Sarhad J. Agric, Vol. 26, No.4, 2010 629 PREVALENCE OF AVIAN INFLUENZA AND ITS ECONOMIC IMPACT ON POULTRY POPULATION OF HAZARA REGION PAKISTAN MUHAMMAD AYAZ*, MUHAMMAD SAJID*, SARZAMIN KHAN**, MUHAMMAD SUBHAN QURESHI**, ALTAF UR REHMAN**, NAEEM KHWAJA***, MUHAMMAD RAFIQ**** and MUHAMMAD MAQBOOL**** * Veterinary Research and Diagnostic Center, Abbottabad, Pakistan ** Faculty of Animal Husbandry and Veterinary Sciences, KP, Agricultural University Peshawar *** National Reference Lab for poultry diseases ASI NARC Islamabad **** Hazara University Mansehra KP, Pakistan. Corresponding author: Dr.Sarzamin Khan, Associate Professor and Chairman, Poultry Science Department, KP, Agricultural University, Peshawar-25120, Pakistan, Tel.92-91-9218315, Fax 92-91-9216520; Mobile 92-300- 8592606, E.mail:dr_zamin@hotmail.com,dr.zaminaup@gmail.com ABSTRACT Prevalence of Avian Influenza (AI) in poultry population in Hazara region of North West Frontier Province of Pakistan was studied in broiler breeder stocks (4 millions), layers (0.5 millions), broilers (2.5 millions) and nondescript captive layers (0.5 million), for prevalence of AI viruses (AIV) during a period of one year. Five hundred flocks were sampled between May 2004 through April 2005. The isolation and identification was conducted. Virus was isolated using embryonating eggs and the allantoic fluid of egg containing dead or dying embryo was recovered and tested for HA (Haemagglutination) activity. The virus was typed through (HI) Haemagglutination inhibition test using antisera. The data were analyzed statistically through chi square test. An incidence of AIV in 8.8 % of the flocks was recorded; highest in non-descript layers (16.7 %) followed by broilers, breeders and commercial layers (9%, 6.8 % and 4 %, respectively). Prevalence of H7 subtype was highest in non- descript layers (13 %) followed by 5 % in breeders, 4 % in layers, 3.8 % in broilers. H9 was highest in broilers (5%) followed by 1.8 % in breeders, 0.25 % in layers. No highly pathogenic Avian Influenza (HPAI) infection was recorded during study period. The economic loss due to low pathogenic Avian Influenza (LPAI) was estimated to as Rs. 2.2 billion per annum (US$ 1 = Pak Rs. 62.6). It was concluded that AI was found in low pathogenic form causing huge population of the region was probably the predisposing factor of transmitting the disease to the commercial flocks. Key Words: Avian Influenza, AI, economics, Pakistan, serotypes Citiation: Ayaz, M., M. Sajid, S. Khan, M. S. Qureshi, A. Rehman, N. Khwaja, M. Rafiq and M. Maqbool. 2010. Prevalence of Avian Influenza and its economic impact on poultry population of Hazara region Pakistan. Sarhad J. Agric 26(4): 629-633 INTRODUCTION Hazara region, an area of 17000 sq km, is northeastern region of KP, Pakistan comprises five districts. Over four million broiler breeder stock is annually reared in this region, in addition to 2.5 million broilers, 0.5 million commercial layers and 3.00 million rural poultry. This region is also rich in wild fauna and also lies on the route of migratory birds specially the ducks, coming from Russia and stay at Tarbela Lake during their migration. This scenario is quite suitable for the propagation of Avian Influenza viruses in the area. Highly pathogenic Avian Influenza (HPAI) is an extremely contagious, multi-organ system disease of poultry leading to high mortality and is caused by some of the H5 and H7 subtypes of type-A Influenza virus. However, most Avian Influenza virus strains are mildly pathogenic and produce either sub-clinical infections or respiratory or reproductive diseases in a variety of wild and domestic bird species (Swayne and Suarez , 2000; Suarez and Schultz, 2000; Compiletti et al. 2004; Tollis and DiTrani, 2002; Suarez, 2000; Fouchin et al., 2004). Capua et al.,(1999) reported the presence of Avian Influenza H7N1 outbreak in Italy, where low pathogenic strain causing 2-10 percent mortality mutated to high pathogenic Avian Influenza infection resulting in a mortality of 70-90 %. Some of the major outbreaks occurring in other places of the HPAI of H7 or H5 serotypes in recent years included Mexico (H5), Pakistan (H7), China (H5), Australia (H7), Vietnam (H5), Hong Kong (H5), North Korea (H7) and Thailand (H5) (Yamaguchi, 2000).