Analyzing risk factors for herd seropositivity to classical swine fever in West Timor, Indonesia

A cross-sectional study was undertaken to identify factors associated with herd-level seropositivity to Classical Swine Fever (CSF) in smallholder pig farms in West Timor, Indonesia. Questionnaires were distributed to 240 pig farmers from 8 villages in two districts to collect information about farm structure and herd information, reproductive management and performance, husbandry, pig introductions and exits, health status, farmers' knowledge and history of vaccination. Three risk factors were found to be associated with the presence of antibodies to CSF in the herd in a multivariable logistic regression model. Seropositivity was associated with the introduction of pigs in the 12-month period preceding the survey (OR 4.78, 95% CI: 1.46, 15.71). Farmers who kept goats were 3.42 (95% CI: 1.20, 9.81) times more likely to have seropositive pigs than farmers without goats. Herds that had been vaccinated against CSF were also 2.33 (95% CI: 1.10, 5.12) times more likely to be seropositive than non-vaccinated herds. This latter positive association is likely to be as a result of antibodies induced by vaccination rather than a true risk factor for infection. The results of the questionnaire highlighted the lack of implementation of biosecurity measures by smallholder farmers in West Timor, which has the potential to increase the risk of their pigs to CSF, as well as other diseases.