Flu

The latest human case of bird flu in the U.S. occurred in a patient with no reported exposure to affected animals, sparking questions over whether the virus is spreading between people. Experts say that's unlikely but argue the case raises other concerns.

People could previously get the nasal spray flu vaccine, called FluMist, from a health care provider, but now they can administer it themselves.

Flu viruses that can use a second cellular entry point may move more effectively between animals and humans, scientists say.

Bird flu in cows and goats has raised alarm in the U.S. To date, four people are thought to have caught the virus from cattle, but the risk to the general public is low.

A fourth person in the U.S. has caught bird flu after working with infected cows on a farm.

Scientists found that contaminated milking equipment can harbor the H5N1 virus for more than an hour, increasing the risk of dairy farmers getting infected.

A man in Mexico died after catching the world's first laboratory-confirmed case of H5N2 bird flu in humans. However, authorities think he likely died of existing conditions, rather than the infection itself.

This infection, tied to an ongoing outbreak in cows, is the first in the U.S. to cause respiratory symptoms, but not the first H5N1 case in the world to do so.

A dairy worker in Michigan contracted an eye infection on a dairy farm where H5N1 had been identified in cows.

The patient is being treated with an antiviral drug and is believed to have been in contact with dairy cows infected with H5N1 avian influenza.