Title: Seroprevalence of brucellosis in different small ruminant husbandry systems and associated risk behaviors in Mali: A cross-sectional study

Abstract

Background: In Mali, there are different animal’s production systems which have been key driver for interaction between animals and humans which is likely a potential risk for transmission of brucellosis. The objectives of this study were: to (i) identify different small ruminants husbandry systems in Mali; (ii) determine seroprevalence of brucellosis according to the husbandry systems identified; and (iii) identify human risk behaviours. Methods: A cross-sectional study using cluster sampling was conducted in the Sikasso, Segou and Bamako districts. Blood was collected from 860 small ruminants. The sera obtained were examined using Rose Bengal and cELISA tests paralelly. In addition, 119 breeders were interviewed using a structured questionnaire. The statistical analyses were performed with R software (RStudio-1.0.136). A herd was considered positive if at least one animal in that herd was positive either to RB or cELISA. Chi-square test was undertaken and it was deemed significant when p≤0.05. Results: Agropastoral systems accounted for 43.7% [34.5 - 53.1% (95% CI)] of the systems identified and pastoral systems for 31.1% [22.9 - 40.2% (95% CI)]. Peri-urban and urban farms accounted for 17.6% [11.2 - 25.7% (95% CI)] and 7.5% [3.5 - 13.8% (95% CI)] respectively of the farms. Individual seroprevalence was 4.1% [2.8 – 5.6 % (95% CI)]. Herd seroprevalence was estimated at 25.2% [17.7 - 33.9 % (95% CI)]. Peri-urban farms seem to be more affected 38.1% [18.1– 61.5% (95% CI)], followed by pastoral farms 24.3% [11.7 – 41.1% (95% CI)]. Risk behaviours such as exchange of reproductive bulls (30.2 %), suspension of placentas (31.1 %) in the farms, keeping of females having already aborted (69.7 %) The close and prolonged contact (51.2%) with the animals, the consumption of unpasteurized dairy products (26.9 %), assisting females for delivery without any protection (40.3%) are practices identified that can promote the transmission of brucellosis to both animals and humans. Conclusion: Brucellosis seems to be a problem in all husbandry systems in the studied regions. High seroprevalence and presence of practices provide a possibility of cross transmission between animals and humans.