Abstract:
important tick-borne pathogens of cattle. A cross-sectional
survey was undertaken to determine the seroprevalence of
A. marginale and B. bigemina infections and identify associated
risk factors on traditional smallholder farms in Machakos
County, Kenya. A total of 421 cattle from 127 farms from four
divisions in the county were sampled and visited between
September and November 2007. The farms were selected by
a proportional allocation approach based on the number of
farms in the four divisions previously selected by stratified
random sampling method. Information on animal and individual
farm management variables was obtained using standardized
questionnaires. Prevalence of serum antibodies due to
A. marginale and B. bigemina pathogens was determined
using the enzyme-linked immunosorbent assay (ELISA) technique.
The relationship between the seropositivity and associated
risk factors was assessed by multivariable analyses using
standard logistic regression models. The overall estimation
(and their 95% confidence intervals) of A. marginale and
B. bigemina seropositivity at the animal level was 53.4%
(48.5%, 58.2%) and 40.6% (35.8%, 45.4%), respectively.
Two variables, Banimal age^ and Badministrative division,^
were significantly associated with the A. marginale
seroresponse. Three variables, Banimal age^ Bgrazing system^
and Badministrative division^ were significantly associated
with the B. bigemina seroresponse. These findings suggest
possible indicators of existence of endemic instability for the
two infections. The study identifies characterization of environmental
suitability for the vectors and how they interact
with grazing systems to cause the infections as an area for
further studies, for improved understanding of the infections
and in designing disease control programs.
Keywords Anaplasma marginale . Babesia bigemina .
Seroprevalence . Machakos . Kenya
