Figure 5

Percent of influenza positive by month of illness onset among hospitalized severe acute respiratory infection (SARI) patients and influenza like illness (ILI) outpatients, China, Febuary 1, 2011 to October 27, 2013. Panel A. Four Northern Hospitals. Panel B. Six Southern Hospitals. *positive rate (%): (1) ILI flu positive rate = percent of influenza positive specimens among all tested specimens for influenza like illness patients. (2) SARI flu positive rate=percent of influenza positive specimens among all tested specimens for severe acute respiratory infection patients.