Neurologic complications and outcomes of pandemic (H1N1) 2009 in Korean children

Neurologic complications of children with influenza A H1N1 2009 pandemic, diagnosed in two consecutive influenza seasons were retrospectively reviewed to seek better outcomes in future outbreaks. Patient demographics, clinical manifestations and neurologic outcomes were reviewed. A total of 1,389 children were diagnosed with influenza A H1N1 by real-time reverse transcriptase-polymerase chain reaction. Of these, 23 (1.7%) patients had neurologic involvement. Their mean age was 5.9 ± 3.6 yr (range, 6 months to 11 yr) and 16 (69.9%) were boys. None of the 23 patients had been vaccinated for influenza A H1N1 and seasonal influenzas. Twenty-two of the 23 patients presented with seizures. Clinical features included febrile convulsion (n = 19), afebrile convulsion (n = 1), aseptic meningitis (n = 1), encephalopathy (n = 1), and acute necrotizing encephalopathy (n = 1). They all were treated with Oseltamivir twice daily for 5 days immediately after nasal and throat swab testing. Twenty-one of the subjects recovered fully, but the youngest two infants experienced severe neurological sequelae. The results indicate that neurologic complications associated with influenza A H1N1 2009 pandemic were mostly mild, but rarely were serious. Prompt intervention leads to a better outcome and vaccination may prevent the disease, thus staving off serious neurological complications following influenza, especially in young infants.