First encounter of subclinical human Leishmania (Viannia) infection in State of Rio Grande do Sul, Brazil

The objective of the present study was to evaluate the specificity of the Montenegro skin test (MST) in an area in Brazil, state of Grande do Sul State (RS), which was considered to be non-endemic for leishmaniasis. Sixty subjects presented a positive MST and were reevaluated by clinical examination, serology and polymerase chain reaction (PCR) of peripheral blood for the detection of subclinical Leishmania infection. None of the subjects presented clinical signs or symptoms of current leishmaniasis or a history of the disease.Leishmania (Viannia) DNA was detected in blood by PCR and hybridization in one subject. The PCR skin test-positive individual remained asymptomatic throughout the study. Clinical examination showed no scars suggestive of past cutaneous leishmaniasis. Human subclinical infection with Leishmania (Viannia) in RS was confirmed by PCR. This is the first report of subclinical infection with this parasite in the human population of this area.

Sobre a origem e dispersão das leishmanioses cutânea e mucosa com base em fontes históricas pré e pós-colombianas / On the origin and spread of cutaneous and mucosal leishmaniasis, based on pre-and post- Colombian historical sources

Concentra-se sobre a origem, difusão e história das leishmanioses tegumentares americanas (LTA), com especial enfoque sobre a leishmaniose mucosa (LM) no continente sul-americano, cuja análise foi feita através de fontes históricas.

Phase 1 study of an inactivated vaccine against American tegumentary leishmaniasis in normal volunteers in Brazil

A phase 1 double-blind placebo-controlled study was performed to evaluate a vaccine against American tegumentary leishmaniasis in 61 healthy male volunteers. Side effects and the immune response to the vaccine were evaluated, with 1- and 2- dose schemes, with intervals of 7 or 21 days, each dose containing 1440 mg of protein N antigen of a single strain of Leishmania amazonensis (PH 8) diluted in merthiolated saline (1:10,000). Merthiolated saline and an inert substance were used as placebos. No significant clinical alterations were found following the respective injections in the vaccinated individuals as compared to the placebos, except for local pain, which was associated significantly with injection of the vaccine. The laboratory alterations we observed bore no association with the clinical findings and were unimportant. We observed no differences between the groups with regard to seroconversion or the Montenegro skin test. However, the group that received a single dose of the vaccine and the one that received two doses with a 21-day interval displayed cutaneous induration significantly larger than in the control group, with 100 per cent and 66 per cent conversion in the skin test, respectively. We concluded that the vaccine does not present any major side effect that would contraindicate its use in healthly individuals.

Dengue epidemic in the state of Rio de Janeiro, Brazil: virological and epidemiological aspects

Laboratory studies were carried out on 3178 patients with signs and symptoms suggestive of dengue infection from April 1986 to December 1987 in the State of Rio de Janeiro, Brazil. The epidemic had two peaks following the first virus isolation and affected the inhabitants of 17 counties. Both sex and all age groups were affected. Dengue virus type 1 was isolated from 1039 sera and the number of confirmed cases was increased to 1874 (59) by MAC-ELISA. Isolation rate confirmed cases reached 80 in the specimens obtained until the 4th day after the onset of disease and viraemia ranged from 10(3.0) to 10(8.5) TCID50/ml.