Detection of Onchocerca volvulus Infection by O-150 Polymerase Chain Reaction Analysis of Skin Scratches

The standard assay for onchocerciasis diagnosis is microscopic detection of parasites in skin snips. Skin snipping is painful and may potentially transmit bloodborne infections. Thus, an alternative method for the diagnosis of onchocerciasis that does not require skin snipping is needed. A polymer-ase chain reaction (PCR)–based assay was shown to detect the presence of parasite DNA in superfi-cial skin scrapings. Detection of parasite DNA in both skin snips and skin scratches was found to be more sensitive for detecting low-density infections than was microscopic examination of skin snips. The skin scratch PCR assay is minimally invasive and painless and does not present the risk of transmitting bloodborne infections. These properties make the skin scratch an attractive alterna-tive to the skin snip for detecting O. volvulus infection. Onchocerciasis, or river blindness, is caused by infection O. volvulus micro®lariae reside in the uppermost layers of the dermis [6] and may be detected by skin scari®cation [7]. Wewith the ®larial parasite Onchocerca volvulus. When measured in terms of the socioeconomic effects on af¯icted communities, therefore hypothesized that it might be possible to detect O. volvulus DNA in the skin of infected persons, without resortingonchocerciasis is one of the most important infectious diseases worldwide [1]. As a result of the large socioeconomic impact to skin biopsy, by using the O-150 PCR. of the disease, several international programs underway in Af