Estimation of influenza and severe acute respiratory illness incidence (burden) in three provinces of the Islamic Republic of Iran, 2012 and 2013M. Gouya, F. Rezaei, A. Haghdoost, M. Nabavi, K. Seif Farahi, E. Mostafavi, T. Mokhtari Azad, H. Akbari, M. Soroush, H. Riazi, E. Bitaraf, M. N. Dadras, H. Barati, H. Shakoori, J. Bathaei, M. Rezvani and P. Hemmati