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

Memórias do Instituto Oswaldo Cruz

Verônica Marchon-silva¹  Julien Charles Caër¹  Rory James Post¹  Marilza Maia-herzog²  Octavio Fernandes¹ 

[1] ,Fiocruz Instituto Oswaldo Cruz Departamento de Entomologia

关键词: Simulium;    Onchocerca volvulus;    polymerase chain reaction;    onchocerciasis;    ivermectin;    Brazil;   

DOI  :  10.1590/S0074-02762007005000010

来源: SciELO

【 摘 要 】

Detection of Onchocerca volvulus in Simulium populations is of primary importance in the assessment of the effectiveness of onchocerciasis control programs. In Brazil, the main focus of onchocerciasis is in the Amazon region, in a Yanomami reserve. The main onchocerciasis control strategy in Brazil is the semi-annually mass distribution of the microfilaricide ivermectin. In accordance with the control strategy for the disease, polymerase chain reaction (PCR) was applied in pools of simuliids from the area to detect the helminth infection in the vectors, as recommended by the Onchocerciasis Elimination Program for the Americas and the World Health Organization. Systematic sampling was performed monthly from September 1998 to October 1999, and a total of 4942 blackflies were collected from two sites (2576 from Balawaú and 2366 from Toototobi). The molecular methodology was found to be highly sensitive and specific for the detection of infected and/or infective blackflies in pools of 50 blackflies. The results from the material collected under field conditions showed that after the sixth cycle of distribution of ivermectin, the prevalence of infected blackflies with O. volvulus had decreased from 8.6 to 0.3% in Balawaú and from 4 to 0.1% in Toototobi.

【 授权许可】

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