title: High prevalence of typhoidal Salmonella enterica serovars excreting food handlers in Karachi-Pakistan: a probable factor for regional typhoid endemicity.
abstract: BACKGROUND
  Typhoid fever is the persistent cause of morbidity worldwide. Salmonella enterica serovar's carriers among food handlers have the potential to disseminate this infection on large scale in the community. The purpose of this study was to determine the prevalence of typhoidal S. enterica serovars among food handlers of Karachi.
  
  
  METHODS
  This cross-sectional study was conducted in Karachi metropolis. A total of 220 food handlers were recruited on the basis of inclusion criteria from famous food streets of randomly selected five towns of Karachi. Three consecutive stool samples were collected from each food handler in Carry Blair transport media. Culture, biochemical identification, serotyping, and antimicrobial susceptibility tests for S. enterica serovars were done.
  
  
  RESULTS
  Out of 220 food handlers, 209 consented to participate, and among them, 19 (9.1%) were positive for S. enterica serovars. Serotyping of these isolates showed that 9 (4.3%) were typhoidal S. serovars while 10 (4.7%) were non-typhoidal S. serovars. Of the typhoidal S. serovars, 7 were S. enterica serovar Typhi and 1 each of S. enterica serovar Paratyphi A and B. The resistance pattern of these isolates showed that 77.7% were resistant to ampicillin and 11.1% to cotrimoxazole. All typhoidal S. enterica serovar isolates were sensitive to chloramphenicol, ceftriaxone, cefixime, nalidixic acid, and ofloxacin.
  
  
  CONCLUSIONS
  Carrier rate of typhoidal S. enterica serovars in food handlers working in different food streets of Karachi is very high. These food handlers might be contributing to the high endemicity of typhoid fever in Karachi, Pakistan.
authors.affiliation: Gastroenterology and Hepatology unit, Pakistan Medical Research Council, Research Center, Jinnah Postgraduate Medical Center, Refiquee Shaheed Road, Karachi, 75510, Pakistan. elegy_tt@hotmail.com.
authors.forename: Taranum Ruba
authors.initials: TR
authors.lastname: Siddiqui
authors.affiliation: Gastroenterology and Hepatology unit, Pakistan Medical Research Council, Research Center, Jinnah Postgraduate Medical Center, Refiquee Shaheed Road, Karachi, 75510, Pakistan.
authors.forename: Safia
authors.initials: S
authors.lastname: Bibi
authors.affiliation: Pakistan Medical Research Council, Research Center, National Institute of Child Health, Karachi, Pakistan.
authors.forename: Muhammad Ayaz
authors.initials: MA
authors.lastname: Mustufa
authors.affiliation: Gastroenterology and Hepatology unit, Pakistan Medical Research Council, Research Center, Jinnah Postgraduate Medical Center, Refiquee Shaheed Road, Karachi, 75510, Pakistan.
authors.forename: Sobiya Mohiuddin
authors.initials: SM
authors.lastname: Ayaz
authors.affiliation: Microbiology Department, University of Karachi, Karachi, Pakistan.
authors.forename: Adnan
authors.initials: A
authors.lastname: Khan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D057138:Bacterial Shedding; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D003430:Cross-Sectional Studies; D003906:Developing Countries; D019353:Endemic Diseases; D005243:Feces / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D005511:Food Handling; D006801:Humans; D008297:Male; D008875:Middle Aged; D010154:Pakistan / Q000453:epidemiology; D015995:Prevalence; D062486:Public Health Surveillance; D012147:Restaurants; D012307:Risk Factors; D012485:Salmonella typhi / Q000302:isolation & purification*; D014435:Typhoid Fever / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D014504:Urban Health; D000078329:Workforce; D055815:Young Adult
references.citation: J Glob Health. 2012 Jun;2(1):010401
references.pmid: 23198130
references.citation: Trop Med Int Health. 2001 Jun;6(6):484-90
references.pmid: 11422963
references.citation: J Med Microbiol. 2008 Oct;57(Pt 10):1247-50
references.pmid: 18809553
references.citation: J Clin Microbiol. 2005 Mar;43(3):1158-65
references.pmid: 15750077
references.citation: Int J Infect Dis. 2006 May;10(3):215-22
references.pmid: 16431148
references.citation: J Pak Med Assoc. 2011 May;61(5):462-5
references.pmid: 22204180
references.citation: Indian J Med Microbiol. 2005 Apr;23(2):92-4
references.pmid: 15928436
references.citation: East Afr Med J. 2004 Jul;81(7):358-61
references.pmid: 15490708
references.citation: Bull World Health Organ. 2008 Apr;86(4):260-8
references.pmid: 18438514
references.citation: PLoS One. 2012;7(10):e47342
references.pmid: 23077595
references.citation: J Public Health Med. 1991 May;13(2):101-7
references.pmid: 1906719
references.citation: J Hosp Infect. 1994 Nov;28(3):195-208
references.pmid: 7852733
references.citation: Clin Infect Dis. 2010 Jan 15;50(2):241-6
references.pmid: 20014951
references.citation: J Coll Physicians Surg Pak. 2008 Jan;18(1):13-6
references.pmid: 18452661
references.citation: East Mediterr Health J. 2005 Sep-Nov;11(5-6):1038-44
references.pmid: 16761675