Submitted to: Developments in Biologicals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 31, 2005
Publication Date: February 2, 2006
Citation: Swayne, D.E. 2006. Occupational and consumer risks from Avian Influenza viruses. Developments in Biologicals. (Basel)124:85-90. Interpretive Summary: Human infections have been caused by avian influenza (AI) viruses, but they have been rare. Most of the infections have involved an AI virus from Holland (H7N7) and viruses from Asia (H5N1). These viruses cause severe disease and death in chickens and are termed highly pathogenic AI viruses. For human infections, people who work directly with poultry have had the greatest risk for infection. In Asia, the exposure has been to infected chickens and other poultry grown in backyards or small farms, and not commercial poultry. No human infections have been documented from the consumption of infected or contaminated poultry products, but AI virus can be present in meat of chickens infected with highly pathogenic AI viruses. Heat, through cooking or pasteurization kills AI viruses. Vaccination of poultry will prevent highly pathogenic AI virus in meat.
Technical Abstract: Sporadic human infections have been reported with a few select avian influenza (AI) viruses over the past 50 years. Most of the infections resulted from the H7N7 high pathogenicity (HP) AI virus from The Netherlands (2003) and H5N1 HPAI viruses from several Asian countries (1997-2005). Epidemiological studies have identified direct exposure to infected poultry as the primary risk factor for human infection. In The Netherlands, veterinarians, cullers and poultry framers had an occupational risk for infection through exposure to infected commercial poultry and presented with conjunctivitis and/or influenza-like illnesses. In Asia, most of the clinical infections involved direct exposure to poultry in the smallholder sector or live poultry markets, and not commercial poultry. However, serological data from Hong Kong during 1997 indicated H5N1 infections without clinical disease were associated with occupational exposure. No cases of human AI infection have been linked to consumption of infected or contaminated poultry products. However, HPAI virus can be present in blood, bone and meat of infected poultry, and if consumed raw, are a potential source of virus for human infections. Cooking and pasteurization are effective methods for killing AI viruses. Proper vaccination of poultry has been shown to prevent HPAI virus from localizing in the meat