Risk Factors of Exposure to Brucella Through Milk Consumption in Cattle Keeping Households in Rwanda

Milk produced in Rwanda and consumed in cattle keeping households poses undocumented food safety risks including the transmission of the zoonotic brucellosis from animals to humans. The aim of this study was, therefore, to determine the risk factors of exposure to Brucella species through milk consumption in zero grazing and open grazing cattle keeping households in Rwanda. The study was a cross-sectional study which involved 198 and 132 households practicing zero grazing and open grazing cattle production systems, respectively. To determine the risk factors exposure to Brucella through milk consumption, a questionnaire was used to collect data on milk consumption habits and indirect Enzyme-Linked Immuno-Sorbent Assay (i-ELISA) was used to collect data on farm bulk milk contamination with Brucella. Collected questionnaire and i- ELISA data were then analyzed using SPSS descriptive statistics and logistic regression. In nearly half (49.1 %; 162/330) of all surveyed households, raw milk was consumed. And overall, 14.2% (47/330) of all surveyed households were exposed to Brucella by having at least one household member consuming raw milk in a household for which the farm bulk milk sample tested positive for Brucella. The proportion of open grazing households in which raw milk was consumed and from which the farm bulk milk sample tested positive for Brucella (34.8 %; 46/132) was significantly high (p < 0.05) compared to the proportion of zero grazing households consuming raw milk and having a Brucella positive farm bulk milk sample (0.5 %; 1/198). While in total 4.8 % (77/1589) of all surveyed individual household members were exposed to Brucella by consuming raw milk in a household for which the farm bulk milk sample had tested positive for Brucella, the cattle keeper was the most exposed household member (OR=50.82, 95 % CI [17.9-143.9], p < 0.05). Practicing open grazing cattle production system was significantly associated with raw milk consumption and raw milk consumption in a household with a Brucella positive farm bulk milk. There is a risk of exposure to Brucella through milk consumption especially in households practicing open grazing cattle production in Rwanda. Educational campaigns are needed to raise awareness about the dangers of drinking raw milk in regards to zoonotic brucellosis.