Objective: Soil-transmitted helminthiasis (STH) is among the neglected tropical diseases that commonly affect children in tropical and subtropical regions, especially in countries with finite resources like the Philippines. Although mass drug administration of anthelminthics is done annually, little is still known about the effectiveness of deworming, the prevalence and intensity of STH infection among preschoolers.

Materials and Methods: This is a descriptive, cross-sectional study conducted with 101 preschoolers in five daycare centers.

Results: Overall, STH infections observed were about 45.54%, with A. lumbricoides predominating and most cases were classified as light infection. Other parasites observed were T. trichiura and hookworm, of which the majority were co-infections with A. lumbricoides.

Conclusions: The data gathered from this study indicate a high possibility of reinfection, despite the study participants being dewormed consistently twice a year. Thus, other interventions, such as proper hygiene and sanitation, together with consistent deworming, should be implemented to prevent reinfection with STH.