Air samplers placed near customs areas at four major U.S. international airports detected COVID-19 genetic material in 98.3% of samples and influenza A in 17.2%, according to a CDC-led study in PLOS Global Public Health. The monitoring covered San Francisco International, Newark Liberty, Washington Dulles, and Dallas/Fort Worth airports from October 2023 through August 2024.
The more useful finding for public health is not how often the viruses showed up. Flu levels in the air rose and fell in step with airplane wastewater, traveler nasal swabs, and national clinical lab data, but COVID readings did not track those signals in a statistically meaningful way. The authors concluded that air sampling "can complement aviation wastewater surveillance at ports of entry," while noting that performance varies by pathogen and sample type.
