Biomedical survey in North Samar Province, Philippine Islands.

ABSTRACT

A biomedical survey was carried out in North Samar Province, Philipines to update information on the prevalence of parasitic and other infectious diseases. A total of 1,394 stool specimens, 1,859 blood smears and 1,274 sera were collected from persons living in 8 barrios. Stools were examined for intestinal parasites, bloods smears for malaria and filariasis and sera tested for antibodies to Schistosoma japonicum, Entamoeba histolytica, Toxoplasma gondii, influenza A and B, and Japanese encephalitis virus. The prevalence rates for intestinal parasites were Trichuris trichiura 90%, Ascaris lumbricoides 78%, hookworm 65%, Schistosoma japonicum 15%, Strongyloides stercoralis 1%, Entamoeba coli 16%, Endolimax nana 6%, entamoeba histolytica 5%, Giardia lamblia 3%, Entaemoeba hartmanii 1%, Chilomastix mesnili 1%. No malaria was found but microfilariae of Wuchereria bancrofti were detected in 4% of the blood smears; the MfD50 was 12.9. The circumoval precipitin test (COPT) was used to detect antibodies to Schistosoma japonicum and 65% of 994 sera was considered positive. The indirect hemagglutination test (IHA) was used for detecting antibodies to Entamoeba histolytica and Toxoplasma gondii and 5% and 3% of 1,274 sera tested were positive at titers equal to or greater than 1128 and 1256, respectively. Hemagglutination inhibition tests (HI) were used to detect antibodies to Influenza A2HK68, Influenza A2HK68, Influenza B2T62 and Japanese encephalitis virus and 72%, 12% and 78%, respectively, of 1201 sera were considered positive at titers equal to or greater than 120.