Seroprevalence of Peste des Petits Ruminants (PPR) and associated risk factors in selected sub-counties of Lyantonde district, South Western Uganda

Background: Lyantonde District in Uganda, a recognized hotspot for Peste des Petits Ruminants (PPR) outbreaks. However, the magnitude and risk factors of PPR in this area remain poorly characterized. This study aimed to determine the prevalence of PPR antibodies in goats and sheep and to identify associated risk factors in selected sub-counties of Lyantonde District. Methods: A cross-sectional serosurvey was conducted in July 2024 in three purposively selected sub-counties (Lyantonde, Lyakajula, and Kinuuka), chosen for their large small ruminant populations, high livestock trade activity, and active animal movement. Farms without a history of PPR vaccination were randomly selected, and simple random sampling was used to select study animals. Whole blood samples were collected from the jugular vein and analyzed using the ID Screen® PPR competitive ELISA kit to detect virus-specific IgG antibodies. Multivariate analysis was performed using Modified Poisson regression to identify risk factors associated with PPR seroprevalence. Adjusted prevalence ratios (aPRs), 95% confidence intervals (CIs), and p-values were reported. Results: A total of 351 goats and sheep were sampled, with an overall apparent seroprevalence of 42.17% (n=148). The Rogan-Gladen estimator gave a true prevalence of 44.27%, with goats showing a significantly higher prevalence (46.27%) compared to sheep (33.62%) (p=0.046). Age was strongly associated with seropositivity: animals aged >1–3 years (aPR=1.86; 95% CI: 1.16–2.97) and >3–5 years (aPR=2.56; 95% CI: 1.54–4.24) had higher risk compared to those <1 year. Goats were more likely than sheep to test positive (aPR=1.59; 95% CI: 1.01–2.53). Farms reporting wildlife interactions had a 43% higher prevalence (aPR=1.43; 95% CI: 1.07–1.91), and acquisition of new animals from other farmers also increased risk (aPR=1.32; 95% CI: 1.02–1.71). Conclusion: PPR transmission in Lyantonde District is driven by host factors, farm-level practices, and livestock-wildlife interactions. Risk-based control strategies, including targeted vaccination in areas with intense animal trade and movement, are essential. Strengthened collaboration between MAAIF and UWA is needed to minimize livestock–wildlife contact, alongside improved farm biosecurity practices.