This week’s Joint International Conference of the Association of Institutions for Tropical Veterinary Medicine and the Society of Tropical Veterinary Medicine featured a poster on the occurrence of selected bacterial and viral pathogens in smallholder pig production systems in Uganda by Michel Dione (ILRI), Charles Masembe (Makerere University), Joyce Akol (Makerere University), Joseph Kungu (National Livestock Resources Research Institute, Uganda), Winfred Amia (ILRI) and Barbara Wieland (ILRI).
Smallholder pig production plays a big role in the livelihoods of several communities in Uganda. Pigs potentially harbour several pathogens, most of which might be insidious. In order to check for presence and determine the level of bacterial and viral pathogens in smallholder pig herds in two districts (Masaka and Lira) of high pig population in Uganda, a survey was undertaken between June and July 2015. These pathogens were purposively selected based on one of the following criteria: good marker for biosecurity at farm, or pathogen which provokes clinical signs that resemble to those that were described by farmers in their swine herds during a previous study in the same locations.
In total 320 clinically healthy pig herds were selected from 32 villages, with 10 herds per village. In each herd, a maximum of 3 pigs were included in the study resulting in 623 serum samples. The samples were subjected to antibody serology for eight pathogens using commercial ELISA kits. In addition data was collected on potential risk factors, biosecurity knowledge and practices, as well as husbandry practices of pig farmers.
Streptococcus suis and Leptospira spp. were highly prevalent in most herds with animal level prevalence of 83.3% (CI95: 74.1-89.7) and 70.6(61.1-79.6) respectively. Additionally, high prevalence was found for Porcine circovirus type 2 with 43.7% (CI95: 34.08-54.3), Actinobacillus pleuro-pneumoniae 23.0% (CI: 15.0-33.40, Mycoplasma hyopneumonia 15.4% (CI95: 8.6-23.5), Influenza A 5.8% (CI95:2.2-12.6) and Porcine parvovirus 4.5 % (1.6-11.3). Significant differences were observed in prevalences of infected animals between districts with Streptococcus suis being higher in Masaka (P=0.016) and Mycoplasma hyopneumonia, Influenza A, and Porcine circovirus type 2 being higher in Lira (P=0.00, P=0.00, P=0.03 respectively). Porcine Reproductive and Respiratory Syndrome Virus 1.3% (CI95: 1.6-11.3) and Aujeszky’s disease virus 0.2% (CI95: 0.0-03.6) were less common.
The observed patterns of multiple infections, the related risk factors, biosecurity perceptions and practices of farmers provide important entry points to improve the current production systems and thus contribute towards reducing the economic impact of commonly occurring pig pathogens. These pathogens, which might be silent killers, are under diagnosed given the fact that the disease of focus of farmers is African swine fever, which they know most about. The findings of this study constitute baseline data to measure impact of future interventions aiming to reduce disease burden. This is the first report in Uganda examining occurrence of this range of pathogens of economic and public health importance in pigs. Follow up investigations are needed to characterise the most commonly pathogenic serotypes and genotypes of the above pathogens, and study the dynamics and impact of these pathogens in current smallholder pig production systems.