Mosquitoes infected with dengue viruses in Brazil.

Dengue epidemics have been reported in Brazil since 1985. The scenery has worsened in the last decade because several serotypes are circulating and producing a hyper-endemic situation, with an increase of DHF/DSS cases as well as the number of fatalities. Herein, we report dengue virus surveillance in mosquitoes using a Flavivirus genus-specific RT-Hemi-Nested-PCR assay. The mosquitoes (Culicidae, n = 1700) collected in the Northeast, Southeast and South of Brazil, between 1999 and 2005, were grouped into 154 pools. Putative genomes of DENV-1, -2 and -3 were detected in 6 mosquito pools (3.8%). One amplicon of putative DENV-1 was detected in a pool of Haemagogus leucocelaenus suggesting that this virus could be involved in a sylvatic cycle. DENV-3 was found infecting 3 pools of larvae of Aedes albopictus and the nucleotide sequence of one of these viruses was identified as DENV-3 of genotype III, phylogenetically related to other DENV-3 isolated in Brazil. This is the first report of a nucleotide sequence of DENV-3 from larvae of Aedes albopictus.

Widespread occurrence of antibodies against circumsporozoite protein and against blood forms of Plasmodium vivax, P. falciparum and P. malariae in Brazilian wild monkeys

Background A survey of malaria antibodies was carried out over 7 years and a total of 777 serum samples from wild monkeys were collected in three distinct ecological areas of Brazil where autochthonous malaria has been reported: the 'Cerrado' (similar to savanna), the Atlantic Forest and the Atlantic Semideciduous Forest. Methods We carried out enzyme-linked immunosorbent assay to investigate the presence of IgG antibodies against peptides of the circumsporozoite protein (CSP) repeat region of 'classic'Plasmodium vivax, P. vivax VK247, human P. vivax-like/P. simiovale, P. brasilianum/P. malariae and P. falciparum. We also carried out immunofluorescence assay with asexual forms of P. vivax, P. malariae and P. falciparum. Results The high prevalence of antibodies against CSP in all areas indicates that the monkeys had intense contact with sporozoites from infected anophelines. The immune response against asexual forms of Plasmodium in the monkeys from the Atlantic Forest indicates the development of the infection. Conclusions We discuss the possibility of monkeys being malaria reservoirs in non-endemic areas.