Assessment of Pathogenic Potential of Two Indian H5N1 Highly Pathogenic Avian Influenza Virus Isolates by Intravenous Pathogenicity Index Test

Intravenous Pathogenicity Index (IVPI) test was conducted to assess the pathogenicity of two H5N1 (A/Ck/lnd/7966/06 and A/Ck/lnd/7972/06) AIV isolates. Both the H5N1 virus isolates were isolated from natural outbreaks during 2006, both isolates caused death of all birds with in 48 h after inoculation experimentally, birds showed typical clinical signs, gross and microscopic lesions of Avian influenza. IVPI of A/Ck/lnd/7966/06 and A/Ck/lnd/7972/06 was 2.96 and 2.95 respectively. This test showed that both H5N1 isolates are highly pathogenic. Virus could be re-isolated from all the organs of infected chickens and it was reconfirmed by RT-PCR using WHO and Lee primers.