When did the last strain of bird flu break out?

There have been several outbreaks of bird flu in recent years. The most recent major outbreak was the H5N1 strain, which began in 2003 and spread to over 60 countries. The outbreak resulted in the deaths of millions of birds and led to the culling of millions more. The H5N1 strain has also caused a small number of human infections, but these have been rare and typically mild.