As 48 countries converge on 11 U.S. cities for the 2026 World Cup, epidemiologists at Northeastern University are quietly preparing for an invisible threat: the rapid spread of infectious disease across hundreds of thousands of arriving fans and athletes.
The scale is unprecedented. The World Cup will draw between 750,000 and 1.5 million additional visitors to the United States, a surge that demands careful public health planning. Alessandro Vespignani, director of Northeastern University's Network Science Institute, has seen firsthand how global events can accelerate outbreaks—his network science models are currently tracking Ebola across the Democratic Republic of the Congo. But for the World Cup, he and his team have taken a different approach: rather than wait for crisis, they built a tool to predict it.
Working with colleagues Jessica Davis, Alessandra Urbinati, and epidemiologist Justin Lessler, Vespignani created a publicly accessible dashboard that assesses disease risk across all 11 host cities. The team, collaborating with the CDC and the research network Insight Net through Epistorm (Northeastern's disease forecasting project), analyzed 12 diseases: dengue fever, chikungunya, yellow fever, measles, pertussis, mumps, rubella, Mpox, Ebola, Marburg virus, cholera, and typhoid.
The findings are reassuring but not dismissive. The excess risk of disease spread during the World Cup is "generally small," Vespignani said—a crucial distinction that reflects the reality of modern travel. On any given June or July, roughly 10 million international travelers arrive in the U.S.; the World Cup visitors represent only a fraction of that flow. Yet the concentration of 48 nations in 11 cities creates pockets of elevated vulnerability.
Dengue fever emerged as the disease with the largest elevated risk, driven by the movement of travelers from dengue-endemic regions. Measles and mumps face slight increases, particularly concerning given that the U.S. is currently experiencing its largest measles outbreak since the disease was declared eradicated domestically in 2000. Mosquito-borne viruses like chikungunya also pose higher potential risk, as do Lassa fever, which often goes undiagnosed and spreads silently through populations.
Seattle, according to the dashboard, appears to be the safest host city. COVID-19, notably, wasn't included in the analysis—not from lack of concern, but because cases are all but certain to occur anyway, given that some attending nations will be in winter season. More importantly, COVID-19 is treatable and containable, reducing pandemic potential.
For Vespignani, the real value of the tool isn't panic prevention but precision. "This is what we call intelligence," he explained, "and intelligence is always a way to play better against the enemy." Public health officials can now see exactly which cities face which threats, allowing them to allocate finite resources where they matter most. It's situational awareness in its purest form—knowing what to prepare for and, just as importantly, what not to.
The message is measured: don't panic, but don't dismiss. The World Cup is coming. Now, the machinery of modern epidemiology is ready.