From Perpetual Wetness to Soil Chemistry: Enumerating Environmental and Physicochemical Factors Favoring Snail Presence in the Municipality of Gonzaga, Cagayan, Philippines.

Snail control to complement mass drug administration is being promoted by the World Health Organization for schistosomiasis control. , the snail intermediate host of in the Philippines, has a very focal distribution; thus, scrutinizing baseline data and parameters affecting this distribution is very crucial. In this study in Gonzaga, Cagayan, Philippines, snail habitats were surveyed, and the various factors affecting the existence of the snails were determined.

Analysis of Environmental DNA and Edaphic Factors for the Detection of the Snail Intermediate Host .

Background: The perpetuation of schistosomiasis japonica in the Philippines depends to a major extent on the persistence of its intermediate host an amphibious snail. While the malacological survey remains the method of choice in determining the contamination of the environment as evidenced by snails infected with schistosome larval stages, an emerging technology known as environmental DNA (eDNA) detection provides an alternative method. Previous reports showed that eDNA could be detected in water, but no reports have been made on its detection in soil.

Genetic structure inferred from mitochondrial 12S ribosomal RNA sequence of Oncomelania quadrasi, the intermediate snail host of Schistosoma japonicum in the Philippines.

Species and subspecies of the Oncomelania hupensis species complex are recognized as intermediate hosts of Schistosoma japonicum. Of these species and subspecies, O. quadrasi is distributed throughout the Philippines.

New endemic foci of schistosomiasis infections in the Philippines.

Schistosomiasis affects 28 provinces in the Philippines found along the southeastern part where there is continuous rainfall throughout the year. In 2002 and 2005 respectively, two new endemic foci were reported in the northernmost (Gonzaga, Cagayan) and central (Calatrava, Negros Occidental) parts of the country. This study conducted in March 2008-March 2009 confirmed the presence of the disease by determining its prevalence using four diagnostic tests - Kato-Katz, circumoval precipitin test (COPT), ELISA and ultrasonography.