This study states that Pandemic and seasonal influenza viruses have been associated with a heavy burden on morbidity and mortality worldwide.1, 2 Influenza surveillance, which provides real-time information to inform prevention and control policy, focused on cases seeking medical care. There are some barriers to assess influenza disease burden at community level using existing surveillance platforms. The data derived from surveillance could not capture infections associated with mild symptoms or not requiring medical attention. Information on the community burden of influenza is a key to informing control. Some community-based cohort studies have been conducted to provide important insight into the disease burden and transmission behavior of influenza.3-9 These studies largely took place in the United States between 1948 and 2013,3-6 and recently, similar studies were undertaken in England, Hong Kong, Vietnam, etc.7-9 Additionally, more cohort studies were conducted to estimate disease burden of influenza during 2009-10 pandemic influenza.Although hospital-based influenza-like illness (ILI) sentinel surveillance has been established in mainland China to monitor influenza activity,12, 13 the incidence rate of influenza virus infections in the community is difficult to determine due to the lack of well-defined catchment populations of surveillance sentinel hospitals.

Reference link-