It’s a contagious disease that is often referred to as “bird flu”.  Usually it is caused by a virus that only affects birds and sometimes pigs.  There are two types of Avian Flu.  One type is mild and makes the birds ill, and the other is more virulent and kills all of the birds that it infects.  This is a very serious problem because now this virus is infecting human beings.  The first outbreak occurred in Asia in 2003.  Of course, the virus has been around for years without causing any serious problem.  The Asian outbreak killed over one hundred thousand birds, and was hard to contain.  Within one year, this virus had struck in about 12 other countries including Japan, Thailand, China, Cambodia and Viet Nam.  This virus is now know as H5N1. It has killed about 18 people since 2004; but what scientists are worried about is that the virus will mutate and become an illness that is easily passed from one human being to another.  At this moment, researchers are working on vaccines to protect humans from this virus.