Mohammad A. Muneer, Ali Mohammad Bahram, Zahid Munir, I. Hussain, K. Muhammad, Masood Rabbani, S. Akhtar, M. Aleem, Bakht Sultan1, MunirA. Tariq and K. Naeem2
Microbiology Section, College of Veterinary Sciences, Lahore, 1Grand Parent Poultry Laboratory, Shadman, Lahore, 2Microbiology Laboratory, Animal Sciences Institute, NARC, Islamabad, Pakistan
Abstract
Avian influenza virus (AIV) type H9 N2 was isolated from poultry flocks which were suffering from acute respiratory illness in Karachi area. High haemagglutination inhibition (HI) titers against AIV virus type H9N2, ranging from 6.38 to 7.81, in the convalescent sera of birds were demonstrated. The infected flocks had mortality between 30 to 80 per cent. Those flocks also had considerable of HI titres against infectious bronchitis (IB) virus stains D274 and D1466, against which they were never vaccinated. It is believed that AI H9 N2 virus in collaboration with IBV and some unidentified bacterial species caused high mortality in the infected flocks.
Key words: Avian influenza, Haemagglutination inhibition, Karachi .