Human onchocerciasis in Brazil: an overview

Abstract

Human onchocerciasis was recently discovered in Brazil among Yanomámi Indians living along the border region with Venezuela in the States of Amazonas and Roraima. The article reports on the history of the disease's discovery, its distribution, and incrimination of vector simuliid species. The literature that has been generated on the parasite, its vectors, and control of the disease is critically analyzed as well as the organization of epidemiological surveys and the control program developed by the Brazilian government and an international agency. Suggestions for future work are made.

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

“…In Brazil, O. volvulus is found in the northwestern state of Roraima (RR) and in the northern state of Amazonas (AM), where it mainly affects Yanomami Indians (Shelley 2002), but another focus of the disease has been described in Central-western Brazil (Maia-Herzog et al 1999). The less pathogenic M. ozzardi occurs mainly in AM, south of the Amazon River, and in an area in northern RR; it occurs sympatrically with O. volvulus in some areas within the Amazonian onchocerciasis focus (Shelley 2002, Medeiros et al 2009). Following several years of control programmes, W. bancrofti is now uncommon and is restricted to urban and peri-urban areas of Belém and Recife, with some cases of autochthonous transmission in neighboring states (Medeiros et al 2003).…”

Influence of temperature on microsporidia infections in a natural population of Simulium pertinax Kollar, 1832 (Diptera; Simuliidae)

“…The importance of family Simuliidae for human health lies in the fact that the females of certain species within the genus Simulium Latreille, 1802 are vectors of Onchocerca volvulus (Leuckart, 1893) Railliet and Heney, 1910 (Nematoda: Onchocercidae), a filarid that causes human onchocerciasis, found in the Neotropical Americas and Western and Central Africa (Shelley, 2002). In Brazil, the onchocerciasis was reported in the northern part of the state of Roraima by Moraes and Chaves (1974); in northern Goiás, where the first autochthonous case outside of the Amazonian region was reported (Gerais and Ribeiro, 1986), and more recently, it was described in northern Amazonas (Shelley et al, 1997).…”

Detection of Onchocerca volvulus (Nematoda: Onchocercidae) infection in vectors from Amazonian Brazil following mass Mectizan™ distribution

“…In Brazil, the only known active focus of the disease is located in the Amazonian region, and extends across the border to form the southern focus of Venezuela. It corresponds to more or less the whole territory of the Yanomami in the northwest of the state of Roraima and central north of the state of Amazonas (Shelley 1991(Shelley , 2002, exposing 13,767 indians to the infection (Funasa 2002).In the New World the control program has been sponsored by the Onchocerciasis Elimination Program for the Americas (OEPA). This program has as its main strategy the elimination of the disease through the semi-annually distribution of the ivermectin (Mectizan™) for 10 to 15 years to the population at risk (Blanks et al 1998).…”

“…In Brazil, the only known active focus of the disease is located in the Amazonian region, and extends across the border to form the southern focus of Venezuela. It corresponds to more or less the whole territory of the Yanomami in the northwest of the state of Roraima and central north of the state of Amazonas (Shelley 1991(Shelley , 2002, exposing 13,767 indians to the infection (Funasa 2002).…”