September 24, 2007
UNIT 6: Classification and DiversityAvian Flu: The Current Situation
You haven’t heard about the bird flu infecting any people in North America — yet. H5N1 avian influenza A virus, commonly knows as bird flu, was reported originally in poultry and some wild migrating birds from Southeast Asia. There were human H5N1 cases in that region involving people who worked with infected poultry as well.
Current research shows that H5N1 virus strains are getting stronger than earlier strains, but for now they have only been found in Asia, Europe, and Africa. The virus has mutated enough to move from birds to other animals. It has since infected mammals like domestic cats and dogs, pigs, zoo tigers, and leopards, making them sick or killing them. Researchers have also reported that the virus can start as a mild strain in one bird then mutate into a very deadly strain that is then passed to other birds in the area, including migrating birds.
Bird flu outbreaks are a huge public health threat where they occur. There is little or no preexisting immunity to protect human populations. If the virus mutates and evolves the ability to move to and among humas in an efficient and sustained way, a pandemic could result in high rates of illness and death worldwide. Local, regional, and national authorities take actions to stop outbreaks, often at great costs. Millions of birds have been killed to contain bird flu, resulting in huge economic losses. However these efforts have not stopped the virus from spreading and the threat in areas were bird flu is found is not likely to be reduced anytime soon.
Currently, there is no evidence that the H5N1 virus can spread even more easily from animal to person, and from person-to-person. Scientists and public health agencies are working to prepare for a possible pandemic, with mixed results. Two of the four antiviral medications on the market can be somewhat effective against bird flu, but the H5N1 virus is resistant to the other two. There is a human vaccine for one strain of bird flu, however that vaccine is ony available for public health official as needed for an emergency. Research is ongoing to develop vaccines for more strains of bird flu. As the H5N1 avian influenza A virus continues to evolve, it will be humanity’s challenge to find ways to keep people and the animals rely on safe.