Soil-transmitted infections persist in areas where personal hygiene and environmental sanitation practices are poorly carried out and where cases remain untreated and become continuing sources of infection. A high prevalence of helminthiasis is also generally associated with areas that are basically agricultural and low in the economic and human development scale.

The three major causes of intestinal parasitism in the Philippines are:
-ascariasis or roundworm infection
-trichuriasis or whipworm infection
-and hookworm infection.

Other causes of parasitoses that continue to affect some areas are:
-paragonimiasis
-capillariasis
-echinostomiasis
-taeniasis or tapeworm infection.

Source: National Objectives for Health, Philippines, 2005-2001, Department of Health, Manila, Philippines.