Norovirus as cause of benign convulsion associated with gastro-enteritis

Rotavirus and norovirus gastro-enteritis (GE) are common in children. Complications, except severe dehydration, are rare. Rotavirus was known to cause seizures and even GE encephalopathy, but these complications are less described in norovirus infection. The objective of this study is to compare the demographic features, clinical manifestations including the incidence of afebrile seizure, and the outcomes in children with rotavirus and norovirus infections.

This is a retrospective review of children between age 1 month and 6 years admitted to the paediatric department of a regional hospital in Hong Kong with rotavirus and norovirus infections over a period of 3 years from 1 June 2006 to 31 May 2009. Their demographic data, clinical features, laboratory results and outcomes were compared and analysed.

Two hundred and thirty-two children with rotavirus and 173 children with norovirus GE were admitted within the study period. Afebrile seizure commonly occurred in norovirus infection (8.67% vs. 1.29%, P < 0.001). Children with rotavirus infection had higher temperature and more diarrhoea episodes, while more blood-stained stool was noted in the norovirus group. Rotavirus-infected patients stayed longer in hospital. All of them had full recovery without any complication. Among the 18 patients who developed afebrile convulsions, 17 of them had neuroimaging performed, which was normal. Fourteen of them had electroencephalogram (EEG) performed, demonstrating normal or non-specific findings. None of them developed subsequent seizure attack after the GE episode.

Norovirus is more commonly associated with benign convulsion in GE than rotavirus. We need to identify the presence of virus, in particular norovirus, in children with GE and afebrile generalised tonic-clonic seizure. Further neuro-investigations may not be necessary once the aetiology is established. Prognosis is excellent in this group of children and prophylactic anticonvulsant is not needed.