title: Variations in the prevalence of antibody to brucella infection in cattle by farm, area and district in Kenya.
abstract: Variations in the sero-prevalence of antibody to brucella infection by cow, farm and area factors were investigated for three contrasting districts in Kenya: Samburu, an arid and pastoral area: Kiambu, a tropical highland area; and Kilifi, a typical tropical coastal area. Cattle were selected by a two-stage cluster sampling procedure and visited once between August 1991 and 1992. Schall's algorithm, a statistical model suitable for multi-level analysis was used. Using this model, older age, free grazing and large herd size (> or = 31) were associated with higher seroprevalence. Also, significant farm-to-farm, area-to-area and district-to-district variations were estimated. The patterns of high risk districts and areas seen were consistent with known animal husbandry and movement risk factors, but the larger than expected farm-to-farm variation within high risk areas and districts could not be explained. Thus, a multi-level method provided additional information beyond conventional analyses of sero-prevalence data.
authors.affiliation: Department of Population Medicine, University of Guelph, Ontario, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Kadohira
authors.forename: J J
authors.initials: JJ
authors.lastname: McDermott
authors.forename: M M
authors.initials: MM
authors.lastname: Shoukri
authors.forename: M N
authors.initials: MN
authors.lastname: Kyule
mesh_terms: D000367:Age Factors; D000818:Animals; D000829:Animals, Domestic / Q000382:microbiology; D002003:Brucella abortus / Q000276:immunology*; D002007:Brucellosis, Bovine / Q000097:blood / Q000453:epidemiology*; D002417:Cattle; D003612:Dairying / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005843:Geography; D007630:Kenya / Q000453:epidemiology; D008297:Male; D015999:Multivariate Analysis; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D016036:Seroepidemiologic Studies