Assessment of device-associated infection rates in teaching hospitals in Islamic Republic of IranShirin Afhami, Arash Seifi, Mahboubeh Hajiabdolbaghi, Negin Esmailpour Bazaz, Azar Hadadi, Mehrdad Hasibi, Parvin Rezaie, Esmail Mohamadnejad, Azam Ghahan, Mitra Hajinoori, Fatemeh Veyceh, Shahnaz Adinehkharrat, Zahraparvin Hojjati and Zohre Azimbeik