Seroprevalence estimates of brucellosis and its associated risk factors in domestic ruminants in Nandi County, Kenya

Abstract

Background: Brucellosis is a contagious zoonotic disease that affects domestic animals, wildlife and humans with socio-economic and public health significance.
Objectives: To determine seroprevalence of brucellosis in domestic ruminants and associated risk factors in Nandi County, Kenya.
Design: Cross-sectional study.
Setting: Sampling sites were six wards, each from the six Sub-Counties.
Subjects: Cattle, sheep and goats of all sex and breeds above 12 months of age.
Interventions: Assess prevalence and risk factors of brucellosis in domestic ruminants.
Main outcome measures: Improved health of domestic ruminants and humans.
Results: A total of 1,140 blood samples were collected from cattle 63.6% (n=725), sheep 24.8% (n=283) and goats 11.6% (n=132) from 366 households. This was multistage random sampling. Sera were screened for brucella antibodies with Rose Bengal Plate Test (RBPT) and confirmed with indirect Enzyme-Linked Immunosorbent Assay (iELISA).
Results showed an overall animal seroprevalence of 0.088%(1/1140) for brucellosis. In cattle, seroprevalence was 0.138%(1/725) and 0% seropositivity in both sheep and goats on iELISA, despite recording 0.414%(3/725), 3.180%(9/283) and 1.515%(2/132) on screening using RBPT in cattle, sheep and goats respectively. The significant potential predictors for sero-positivity of brucellosis were species (p-value 0.00, CI95%), age (p-value 0.042, CI95%) and breed (p-value 0.037, CI95%).
Conclusions: Results demonstrated low seroprevalence of brucellosis in domestic ruminants in Nandi County, which implied minimum risk of animals contracting the disease and by extension humans. Confirmation of brucellosis was recommended to minimize misdiagnosis hence unnecessary treatment in addition to enhanced surveillance, awareness and preventive measures to maintain this favourable situation.