CHICAGO/NEW YORK, Dec 29 (Portal) – As COVID-19 infections surge in China, the US Centers for Disease Control and Prevention is considering collecting sewage samples from international planes to track any emerging new variants , said the agency Portal.
Such a policy would provide a better solution for tracking the virus and slowing its entry into the United States than new travel restrictions announced this week by the US and other countries mandating mandatory negative COVID tests for travelers from China, three infectious disease experts told Portal.
Travel restrictions like mandatory testing have so far not significantly stemmed the spread of COVID and largely serve as optics, said Dr. Michael Osterholm, an infectious disease expert at the University of Minnesota.
“They seem essential from a political point of view. I think every government feels that if it doesn’t do this, it will be blamed for not doing enough to protect its citizens,” he said.
The United States also expanded its voluntary airport genome sequencing program this week, adding Seattle and Los Angeles to the program. This brings the total number of airports collecting information from positive tests to seven.
But experts said that may not provide a meaningful sample size.
A better solution would be testing airline effluents, which would provide a clearer picture of how the virus is mutating given the lack of data transparency in China, said Dr. Eric Topol, a genomics expert and director of the Scripps Research Translational Institute in La Jolla. California.
Getting sewage from airplanes out of China “would be a very good tactic,” Topol said, adding that it’s important for the United States to improve its surveillance tactics “because China is so reluctant to share its genomic data.”
China said criticism of its COVID statistics was unfounded and downplayed the risk of new variants, saying it expects mutations to be more contagious but less serious. Still, doubts over official Chinese data have prompted many places, including the United States, Italy and Japan, to impose new testing rules on Chinese visitors as Beijing lifted travel controls.
Analysis of aircraft wastewater is one of several options the CDC is considering to slow the introduction of new variants into the United States from other countries, CDC spokeswoman Kristen Nordlund said in an email.
The agency has grappled with a lack of transparency about COVID in China, after the country of 1.4 billion abruptly lifted strict COVID lockdowns and testing guidelines, unleashing the virus on an unvaccinated and previously unexposed population.
“Previous COVID-19 wastewater monitoring has proven to be a valuable tool, and aircraft wastewater monitoring could potentially be an option,” she wrote.
French researchers reported in July that aircraft sewage tests showed that requiring negative COVID tests before international flights does not protect countries from the spread of new variants. They found the Omicron variant in the sewage from two airliners that flew from Ethiopia to France in December 2021, despite passengers being required to take COVID tests before boarding.
California researchers reported in July that sampling San Diego municipal wastewater detected the presence of the alpha, delta, epsilon, and omicron variants up to 14 days before they showed up on nasal swabs.
Osterholm and others said mandatory testing before traveling to the United States is unlikely to keep new variants out of the country.
“Border closures or border tests really make little difference. Maybe it slows it down a few days,” he said, because the virus could likely spread globally and infect people in Europe or elsewhere, who might then bring it into the United States.
David Dowdy, an infectious disease epidemiologist at the Johns Hopkins Bloomberg School of Public Health, said increased genomic surveillance is important and wastewater samples could be helpful, but testing takes time.
“I think we should be careful about how much we expect this data to really inform our responsiveness,” he said.
Reporting by Julie Steenhuysen and Nancy Lapid; additional reporting from Jeff Mason, Trevor Hunnicutt and Alexandra Alper in Washington. Editing by Gerry Doyle
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