Submitted to: Avian Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/7/2005
Publication Date: 9/1/2005
Citation: Swayne, D.E., Perdue, M. 2005. Public health risk from avian influenza viruses. Avian Diseases. 49(3):317-327. Interpretive Summary: Since 1997 in Europe and Asia, a few avian influenza (AI) viruses have caused sporadic infections in humans with severe illness and death. These AI infections have increased public health concern that the mixing of AI and human influenza viruses could produce a hybrid influenza and lead to the next human influenza pandemic. Of special concern are the H5N1 high pathogenicity (HP) AI viruses present in poultry in several Asian countries. These viruses have become entrenched in some poultry populations and have infected not only people but also tigers and leopards. Successful control methods vary for different countries and have ranged from vaccination to depopulation of infected poultry.
Technical Abstract: Since 1997, avian influenza (AI) virus infections in poultry have taken on new significance with increasing numbers of cases with bird-to-human transmission, and the resulting production of clinically severe and fatal human infections. Such human infections have been sporadic and caused by H7N7 and H5N1 high pathogenicity (HP), and H9N2 low pathogenicity (LP) AI viruses in Europe and Asia. These infections have raised the level of concern by human health agencies for the potential reassortment of influenza virus genes and generation of the next human pandemic influenza A virus. The presence of endemic infections by H5N1 HPAI viruses in poultry in several Asian countries indicates these viruses will continue to contaminate the environment and be an exposure risk with human transmission and infection. Furthermore, the reports of mammalian infections with H5N1 AI viruses and in particular mammal-to-mammal transmission in humans and tigers are unprecedented. However, the subsequent risk for generating a pandemic human strain is unknown. More international funding from both human and animal health agencies for diagnosis or detection, and control of AI in Asia is needed. Additional funding for research is needed to understand why and how these AI viruses infect humans, and what pandemic risks they pose.