Sero-prevalence and Risk Factors Associated With Coxiella Burnetii From Cattle in the Masaai Mara Ecosystem in Narok, Kenya

Abstract

In Sub-Saharan Africa, livestock keeping is the backbone of livelihoods for most inhabitants and plays a key role in rural poverty alleviation strategies. In countries like Kenya, livestock keeping has a higher socio-economic role; people’s livelihoods are intertwined with those of their livestock with a bigger proportion of people directly dependent on livestock products and indirectly through the income generated through livestock sales and their products or employment in livestock-related sectors. Infectious diseases such as Q fever caused by Coxiella burnetii in the livestock industry affects its productivity and ability to support livelihoods. The aim of this study was to conduct a seroprevalence and risk factor analysis of C. burnetii in cattle in Mara ecosystem in an effort to strengthen baseline data. 589 samples were collected in a cross sectional design-multistage sampling and stored at a Sera bank at the International Livestock Research Institute (ILRI). These sera samples were then tested for the Q fever antibodies using IDEXX ELISA. The sera were previously collected from 390 herds in 5 different villages from 3 zones subdivided based on the livestock-wildlife interactions and land use patterns. Zone was 1 characterized by extensive pastoralism where animals grazed in surrounding wildlife reserves, zone 2 was characterized by sedentary husbandry system with animal grazing zones fenced and zone 3 was characterized with mixed agriculture and livestock systems.A questionnaire was used to collect data on farm and animal levels factors. The sera samples were analyzed using an IDEXX ELISA kit to detect the presence of Coxiella burnetii IgG antibodies which were measured by means of colorimetry. Univariable and multivariable logistic regression analyses were used to analyze for the risk factors for C. burnetii seropositivity, with the outcome variable being the exposure to C. burnetii antibodies The seroprevalence of C. burnetii was (1.9%) where 11 samples revealed the presence of C.

burnetii IgG antibodies. Zone 3 with a lower livestock-wildlife interaction, had a higher seroprevalence [2.48% (CI 0.51 ± 7.07)] than zone 1, which had higher interaction at the livestock-wildlife interphase [1.75% (CI 0.48 ± 4.42)]. Significant risk factors on univariate analysis at animal level was bull ownership {OR=4.8 (CI 0.4±16.2) P value 0.016}, while at at the herd level the significant variables were animals grazing in shared areas between villages {OR 2.3CI 1.0 ± 5.0) P value 0.046}, mixing of cattle in different herds had an {OR 0.4 CI 0.2 ± 0.9 P value 0.029}, herds that had newly purchased livestock {OR 10.1 CI 1.3±75.8 P value 0.025}, bull ownership P value 0.003, history of abortion in the herd { OR 0.3 CI 0.1 ± 10.9 P value 0.018} and communal grazing had a borderline significance of (OR=2.2 P-Value). At the multivariable analysis bull ownership was the only significant variable {OR 5.2 CI 1.5 ±18.4) P value 0.010). The study confirmed the previous exposure of the cattle in Mara ecosystem to the Coxiella burnetii representing the risk to human transmission and qualifying the need to have better veterinary and public health interventions.