Hospitalized Children with 2009 Influenza a (H1N1) Infection in Shenzhen, China, November-December 2009

Objectives: During the winter outbreak of 2009 influenza A (H1N1) infection in China, the number of confirmed cases and the fatal cases has grown rapidly. We describe the clinical characteristics of hospitalized children with 2009 influenza A (H1N1) infection in Shenzhen, China, November-December 2009.

Methods: Using a standardized form, we collected data on 148 hospitalized children. 2009 influenza A (H1N1) infection was confirmed in nasopharyngeal swab specimens with the use of a real-time reverse transcriptase-polymerase chain reaction assay.

Results: Of the 148 hospitalized children with 2009 influenza A (H1N1) infection, 81 (55%) were 5 years of age or older and 85% of the patients were previously healthy. The common presenting symptoms were fever (94%), cough (89%), runny nose (36.5%), vomiting (24%), sore throat (19.6%), wheezing (18%), abdominal pain (16%), mental status changes (9%), seizures (6%), diarrhea (6%), myalgia (6%), and chest pain (4%). Twenty-nine (20%) patients were admitted to an ICU, 10 (7%) patients required mechanical ventilation. The overall complication rate was 65.5%, they were pneumonia in 94 (64%), neurologic complications in 18 (12%), parapneumonic effusion in 12 (8%) and myocarditis in 7 (5%). One hundred seven (72%) patients received oseltamivir treatment, 34 (23%) received within 48 hr after the onset of symptoms. All patients received antibiotics before admission or on admission. One hundred forty-four (97%) patients were discharged; four (3%) previously healthy patients died, three died from severe encephalopathy, one died from secondary fungal meningitis.

Conclusion: Hospitalized children with 2009 influenza A (H1N1) infection can have a wide range of presentation and clinical complications including neurologic complications. The severe cases and deaths concentrate in previously healthy older children.