallbladder carriage of Salmonella paratyphi A may be an important factor in the increasing incidence of this infection in South Asia","volume":"150","author":"NS Khatri","year":"2009","journal-title":"Ann Intern Med"},{"issue":"1","key":"pntd.0011775.ref004","doi-asserted-by":"crossref","first-page":"e0145839","DOI":"10.1371\/journal.pone.0145839","article-title":"World Health Organization Estimates of the Relative Contributions of Food to the Burden of Disease Due to Selected Foodborne Hazards: A Structured Expert Elicitation","volume":"11","author":"T Hald","year":"2016","journal-title":"PLoS One"},{"issue":"14","key":"pntd.0011775.ref005","doi-asserted-by":"crossref","DOI":"10.1128\/JB.00774-18","article-title":"Pathoadaptive Alteration of Salmonella Biofilm Formation in Response to the Gallbladder Environment","volume":"201","author":"MR Neiger","year":"2019","journal-title":"J Bacteriol"},{"issue":"11","key":"pntd.0011775.ref006","doi-asserted-by":"crossref","first-page":"648","DOI":"10.1016\/j.tim.2014.06.007","article-title":"Salmonella chronic carriage: epidemiology, diagnosis, and gallbladder persistence","volume":"22","author":"JS Gunn","year":"2014","journal-title":"Trends Microbiol"},{"issue":"22","key":"pntd.0011775.ref007","first-page":"1770","article-title":"Hien 1Tr, Douqan G, et a1., Typhoid fever","volume":"347","author":"CM Parry","year":"2002","journal-title":"N Engl J Med"},{"issue":"9161","key":"pntd.0011775.ref008","doi-asserted-by":"crossref","first-page":"1354","DOI":"10.1016\/S0140-6736(98)11315-6","article-title":"Mr N the milker, and Dr Koch\u2019s concept of the healthy carrier","volume":"353","author":"P.P. Mortimer","year":"1999","journal-title":"Lancet"},{"issue":"9487","key":"pntd.0011775.ref009","doi-asserted-by":"crossref","first-page":"749","DOI":"10.1016\/S0140-6736(05)67181-4","article-title":"Typhoid and paratyphoid fever","volume":"366","author":"M Bhan","year":"2005","journal-title":"Lancet"},{"issue":"6","key":"pntd.0011775.ref010","doi-asserted-by":"crossref","first-page":"ofad301","DOI":"10.1093\/ofid\/ofad301","article-title":"Poor Sensitivity of Stool Culture Compared to Polymerase Chain Reaction in Surveillance for Vibrio cholerae in Haiti, 2018\u20132019","volume":"10","author":"Y Guillaume","year":"2023","journal-title":"Open Forum Infect Dis"},{"issue":"1","key":"pntd.0011775.ref011","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1186\/s13104-019-4340-y","article-title":"Performance of Widal test and stool culture in the diagnosis of typhoid fever among suspected patients in Dar es Salaam, Tanzania.","volume":"12","author":"A Mawazo","year":"2019","journal-title":"BMC Res Notes"},{"issue":"5","key":"pntd.0011775.ref012","doi-asserted-by":"crossref","first-page":"496","DOI":"10.1097\/00006454-198509000-00011","article-title":"Efficacy of bone marrowblood, stool and duodenal contents cultures for bacteriologic confirmation of typhoid fever in children","volume":"4","author":"C Vallenas","year":"1985","journal-title":"Pediatr Infect Dis"},{"issue":"2","key":"pntd.0011775.ref013","first-page":"3","article-title":"New advances in the diagnosis of typhoid and detection of typhoid carriers","volume":"7","author":"A. Ismail","year":"2000","journal-title":"Malays J Med Sci"},{"issue":"4","key":"pntd.0011775.ref014","first-page":"170","article-title":"Detection of serum IgM against salmonella typhi: a rapid diagnostic technique.","volume":"8","author":"K. KA","year":"1998","journal-title":"J. Coll. Physicians Surg. Pak"},{"issue":"1","key":"pntd.0011775.ref015","first-page":"29","article-title":"Paediatric prescribing in Karachi.","volume":"47","author":"S Nizami","year":"1997","journal-title":"J Pak Med Assoc"},{"issue":"5","key":"pntd.0011775.ref016","doi-asserted-by":"crossref","first-page":"1698","DOI":"10.1128\/JCM.40.5.1698-1704.2002","article-title":"Quantitative microbiological study of human carious dentine by culture and real-time PCR: association of anaerobes with histopathological changes in chronic pulpitis","volume":"40","author":"FE Martin","year":"2002","journal-title":"J Clin Microbiol"},{"issue":"6","key":"pntd.0011775.ref017","doi-asserted-by":"crossref","first-page":"2362","DOI":"10.1128\/JCM.38.6.2362-2365.2000","article-title":"Leys, Quantitative real-time PCR for Porphyromonas gingivalis and total bacteria","volume":"38","author":"SR Lyons","year":"2000","journal-title":"J Clin Microbiol"},{"key":"pntd.0011775.ref018","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1186\/1471-2334-10-125","article-title":"The sensitivity of real-time PCR amplification targeting invasive Salmonella serovars in biological specimens","volume":"10","author":"TV Nga","year":"2010","journal-title":"BMC Infect Dis"},{"issue":"8","key":"pntd.0011775.ref019","doi-asserted-by":"crossref","first-page":"e2335","DOI":"10.1371\/journal.pntd.0002335","article-title":"Identification of immunogenic Salmonella enterica serotype Typhi antigens expressed in chronic biliary carriers of S. Typhi in Kathmandu, Nepal.","volume":"7","author":"RC Charles","year":"2013","journal-title":"PLoS Negl Trop Dis"},{"issue":"2","key":"pntd.0011775.ref020","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1111\/j.1348-0421.2005.tb03709.x","article-title":"Epidemiology of typhoid carriers among blood donors and patients with biliary, gastrointestinal and other related diseases","volume":"49","author":"C Vaishnavi","year":"2005","journal-title":"Microbiol Immunol"},{"issue":"1","key":"pntd.0011775.ref021","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1038\/nrmicro2490","article-title":"Chronic and acute infection of the gall bladder by Salmonella Typhi: understanding the carrier state","volume":"9","author":"G Gonzalez-Escobedo","year":"2011","journal-title":"Nat Rev Microbiol"},{"issue":"10","key":"pntd.0011775.ref022","doi-asserted-by":"crossref","first-page":"e47342","DOI":"10.1371\/journal.pone.0047342","article-title":"The microbiological and clinical characteristics of invasive Salmonella in gallbladders from cholecystectomy patients in Kathmandu, Nepal.","volume":"7","author":"S Dongol","year":"2012","journal-title":"PLoS One"},{"issue":"6","key":"pntd.0011775.ref023","doi-asserted-by":"crossref","first-page":"724","DOI":"10.1093\/infdis\/146.6.724","article-title":"Precise estimation of the numbers of chronic carriers of Salmonella typhi in Santiago, Chile, an endemic area","volume":"146","author":"MM Levine","year":"1982","journal-title":"The Journal of infectious diseases"},{"issue":"4","key":"pntd.0011775.ref024","doi-asserted-by":"crossref","first-page":"410","DOI":"10.3855\/jidc.7306","article-title":"Carriage prevalence of Salmonella enterica serotype Typhi in gallbladders of adult autopsy cases from Mozambique.","volume":"10","author":"L Lovane","year":"2016","journal-title":"J Infect Dev Ctries"},{"issue":"1","key":"pntd.0011775.ref025","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.diagmicrobio.2013.05.014","article-title":"Nayak, Study on Salmonella Typhi occurrence in gallbladder of patients suffering from chronic cholelithiasis-a predisposing factor for carcinoma of gallbladder","volume":"77","author":"YD Walawalkar","year":"2013","journal-title":"Diagn Microbiol Infect Dis"},{"issue":"4","key":"pntd.0011775.ref026","doi-asserted-by":"crossref","first-page":"259","DOI":"10.3855\/jidc.820","article-title":"Does Salmonella Typhi primarily reside in the liver of chronic typhoid carriers?","volume":"4","author":"G Nath","year":"2010","journal-title":"J Infect Dev Ctries,"},{"issue":"5","key":"pntd.0011775.ref027","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1007\/s00430-020-00667-1","article-title":"Evaluation of Salmonella Typhi antigen YncE alongside HlyE for the detection of typhoid fever and its carriers","volume":"209","author":"F Franklin","year":"2020","journal-title":"Med Microbiol Immunol"},{"issue":"3","key":"pntd.0011775.ref028","first-page":"636","article-title":"Comparison of Vi serology and nested PCR in diagnosis of chronic typhoid carriers in two different study populations in typhoid endemic area of India","volume":"41","author":"G Nath","year":"2010","journal-title":"Southeast Asian J Trop Med Public Health"},{"issue":"14","key":"pntd.0011775.ref029","doi-asserted-by":"crossref","first-page":"8508","DOI":"10.1073\/pnas.1431769100","article-title":"Use of in vivo-induced antigen technology (IVIAT) to identify genes uniquely expressed during human infection with Vibrio cholerae","volume":"100","author":"L Hang","year":"2003","journal-title":"Proc Natl Acad Sci U S A"},{"issue":"4","key":"pntd.0011775.ref030","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1016\/j.ijid.2005.06.005","article-title":"Evaluation of community-based serologic screening for identification of chronic Salmonella typhi carriers in Vietnam","volume":"10","author":"A Gupta","year":"2006","journal-title":"Int J Infect Dis"},{"issue":"19\u201320","key":"pntd.0011775.ref031","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1007\/s10354-006-0346-x","article-title":"Gender and gallstone disease","volume":"156","author":"G. Novacek","year":"2006","journal-title":"Wien Med Wochenschr"},{"issue":"15","key":"pntd.0011775.ref032","doi-asserted-by":"crossref","first-page":"1886","DOI":"10.3748\/wjg.15.1886","article-title":"Gender and metabolic differences of gallstone diseases","volume":"15","author":"H Sun","year":"2009","journal-title":"World J Gastroenterol"}],"container-title":["PLOS Neglected Tropical Diseases"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pntd.0011775","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,6,12]],"date-time":"2024-06-12T17:23:15Z","timestamp":1718212995000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pntd.0011775"}},"subtitle":[],"editor":[{"given":"Mathieu","family":"Picardeau","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2024,6,12]]},"references-count":32,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2024,6,12]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pntd.0011775","relation":{},"ISSN":["1935-2735"],"issn-type":[{"value":"1935-2735","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,6,12]]}}}