[The analysis of clinical character in different age patients suffered from A-H1N1]

To describe the feature of different age patients with A-H1N1.

Cross-sectional study was performed in 95 patients who were confirmed to be infected with A-H1N1 from May, 2009 to July, 2009, in according to their age.

The average age of patients with A-H1N1 infection was 23.44 +/- 14.73. Accumulative prevalence in children and young adult reached 74.7% of total patients. There was a trend that the subclinical infection rate raised gradually from 0-15 years group to over 45 years group. The percent of lymphocyte in 0-15 years group was significantly higher than other age groups, P = 0.039. The average time of virus shedding were 6.5 +/- 2.10 days (from 2 days to 12 days) , and there were no significant difference in diverse age groups, P = 0.272. 13 out of 95 (13.7%) patients presented complications related with A-H1N1 infection, and 4 of 6 patients complicated with pneumonia were in the 0-15 years group.

The distribution of age in A-H1N1 infection is markedly different from seasonal influenza, with more cases in school children and young adults and fewer cases in older adults. Flu-like symptoms in children were apparent and pneumonia was the major complication in children.