DES MOINES, Iowa (AP) — Wild birds are believed to be behind the first major widespread outbreak of bird flu in the United States, with the virus confirmed in wild birds in 10 states. The number of commercial chickens and turkeys infected climbed to more than 9 million Monday with more reported cases in Iowa. Here are some questions and answers about how wild birds remain healthy even when carrying and spreading the virus.
WHAT'S THE LATEST ON THE NUMBER OF BIRDS INFECTED?
The number of chickens and turkeys infected with avian influenza climbed again with four more probable cases in northwest Iowa totaling an estimated 2.3 million birds. A national laboratory is doing additional testing, but Iowa officials said four chicken farms appear to be infected, including an egg-laying operation with about 1.7 million birds.
HOW DID THE VIRUS ARRIVE STATESIDE?
Disease experts believe a portion of it came from European and Asian strains of bird flu that readily cause illness and death in birds and mixed with a North American strain that was less likely to cause severe illness as birds from different regions crossed migratory paths.