High Frequencies of Exposure to the Novel Human Parvovirus PARV4 in Hemophiliacs and Injection Drug Users, as Detected by a Serological Assay for PARV4 Antibodies

Abstract

Background PARV4 is a human parvovirus first detected and cloned from an individual with a HIV seroconversion-like illness and which subsequently persists in lymphoid tissue and bone marrow. In contrast to B19V, PARV4 infections are most frequently detected in injecting drug users (IDUs), particularly those co-infected with HIV-1. To investigate its transmission routes and whether infections are acquired through plasma-derived blood products, we developed a novel anti-PARV4 ELISA to determine seroprevalence in parenterally exposed and non-exposed subjects. Methods PARV4 VP2 was expressed and used as antigen in an indirect ELISA to detect anti-PARV4 IgG. Results All 50 non-parenterally exposed adult controls were anti-PARV4 negative, in contrast to 67% and 33% antibody frequencies in HIV-positive and –negative IDUs respectively. Predominantly parenteral transmission was confirmed by the finding of similar infection frequencies (11/20 and 4/15) among HIV-coinfected and –uninfected haemophiliacs treated with non-virally inactivated FVIII/IX, whereas all but one of their 35 non-haemophiliac siblings were seronegative (despite close household contact). Conclusions This study provides convincing evidence that PARV4 is primarily transmitted parenterally. Evidence for widespread infection of haemophiliacs treated with non-virally inactivated clotting factor creates fresh safety concerns for plasma-derived blood products, particularly as parvoviruses are relatively resistant to virus inactivation.

Human parvoviruses B19, PARV4 and bocavirus in pediatric patients with allogeneic hematopoietic SCT

“…The absence of PARV4 in these immunocompromised patients is in agreement with the recent study by Tolfvenstam et al and with the previous studies reporting PARV4 appearing to be primarily blood-borne in Northern Europe, but could possibly also reflect a lower prevalence in Northern Europe. 38,[41][42][43][44]47 It has been found among infants in West Africa with no evidence of parenteral exposure. 35,36 Pediatric patients with HSCT J Rahiala et al…”

“…37,[42][43][44][45] Viremia seems to accompany acute PARV4 infection, and the viral DNA has been demonstrated also in blood products, indicating a risk for parenteral transmission. 34,39,[42][43] The seroprevalence in Northern Europe reaches 78% among HIV-positive i.v. drug users, but is negligible among non-users.…”

“…drug users, but is negligible among non-users. 42,44 In all, the epidemiology and clinical implications of PARV4 are still under evaluation. 46,47 The aim of this study was to determine the occurrence and clinical associations of B19V, PARV4 and HBoV1 viremias among pediatric patients immunocompromised due to allogeneic HSCT.…”

Frequency of human parvovirus 4 (PARV4) viremia among HBV-infected patients and healthy donors in Shiraz, Iran

“…Initially it was suggested that this virus is transmitted only through parenteral routes because it is more common in people who have been exposed to blood. It had been detected in hemophiliacs that received nonvirally inactivated clotting factors (5)(6)(7)(8). However, a study in Africa detected PARV4 DNA in nasal and fecal samples; thus respiratory and fecal-oral transmission of the virus was suggested (9).…”

“…So far, the virus has been isolated from many tissues including bone marrow of HIV-positive individuals (13) and the liver of HBVand HCV-infected patients (14,15). Moreover, the virus has been diagnosed in plasma, cerebrospinal fluid (CSF), skin, myocardium, and blood products around the world (1,3,7,8,11,(15)(16)(17). Despite the detection of viral nucleic acid in many organs, PARV4 has scarcely been linked to specific symptoms, except for a recent study that was conducted in Africa linking PARV4 to encephalitis (11) and another study in which the virus was diagnosed in people with symptoms including pharyngitis, nausea, and joint pain (1).…”