The World Health Organization has this week expressed concern regarding the potential for transmission of avian influenza to other species, including humans.

During a press briefing in Geneva Thursday, WHO's chief scientist, Jeremy Farrar, referred to the situation as one of "enormous concern".

“H5N1 is (an) influenza infection, predominantly started in poultry and ducks and has spread effectively over the course of the last one or two years to become a global zoonotic (animal) pandemic,” he said. “The great concern, of course, is that in doing so and infecting ducks and chickens - but now increasingly mammals - that that virus now evolves and develops the ability to infect humans. And then critically, the ability to go from human-to-human transmission.”

The current outbreak, which began in 2020, has affected not only ducks and chickens but also cows and goats.

The Food and Agriculture Organization of the United Nations, the World Organisation for Animal Health and the WHO, are urging countries to work together across sectors to save as many animals as possible and to protect people.

Roger Kember, the former Deputy Director of Capabilities at the Civil Contingencies Secretariat who commissioned the Department of Health to produce an Influenza Pandemic Plan in 2001, says now is the time to review plans.

"All business continuity and crisis managers had a pandemic flu plan before the Covid outbreak and most will have conducted a post-Covid debrief on the impact," he said. "The business impacts of pandemic ‘flu would be similar to Covid on employees; supply lines; customers and disruption to all aspects of the national infrastructure and government. It is now prudent to review pandemic flu plans in the light of the Covid impact on businesses and organisations. The warning from WHO cannot be ignored."

Avian influenza viruses normally spread among birds, but the increasing number of H5N1 avian influenza detections among mammals – which are biologically closer to humans than birds – raises concern that the virus might adapt to infect humans more easily. In addition, some mammals may act as mixing vessels for influenza viruses, leading to the emergence of new viruses that could be more harmful to animals and humans.

The UK government last updated its advice on avian flu on 5th April 2024. At that point, there had been 4 cases of highly pathogenic avian influenza in England since October 2023 (and 298 since October 2021); and 2 cases in Scotland since that date (and 51 since October 2021); with no reported cases in Wales or Northern Ireland since October 2023, but 15 and 7 cases respectively since October 2021.

The UK has self-declared zonal freedom from highly pathogenic avian influenza for Great Britain with effect from 29 March 2024. This is in line with World Organisation for Animal Health rules. The declaration is being reviewed and is expected to be published by WOAH shortly. This follows Northern Ireland declaring itself free on 31st March 2023.

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