Absence of novel human parvovirus (PARV4) in Danish mothers and children.
The recently discovered human parvovirus 4 (PARV4) is found most frequently in injection drug users, HIV-positive patients, and in haemophiliacs. Studies from Ghana report the finding of PARV4 in plasma from 2 to 12% of children without acute infection, and in nasal secretions and faecal samples. Studies of PARV4 in children from industrialized countries are few. We aimed to describe the occurrence of PARV4 in a population-based birth cohort of 228 Danish mothers and their healthy children who previously participated in a study of respiratory tract infections in infancy. Children were included over a whole calendar year and were monitored through monthly home visits through the first year of life. Plasma samples for the present study were available from 228 mothers, 176 newborns, and 202 12-months-old children. All samples were analysed for the presence of PARV4 antibodies by enzyme immunoassay, and samples with detectable antibodies were in addition studied by real-time PCR. One (0.4%) of 228 mothers had PARV4 IgG exceeding the cut-off absorbance level and another had borderline IgG reactivity. No mother among these two had an acute infection, as they were IgM and PARV4 DNA negative. All blood samples from newborns and one-year-old children had IgG and IgM reactivity below cut-off. PARV4 is rare in Danish mothers and infants. Further studies are needed, in both rural and urban settings, to investigate the epidemiology and clinical significance of this novel human parvovirus.