Credit USDA
Yesterday the USDA unveiled their new avian flu (in livestock) dashboard, which depicts the 6 states with confirmed H5N1 in cattle, but curiously does not show the outbreak in goat kids in Minnesota reported in March (see Minnesota BOAH Statement On HPAI H5N1 Infected Goat Kids).
This joins USDA dashboards for HPAI in wild birds, in commercial & backyard poultry, and in mammalian wildlife.
Since testing is both limited, and often optional, these dashboards can only depict reported outbreaks or spillovers. And even those reports may be delayed by days or weeks. They can, however, provide us with some sense of the spread and incidence of HPAI around the nation.
Case in point, the mammalian wildlife map (below) only shows 7 new detections in the first quarter of 2024, and a total of only 214 detections since May of 2022.
There is great disparity in the reporting of mammalian wildlife (excludes domestic animals & pets) with HPAI H5 (see map below). Only 20 states have reported finding cases, with Wisconsin, Colorado, and California leading the pack.Why nearly all of the reports to date have come from northern states isn't clear, although it may come down to differences in climate and terrain (swamps vs. forests vs. deserts), and the fact that some states may be looking harder than others.
Mammals often die in remote and difficult to access places where their carcasses are quickly scavenged by other animals, meaning most never discovered or tested. Those that are reported likely only represent a small fraction of actual infections.
Since testing and surveillance resources are limited, and testing is often reactive - usually only invoked after unusual mortality events or obvious illness - we are probably missing a lot of HPAI infections.
Add in the fact that livestock testing remains voluntary, and we've seen instances of `don't test, don't tell' in the past, and the full scope of the problem is likely larger than these charts would suggest.
In a case of unfortunate timing, the USDA has recently revamped their website (see notice below), and already I've been stymied trying to find older links.
Hopefully this will be resolved sooner rather than later.
