title: Differing burden and epidemiology of non-Typhi Salmonella bacteremia in rural and urban Kenya, 2006-2009.
abstract: BACKGROUND
  The epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change.
  
  
  METHODS
  As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006-2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on persons with compatible illnesses, but whose blood was not cultured.
  
  
  RESULTS
  NTS accounted for 60/155 (39%) of blood culture isolates in the rural and 7/230 (3%) in the urban sites. The adjusted incidence in the rural site was 568/100,000 person-years, and the urban site was 51/100,000 person-years. In both sites, the incidence was highest in children <5 years old. The NTS-to-typhoid bacteremia ratio in the rural site was 4.6 and in the urban site was 0.05. S. Typhimurium represented >85% of blood NTS isolates in both sites, but only 21% (urban) and 64% (rural) of stool NTS isolates. Overall, 76% of S. Typhimurium blood isolates were multi-drug resistant, most of which had an identical profile in Pulse Field Gel Electrophoresis. In the rural site, the incidence of NTS bacteremia increased during the study period, concomitant with rising malaria prevalence (monthly correlation of malaria positive blood smears and NTS bacteremia cases, Spearman's correlation, p = 0.018 for children, p = 0.16 adults). In the rural site, 80% of adults with NTS bacteremia were HIV-infected. Six of 7 deaths within 90 days of NTS bacteremia had HIV/AIDS as the primary cause of death assigned on verbal autopsy.
  
  
  CONCLUSIONS
  NTS caused the majority of bacteremias in rural Kenya, but typhoid predominated in urban Kenya, which most likely reflects differences in malaria endemicity. Control measures for malaria, as well as HIV, will likely decrease the burden of NTS bacteremia in Africa.
authors.affiliation: Field Epidemiology and Laboratory Training Program, Nairobi, Kenya.
authors.forename: Collins
authors.initials: C
authors.lastname: Tabu
authors.forename: Robert F
authors.initials: RF
authors.lastname: Breiman
authors.forename: Benjamin
authors.initials: B
authors.lastname: Ochieng
authors.forename: Barrack
authors.initials: B
authors.lastname: Aura
authors.forename: Leonard
authors.initials: L
authors.lastname: Cosmas
authors.forename: Allan
authors.initials: A
authors.lastname: Audi
authors.forename: Beatrice
authors.initials: B
authors.lastname: Olack
authors.forename: Godfrey
authors.initials: G
authors.lastname: Bigogo
authors.forename: Juliette R
authors.initials: JR
authors.lastname: Ongus
authors.forename: Patricia
authors.initials: P
authors.lastname: Fields
authors.forename: Eric
authors.initials: E
authors.lastname: Mintz
authors.forename: Deron
authors.initials: D
authors.lastname: Burton
authors.forename: Joe
authors.initials: J
authors.lastname: Oundo
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Feikin
mesh_terms: D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology; D016470:Bacteremia / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D001800:Blood Specimen Collection; D002648:Child; D002675:Child, Preschool; D017281:Cost of Illness; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D016521:Electrophoresis, Gel, Pulsed-Field; D005243:Feces / Q000382:microbiology; D006801:Humans; D015994:Incidence; D007630:Kenya / Q000453:epidemiology; D008288:Malaria / Q000150:complications / Q000401:mortality; D012424:Rural Population / Q000706:statistics & numerical data*; D012480:Salmonella Infections / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology* / Q000401:mortality; D012485:Salmonella typhi / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D014505:Urban Population / Q000706:statistics & numerical data*
chemical_list: D000890:Anti-Infective Agents