Vol 35 (Suppl 1) 2004 123 SCHOOL-BASED ASSESSMENT OF SOIL-TRANSMITTED HELMINTHIASES AND FOOD-BORNE PARASITOSIS (INTESTINAL FLUKE INFECTION) IN MONKAYO, COMPOSTELA VALLEY Vicente Y Belizario, Jr 1 , Mary Joan J Bersabe 2 , Ana Belinda E de los Reyes 3 and Winifreda U de Leon 4 1 Department of Parasitology, College of Public Health, University of the Philippines, Manila; 2 Center for Health Development for Southern Mindanao, Department of Health, Regional Field Office XI, Davao City; 3 Department of Parasitology, College of Public Health, University of the Philippines, Manila; 4 Department of Parasitology, College of Public Health, University of the Philippines, Manila, Philippines Abstract. The objectives of the study were: 1) to determine the prevalence and intensity of intestinal helminthiasis, including soil-transmitted helminthiases and heterophyid infections using school-based assessment; 2) to determine the impact of mass treatment using albendazole for soil-transmitted helminthiases in terms of prevalence and intensity of infection, cure rate, and egg reduction rate; 3) to determine the effectiveness of selective treatment using praziquantel for heterophyid infection; 4) to determine reinfection rates of intestinal helminths under study after 6 months; and 5) to attempt to determine intestinal fluke species. The study was conducted in two barangays of Monkayo, Compostela Valley in Southern Mindanao, ie San Isidro and Casoon. Grades III and IV pupils were targeted as the indicator group. Parasitologic assessment was done at baseline or Day 0 using Kato-Katz technique. Targeted mass treatment for soil-transmitted helminthiases was done using albendazole 400 mg tablets, while selective treatment for intestinal fluke infection was done with praziquantel 25 mg/kg p.o. three doses in one day. Follow-up parasitologic assessments were done at Days 7 to 14 to document response to treatment and at Day 180 (for Grades IV and V pupils in the next school year) to determine reinfection with soil-transmitted helminths and heterophyid. Data were collated and processed using EpiInfo 6 software, which allowed derivation of descriptive statistics. Of 84 pupils examined at baseline, the overall cumulative prevalence of soil-transmitted helminthiases was 48.6%. Hookworms were the most common soil-transmitted and intestinal helminth in both barangays, with 35.3% of pupils infected. Heterophyid infection was the next most common intestinal helminth, at 32.4%. Multi-parasite infections were common. The cure rate for heterophyid infection was highest, at 92.9%, with excellent cure rates for those with initially light to moderate intensities. The cure rate for hookworm infection was good, at 88.5%. Egg reduction rates for hookworms and heterophyid infections were also excellent, at 95.3 and 82.9%, respectively. At Day 180, the cumulative prevalence of soil-transmitted helminthiases was 41.3%. The hookworm and heterophyid infections were still most common at 27.7 and 29.0%, respectively. Hookworm infection rates were not markedly different between the two barangays. Reinfection by heterophyids was highest among all intestinal helminthiases. The hookworm reinfection rate was 26.3%, with rates similar in the two barangays, and an overall egg reduction of 45.6% compared with baseline. Heterophyid flukes were collected from adult patients with heterophyid eggs on stool examination. Preliminary studies on the flukes indicate the species to be Haplorchis taichui. Correspondence: Vicente Y Belizario, Department of Parasitology, College of Public Health, University of the Philippines, 625 Pedro Gill Street, Ermita, Manila 100, Philippines. E-mail: vbelizar@yahoo.com INTRODUCTION Soil-transmitted helminthiases remain one of the leading causes of morbidity among school-age children. Long-term effects of chronic infections include malnutrition, poor cognitive function, anemia, and other states of poor health. These infections continue to affect the majority of public elementary schoolchildren in the Philippines, posing a threat to children’s productivity and future. Intestinal fluke or heterophyid infection until recently was thought to be uncommon but widely distributed in the Philippines. This infection, which is transmitted by ingestion of raw or insufficiently cooked fish, is known to cause gastrointestinal disturbance, mainly peptic ulcer-like symptoms and is known to have destructive effects on the brain, spinal cord, and heart, as parasite eggs are carried to these organs. Recent studies by the proponent’s group have shown that contrary to reported findings in the 1980s, it is not uncommon, with prevalence rates ranging from 16 to 36% in villages in Monkayo, Compostela Valley Province (Cross and Basaca-Sevilla, 1984). At present, heterophyid infection is known to exist in 11 out of 21 barangays in Monkayo. In Barangay San Isidro, of 242 individuals examined for this parasitic infection, 87 people (35.9%) were found infected in a survey in