PARV4 is a member of the Parvoviridae family discovered in 2005 in plasma from an intravenous drug user, with symptoms consistent with acute HIV infection, but confirmed to be HIV RNA negative [
1]. It seemed to be not closely related to any of the known human or animal parvoviruses until 2008 when novel porcine and bovine parvoviruses highly similar to PARV4 were identified so that it was proposed the inclusion of PARV4 in a new genus Hokovirus [
2]. Three genotypes of PARV4 have been identified at present [
3,
4]. Till now, it has not been associated with any disease and its spread in the human population has not been clearly assessed. In fact, the serological assays for anti-PARV4 antibody detection, only recently developed, till now have been applied on small groups of individuals only [
5]. Viremia seems to be a hallmark of PARV4 infection. PARV4 was found in 5% of plasma pools at levels suggesting the existence of donations with high viral load [
6], in 16% of clotting factor VIII concentrates [
7], in 2% of plasma samples from healthy donors [
8] and in 7,95% of serum samples from intravenous drug users in Thailand [
9]. Several data indicate that the transmission of the virus predominantly occurs by parenteral route [
5,
10] whereas the respiratory transmission seems to be unlikely [
11]. As regards tissue distribution, PARV4 DNA was demonstrated frequently in bone marrow and lymphoid tissue from HIV infected individuals [
12] and also in liver of non HIV-infected adults [
13]. One study reports that PARV4 DNA can be detected, with a low frequency, in healthy and pathological skin samples [
14].
The aim of this study was to assess whether PARV4 is able to persist in different tissues, like B19V, or if it shows a particular tissue tropism.