UK: Defra Announces 5th H5 Poultry Outbreak In A Week

 

#18,819

Yesterday, in The UK's Summer HPAI H5 Surge In Poultry, we looked at an unexpected surge in H5N1 poultry outbreaks (n=4) over less than a week, which began just 3 days after Defra lowered the nation's risk level: 

The risk of infection of poultry in Great Britain with suboptimal biosecurity is therefore lowered to LOW (rare but does occur) with high uncertainty. The risk to poultry with stringent biosecurity is maintained at LOW (rare but does occur) with low uncertainty.

I won't rehash the background information from yesterday's blog, but after I posted that blog, Defra announced a 5th outbreak - once again in Sommerset County - albeit roughly 40 miles east  of the outbreak near Dulverton, Tiverton and Minehead  reported on the 28th.

Details are typically scant:

31 July 2025

Highly pathogenic avian influenza (HPAI) H5N1 was confirmed in other captive birds at a premises near Yeovil, Yeovil, Somerset (AIV 2025/54). A 3km captive bird (monitoring) controlled zone has been declared surrounding the premises.

While not unheard of, summer outbreaks of HPAI H5 in UK captive birds are fairly rare. Last year, zero outbreaks were reported between late February and early November. 

Given that much of what happens with the evolution and spread of HPAI H5 occurs  outside of our view, it is important to take note of any changes in the virus's behavior. 

While this spate of summer HPAI outbreaks could prove to be little more than a transient event, it is worth keeping our eye on. 

Stay tuned.