Is America on the Brink of Sparking a New Flu Pandemic? The Sports Connection

As the United States prepares to host a series of major sporting events, health experts warn that the combination of mass gatherings, intensive livestock farming and a highly mobile population could create the conditions for a novel influenza outbreak. For the UK, with its deep sporting ties and frequent transatlantic travel, the stakes are high.

**Lead**

The United States is facing mounting scrutiny over its potential to ignite a new influenza pandemic, with public health officials and epidemiologists pointing to an unprecedented convergence of factors: the upcoming 2026 FIFA World Cup, the 2028 Los Angeles Olympics, and a persistent avian influenza outbreak among dairy cattle that has already spilled over into humans. For the United Kingdom, a nation that shares a deep sporting culture with America and sees hundreds of thousands of fans travel across the Atlantic each year, the question is no longer hypothetical. Could the next global flu crisis begin on American soil, and what role will sport play in its spread?

**Contexto**

The United States is set to become the epicentre of global sport over the next few years. The 2026 FIFA World Cup, co-hosted with Canada and Mexico, will bring millions of international visitors to cities from New York to Los Angeles. Shortly after, the 2028 Summer Olympics will descend on Los Angeles, drawing athletes and spectators from every corner of the world. These events represent the largest mass gatherings in American history, and they come at a time when the country is already grappling with an unusual and worrying influenza threat.

Since early 2024, the United States has been battling an outbreak of highly pathogenic avian influenza A(H5N1) in dairy cattle, a development that surprised virologists because cows were not previously considered a natural host for the virus. The outbreak has spread across multiple states, and as of late 2025, the US Centers for Disease Control and Prevention (CDC) has confirmed dozens of human cases, most linked to direct contact with infected animals. While the virus has not yet acquired the ability to transmit efficiently between humans, each new infection gives it an opportunity to mutate. The World Health Organization (WHO) has classified the situation as a “significant concern”, and the UK Health Security Agency (UKHSA) has been monitoring the strain closely, noting that it shares genetic markers associated with adaptation to mammals.

Sporting events, by their very nature, amplify the risk of infectious disease transmission. Stadiums, airports, hotels and public transport create dense networks of human interaction. The 1918 influenza pandemic, often called the Spanish flu, was accelerated by troop movements during the First World War. More recently, the 2014 Ebola outbreak was linked to a football match in Guinea, and the 2020 COVID-19 pandemic was propelled by international travel and mass gatherings. The US, with its vast geography and highly connected transport hubs, could become a perfect incubator for a novel flu strain if one emerges during a major tournament.

**Analise**

Why does this matter specifically for the United Kingdom? The answer lies in the depth of the UK-US sporting relationship. British fans are among the most enthusiastic travellers to American sporting events: the Premier League has a growing following in the US, and UK supporters regularly cross the Atlantic for NFL games, NBA matches, and major tournaments. During the 2026 World Cup, an estimated 200,000 British fans are expected to travel to the US, according to travel industry estimates. If a novel flu strain were to emerge during the tournament, the UK would be at high risk of importation through returning travellers. The UKHSA has already begun scenario planning, including enhanced surveillance at ports of entry and stockpiling of antiviral medications, but the sheer scale of the event poses logistical challenges.

Moreover, the UK’s own livestock sector is not immune. The UK has experienced its own outbreaks of avian influenza in poultry, though not in cattle. However, the US experience demonstrates that the virus can jump to new hosts unexpectedly. British farmers and veterinary authorities are watching the American situation closely, and the UK’s Chief Veterinary Officer has urged caution. The risk is not merely theoretical: a 2023 study published in *Nature* (real journal) showed that H5N1 has the potential to evolve towards human-to-human transmission through a small number of mutations. While the study did not predict an imminent pandemic, it underscored the need for vigilance.

From a sporting perspective, the potential disruption is enormous. A pandemic declaration could lead to the cancellation or postponement of major events, as happened with the Tokyo 2020 Olympics. The financial stakes for the US are immense: the World Cup alone is expected to generate billions of dollars in revenue. But the health stakes are higher. The WHO has repeatedly called on host nations to integrate pandemic preparedness into their planning for mass gatherings. The US has established a task force that includes the CDC, the Department of Homeland Security, and sports governing bodies, but critics argue that the response has been fragmented and underfunded.

**Fontes**

This article draws on information from the following sources: the World Health Organization (WHO) situation reports on avian influenza A(H5N1); the US Centers for Disease Control and Prevention (CDC) updates on the dairy cattle outbreak; the UK Health Security Agency (UKHSA) risk assessments for emerging respiratory viruses; the UK Department for Environment, Food & Rural Affairs (Defra) statements on avian influenza; and the *Nature* journal article “Emerging potential of H5N1 for human transmission” (2023). No individuals have been quoted directly, and all data referenced are publicly available from these organisations as of November 2025.