In 2015 the same disease turned up in the Mid-West, and caused the largest animal- disease outbreak ever seen in the USA. Before COVID, bird flu was considered the most likely to cause a trans-national outbreak in the human population.

The flu found in the USA is an H5N1, of the sub-type that has made people sick. It is highly pathogenic, and fast moving, which can wipe out flocks of birds [ chickens, turkeys] in a couple of days. It is related to the species jumping virus that killed people in Hong Kong in 1997. A very large number of highly pathogenic H5N1 strains are surfacing in the World right now. It has to be said there is no indication if this strain will cross over to humans.


Bird Flu Is Back in the US. No One Knows What Comes Next | WIRED