Persistence of novel human parvovirus PARV4 in liver tissue of adults.

Human parvovirus 4 (PARV4) is a recently identified virus whose biology, epidemiology and pathogenic potential have yet to be determined. Recently, it was reported that PARV4 DNA persists in tissues of some HIV-infected individuals, whilst PARV4 DNA was not detected in tissues of subjects not infected with HIV. In the present study, liver tissue from 87 individuals, none of who were infected with HIV, with the exception of a single subject, was analyzed for the presence of PARV4 DNA. Overall, PARV4 DNA was detected in 13 specimens (15%). In other tissues examined, PARV4 genotype 2 (also termed PARV5) DNA was detected in one of four paired bone marrow specimens. Tissue viral loads did not exceed 100 copies per microg of genomic DNA. In addition, serum samples from 40 of these individuals all tested negative for PARV4 DNA. In the subjects analyzed in this study, PARV4 genotype 2 appeared to be genetically more heterogeneous than PARV4 genotype 1. The results show that PARV4 DNA can be detected in liver, and that infection with PARV4 is not restricted to HIV-infected individuals. Previous studies showing the presence of PARV4 in plasma, suggest that during infection with PARV4, a viraemic stage occurs, allowing systemic spread to a variety of tissues.