The risk that a traveller infected with Ebola could arrive in the United States during the 2026 World Cup tournament that kicked off ⁠last week is low but not zero, and if ⁠that happens, US hospitals are ready to respond, US infectious disease experts say.

It was not always so.

During the 2014 West African Ebola outbreak, a Liberian man, Thomas Eric Duncan, arrived in a Dallas hospital with Ebola symptoms and was turned away before being admitted.

Two nurses were infected but survived.

That led to $260m in US funding for Ebola preparedness training and response capabilities and 13 ⁠specialised treatment centres – all intended to help hospitals identify, isolate and safely care for suspected Ebola patients.

“We’re not going to be able to prevent 100% of infections, but we certainly are the most prepared that we have ever been,” said Dr Gavin Harris, an expert in serious communicable diseases at Emory University in Atlanta, one of 11 US World Cup host cities.

Public health officials and hospitals in the US host cities have been preparing for a range of infectious ⁠disease threats, as 6.5 million fans travel across North America during the 39-day event featuring 104 matches in the US, Mexico and Canada.

The US Centers for Disease Control and Prevention (CDC), the Pan American Health Organization and the World Health Organization (WHO) have all described the risk of Ebola to World Cup host countries as low, citing measles, COVID-19 and influenza – which spread when large crowds gather – as the most likely threats.

But the Ebola outbreak in the Democratic Republic of the Congo (DRC) that has infected more than 675 people and killed more than 135 remains a concern.

“The risk of Ebola to anyone at the World Cup is extremely low. Ebola isn’t airborne and doesn’t spread through casual contact – it requires direct contact with the body fluids ‌of someone who is ill,” said Dr Tom Frieden, chief executive of Resolve to Save Lives and former director of the CDC.

“But low isn’t zero, and it won’t be zero until the outbreak is stopped at its source in DRC.”

US Ebola preparedness efforts that began in 2015 were born out of a collaboration between Emory University, the University of Nebraska Medical Center, and NYC Health + Hospitals/Bellevue in New York City – facilities that cared for Ebola patients during the West African Ebola outbreak, the largest to date.

“There was a recognition that we had a duty to train other facilities to recognise potential patients who might be exposed or sick with something like Ebola,” Emory’s Harris said.

Thousands of healthcare workers have since been trained to recognise and treat patients with Ebola and other serious pathogens.

For the World Cup, preparedness experts have conducted nationwide training exercises simulating a potential MERS outbreak at the games.

They have also compiled guidance for physicians, raising awareness of illnesses not typical of their home cities, including mosquito-borne conditions such as malaria, dengue and chikungunya.

The US, Mexico and Canada have instituted airport ⁠screening and travel bans restricting the entry of non-citizens who have recently travelled to countries affected by the outbreak, and the US has urged Europe to impose similar restrictions. Harris said those ⁠bans are likely to decrease the chances of Ebola at World Cup venues.

To comply with US restrictions, the DRC national football team left the country in May and trained in Belgium before travelling to the US.

In each host city, FIFA, local public health officials and hospital systems have formed medical committees that have been conducting Ebola and other infectious disease threat assessments based on the teams that will play in their cities, diseases prevalent within their home countries, visa restrictions and stadium logistics, Harris said.

Some areas have discussed supplying disease-specific ⁠treatments or protective gear to the venues and are using surveillance tools, including wastewater monitoring, air quality data and electronic medical records, to detect unusual illness clusters.

FIFA said medical-related risks are assessed as part of overall tournament planning and managed in close coordination with the host cities, which provide medical leaders to oversee and coordinate services.

It said it is ⁠monitoring the Ebola outbreak and is in contact with sporting and health authorities in the DRC and the three host countries.

Dr ⁠Michael Osterholm, an infectious disease expert at the University of Minnesota, said planning for mass gatherings in the US is not new.

“State and local health departments working in conjunction with CDC have for many years been at the forefront of individuals coming into this country,” he said.

To help with disease monitoring and coordination, Georgetown University has set up an independent Health Security Operations Center, in collaboration with more than 30 public and private sector entities.

More than 700 state and local health authorities have signed up for the group’s daily reports, as have some 60 federal partners, FIFA and ‌the CDC.

Still, staff cuts at the CDC, the US departure from WHO, and strain on state and local health departments that have been battling the biggest US measles outbreak in decades have taken a toll, Frieden and two other experts said.

“My biggest concern is whether a CDC that’s lost thousands of staff has the capacity, support, and mandate to move fast enough – both here and in DRC,” Frieden said.

The US Department of Health and Human Services, which oversees the ‌CDC, ‌did not respond to a request for comment.

Jeanne Marrazzo, chief executive of the Infectious Diseases Society of America, said Health Secretary Robert F Kennedy Jr’s cuts to public health have led to an exodus from government agencies.

“Nonetheless, we know the people who are still there are working around the clock in many cases to try to keep us safe,” she said in a briefing.