title: Consecutive outbreaks of Vibrio cholerae O139 and V. cholerae O1 cholera in a fishing village near Karachi, Pakistan.
abstract: In July 2002 and June 2003, cholera outbreaks were detected by a diarrhoea surveillance system in a village outside Karachi, Pakistan. Specimens were culture confirmed. The first outbreak was caused by Vibrio cholerae O139 (n = 30) and the second outbreak by V. cholerae O1 (n = 39). Demographic and clinical features of patients were recorded and case-control studies were conducted following each outbreak. Clinical information was obtained for 29 of the 30 patients in the first outbreak, and 2 of the patients in the second outbreak were either out of the area or lost to follow-up, leaving 29 and 37 cases in the analysis for the first and second outbreak, respectively. Eighteen (49%) of the 37 V. cholerae O1 patients were under 2 years of age compared with 6 (21%) of the 29 V. cholerae O139 patients (P = 0.02). Vibrio cholerae O139-infected patients were more likely to be febrile (16/29) than those infected with V. cholerae O1 (2/37; P<0.001). A household contact with cholera was a risk factor in both outbreaks; water source was a risk factor in the first outbreak only. Geographically, cases were clustered during the first outbreak but not during the second. Person-to-person contact and water reservoirs appear to be the main transmission routes for cholera in this setting.
authors.affiliation: Department of Paediatrics, Aga Khan University, P.O. Box 3500, Stadium Road, Karachi 74800, Pakistan.
authors.forename: Fahad J
authors.initials: FJ
authors.lastname: Siddiqui
authors.forename: Naveed S
authors.initials: NS
authors.lastname: Bhutto
authors.forename: Lorenz
authors.initials: L
authors.lastname: von Seidlein
authors.forename: Irfan
authors.initials: I
authors.lastname: Khurram
authors.forename: Shahid
authors.initials: S
authors.lastname: Rasool
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ali
authors.forename: Afia
authors.initials: A
authors.lastname: Zafar
authors.forename: Jacqueline L
authors.initials: JL
authors.lastname: Deen
authors.forename: John D
authors.initials: JD
authors.lastname: Clemens
authors.forename: Qumaruddin
authors.initials: Q
authors.lastname: Nizami
authors.forename: Zulfiqar A
authors.initials: ZA
authors.lastname: Bhutta
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002771:Cholera / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D003906:Developing Countries; D004196:Disease Outbreaks; D004197:Disease Reservoirs; D018562:Disease Transmission, Infectious; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010154:Pakistan / Q000453:epidemiology; D012424:Rural Population; D041241:Vibrio cholerae O1 / Q000302:isolation & purification*; D041242:Vibrio cholerae O139 / Q000302:isolation & purification*; D014871:Water Microbiology