Overview

Although we have considerable experience with different viral diseases caused by Newcastle Disease Virus (paramyxo virus), Marek's Disease Virus (herpes virus), Infectious Bursal Disease Virus (birna virus), and Infectious Bronchitis Virus (corona virus), etc, our recent research focus has been on influenza virus, including both basic and applied research.

Avian influenza (AI) is caused by type A influenza virus and infects many animal species. Avian influenza virus is not usually considered a zoonotic infection, but under certain circumstances, the virus poses a serious public health threat. The first documented case of direct transmission of H5N1 AI virus from poultry to humans was in Hong Kong in 1997 where 6 out of 18 people died. More recently, an unprecedented outbreak of H5N1 highly pathogenic avian influenza was reported in poultry from different countries worldwide since December 2003. This AI also had a zoonotic component with more than 200 fatal cases in several different countries. Clearly, some strains of AI virus are capable of being transmitted directly from poultry to humans and therefore further understanding of AI virus is important not only for poultry, but also for preventing human infections and potentially preventing a human pandemic.

The recent understanding of influenza viruses is significantly facilitated by the development of reverse genetics, which can generate infectious virus from cloned cDNA. Using this technique, we can study the function of the individual gene as well as identify the gene or specific amino acid that is related to pathogenicity or attenuation, host specificity, etc. which may be useful in understanding the virus and developing advanced vaccines. We have been applying this technique in combination with site-directed mutagenesis and in vivo experimental infection studies to assess the pathogenic potential of low pathogenic H7 virus in the U.S. and also to develop reassortant vaccine strains for influenza.

We believe that all of our research tools can be used to address public health concerns as well as poultry disease issues. Our ongoing research will enhance the understanding of the genetic factors that determine interspecies transmission of avian influenza viruses to humans and potential pathogenicity in humans, and will more generally expand our overall understanding of influenza.