Study on simultaneous prevalence rate of Newcastle disease and Avian Influenza (H9N2) in broiler chickens in Shahrekord.

In this study, the simultaneous prevalence of Newcastle (ND) and avian influenza (AI) was investigated in broiler chicken flocks using HI and PCR methods. Blood samples were taken twice from 15 flocks with high mortality (in the beginning and 14 days after disease). HI results revealed six flocks possessed antibody titer against both ND and AI simultaneously. In this study, 53.3 % and 60 % of flocks possessed antibody titer against AI and ND exceed of 2 (based on HI test), respectively. RT-PCR results showed that 11 flocks were infected to ND and AI simultaneously (73.33 %). The pathotyping of identified viruses using AVLTe and VLTe primer demonstrated 33.33 % and 66.66 % of infected flocks to ND were infected to velogenic and non-velogenic type, respectively. The typing of AI viruses with specific H5N1 and H9N2 primers illustrated all of identified strains were belonged to H9N2 type. It is concluded the high mortality in these flocks may be related to concurrent infection of AI and ND viruses.