Figure 4

The monthly incidence of CAP amongst elderly ≥ 65 years and young adult 15–64 years and number of 2009pH1N1 influenza infections. The 2009pH1N1 season was defined between September 2009 and December 2009. The bars indicate number of 2009pH1N1 detected in our study. The estimated monthly incidences per 100,000 population amongst elderlies ≥ 65 years old were showed in solid line, those amongst young adults in dashed line.