A small trial has proven that aircraft wastewater is simple and useful in monitoring SARS-CoV-2 variants that land in the United States, the Centers for Disease Control and Prevention reported Thursday.
The study found that testing can be done cheaply and easily. It only added about 3 minutes to aircraft maintenance time at the airport and didn’t bother passengers with nasal swabs or other sampling methods. Additionally, the world has largely abandoned other SARS-CoV-2 testing and surveillance strategies, so testing can be easily scaled up if needed, the CDC authors conclude.
“This study demonstrates the effectiveness of aircraft wastewater monitoring compared to separate tests for monitoring SARS-CoV-2 variants without direct traveler involvement or disruption of airport operations. We have shown that it is a feasible low-resource approach,” the authors conclude.
CDC conducted this study in collaboration with biotechnology company Ginkgo Bioworks. Together, they collected and tested wastewater samples from his Flight 80 to New York City’s John F. Kennedy International Airport between August 1, 2022 and his September 9, 2022. All flights were international flights departing from the UK, Holland and France.
Overall, 65 air sewage samples (81%) from 80 flights were positive for SARS-CoV-2. The proportion of positive specimens was the same in the three countries. Samples from the Netherlands were 81% positive, with 22 of 27 samples positive. The same was true for France, where 22 of 27 samples were positive. As in the UK, 21 of 26 samples were positive.
Researchers were able to obtain 27 genome sequences from 25 samples. All genomes revealed an omicron subphylegy, mostly BA.5, BA.4.6 and BA.2.75.
This study adds to other evidence that airport and aircraft wastewater monitoring can play a role in monitoring the spread of pathogens such as SARS-CoV-2. And there is growing relevance to CDC’s large-scale pandemic-era efforts and the integration of wastewater sampling into pathogen surveillance systems.
This has proven useful in various locations around the country to monitor the initial spike in COVID-19 and track the spread of polio in New York. In the case of SARS-CoV-2, faecal viral shedding may begin very early in infection, possibly even before symptoms appear.
Of course, aircraft surveillance has its limits. This is most useful on long flights where people are more likely to use the restroom. It is also unclear whether all airlines will agree to sampling. Finally, international travelers can take a variety of connecting flights before arriving in the United States, so it may not be possible to trace the origin of variants that arrive in the United States.
Still, the authors say surveillance has its place. “Combined with traveler-based surveillance, aircraft wastewater surveillance can provide a complementary early warning system for detecting SARS-CoV-2 variants and other pathogens of public health concern. .”
