Olympic Games Ripe for Communicable Disease Transmission

With nearly 3,000 athletes from more than 90 countries; more than one million spectators; and tens of thousands of staff, volunteers, and media personnel expected at the Winter Olympic Games which began on February 2, there is distinct potential for communicable disease transmission. In fact, with the Olympic period coinciding with peak winter respiratory virus activity and seasonal norovirus activity elevated in several European countries, the virus has already affected some women’s hockey teams. Team Finland’s game against Canada was postponed after an outbreak on the Finland team, and Team Switzerland did not walk at the opening ceremony after a player was infected.

According to the ECDC, such spread is not uncommon, as the Winter Olympics have historically experienced significant norovirus outbreaks, most notably during the 2018 Winter Olympic Games in PyeongChang. With so many international visitors in a single area, the center notes multiple factors that can lead to a public health threat, such as an imported disease, increased numbers of susceptible people, risk behavior, sale of food and beverages by street vendors, etc. – all of which augment transmission of any communicable diseases that may be circulating in the local or visiting populations.

Even with that, however, ECDC rates the probability of EU/EEA citizens becoming infected with communicable diseases as low – as long as general preventive measures are applied (being fully vaccinated, following good hand and food hygiene, self-isolating when ill, etc.). Such practices are particularly important as several diseases may be on the rise in the EU/EEA, such as measles, whooping cough, and respiratory infections, including influenza and COVID-19.

In relation to vaccine-preventable diseases, the Boston University Center on Emerging Infectious Diseases notes measles as having the highest risk due to its high transmissibility; recent resurgence in Europe, including Italy; and persistent immunity gaps in key travel-age groups, such as adolescents and young adults. Additionally, while the majority of cases are occurring among unvaccinated individuals, the Winter Olympic Games have experienced measles outbreaks, with a single introduction of the virus during the 2010 Vancouver Games seeding a broader outbreak.

For those at the Games, going to the Games, or even just traveling or gathering in groups, the best protection is prevention. Vaccination, handwashing, staying in when ill, and wearing masks as applicable will help to protect both yourself and others.

COVID Risk Matrix:

Influenza:

Public Health News:

• A Cross-Canada study of patients with acute respiratory illness, from October 2025-January 2026, has determined that the effectiveness of this season’s flu vaccine is at about 40%, though effectiveness against the newly emergent subclade K is lower. 
• Peguis First Nation in Manitoba has started urging their community and those who may have had contact with them, to get a Hepatitis A vaccine. Although the overall risk of Hep A transmission is low, there have been more than 300 cases reported as of mid-January. 
• The Center for Health Protection in Hong Kong has issued a public advisory in response to a rise in norovirus cases linked to the consumption of raw oysters imported from Korea, France, Ireland, and Spain. Since mid-January, 57 cases have been reported. There are warnings to avoid consuming raw oysters.
• The 2026 Winter Olympics are tracked by relevant public health officials as a large-scale mass gathering, to ensure that adequate surveillance, infection prevention and control, and emergency preparedness measures are in place. So far, norovirus cases have been reported among various personnel, including players on the Swiss and Finnish women’s hockey teams and staff on the Australian team, who have tested positive for COVID-19.