Polymerase Chain Reaction-Based Assessment after Macrofilaricidal Therapy in Onchocerca volvulus Infection.

Arecently developed polymerasechain reaction (PCR)-based assay is significantly more sensitive than current methods for diagnosing Onchocerca volvulus infection, and it overcomes many difficulties in identifying active onchocerciasis. Since chemotherapy is widely used to treat onchocerciasis, the utility of PCR in assessing responses to treatment and in predicting recrudescenceis important. Twenty-eight patients who had skin snips positive for microfilariae (Mf) were studied 120 days after receiving amocarzine, when each was negative for Mf: 16 (57%) were positive for O. volvulus DNA in the PeR-based assay. Of these, 14 (88%) were Mf positive when reassessed parasitologically on day 240, and all were Mf positive on day 365. Equally important was the finding that 12 patients had cleared both Mf and Mf DNA; only 1 was Mf positive at day 240. This suggests that the PeR-based assay provides a sensitive means for assessing infection status after macrofilaricidal chemotherapy and is an early predictor of persons likely to have a recurrence of Mf. [ABSTRACT FROM PUBLISHER]