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Confirmed primary HHV-6 infection in children with suspected encephalitis

J O Virtanen1, E Herrgård, P Valmari

  • 1Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland. oskari.virtanen@helsinki.fi

Neuropediatrics
|May 8, 2008
PubMed

Insights

Human herpes virus 6 (HHV-6) primary infection is linked to neurological issues in young children. An IgG-avidity test can help diagnose acute HHV-6 infections from a single blood sample.

Area of Science:

  • Virology
  • Pediatric Neurology
  • Immunology

Background:

  • Human herpes virus 6 (HHV-6) infection is associated with neurological symptoms in children.
  • Two variants, HHV-6A and HHV-6B, exist, but their role in neurological infections remains unclear.

Purpose of the Study:

  • To investigate the association between HHV-6A and HHV-6B primary infections and neurological symptoms in children.
  • To evaluate the utility of indirect immunofluorescence and IgG-avidity tests in diagnosing acute HHV-6 infections.

Main Methods:

  • Studied 53 children with suspected encephalitis for HHV-6A and HHV-6B antibodies using indirect immunofluorescence.
  • Employed IgG-avidity testing to differentiate primary from past HHV-6 infections.
  • Utilized PCR to detect HHV-6 DNA in patients with confirmed primary infections.

Main Results:

  • Forty-one out of 53 children showed IgG antibodies to HHV-6.
  • Six children had low IgG avidity, indicating acute primary infection (4 HHV-6A, 1 HHV-6B, 1 mixed).
  • HHV-6 was suggested as the viral etiology in 11.3% of cases; HHV-6 DNA was detected in serum/CSF of primary infection cases. Children with primary HHV-6 infection were significantly younger (2.3 vs. 6.4 years).

Conclusions:

  • Primary HHV-6 infection is an important potential cause of neurological infections in young children.
  • The IgG-avidity test is a valuable tool for diagnosing acute HHV-6 infection using a single serum specimen.

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