The Detection of Igg to Human Herpesvirus Type 7 in Children

Abstract

Background. There are no data on HHV-7 seroprevalence in Russia. Previously we detected HHV-7 DNA in plasma of 8-10% children with exanthem subitum and fever without rash. Aim. To perform the comparative study of the seroprevalence of HHV-7 and HHV-6 in children in Russia. Materials and methods. The pilot study included 116 children, aged from 10 days to 10 years. Serum samples were tested for IgG to HHV-7 and HHV-6 by indirect immunofluorescent assays and ELISA correspondingly. Results. The prevalence rate antibodies to HHV-7 was three times lower than for antibodies to HHV-6. There were only 18% of patients seropositive to HHV-7, whereas 50% of cases appeared to be seropositive to HHV-6. In infants younger 6 months the frequency of HHV-7 seropositivity amounted to 14.8%, which possibly was due to maternal antibodies. In babies aged from 7 months to 4 years, the HHV-7 seroprevalence was about 7-13%. In children older than 4 years the rate of seropositivity raised to 31%. Conclusion. We can conclude that in life the contact with HHV-7 occurs later than to HHV-6, predominantly after the age of four years. In children under 10 years, the seroprevalence to HHV-7 is lower than to HHV-6. The sample size of our study is too small to extrapolate on Russian population and other seroprevalence studies are needed.