Sero-prevalence and Associated Risk Factors of Brucellosis and Q-fever in Livestock and Humans in Kajiado County, Kenya
Abstract
Animal and human health is inextricably linked. People depend on animals for nutrition,
socio-economic development and companionship. A cross-sectional serological study was
carried out to determine the sero-prevalence of two related zoonotic diseases namely
brucellosis and Q-fever in cattle, sheep, goats and humans in three sub-counties of Kajiado
County. Animal serum samples were collected for three months (July to September 2012)
from different farms and watering points by systematically sampling a healthy adult animal in
each herd. Human blood samples were collected at the health facilities serving the study areas
from patients presenting with flu-like symptoms. A total of, 250 (cattle), 167 (sheep), (167)
goats and 317 (humans) samples were collected. A total of 400 samples were subjected to
cELISA (COMPELISA, VLA, UK) test. 382 livestock samples from the 400 cELISA test
samples were subjected to Q-fever Indirect Multispecies (cattle, sheep and goats) and 90
human samples to Coxiella burnetii ELISA IgG test. In addition, information regarding risk
factors for the two zoonoses in both livestock and humans was collected using questionnaires.
Risk factors were management (grazing, watering and breeding system) introduction of new
stock, level of awareness of the livestock owners regarding the zoonoses and frequency of
contact with veterinary extension staff; contact with contaminated environment, consumption
of raw/unprocessed/under processed livestock products, close association with livestock and
awareness of the diseases for human. The harvested serum samples were tested for the
presence of antibodies to the Brucella organisms using the Competitive Enzyme Linked
Immunosorbent Assay (Com- ELISA) and C burnetii ELISA IgG.
Results indicated a low prevalence of brucellosis in humans 1.3 %but a higher prevalence of
Q-fever 26%. The overall prevalence in livestock was 12.91 % and 79.3 % for brucellosis and
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Q-fever respectively. The prevalence estimates in cattle, sheep and goats were 21.92%, 8.6 %
and 7.3% for brucellosis respectively and 89.7% , 57.5% and 83.1 % for Q-fever respectively,
indicating a high risk of transmission of the diseases to humans through contact or
consumption of livestock products such as milk. A univariate analysis of risk factors showed
that using a communal bull and introduction of new animals especially bulls were important
risk factors. However other factors that were found to be significantly (p < 0.05) associated
with testing positive to the disease in humans were occupation (p<0.05), method of processing
meat (p<0.01), whether they process blood before taking (p<0.001), contact with aborted
foetuses (p<0.029), and method of disposal of aborted foetuses and placentas (p<0.028), while
communal grazing system(p<0.005) and introduction of new animals was not significant
(p<0.07). The study and the data obtained strongly suggest that the two zoonotic diseases may
be enzootic in the study area in human, cattle, sheep and goats and presents a serious public
health problem among the inhabitants of the county and that there is need to create
awareness among all concerned on the likely high prevalence of the two diseases to avoid
misdiagnosis and suffering of patients. It is recommended that the veterinary personnel in
Kajiado County make an effort to investigate all cases of abortions and the possible causes
retained placentas that are included in their disease surveillance reports. This calls for
strengthening laboratory diagnostic capacity in the county by training more veterinary and
health staff and providing diagnostic equipment and reagents. Creating awareness on the
causes, modes of transmission and risk factors to the zoonoses should be undertaken as soon
as possible.
Publisher
University Of Nairobi
Rights
Attribution-NonCommercial-NoDerivs 3.0 United StatesUsage Rights
http://creativecommons.org/licenses/by-nc-nd/3.0/us/Collections
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