Abstract 61

Background: In 1990, a novel herpesvirus was discovered and designated HHV7. Most HHV7 infections occur during childhood so that a high antibody seroprevalence of up to 98% is found in adults. In this study, we examined the role of HHV7 in the pathogenesis of various central nervous system (CNS) diseases in children by testing CSF samples with HHV7-specific PCR.

Patients: Between 1994 and 1997, 99 CSF samples were collected from 14 children with aseptic meningitis or encephalitis (ME) (group I), 30 children with febrile convulsions (FC) (group II) and 55 children with other CNS diseases (group III). CSF samples were stored at -80 °C until testing.

Interventions: After DNA preparation using Qiagen® columns, nested PCR was performed with two pairs of primers annealing at the U23 gene region of the HHV7 DNA and synthesizing a 755 bp and a 478 bp product, respectively. The PCR product was visualized by agarose gel electrophoresis. With this procedure as few as 5 target molecules/µl could be detected. The specificity was tested by cleavage of the PCR products with the restriction enzyme Sau3 AI resulting in 127 bp and 351 bp fragments. Crossreactivity against HSV-1/2, CMV, VZV, EBV and HHV6-A/B was excluded.

Results: HHV7 infection of the CNS could be detected in 7/99 patients (7.1%): HHV7 PCR was positive in the CSF samples from 3/14 (21.4%) patients of group I, 1/30 (3.3%) patients of group II and 3/55 (5.5%) patients of group III. The latter group comprised one child with sudden infant death syndrome, one child with vestibular neuritis and one child with facial palsy.

Conclusions: Here, we report that HHV7 may play an important causative role in major CNS diseases of childhood such as aseptic meningitis/encephalitis.