Seroprevalence and potential risk factors of contagious bovine pleuropneumonia in the Huambo province of Angola

From June to September 2023, we performed a cross-sectional study to estimate the seroprevalence of contagious bovine pleuropneumonia in the Huambo province of Angola; the study also characterized associated risk factors. We sampled 142 herds belonging to livestock farmers in four municipalities (Caála, Longonjo, Bailundo, and Mungo). A competitive ELISA approach was used to detect the presence of antibodies against Mycoplasma mycoides subspecies mycoides (Mmm) in 1647 cattle. Herd-level seropositivity was determined using a threshold that accounted for test measurement uncertainty in the laboratory. Data on herd characteristics were collected from livestock farmers using a questionnaire. We explored the relationship between 14 potential risk factors and herd seropositivity using logistic regression models. Overall, apparent herd-level seroprevalence was 55.6% (95% CI 46.9-63.1%). The likelihood that a herd was seropositive was related to the area where cattle had been purchased; it was significantly higher when animals came from the southern region of Huambo (odds ratio: 5.5; 95% CI 1.4-17.5). Although our study was limited by its sampling design (we lacked comprehensive information on the province's farms), our findings suggest that Mmm infections may occur at significant levels in Huambo and highlight distribution patterns that could guide disease control strategies in livestock farming systems.