Hospital workers reported respiratory symptoms after encountering a Missouri patient with H5N1 who had not been exposed to farm animals. Officials say bird flu transmission is unlikely.

Missouri officials are under growing pressure from national public health experts to pinpoint the source of the state’s first human bird flu infection.

A routine flu screening in late summer found the H5N1 virus in a Missouri patient. Unlike the other reported cases of avian flu, this person did not report being in recent contact with animals.

While California reports more human cases of bird flu, experts say the true number of cases could be much higher

None of the health care workers or other contact have tested positive for avian flu antibodies so far — but could their illness signal human-to-human transmission?

The Centers for Disease Control and Prevention last week confirmed the first two human cases of H5 bird flu in California.

As an outbreak of bird flu among dairy cows continues to spread in the United States, two more cases have been reported in

State officials say a dairy worker in the Central Valley likely contracted H5N1 bird flu. They say the risk of infection remains low for the general population.

Two dairy workers in California have been infected with the state’s first human cases of bird flu, federal and state health officials said. The late Thursday announcement of two confirmed

California said on Thursday it confirmed a fourth human case of bird flu in a person who had contact with infected dairy cattle. All four people who have tested positive for the virus in the most populous U.