Public health experts around the world are sounding the alarm as cases of a virulent strain of avian influenza called H5N1 rise in mammals. Bird flu has infected humans in the past, mostly people who work directly with diseased poultry, but there has never been widespread human-to-human transmission of the virus. If there were, it could be a catastrophe: The original H5N1 mutation had a 50 to 60 percent mortality rate in humans.
The latest outbreak of H5N1, which began in the U.S. in late 2021, has resulted in the culling of 58 million birds thus far and led to a marked increase in the cost of eggs and poultry at the supermarket. It's America's second major surge of H5N1since the strain was first detected in southern China in the late 1990s — the first significant U.S. wave kicked off in 2014 and was contained mainly to the Midwest.
