Infection rates and genotypes of Trypanosoma rangeli and T. cruzi infecting free-ranging Saguinus bicolor (Callitrichidae), a critically endangered primate of the Amazon Rainforest.

Parasites of wild primates are important for conservation biology and human health due to their high potential to infect humans. In the Amazon region, non-human primates are commonly infected by Trypanosoma cruzi and T. rangeli, which are also infective to man and several mammals. This is the first survey of trypanosomiasis in a critically endangered species of tamarin, Saguinus bicolor (Callitrichidae), from the Brazilian Amazon Rainforest. Of the 96 free-ranging specimens of S. bicolor examined 45 (46.8%) yielded blood smears positive for trypanosomes. T. rangeli was detected in blood smears of 38 monkeys (39.6%) whereas T. cruzi was never detected. Seven animals (7.3%) presented trypanosomes of the subgenus Megatrypanum. Hemocultures detected 84 positive tamarins (87.5%). Seventy-two of 84 (85.7%) were morphologically diagnosed as T. rangeli and 3 (3.1%) as T. cruzi. Nine tamarins (9.4%) yielded mixed cultures of these two species, which after successive passages generated six cultures exclusively of T. cruzi and two of T. rangeli, with only one culture remaining mixed. Of the 72 cultures positive for T. rangeli, 62 remained as established cultures and were genotyped: 8 were assigned to phylogenetic lineage A (12.9%) and 54 to lineage B (87.1%). Ten established cultures of T. cruzi were genotyped as TCI lineage (100%). Transmission of both trypanosome species, their potential risk to this endangered species and the role of wild primates as reservoirs for trypanosomes infective to humans are discussed.

American cutaneous leishmaniasis due to Leishmania (Viannia) guyanensis as an initial clinical presentation of human immunodeficiency virus infection.

The authors present the first report of Leishmania (Viannia) guyanensis (L.(V.) guyanenesis) associated with human immunodeficiency virus (HIV) in a Brazilian heterosexual man. It is also the first case of HIV infection associated with American cutaneous leishmaniasis in Brazilian Western Amazonia. The patient had cutaneous and mucous lesions with a negative Montenegro skin test. Histopathology showed large numbers of amastigotes, even in a lesion which had clinically healed. L.(V.) guyanenesis was typed by an immunoenzymatic technique. Various therapies were attempted, but the patient relapsed after each episode of treatment.

Epidemiological and nosological aspects of Leishmania naiffi Lainson & Shaw, 1989

Leismania naiffi was isolated from 10 out of 64 armadillos (Dasypus novemcinctus) examined in Amazonas, Pará and Rondônia States in the Brazilian Amazon Region. The isolates were obtained in culture from samples of liver (3), spleen (3), lymph nodes (2), skin (1) and blood (1) from the infected animals. Heavy infections with the same parasite were detected for the first time in Psychodopygus squamiventris, a common man-biting phlebotomine, in amazonas and Pará. A new case of cutaneous leishmaniasis caused by L. naiffi is described from the Manaus area, making a total of three known cases of human infection by this parasite

Epidemiological and nosological aspects of Leishmania naiffi Lainson & Shaw, 1989.

Leishmania naiffi was isolated from 10 out of 64 armadillos (Dasypus novemcinctus) examined in Amazonas, Pará and Rondônia States in the Brazilian Amazon Region. The isolates were obtained in culture from samples of liver (3), spleen (3), lymph nodes (2), skin (1) and blood (1) from the infected animals. Heavy infections with the same parasite were detected for the first time in Psychodopygus squamiventris, a common man-biting phlebotomine, in Amazonas and Pará. A new case of cutaneous leishmaniasis caused by L. naiffi is described from the Manaus area, making a total of three known cases of human infection by this parasite.

Distribution of Histoplasma capsulatum in Amazonian wildlife.

In a survey of 296 sylvatic animals captured from virgin forests in the north-eastern and south-western Amazon of Brazil, Histoplasma capsulatum was isolated, via the indirect hamster inoculation method, from the liver and spleen of four common opossums Didelphis marsupialis and two pacas Agouti paca. The infected animals did not show any clinical symptoms or histopathology. The known Amazonian mammalian species with natural histoplasmosis now total five, the previously reported species being the spiny rat Proechimys guyannensis, the two-toed sloth Choloepus didactylus and the nine-banded armadillo Dasypus novemcinctus.

Chagas' disease in the Amazon basin IV. Host records of Trypanosoma cruzi zymodemes in the states of Amazonas and Rondonia, Brazil.

Of 151 Trypanosoma cruzi stocks from 117 different individual hosts collected in the states of Amazonas and Rondonia, 147 from 113 hosts were identified as zymodeme 1 (Z1). These included T. cruzi stocks from three marsupial species, two rodent species and three triatomine species although most were from the common opossum, Didelphis marsupialis. One T. cruzi stock from Rhodnius robustus was identified as Z1 with a Z3 PGM character, one from Sciurus sp. as Z3 and two from Monodelphis brevicaudata and Panstrongylus geniculatus as Z3 with a Z1 ASAT character. The ways in which stocks were isolated and grown up in vitro did not influence isozyme profile. These results support earlier evidence from Pará State that Z2 is absent from the Amazon basin and that the distribution of T. cruzi zymodemes in this region is quite different to that in endemic areas on the south of the continent.