Co-infections of respiratory pathogens and gastro-intestinal parasites in smallholder pig production systems in Uganda

Abstract

Abstract A cross-sectional study was conducted to identify factors for infections of pigs with key respiratory pathogens: porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PPRSv), Mycoplasma hyopneumoniae (M. hyo), Actinobacillus pleuropneumoniae (App) and gastro-intestinal (GIT) parasites in Uganda. A structured questionnaire was used to collect data on management practices associated with infections. Ninety (90) farms and 259 pigs were sampled. Sera were screened against 4 pathogens using commercial ELISA tests. The Baerman’s method was used to identify parasite species in faecal samples. Logistic regression was done to identify risk factors for infections. Cluster analysis was done using a hierarchical K-means partitioning algorithm. Results showed individual animal seroprevalence of PCV2 was 6.9% (95% CI 3.7–11.1), PRRSv 13.8% (95% CI 8.8–19.6), M. hyo 6.4% (95% CI 3.5–10.5) and App 30.4% (95% CI 24.8–36.5). The prevalences of Ascaris spp was 12.7% (95% CI 8.6–16.8), Strongyles spp was 16.2% (95% CI 11.7–20.7) and Eimeria spp was 56.4% (95% CI 50.3–62.4). Pigs infested with Ascaris spp were more likely to test positive to PCV2, odds ratio (OR) 1.86 (CI 1.31–2.60; p = 0.0002). For M. hyo, infection with Strongyles spp was a risk factor (OR 12.9, p < 0.001). Pigs that had parasite infestations were more likely (Strongyles spp. and Ascaris spp. ORs 3.5 and 3.4, p < 0.001, respectively) to have respiratory co-infections. Overall, 3 farm clusters were characterized by housing, biosecurity practices and pathogens. This study provides evidence that improving hygiene and biosecurity is critical in reducing pathogen incidence in herds.