Neurologic complications associated with influenza A in children during the 2003-2004 influenza season in Houston, Texas

Objectives. Our objectives were to ( 1) describe the clinical characteristics of and viruses isolated from patients who presented with neurologic symptoms associated with influenza A infection and were hospitalized at Texas Children's Hospital during October and November 2003 and ( 2) to raise awareness of the neurologic complications of influenza among US children. Methods. We reviewed the medical and laboratory records of all children who were hospitalized with neurologic symptoms and who also had evidence of influenza virus infection by rapid antigen testing or viral isolation. Results. Eight children aged 5 months to 9 years with neurologic complications associated with influenza A were identified. None of the children had received the influenza vaccine. Four presented with seizures, 3 with mental status changes, and 1 with mutism. All but 1 of the patients had influenza A viral antigen detected in nasal wash samples. Influenza A virus was isolated in culture from nasal wash specimens obtained from 6 of the patients; influenza A virus was also isolated from the cerebrospinal fluid of 1 of these patients. None of the patients had serum metabolic abnormalities or other cerebrospinal fluid abnormalities. Three of the patients had brain imaging abnormalities. Five of the patients were treated with antivirals. All 8 of the patients survived, 6 with complete recovery and 2 with sequelae (1 mild and 1 severe). Conclusions. Neurologic symptoms and sequelae were associated with influenza A virus infection in children during the 2003-2004 influenza season in Houston, Texas. Influenza should be considered in the differential diagnosis in patients with seizures and mental status changes, especially if they present with respiratory symptoms or during an influenza outbreak.