The report says the latest total has risen from 48 cases by the end of June and is the highest recorded for this stage of the year since 2004. The average for the same period since then was 10 cases.
The timing is also significant. The US mosquito season generally runs from June to October, with the highest levels usually appearing in August and September. That could keep the issue in focus as the tournament moves through its later stages.
Most infected people are said to experience no symptoms, but the report notes that illness can resemble flu, with fever, fatigue, vomiting and joint pain. The neuroinvasive cases underline why medical teams cannot treat the risk as a minor inconvenience.
The recommended measures are straightforward and can be built into daily routines:
For squads moving between host cities, consistent guidance may be more effective than isolated warnings. Training grounds, hotels and fan zones all require attention.
The report says health professionals were already monitoring several infectious-disease risks before and during the World Cup. West Nile adds a seasonal threat that is harder to detect because many infections produce no obvious symptoms.
The next storyline to watch is whether host cities and teams make mosquito precautions routine as the competition enters the peak period. The reported figures do not establish a threat to fixtures, but they do show that tournament planning extends well beyond the pitch.