Discovery of a new focus of human onchocerciasis in central Brazil

Abstract

An autochthonous case of human onchocerciasis was reported 13 years ago in the town of Minaçu, northern Goiás (Brazil), but a subsequent survey of the population using the traditional technique of examining skin biopsies with the light microscope failed to detect other cases. Recent surveys using more sensitive diagnostic techniques (serodiagnosis, DNA probes, Mazzotti test) that are detailed in this paper revealed the presence of other cases of the disease in Minaçu, the nearby town of Formoso and at the Buracão gold mine near Paranã. The data show that transmission of the disease has occurred to local people living in town and on farms and that gold miners (garimpeiros) are a likely source of infection.

Nested PCR to detect and distinguish the sympatric filarial species Onchocerca volvulus, Mansonella ozzardi and Mansonella perstans in the Amazon Region

“…Strategically, the polymerase chain reaction (PCR) approach fulfils several objectives related to the diagnosis of filariasis in the human host and the detection of filarial larvae in the vector because it can detect a single worm and is cost effective (Ramzy 2002). Several PCR methods have been described for the specific diagnosis of filariasis, most of which use repetitive DNA, including ribosomal genes, to detect M. streptocerca (Fischer et al 1998) tivity with other filarial species; thus, a species-specific probe was required for diagnosis (Meredith et al 1991, Zimmerman et al 1994, Maia-Herzog et al 1999.…”

Sensitive and specific serodiagnosis of onchocerciasis with recombinant hybrid proteins.

“…3 None of these antigens has a sensitivity and specificity of 100%, and only a cocktail of antigens has been reported to have the qualities required for a reliable diagnosis. 13,16,17 This cocktail, consisting of three fusion proteins, is difficult to produce and requires parallel tests for controlling seroreactivity with the carrier protein. 13 To improve this situation, we attempted to emulate the potential of the two well-described immunodiagnostic proteins (Ov33 and Ov20).…”

“…[8][9][10][11][12][13][14] Some of these antigens were tested in a multicenter trial organized by the Tropical Diseases Research Program of the WHO that identified highly specific proteins, 15 and high sensitivity of these tests was achieved by combining three proteins in a diagnostic cocktail. 13,16,17 However, these antigens were difficult to produce and the fact that they were expressed as fusions with a carrier protein made it necessary to run parallel tests to rule out antibody reactions with the carrier. These limitations have prevented the O. volvulus antigen cocktail from becoming a widely used diagnostic tool.…”

Distribuição de espécies de borrachudos (Diptera: Simuliidae) do Espírito Santo, Brasil

“…No Brasil, casos da doença foram registrados nos Estados de Roraima e Amazonas, sempre associados à presença desses dípteros (Cerqueira 1959, Moraes & Chaves 1974, Shelley & Coscarón 2001 (Shelley 1988, Maia-Herzog et al 1999.…”