Swine influenza A (H1N1) virus infection in infants

There are few reports on pandemic swine influenza A (H1N1) virus infection in very young infants. We aimed to discuss the clinical characteristics and management of the H1N1 influenza infection in very young infants. Clinical characteristics of ten infants diagnosed with H1N1 influenza virus infection during the 2009 outbreak season in a tertiary neonatal intensive care unit were evaluated. The diagnosis was confirmed by testing of respiratory samples with pandemic H1N1 influenza specific real-time PCR assay. Of the 46 patients with fever or respiratory problems, ten (22%) were diagnosed with H1N1 influenza virus infection during the 2009 (October-December) peak outbreak season. All infants including the preterms were admitted from home, seven (70%) were full-term and three (30%) were preterm. Median age of the patients at admission was 24.5 days. Fever and cough were the most common symptoms. Apnea was the initial symptoms in three patients. Two patients required oxygen support, one of which, a preterm baby, had been mechanically ventilated for 2 days. Mean duration of hospitalization was 7.8 +/- 4.9 days. Chest radiography revealed radio-opacities on both lung fields in six patients. In addition, two patients had co-infection. All patients with proven infection were given oseltamivir medication. Recovery was achieved in all patients with no residual deficits or side effects from the antiviral oseltamivir treatment. The H1N1 influenza virus infection in very young infants appears to be mild to moderate in severity. The outcomes of the infants may be influenced by antiviral therapy. Treatment with antiviral oseltamivir appears to have no major adverse effects.