Bird Flu: An Emerging Worldwide Concern

摘要

Contrary to what many might conclude because of its recent headline status, avian influenza is not a new disease. Fowl Plague was first described in Italy in 1878 and reported to be caused by a filterable virus in 1900. It was later determined in 1955 that Fowl Plague was actually one of the group of avian influenza (AI) viruses, commonly called "bird flu." This group of viruses has migratory waterfowl, seabirds, and shorebirds as their natural hosts and usually does not cause them severe disease. This almost perfect host-parasite relationship, where the highly mobile hosts are not significantly impaired, greatly facilitates the worldwide distribution of the AI viruses. It is when these viruses, which are present in the intestinal tract of the hosts, are shed in the feces to infect domestic poultry species such as chickens, turkeys, or quail that problems can result.