The US Centers for Disease Control and Prevention is considering sampling wastewater taken from international aircraft to track any emerging new variants, reports Reuters.
CDC is announcing this step to slow the spread of Covid-19 in the United States during the surge in Covid-19 cases in the People’s Republic of China (PRC) given the lack of adequate and transparent epidemiological and viral genomic sequence data being reported from the PRC. These data are critical to monitor the case surge effectively and decrease the chance for entry of a novel variant of concern. CDC will continue to monitor the situation and adjust our approach as necessary.
It would help the agency track the virus and slowing its entry into the United States than new travel restrictions announced this week by the US and other countries, which require mandatory negative Covid-19 tests for travelers from China, infectious disease experts told Reuters.
Meanwhile, the US has announced new Covid-19 testing requirements Wednesday for all travelers from China, joining other nations imposing restrictions because of a surge of infections. The new US requirements, which start Jan. 5, apply to travelers regardless of their nationality and vaccination status, according to AP.
CDC said in a press release that it will implement a requirement for a negative Covid-19 test or documentation of recovery for air passengers boarding flights to the United States originating from the PRC and the Special Administrative Regions of Hong Kong and Macau.
Travel restrictions, such as mandatory testing, have so far failed to significantly curb the spread of Covid-19 and function largely as optics, said Dr. Michael Osterholm, an infectious disease expert at the University of Minnesota. “They seem to be essential from a political standpoint. I think each government feels like they will be accused of not doing enough to protect their citizens if they don’t do these,” he said.
A better solution would be testing wastewater from airlines, which would offer a clearer picture of how the virus is mutating, given China’s lack of data transparency, said Dr. Eric Topol, a genomics expert and director of the Scripps Research Translational Institute in La Jolla, California.
Getting wastewater off planes from China “would be a very good tactic,” Topol said, adding that it’s important that the United States upgrade its surveillance tactics “because of China being so unwilling to share its genomic data.”
Airplane wastewater analysis is among several options the CDC is considering to help slow the introduction of new variants into the United States from other countries, CDC spokeswoman Kristen Nordlund said in an email to Reuters. The agency is grappling with a lack of transparency about Covid-19 in China after the country of 1.4 billion people abruptly lifted strict Covid-19 lockdowns and testing policies, unleashing the virus into an undervaccinated and previously unexposed population.
“Previous Covid-19 wastewater surveillance has shown to be a valuable tool and airplane wastewater surveillance could potentially be an option,” she wrote.
French researchers reported in July that airplane wastewater tests showed requiring negative Covid-19 tests before international flights does not protect countries from the spread of new variants. They found the omicron variant in wastewater from two commercial airplanes that flew from Ethiopia to France in December 2021 even though passengers had been required to take Covid-19 tests before boarding. California researchers reported in July that sampling of community wastewater in San Diego detected the presence of the alpha, delta, epsilon and omicron variants up to 14 days before they started showing up on nasal swabs.