Fans from around the world are starting to arrive in North America for the largest-ever World Cup, but an outbreak of the Ebola virus in East Africa has put health officials in the host nations on high alert.

Authorities are racing to contain the outbreak of the rare Bundibugyo strain of the virus, which was first declared in the Democratic Republic of the Congo (DRC) on May 15. It has since infected at least 488 people there, causing 86 deaths.

The disease has also spread to neighbouring Uganda, and the World Health Organization (WHO) has declared the outbreak a “public health emergency of international concern”.

Uganda has confirmed 19 cases and two deaths and has largely closed off its western border with the DRC in an effort to curb cross-border contagion, frustrating traders who rely on border crossings for business.

The US Centers for Disease Control and Prevention (CDC) has warned that the current outbreak could swell to become the largest Ebola epidemic on record, rivalling the 2014-16 epidemic in West Africa.

With more than a million fans expected to travel to North America for the World Cup, here’s how authorities in the United States, Canada and Mexico are preparing to stop the spread of Ebola during the tournament.

Travel restrictions and airport screening

The World Cup host nations announced “aligned public health travel measures for individuals coming from African regions at greatest risk from the Ebola virus”, according to a joint statement from the three countries, which did not provide details of the aligned measures.

In May, the US banned all noncitizens who had travelled to the DRC, Uganda or South Sudan in the previous 21 days from entering the country. This ban was then extended to green card holders who were in those countries in the previous 21 days.

A number of US airports, including Washington Dulles and Hartsfield-Jackson Atlanta, have also implemented enhanced screening measures for travellers from affected regions.

Canada has temporarily banned residents of the DRC, Uganda and South Sudan from entering the country for ⁠90 days, according to the country’s public health agency.

Canadian citizens, permanent residents and other foreign nationals who have been in affected areas in recent weeks and do not have symptoms will ⁠have to quarantine for 21 days, with the new rule kicking in from May 30.

Mexico’s health secretary has outlined ⁠tighter Ebola screening measures at airports, urging the public to avoid travel to the DRC and asking arrivals from the country to observe a 21-day quarantine.

DRC forced to isolate in Belgium

The DRC, who have qualified for their first World Cup since 1974, cancelled a planned pre-World Cup training camp at home due to the Ebola outbreak and have been based in Belgium instead.

Andrew Giuliani, executive director of the White House Task Force for the World Cup, confirmed to ESPN on May 23 that the Congolese delegation must maintain a bubble in Belgium and isolate for 21 days or risk being denied entry to the US.

The team’s World Cup preparations were further thrown into chaos when a planned warm-up match against Chile in Spain was cancelled due to fears over the spread of the virus.

“I have signed the decree banning the holding of the June 9 match between the Democratic Republic of Congo and Chile,” said Juan Franco, mayor of La Linea de la Concepcion in southern Spain.

DRC coach Sebastien Desabre has offered to play the match behind closed doors instead.

“The only thing I can say is that we’re used to adapting, and whatever happens, we’ll have no problem adapting to all these situations,” he added.

During the tournament, the East African team plan to be based in Houston, Texas, where they will play their first Group K match on June 17 against Portugal.

The DRC are then scheduled to play Colombia on June 24 in Guadalajara, Mexico, before their last group match against Uzbekistan in Atlanta, Georgia, US, on June 28.

Tracking outbreaks

Boston University’s Center on Emerging Infectious Diseases will be monitoring the World Cup to track any outbreaks of infectious diseases.

Their Biothreats Emergence Analysis and Communications Network (BEACON) programme aims to “keep public health officials, participants, and the global community informed, safe, and one step ahead”, according to an update on their website.

The National Special Pathogen System (NSPS) also recently conducted a tabletop exercise, simulating responses to any disease outbreaks during the tournament.

Their mock scenario focused on an outbreak of Middle East Respiratory Syndrome during the World Cup.

The exercise highlighted the “importance of timely actions, coordinated efforts, and comprehensive planning”, according to NSPS.

‘Very low risk’ to fans

Despite these measures, health experts are not overly concerned about the risks facing fans who are travelling to North America this summer.

“If you are a casual visitor to the World Cup from around the world, I think there is a very low risk that you would be at risk of Ebola,” Oliver Johnson, a global health academic at King’s College London, told the Reuters news agency.

“Ebola has never really caused transmission in high-income country settings, where there have been very occasional cases.

“That is because it is not airborne. You had to normally have direct contact with someone who is quite sick, and there ‌is ⁠usually good contact tracing. If a case does occur, it is identified quickly,” he added.

Fans travelling for the tournament should follow basic precautions such as good hand hygiene and ⁠avoiding close contact if unwell, Johnson said.