Thursday, March 09, 2023

USDA Update On H5N1 In Mammalian Wildlife



Although its only been 9 days since the last update (see Feb 29th USDA Updatethe USDA today added an additional 13 confirmed H5N1 infections in mammals to their list, bringing the total to 144.

Added to this list are 5 mountain lions (3 from Wyoming, 1 from Utah, 1 from Colorado)5 striped skunks (4 from Colorado, 1 from New York), and a bobcat (CO), a raccoon (MT), and a North American River Otter (WI)

The latest entries are listed below.

These are assumed to represent only a fraction of the mammals that have been affected by H5 avian flu, since many birds and mammals die in remote and difficult to access places, and are never discovered or tested. 

Additionally, some states appear to be more proactive in investigating outbreaks than others. With the exception of a single infected Bottlenose Dolphin detected in Florida, all of the reports of mammalian infection have come from the northern tier of states.

Peridomestic mammals, like red foxes and skunks, remain the most commonly reported terrestrial mammals infected, although we are seeing an increasing number of big cats and bears being infected in recent months.

While these spillover events are concerning, unlike with SARS-CoV-2 in deer, we haven't seen signs of H5N1 transmitting efficiently in mammalian wildlife (possible, but unproven exceptions are in marine mammals). But once again, surveillance is extremely limited.

Over the past 90 days, the USDA has added 46 entries to this list, averaging one about every 2 days.