July 27, 2026
 

Spain's Newcastle disease outbreak reaches 29 confirmed sites with over 1.3 million birds affected

Two distinct virus strains are circulating simultaneously across separate regions, with Spain's Agriculture Ministry now mandating vaccination across the entire Castilla y León region from September 2026.

Spain has confirmed 29 Newcastle disease outbreaks in commercial poultry operations since December 2025, with the outbreak expanding rapidly through Castilla y León and a total of more than 1.3 million birds affected across the two active fronts.

The outbreak began on 29 December 2025 in Llutxent, Valencia, in a broiler farm of approximately 15,000 birds - the country's first Newcastle disease case since 2022. Three secondary outbreaks were confirmed in the same municipality on 2 January 2026. The Valencia front has since grown to 10 confirmed outbreaks in the Vall d'Albaida comarca, all involving genotype VII.1.1 of the virus, and is considered largely contained.

A second and more severe front has since opened in Castilla y León, centred on the province of Valladolid and now spreading to Zamora, Segovia, Ávila and Salamanca. Genetic sequencing by Spain's Central Veterinary Laboratory confirmed that the Castilla y León strain - genotype VII.2 - is epidemiologically unrelated to the Valencia strain, indicating two independent introduction events. Six new outbreaks were confirmed in Castilla y León between 13 and 22 July alone, affecting farms in Segovia, Valladolid, Ávila and Salamanca. The affected farms were predominantly unvaccinated broiler operations.

In response to the escalating situation in Castilla y León, Spain's Ministry of Agriculture, Fisheries and Food has made vaccination mandatory for all commercial and breeding poultry operations in the provinces of Valladolid and Segovia from 1 August 2026, with the obligation extending to all of Castilla y León from 1 September 2026. Vaccination had not previously been compulsory in Spain.

Standard control measures have been applied at all confirmed sites, including culling of affected flocks, establishment of protection and surveillance zones, movement restrictions, traceability investigations, disinfection and official disposal of carcasses, feed and other materials capable of transmitting the virus. Authorities have emphasised that Newcastle disease poses no risk to human health.