Amoebiasis and intestinal parasitic infections in a population on Cebu Island, the Philippines

Abstract

A serological and stool survey was carried out on Cebu Island in the Philippines, confirming reports of a suspected epidemic of amoebiasis. Sera were tested for indirect hemagglutinating antibodies (IHA) to Entamoeba histolytica and the stools examined for this parasite by the direct and formalin-ether concentration methods and the polyvinyl alcohol (PVA) trichrome staining technique. A questionnaire survey was also conducted and information obtained on health and sanitary practices. Positive IHA titers (.gtoreq. 1:128) were detected in 4% of 1029 sera tested and E. histolytica was found in 5% of 1014 stools examined. Parasites found in the stools in relatively high numbers were Trichuris trichiura (53%), Ascaris lumbricoides (50%), hookworm (22%), E. coli and Endolimax nana (12%), Girardia lamblia (10%) and E. hartmanni (3%); 79% of the surveyed group had 1 or more parasites. Other helminthic and protozoan parasites were found rarely. The survey confirmed amoebiasis as endemic, but not epidemic, in the area and the increased reporting of cases was attributed to the laboratory and clinical competence of the hospital staff. Substandard sanitary conditions within the barrio (in which most of the people lived) were considered responsible for the high prevalence of intestinal parasitic infections in the population.