Detection of HPyV12 with PCR.

aSamples collected for BKPyV infection diagnosis.bFrom patients under natalizumab (Tysabri) therapy.cSamples collected for herpesvirus infection diagnosis.dSamples collected for JCPyV infection diagnosis.eCombined results of specific nested PCR and real-time PCR; samples were considered as positive if the result could be independently reproduced on different days.