POLYMERASE CHAIN REACTION-BASED ASSESSMENT AFTER MACROFILARICIDAL THERAPY IN ONCHOCERCA-VOLVULUS INFECTION

A recently developed polymerase chain reaction (PCR)-based assay is si gnificantly more sensitive than current methods for diagnosing Onchoce rca volvulus infection, and it overcomes many difficulties in identify ing active onchocerciasis. Since chemotherapy is widely used to treat onchocerciasis, the utility of PCR in assessing responses to treatment and in predicting recrudescence is important, Twenty-eight patients w ho had skin snips positive for microfilariae (Mf) were studied 120 day s after receiving amocarzine, when each was negative for Mf: 16 (57%) were positive for O. volvulus DNA in the PCR-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 positi ve at day 240, This suggests that the PCR-based assay provides a sensi tive means for assessing infection status after macrofilaricidal chemo therapy and is an early predictor of persons likely to have a recurren ce of Mf.