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Reports from several sites in South America suggest the presence of isolated cases of chloroquine-resistant Plasmodium vivax malaria. To investigate the possibility of chloroquine-resistant P. vivax in Peru, we conducted 28-day in vivo drug efficacy trials at three sites in the Amazon region and one site on the northern Pacific Coast between 1998 and 2001. A total of 242 patients between the ages of 2 and 60 years were enrolled (177 from the Amazon region and 65 from the northern coast). All subjects received directly observed therapy with chloroquine, 25 mg/kg, over a three-day period. On enrollment, 49% had a documented fever and 96% had a history of fever; their geometric mean parasite density was 5,129 parasites/L. A total of 212 (88%) of the 242 subjects completed their 28-day follow-up. Four of the 177 patients from the Amazon region had a recurrence of P. vivax parasitemia on days 21 and 28 after treatment was initiated. Two of these patients had chloroquine-resistant infections, based on polymerase chain reaction−singlestranded conformational polymorphism genotyping and chloroquine-desethylchloroquine blood levels, which were Ն 97 ng/mL at the time of the reappearance of parasitemia. None of the subjects studied on the northern Pacific Coast had recurrent parasitemia.

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Abstract. A longitudinal study of malariometric indicators and their association with potential risk factors was conducted during August 1997-July 1998 at Padre Cocha, a village of 1,400 residents in the Peruvian Amazon. The incidence of Plasmodium falciparum infections during the study year was 166/1,000 persons; that of P. vivax was 826/1,000 persons. The mean duration of symptoms prior to diagnosis was 2 days; presenting geometric mean parasite densities were 3,976 parasites/l for P. falciparum infections and 2,282 parasites/l for P. vivax. There were no malaria-associated deaths. Consistent with the epidemic nature of malaria in the area, the incidence of both parasite species increased with age and there were no age-specific differences in mean parasite densities. No specific occupational risks for malaria were identified. Activities significantly associated with malaria risk reflected local vector behavior and included strolling outdoors after 6:00 PM and arising before 6:00 AM for adults, and attending evening church services for children.

Pentamidine was compared with meglumine antimoniate (Glucantime) for 80 patients with cutaneous leishmaniasis due to Leishmania braziliensis in Peru. Of the 40 patients administered Glucantime (20 mg of antimony [Sb]/kg/day intravenously for 20 days), 31 cured (78%), 6 failed (15%), of which 5 were due to relapse, and 3 were lost to follow-up (7%). Of the 40 patients administered pentamidine (2 mg/kg every other day for seven injections), 14 were cured (35%), 23 failed (58%), and 3 were lost to follow-up (7%). Five pentamidine failures were due to relapse, and 14 failures were due to the presence of parasites two weeks after therapy. Both regimens were well tolerated. Gastrointestinal, musculoskeletal, and total adverse events were not statistically different in either group. Elevations in levels of liver enzymes and pancreatic enzymes were statistically higher in the Glucantime group, but no patient terminated therapy prematurely. In this study, Glucantime was more effective than pentamidine for treatment of L. braziliensis cutaneous leishmaniasis in Peru based on parasitologic as well as clinical criteria.