HHV-6 in Cerebrospinal Fluid in Immunocompetent Children

Background: Human herpes virus-6 (HHV-6) is a ubiquitous virus known as an etiological agent of exanthem subitum. HHV-6-encephalitis in immunocompetent children is a rare complication of the primary infection. There are a lack of data on the prevalence of HHV-6-encephalitis in Russia. The aim of our study was to analyze the prevalence of HHV-6 DNA in the cerebrospinal fluid (CSF) of immunocompetent children with suspected acute meningoencephalitis. Materials and Methods: A total of 712 CSF samples were tested using qualitative PCR over 12 years at N.F. Filatov Children’s City Clinical Hospital No.5, Saint-Petersburg, Russia. Results: HHV-6 DNA was detected in 20 (2.8%) of the samples. Retrospectively, we analyzed the medical records of 15 cases. There were seven boys and eight girls from 1 month to 7 years old; the mean age was 22.3 ± 5.6 months. Most HHV-6 DNA-positive cases were due to the primary form of HHV-6 infection. There were, in total, four cases of HHV-6-meningoencephalitis. All the children had a complete recovery, without neurological deficits or death. Conclusions: HHV-6 encephalitis is a very rare disease in immunocompetent children (four cases among 712 samples over 12 years). Additional studies are needed to develop accurate diagnostic criteria and therapeutic approaches.