Abstract
Background: Classical swine fever (CSF) is a notifiable disease, and the limited epidemiological data in the Philippines underscores the need for effective disease surveillance. Methods: This study aimed to determine the prevalence of antibodies against CSF virus (CSFv) using enzyme-linked immunosorbent assay and CSFv RNA using real-time reverse transcription polymerase chain reaction in pigs from smallhold farms in 21 Philippine provinces. The association between seropositivity and factors from interviews of abattoir officers was analyzed using the least absolute shrinkage selection operator regression. A semi-quantitative method was also adapted to estimate the transmission risk. Results: Our study found an overall seroprevalence of 36.0% (153/425, 95% Confidence Interval: 31.5%-40.8%), while all 423 samples tested negative for CSFv. A positive association was found in water treatment, swill feeding, CSF vaccination, and keeping vaccination records, while CSF history, proximity to residential areas, and raising native pigs negatively impacted seropositivity. Nueva Ecija was considered high-risk for CSF transmission, while others fell within the moderate, low, and very low risk categories. Conclusions: Our findings highlight the CSF seroprevalence and factors to consider for improved prevention and control. Classifying the provinces according to transmission risk also provided insights on future targeted surveillance and efficient resource allocation.
Keywords: Philippines, Prevalence, Risk scoring, Transmission