Testing wastewater collected from commercial aircraft could provide health authorities with an early warning of emerging infectious diseases weeks before they are detected through conventional surveillance systems, according to a joint pilot study by researchers in the United States and the United Kingdom.
The study, conducted by the US Centers for Disease Control and Prevention (CDC) and the UK Health Security Agency (UKHSA), examined whether wastewater from international flights could be used to monitor the spread of viruses and other pathogens across borders without affecting passenger privacy or airport operations.
Researchers collected 424 wastewater samples from flights travelling between the United States and the United Kingdom over a ten-month period from March 2024 to January 2025.
The results showed that nearly 75% of the samples contained at least one respiratory pathogen, including influenza A, influenza B, SARS-CoV-2, the virus responsible for COVID-19, and respiratory syncytial virus (RSV). Around 72% of the samples also tested positive for at least one pathogen linked to gastrointestinal illness.
Scientists said aircraft wastewater provides a concentrated source of human biological material without contamination from agricultural or industrial waste, making it particularly valuable for monitoring infectious diseases.
The researchers said aviation wastewater can be collected and analysed without disrupting flights or requiring direct contact with passengers, allowing authorities to monitor disease trends while protecting individual privacy.
One of the study’s most significant findings involved the XEC variant of COVID-19.
Researchers detected the variant in wastewater from flights arriving from the United Kingdom on 17 September 2024, approximately four weeks before it appeared in wastewater from flights originating in the United States. Although the first confirmed US clinical case had been recorded in July 2024, broader community transmission was not reflected in wastewater surveillance until the middle of October.
The researchers said this demonstrated the ability of aircraft wastewater monitoring to identify the international movement of emerging variants before widespread domestic transmission becomes apparent. The findings also aligned with reports indicating that the XEC variant first circulated in Europe before spreading to North America.
According to the study, international air travel plays a major role in the rapid global movement of infectious diseases because millions of passengers travel between countries every day for work, tourism and family visits. Monitoring wastewater from aircraft arriving at major transport hubs could therefore strengthen cross-border disease surveillance.
The researchers proposed expanding the system into a worldwide network of “sentinel airports” where wastewater samples would be routinely analysed and combined with genomic sequencing and rapid international data sharing.
They believe such a network could provide health authorities with near real-time information on how new pathogens are spreading across continents, allowing governments to introduce targeted public health measures earlier. Early detection could help reduce the need for broader interventions such as travel restrictions or border closures while improving preparedness for future pandemics.
The findings suggest aircraft wastewater surveillance could become an important addition to existing global disease monitoring systems as governments continue to strengthen public health defences against emerging infectious threats.
