Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/5/2004
Publication Date: 1/1/2005
Citation: Swayne, D.E., Beck, J.R. 2005. Experimental study to determine if low pathogenicity and high pathogenicity avian influenza viruses can be present in chicken breast and thigh meat following intranasal virus inoculation. Avian Diseases. 49(1):81-85.
Interpretive Summary: Recent avian influenza (AI) outbreaks in the USA and world have raised questions about the role meat may play in transmitting AI virus. In our experimental studies in chickens, we determined that two H7N2 low pathogenicity (LP) AI viruses were not present in blood, meat or bone marrow of infected chickens, and these AI viruses were not transmitted to other chickens by feeding such meat. By contrast, two high pathogenicity (HP) AI viruses (H5N2 and H5N1) were present in blood, meat and bone marrow, and the H5N1 HPAI virus was transmitted to other chickens by feeding the meat. Vaccination with two different H5 AI vaccines prevented the H5N1 HPAI virus from being in the meat and prevented transmission of the H5N1 HPAI virus to other chickens fed this meat. These studies suggest LPAI virus is unlikely to be transmitted through meat of infected chickens, but there is a potential for HPAI virus being transmitted through meat. Preventive vaccination may eliminate the transmission risk for HPAI virus in meat.
Technical Abstract: Two low pathogenicity (LP) and two high pathogenicity (HP) avian influenza (AI) viruses were inoculated into chickens by the intranasal route to determine the presence of the AI virus in breast and thigh meat, and any potential role that meat could serve as a transmission vehicle. The LPAI viruses caused localized virus infections in respiratory and gastrointestinal (GI) tracts. Virus was not detected in blood, bone marrow or breast and thigh meat, and feeding breast and thigh meat from virus-infected birds did not transmit the virus. In contrast to the two LPAI viruses, A/chicken/Pennsylvania/1370/1983 (H5N2) HPAI virus caused respiratory and GI tract infections with systemic spread, and virus was detected in blood, bone marrow and, breast and thigh meat. Feeding breast or thigh meat from HPAI (H5N2) virus-infected chickens to other chickens did not transmit the infection. However, A/chicken/ES/Korea/2003 (H5N1) HPAI virus produced high titers of virus in the breast meat, and feeding breast meat from these infected chickens to other chickens resulted in AI virus infection and death. Usage of either recombinant fowlpox vaccine with H5 AI gene insert or inactivated AI whole virus vaccines prevented HPAI virus in breast meat. These data suggest the potential for LPAI virus appearing in meat of infected chickens is negligible while the potential for having HPAI virus in meat from infected chickens is high, but proper usage of vaccines can prevent HPAI virus from being present in meat.