Health officials are placing extra focus on infectious disease surveillance during the World Cup as large crowds gather for matches across North America. Multiple outlets report that health “sleuths” and public health teams are on high alert for potential outbreaks tied to increased travel and close-contact settings typical of major sporting events. The emphasis includes monitoring for vaccine-preventable diseases such as measles, which can spread quickly if susceptible people are exposed. Officials are expected to watch for unusual illness reports, track possible cases, and coordinate responses if concerns arise. The monitoring also reflects concern about how germs have previously reached large events, citing past instances where outbreaks or introductions of infections have occurred around major gatherings. Overall, the effort is framed as preventive preparedness: identifying risks early, improving detection, and enabling timely public health actions to limit spread among attendees and surrounding communities while the tournament is underway.