Incidence and risk factors of infectious diseases in smallholder pig farms in Vietnam

Biosecurity is critical for a healthy pig herd. This study aims at understanding incidence risk and risk factors of any farmer reported disease infection and African swine fever outbreaks on Vietnamese small-scale pig farms. Using a cross-sectional survey in the Bac Giang, Ha Nam, and Hoa Binh Provinces, 160 randomly chosen small-scale pig farms provided information about husbandry, hygiene and biosecurity practices and occurrence of disease in the last six months, including African swine fever. Farm-level incidence risk of farmers reported "disease outbreaks" and "African swine fever outbreaks" were estimated, and risk factors were explored using logistic regression analyses. The crude incidence risk of any farmer reported disease was 51 % (95 % CI: 43-59 %) and the risk were 60 %, 52 % and 43 % in the Hoa Binh, Ha Nam, and Bac Giang Province, respectively. The relevant risk and protective factors were: Being close to another pig farm (odds ratio (OR) = 3.81, 95 % CI: 1.40-11.70); checking water contamination annually (OR = 0.25, 95 % CI: 0.07-0.77); and, cleaning and disinfecting the vehicles that enter the farm (OR = 0.37, 95 % CI: 0.16-0.83). The findings from this study will offer scientific evidence for establishing biosecurity guidelines in smallholder pig farms in Vietnam.