Pediatric neurological complications associated with the A(H1N1)pdm09 influenza infection

Background: Influenza-related neurological complications (INC) have been reported during seasonal flu in children. Objectives: To investigate the types, outcomes and incidence of INC occurring during the 2009 A(H1N1) pandemic, a retrospective analyze was conducted in the single French pediatric hospital of Lyon from October 2009 to February 2010. Study design: All children presenting with fever, influenza-like illness, respiratory distress or neurological symptoms were tested for influenza A(H1N1)pdm09 infection from respiratory specimens using real time RT-PCR. Results: INC occurred in 14 A(H1N1) pdm09 positive children (7.7% of A(H1N1) pdm09 positive children admitted to hospital) with a median age of 5.1 years. Admission to the intensive care unit (ICU) was required for nine children (64.3%). Half of the children with INC had comorbidity and three had coinfection, both characteristics mainly found in children requiring the ICU. All children received oral oseltamivir treatment. Febrile seizures were observed in eight children, half of them having a chronic comorbidity (2 epilepsy, 1 nonketotic hyperglycinemia, 1 anoxic encephalopathy). Other INC, less commonly reported, included 2 cases of encephalitis, 1 encephalopathy, 1 basilar artery thrombosis, 1 myasthenic crisis and 1 coma. Eleven of the 14 children (78.6%) recovered, one had a minor disability, one child developed a locked-in syndrome and one died from complications of an acute necrotizing encephalopathy. Discussion: INC can be observed even in children with no underlying disorder. It may lead to dramatic issue in a significant number of cases. (C) 2011 Elsevier B.V. All rights reserved.