Epidemiological Study on Humans, Animals and Snails for Schistosomiasis in Two Endemic Municipalities Nearing Elimination in Bohol, the Philippines.

Purpose: A comprehensive survey was conducted to assess the prevalence of Schistosoma japonicum infection in humans, water buffaloes, and snails in the two endemic municipalities of Talibon and Trinidad in Bohol, Philippines, which are nearing elimination.

Methods And Results: Human stool and blood samples were collected from barangays with snail breeding sites, and results showed higher positivity rates using the rSjTPx-1-ELISA compared to the Kato-Katz technique. Human stool examination for showed a 0.57% positivity rate for S. japonicum in San Vicente, Trinidad, while no cases were found in San Roque, Talibon. On the other hand, 3.43% of human serum samples from San Vicente, Trinidad, and 46.20% from San Roque, Talibon tested seropositive. Similarly, water buffalo samples revealed 16.95% seropositivity in Talibon and 10% in Trinidad. Additionally, snail infection was determined microscopically from collected Oncomelania hupensis quadrasi snails in Talibon, but no schistosome parasites were detected in the crushed snail tissues.

Conclusion: These findings highlight that despite progress towards elimination, schistosomiasis transmission persists in these areas, emphasizing the need for continued surveillance and targeted interventions.