Federal health agencies put it simply: Bird flu is an infection caused by avian (bird) viruses. Wild birds around the globe carry these viruses in their intestines, but are rarely sickened by them. For domestic birds like chicken, turkeys, and ducks, however, bird flu can be a killer.
Just like humans, birds can come down with the flu. The illness varies widely in intensity, from mild to deadly. A particularly vicious avian flu virus hit domestic chickens and ducks in several Asian countries in late 2003 and early 2004. Millions of birds have either died from the flu or had to be destroyed to stop the spread of the disease.
Avian Flu Symptoms In Birds - Best Photos HD
This year, 43,000 samples were taken from 1,800 areas in poultry farms, markets, and rural regions and 120,000 cellular and molecular examinations were carried out by November, when the virus broke out in seven provinces.
Different strains of bird flu have been spreading across Europe and Asia since late last year, leading to large-scale culling of poultry in certain countries and some cases of human deaths in China from H7N9, another strain of the virus.
There are many subtypes of avian influenza viruses, but only some strains of five subtypes have been known to infect humans: H5N1, H7N3, H7N7, H7N9 and H9N2.
The National Headquarters to Fight Bird Flu which meets regularly has also claimed that the situation is under control.