Novel H1N1 influenza in neonates: from mild to fatal disease.

Analysis of pediatric deaths associated with pandemic A H1N1 influenza shows that fatal outcome is more likely in young children, under the age of 5. Neonates, because of the immaturity of their immune system, could represent a high-risk group for severe disease and fatal outcome. We present a group of five neonates with confirmed novel influenza A H1N1 infection. This report indicates that the full spectrum of influenza A H1N1 infection ranging from mild febrile illness with spontaneous recovery to severe disease with fatal outcome may be expected even in neonates.