title: Epidemiology, clinical presentation, and patterns of drug resistance of Salmonella Typhi in Karachi, Pakistan.
abstract: BACKGROUND
  Enteric fever remains a major public health problem in Asia. Planning appropriate preventive measures such as immunization requires a clear understanding of disease burden. We conducted a community-based surveillance for Salmonella Typhi infection in children in Karachi, Pakistan.
  
  
  METHODS
  A de jure household census was conducted at baseline in the study setting to enumerate all individuals. A health-care facility-based passive surveillance system was used to capture episodes of fever lasting three or more 3 days in children 2 to 16 years old.
  
  
  RESULTS
  A total of 7,401 blood samples were collected for microbiological confirmation, out of which 189 S. Typhi and 32 S. Paratyphi A isolates were identified with estimated annual incidences of 451/100,000 (95% CI: 446 - 457) and 76/100,000 (95% CI: 74 - 78) respectively. At the time of presentation, after adjusting for age, there was an association between the duration of fever and temperature at presentation, and being infected with multidrug-resistant S. Typhi. Of 189 isolates 83 were found to be resistant to first-line antimicrobial therapy. There was no statistically significant difference in clinical presentation of blood culture sensitive and resistant S. Typhi isolates.
  
  
  CONCLUSIONS
  Incidence of S. Typhi in children is high in urban squatter settlements of Karachi, Pakistan. Findings from this study identified duration of fever and temperature at the time of presentation as important symptoms associated with blood culture-confirmed typhoid fever. Preventive strategies such as immunization and improvements in water and sanitation conditions should be the focus of typhoid control in urban settlements of Pakistan.
authors.affiliation: Department of Paediatrics, Aga Khan University, Karachi, Pakistan. imran@ivi.int
authors.forename: M Imran
authors.initials: MI
authors.lastname: Khan
authors.forename: Sajid Bashir
authors.initials: SB
authors.lastname: Soofi
authors.forename: R Leon
authors.initials: RL
authors.lastname: Ochiai
authors.forename: Mohammad Jawed
authors.initials: MJ
authors.lastname: Khan
authors.forename: Shah Muhammad
authors.initials: SM
authors.lastname: Sahito
authors.forename: Mohammad Atif
authors.initials: MA
authors.lastname: Habib
authors.forename: Mahesh K
authors.initials: MK
authors.lastname: Puri
authors.forename: Lorenz
authors.initials: L
authors.lastname: Von Seidlein
authors.forename: Jin Kyung
authors.initials: JK
authors.lastname: Park
authors.forename: Young Ae
authors.initials: YA
authors.lastname: You
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ali
authors.forename: S Qamarudding
authors.initials: SQ
authors.lastname: Nizami
authors.forename: Camilo J
authors.initials: CJ
authors.lastname: Acosta
authors.forename: R Bradley
authors.initials: RB
authors.lastname: Sack
authors.forename: John D
authors.initials: JD
authors.lastname: Clemens
authors.forename: Zulfiqar A
authors.initials: ZA
authors.lastname: Bhutta
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D005260:Female; D005334:Fever / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D010154:Pakistan / Q000453:epidemiology; D012485:Salmonella typhi / Q000187:drug effects* / Q000302:isolation & purification; D014435:Typhoid Fever / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology*
chemical_list: D000900:Anti-Bacterial Agents