As of writing, there is a large outbreak of H5Nx avian influenza among wild birds from the 2.3.4.4b clade. These are primarily H5N1. H5N6 and H5N8 specimens of this clade have previously been common as well. Infections of mammals have been observed, although most of these infections are not generally thought to indicate transmission between mammals.
In October 2022, an outbreak of clade 2.3.4.4b H5N1 occurred in farmed mink in Spain. A January 19 2023 paper indicates the strain had evolved mutations associated with infecting mammalian cells. The strain appeared to have high transmissibility between mink.
There is also recent evidence of possible transmission between seals.
This raises concerns of H5Nx strains capable of human-to-human transmission with an R0 above 1, which could cause a pandemic.
Recent zoonotic viruses with respiratory transmission have generally been controlled before reaching 10,000 cases (eg SARS-1 and MERS) or reached uncontrolled worldwide spread with over 500,000 cases (eg Covid-19 and 2009 H1N1 swine flu).
| Indicator | Value |
|---|---|
| Stars | ★★★☆☆ |
| Platform | Metaculus |
| Number of forecasts | 231 |
As of writing, there is a large outbreak of H5Nx avian influenza among wild birds from the 2.3.4.4b clade. These are primarily H5N1. H5N6 and H5N8 specimens of this clade have previously been common as well. Infections of mammals have been observed,...