Dwellers in 6 villages in Talibon and Trinidad in Bohol, Philippines with an approximate population of 5, 740 were examined for schistosomiasis japonica by stool examination and circumoval precipitin (COP) test during the period from 1981 to 1984. Eggs were positive in 3.5% of 4, 117 examinees, whereas COP positives were 9.8% in 4, 094 examinees. Since prevalence of egg positives among COP positives increased from 24.4 and 24.0% to 79.1 and 48.1%, in 2 villages after repeated stool examinations, respectively, COP reactions by standardized method seem to indicate the actual infection of individuals. Among 6 villages, the prevalence did not vary much between 1.4% to 6.9% by a single stool examination while there was greater variation between 3.2% and 22.2% by COP test. Two villages, San Vicente and Sto. Tomas, were identified as the area of highest risk. At San Vicente where no snail colony had previously been found; a new snail colony was first identified at Apao Palawan Swamp in July 1984. The distribution of households of infected persons showing strong COP reactions led to the suspicion of presence and the eventual discovery of the snail colonies in the area.

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Leishmania braziliensis and L. donovani were investigated for the transformation and survival in intraperitoneal (IP), subcutaneous (SC) and intrascrotal (IS) diffusion chambers implanted into hamsters and mice. For a comparison, Trypanosoma cruzi was also examined by using the same procedure. The 2 Leishmania species revealed an unexpectedly short survival time, and no transformation was observed in the parasites in chambers implanted into hamsters or mice. IS chambers seemed to provide a better condition for L. donovani, L. braziliensis and T. cruzi, as compared with IP and SC chambers in hamsters. In the study, no IS chambers were examined in mice because of too small size of the scrotum to insert the diffusion chamber. T. cruzi showed a considerably longer period of survival than L. donovani or L. braziliensis in mice, but not in hamsters. The trypanosome, T. cruzi, transformed from epimastigote to trypomastigote and amastigote in IP and SC chambers in mice. These results seemed to suggest that the factors responsible for the transformation and survival of the organisms might be greatly different between the 2 genera, Leishmania and Trypanosoma, and also between the 2 host animals, hamsters and mice.

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A compound of trimethoprim (TMP) and sulfamethoxazole (SMZ) was effective in the treatment of vivax, ovale and falciparum malaria. Two patients with vivax malaria received 16 mg TMP /80 mg SMZ /kg body weight in 3 divided doses daily for 3 days. A patient with ovale malaria received 10 mg TMP /50 mg SMZ /kg body weight in 4 divided doses daily for 4 days. These doses were followed by 15 mg primaquine daily for 2 weeks. A patient with falciparum malaria received 16 mg TMP /80 mg SMZ /kg body weight in 3 divided doses daily for 3 days. In all patients, radical cures were achieved; neither relapse nor recrudescence has occurred. Trimethoprim-sulfamethoxazole succeeded in causing rapid clearance of asexualparasites from peripheral blood of the patients and producing rapid defervescence. No symptomatic adverse reactions to TMP-SMZ were experienced.

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In a population from an area endemic for Chagas' disease in Ecuador, cellmediated immune activity was assessed using delayed type hypersensitivity (DTH) reaction to PPD. Expression of DTH was significantly suppressed in individuals seropositive to Trypanosoma cruzi, and the suppression was markedly greater in the age group 10-39 years old than those over 40 years. The results show that cell-mediated immune response is apparently suppressed in patients with Chagas' disease, and tends to be restored in chronic stage. No defference was noted in the serum concentration of immunoglobulins between patients and controls.

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