Detection of Merkel cell polyomavirus on environmental surfaces

The Merkel cell polyomavirus (MCPyV) is a human virus identified recently which is associated with the Merkel cell carcinoma. This virus is also detected frequently in the skin of healthy individuals. The presence of MCPyV has been investigated on environmental surfaces in contact with human skin. Various surfaces in four laboratories, public places, and individual homes were swabbed. Human DNA and MCPyV DNA were detected in swabs by real-time PCR. MCPyV DNA levels were measured before and after DNase treatment in a set of 12 MCPyV DNA-positive samples. A total of 60 environmental surface samples were collected. Fifty-one (85.0%) were positive for human DNA detection and 45 (75.0%) were positive for MCPyV DNA detection. All samples positive for MCPyV DNA were positive for human DNA detection. After DNase treatment, a 1.3 log decrease in MCPyV DNA level was observed indicating that about 5% of viral DNA is protected from DNase degradation and might be associated with infectious virus. These results indicate that MCPyV DNA may be detected on environmental surfaces in contact with human skin. Detection of viral DNA might reflect the presence of infectious viral particles and transmission from environmental source to humans cannot be ruled out.