Gripe aviar: ¿cuál es la situación en Cataluña y qué se está haciendo?
This post is based on a report published by the Multidisciplinary Collaborative Group for Scientific Monitoring of COVID-19 (GCMSC), coordinated by ISGlobal. The report provides an overview of the current situation regarding avian influenza H5N1 at the global, European, and Catalan levels, and highlights the importance of maintaining constant and coordinated surveillance across different institutions.
Five years after the onset of the COVID-19 pandemic, its consequences are still being felt: over 7 million officially reported deaths (with real estimates possibly exceeding 20 million), millions of people suffering from persistent symptoms, and economic losses estimated at 16 trillion dollars, which have pushed 130 million people into poverty.
It is difficult to predict when and how the next pandemic threat will emerge, but it is clear that we must remain vigilant about various viruses with the potential to cause global crises. One of the most concerning today is the H5N1 avian influenza virus, which has already infected more than 50 mammal species.
Although sustained human-to-human transmission has not yet been documented, the virus’s growing presence among mammals increases the risk that it could eventually occur. In the United States, the situation is especially concerning: the virus has been circulating actively among poultry and dairy cattle for more than a year, with over 12,000 detections in wild birds, nearly 1,000 infected herds, and at least 70 confirmed human cases following exposure to infected animals, including one death. Additionally, recent changes in the country’s data reporting systems have made it harder to track the virus’s evolution. In Europe, the situation is more controlled, with fewer cases and no known infections in dairy cattle. In this context, Catalonia currently shows a relatively calm situation, although under close surveillance.
In 2024, a total of 1,000 wild bird samples were collected in Catalonia as part of surveillance programs. Of these, only six tested positive for avian influenza, indicating very low virus circulation in the region. Among those six, just one was identified as the H5N1 subtype, detected in a gull. This highlights the importance of ongoing monitoring, as even low incidence in wildlife can pose a latent risk due to highly pathogenic strains. Another reassuring factor is that no outbreaks have been reported in Catalan poultry farms over the last two years, suggesting that protective measures are working. Nevertheless, the situation could change quickly, which is why the surveillance and response systems remain active and coordinated to detect any early warning signs.
Shared and coordinated surveillance
Virus surveillance in Catalonia is carried out jointly by several key actors working in coordination:
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IRTA-CReSA (Animal Health Research Centre) performs passive surveillance, analyzing samples from wild birds —and occasionally mammals— found dead or showing clinical signs compatible with avian influenza.
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CESAC (Poultry Health Centre of Catalonia and Aragon) is responsible for active surveillance in poultry farms, especially when nearby wild cases are detected.
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The Department of Microbiology at the University of Barcelona monitors wastewater in the metropolitan area to detect viruses of public health concern, such as H5N1.
At present, no specific monitoring is being conducted in livestock due to the low circulation of the virus, but screening protocols will be activated if the situation changes.
Prepared to act
The report emphasizes that despite the calm situation in Catalonia, preparedness is crucial. Avian influenza is a highly adaptable virus, and its evolution can be fast and unpredictable. Therefore, the following is recommended:
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Maintain surveillance in both wild and domestic birds.
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Ensure clear response protocols across agriculture and healthcare sectors.
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Promote a One Health approach, linking human, animal, and environmental health, and ensuring medical follow-up for people exposed to infected birds.
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Strengthen international surveillance networks.
Collaboration among research centres, health services, academic institutions, and public administrations is essential to anticipate future scenarios and protect public health in an integrated way.
