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

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.

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

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 percent in Balawaú and from 4 to 0.1 percent in Toototobi.

Human papillomavirus quantification in urine and cervical samples by using the Mx4000 and LightCycler general real-time PCR systems.

During the last decade, growing efforts have focused on human papillomavirus (HPV) detection using liquid hybridization, conventional PCR, and real-time PCR-based methods to increase the overall proportion of patients participating in cervical cancer screening procedures. We proposed a new general HPV DNA real-time PCR on the Mx4000 (Stratagene) and LightCycler (Roche Diagnostics) systems usable for both cervical scrape specimens and urine samples. A linear range was obtained from 5 DNA copies to 8 log(10) DNA copies/ml, and intra- and interassay variations were between 1.8 and 4%. Cervical carcinoma and HPV DNA screening was performed in 333 individual women referred for gynecological examination at the university hospitals of Angers and Brest and enrolled in the PapU study. Among cervical specimens (n = 333), 45% were positive for HPV DNA, with a mean viral load at 5.00 log/ml (+/- 1.73). Among urine samples (n = 177), 37% were positive with a significant 50-fold-lower mean viral load (3.77 +/- 1.32 log/ml; P < 0.0001). Kappa agreement for HPV DNA between cervical and urine specimens was excellent (93%). Thus, we developed a highly sensitive and quantitative general HPV DNA real-time PCR method that allows mass screening of patients with HPV infection. The ongoing longitudinal and prospective multicenter PapU study should give us the opportunity to validate this method adapted to HPV DNA screening in urine samples in a larger population.