AVIAN HEALTH · NEWCASTLE ALERT · UPDATE JULY 1, 2026
The outbreak in Olmedo (Valladolid), confirmed by MAPA on June 30, is the sixteenth of the wave that began in December 2025 and the one with the largest census. Castilla y León now concentrates six outbreaks with the VII.2 genotype, different from the VII.1.1 that struck the Valencian Community until May.
A sixteenth outbreak drives the affected census up to 750,000 birds
The Ministry of Agriculture, Fisheries and Food (MAPA) reported on June 30 a new Newcastle disease outbreak on a laying hen farm in the municipality of Olmedo, in the province of Valladolid. The farm, which was vaccinated against the disease, has a census of approximately 301,191 laying hens; the suspicion was reported on June 23 after a drop in egg laying of nearly 5% was detected in one of the houses, along with a slight increase in mortality. The Central Veterinary Laboratory (LCV) in Algete confirmed by PCR the presence of a velogenic strain of the virus.
With this episode, the wave that began in December 2025 reaches 16 confirmed outbreaks and a cumulative census of 750,681 birds on affected farms. It should be clarified—for the sake of accuracy—that this figure corresponds to the census of the farms where the virus has been confirmed, not the number of birds that died or were culled, which is significantly lower in each outbreak.
The Olmedo outbreak has the largest census of the entire wave: a single vaccinated laying hen farm accounts for 40% of the affected birds recorded in 2026.
66% laying hens and 34% broilers: the census breakdown
The emergence of the virus on June 30 on a large laying farm has shifted the weight of the episode toward laying hens. Of the total birds on affected farms, nearly two-thirds are laying hens and one-third are broilers. As for the cases, out of a total of 16 outbreaks between 2025 and up to July 1, 2026, 9 have been in broilers and 7 in laying hens.
| Bird type | Affected birds (census) | % of total |
| Laying hens | 497,381 | 66% |
| Broilers | 253,300 | 34% |
| TOTAL | 750,681 | 100% |
Source: NeXusAvicultura, based on official MAPA and RASVE data. Updated as of July 1, 2026.
Two epicenters, two genotypes, and no epidemiological link
The Spanish wave today has two clearly differentiated geographic outbreaks. The Valencian Community has accumulated 10 outbreaks between December 2025 and May 2026, all linked to the VII.1.1 genotype. Castilla y León—specifically the province of Valladolid—has added 6 outbreaks since June 15, associated with the VII.2 genotype.
Partial sequencing carried out by the Algete Regional Veterinary Laboratory (LCV) confirms that the virus circulating in Valladolid belongs to a subtype different from the one detected in Valencia, which—according to MAPA itself—corroborates the ruling out of a direct epidemiological link between the two outbreaks. This is, therefore, two independent introductions. The technical context can be consulted in our article «Newcastle Disease or the Vaccination Dilemma».
The complete timeline of the 2025-2026 wave in Spain
The following table lists the 16 outbreaks of Newcastle Disease officially confirmed, with their census, location, genotype, and vaccination status. Cells without data correspond to information not expressly published by official sources.
| Outbreak | Confirmation | Municipality (province) | Type | Census | Genotype | Vacc. |
| 1 | Dec 29, 2025 | Llutxent (Valencia) | Broilers | 15,000 | VII.1.1 | No |
| 2 | Jan 2, 2026 | Llutxent (Valencia) | Broilers | 28,500 | VII.1.1 | — |
| 3 | Jan 2, 2026 | Llutxent (Valencia) | Broilers | 16,500 | VII.1.1 | — |
| 4 | Jan 2, 2026 | Llutxent (Valencia) | Broilers | 20,100 | VII.1.1 | — |
| 5 | Jan 20, 2026 | El Palomar (Valencia) | Broilers | 75,000 | VII.1.1 | Started |
| 6 | Mar 9, 2026 | Terrateig (Valencia) | Layers | 27,000 | VII.1.1 | Yes |
| 7 | Apr 9, 2026 | Ráfol de Salem (Valencia) | Broilers | 26,300 | VII.1.1 | Yes |
| 8 | Apr 10, 2026 | Ráfol de Salem (Valencia) | Layers | 32,000 | VII.1.1 | — |
| 9 | Apr 28, 2026 | Ráfol de Salem (Valencia) | Broilers | 38,900 | VII.1.1 | Yes |
| 10 | May 8, 2026 | Castelló de Rugat (Valencia) | Layers | 20,040 | VII.1.1 | Yes |
| 11 | Jun 15, 2026 | Aldea de San Miguel (Valladolid) | Broilers | 24,000 | VII.2 | No |
| 12 | Jun 19, 2026 | La Pedraja de Portillo (Valladolid) | Layers | 29,500 | VII.2 | Yes |
| 13 | Jun 19, 2026 | La Pedraja de Portillo (Valladolid) | Layers | 49,000 | VII.2 | Yes |
| 14 | Jun 19, 2026 | Montemayor de Pililla (Valladolid) | Broilers | 9,000 | VII.2 | No |
| 15 | Jun 19, 2026 | Íscar (Valladolid) | Layers | 38,650 | VII.2 | Yes |
| 16 | Jun 30, 2026 | Olmedo (Valladolid) | Layers | 301,191 | VII.2 | Yes |
| TOTAL — 16 outbreaks | 750,681 | 8 vaccinated | ||||
Source: NeXusAvicultura, based on official notes from MAPA/RASVE and the Junta de Castilla y León. Approximate figures. “—” = data not officially published.
Olmedo: the largest farm affected to date
The Olmedo outbreak is located in an area close to the surveillance zone of outbreak No. 2026/9, detected the previous week in the municipality of Íscar. Within the 3 km and 10 km restriction radii there are 13 registered commercial farms, of which 8 already belonged to restriction zones from previous outbreaks. The Official Veterinary Services immediately applied the measures set out in Delegated Regulation (EU) 2020/687: movement standstill, epidemiological survey, sanitary emptying with destruction of carcasses and feed, and establishment of the restriction zone.
| The NeXus-Fact Sheet for the Olmedo outbreak (VALLADOLID) | |
| Confirmation date | June 30, 2026 |
| Municipality / province | Olmedo (Valladolid), Castilla y León |
| Type of farm | Laying hens (vaccinated) |
| Approximate flock size | 301,191 birds |
| Warning sign | ~5% drop in egg laying + slight increase in mortality |
| Suspicion date | June 23, 2026 |
| Laboratory confirmation | PCR (LCV Algete): velogenic strain |
| Genotype | VII.2 (different from the Valencian VII.1.1) |
| Link to Valencia | Ruled out by sequencing |
| Outbreak number in the wave | 16th (and 6th in Castilla y León) |
Vaccination back in the spotlight
Eight of the 16 outbreaks have been declared on vaccinated farms, including the one in Olmedo. This is a recurring pattern in this wave and in the broader European crisis: classic vaccines reduce mortality, clinical signs, and viral shedding, but do not fully prevent infection against velogenic strains. MAPA itself points this out precisely—“even though the vaccine does not offer 100% protection, it reduces the risk of birds becoming infected and the amount of virus shed”—and therefore insists on strengthening biosecurity and passive surveillance as first-line measures.
The Valencian Community implemented mandatory vaccination in February 2026, as we reported at the time (“Valencia will implement mandatory vaccination throughout its territory”). The emergence of outbreaks on vaccinated farms in both regions reopens the debate over the quality of vaccine administration and immunity gaps, especially in short-lived broilers.
Eight of Spain’s 16 outbreaks have been declared on vaccinated farms: the vaccine cushions the clinical blow, but does not close the door to infection.
From the Mediterranean arc to Castilla y León: a broken containment
For nearly six months, the disease remained confined to the Valencian Community, where it reappeared in December 2025 after more than three years without cases in Spain («Newcastle disease reappears in Spain after three years without any cases»). On June 15, the outbreak in Aldea de San Miguel broke that geographic confinement and carried the virus to Valladolid, nearly 600 km from the Mediterranean arc («From the Mediterranean Arc to Castile and León»). In two weeks, Castile and León has gone from zero to six outbreaks. For the general framework of the disease, please refer to «What is Newcastle disease?».
Newcastle in Europe in 2026: a front that won’t close
Spain is not an isolated case. Newcastle disease has reestablished itself as an ongoing risk across much of Europe throughout 2026, with the virulent genotype VII circulating in several Member States. This is the situation so far this year, according to official sources and specialized trade press.
| Country / scope | Situation in 2026 (to date) |
| Poland | European epicenter. Ongoing outbreak since September 2024, with nearly 150 commercial farms affected cumulatively. In just the first months of 2026, Defra put the number of affected birds at around 1.8 million. Strong impact on turkeys and broilers. |
| Germany | First outbreak since 2008: reported on February 20, 2026 in Brandenburg, near the Polish border, followed by a second in Bavaria. More than 40 outbreaks by late March and more than 2 million birds culled. Genotype VII.1.1. |
| Spain | 16 outbreaks and 750,681 birds in affected census since December 2025. Two epicenters: Valencian Community (VII.1.1) and Valladolid (VII.2). |
| Czech Republic, Lithuania, Slovakia, Latvia | Outbreaks mainly in non-commercial poultry (captivity) and wild birds, including pigeons and Eurasian collared doves. |
| United Kingdom | No outbreaks, but Defra raised the risk of introduction from low to medium (March 2, 2026) due to continental viral pressure and spring migration. |
| EU context | Actions under Delegated Regulation (EU) 2020/687; data channeled via WAHIS (WOAH) and ADIS. Coincides with HPAI H5 pressure in wild birds. |
Sources: WOAH/OMSA (WAHIS), ADIS (European Commission), Defra/APHA (risk assessments of March 2 and 30, 2026) and MAPA.
The underlying reading is familiar to NeXus readers: the Newcastle virus has once again behaved as an endemic risk in Central and Eastern Europe, with proven ability to jump borders toward the south and west. We expand on the European framework in «Seven outbreaks in Spain, ten in Germany, and 80 in Poland».
An essential note: Newcastle disease poses no risk to human health and the consumption of chicken meat and eggs is completely safe.
Timeline of Newcastle outbreaks in Spain:
After more than three years (since 2022) without any case of Newcastle disease in Spain, the situation has become complicated since the resurgence of this disease in December 2025 in Valencia. This is the updated list of outbreaks as of July 1, 2026:
- The origin (Outbreak 1): The disease reappeared in Spain at the end of December 2025 in the municipality of Llutxent (Valencia), on a farm with 15,000 chickens, breaking the disease-free country status that Spain had maintained since 2022.
- The expansion (Outbreaks 2, 3, and 4): On January 2, 2026, three new secondary outbreaks were confirmed in the same municipality, affecting farms with populations of 28,500, 16,500, and 20,100 birds. The investigation pointed to geographic proximity and links between owners as transmission factors.
- The fifth case (January 20, 2026) on a farm with 75,000 broilers.
- Sixth outbreak (March 9, 2026) in Terrateig, affecting a single house with 27,000 hens in a poultry complex.
- Seventh outbreak (April 9, 2026) on a farm with 26,300 broilers and the eighth outbreak (April 10, 2026) on a farm with 32,000 laying hens. Both in Ráfol de Salem.
- Ninth outbreak (April 28, 2026) on a farm with 38,900 broilers in Ráfol de Salem.
- Tenth outbreak (May 8, 2026) on a farm with 20,040 laying hens in Castelló de Rugat (official statement).
- Eleventh outbreak (June 15, 2026) on a farm with 24,000 43-day-old broilers in Aldea de San Miguel, Valladolid (official statement).
- Outbreaks 12, 13, 14, and 15 from June 22, 2026 in Valladolid affect a total of 117,150 laying hens and 9,000 broilers.
- Outbreak number 16 on June 30, 2026 in Olmedo (Valladolid) affects a farm of 300,000 laying hens (official statement).
To learn more:
-. What is Newcastle Disease?
-. National Newcastle Surveillance Program 2026. (14-page PDF from MAPA published in May 2025)
-. Main page of Newcastle Disease Control from MAPA
-. Newcastle Disease on NeXusAvicultura
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