Prevalence, risk factors, and spatial distribution of Fasciola in carabao and intermediate host in Baybay, Leyte, Philippines.

Fasciolosis remains an important parasitic disease of ruminants in Southeast Asia. We investigated the prevalence and spatial distribution of Fasciola spp. in carabao (Bubalus bubalis) and snail intermediate hosts (IHs) in Baybay, Leyte, Philippines. Using one-stage cluster sampling, we examined 335 fecal samples of carabaos from 138 herds for Fasciola spp. eggs, and in parallel collected IH snail data in the area. Risk factor analyses were performed and GIS maps were created for Fasciola spp. prevalence and IH snail distribution. The prevalence of Fasciola spp. in animal and herd level was 63.58% and 86.96%, respectively. Risk factor analyses showed that increasing age and drinking from irrigation water were highly associated with Fasciola infection in carabaos. Inversely, access to wallowing ponds seemed to be a significant protective factor. Lymnaeid snail presence was higher in areas with intensive networks of irrigated water system and rivers, land elevation above sea level, and moderate vegetation. Our epidemiologic data suggest a high endemicity of Fasciola spp. in Baybay, Leyte and present essential factors to consider in implementing control measures.