CDC testing necessities for vacationers within the UK are like “a sequence hyperlink fence to maintain a mosquito out,” specialists say
The U.S. Centers for Disease Control and Prevention has announced new testing requirements for travelers from the UK. However, research by the agency’s own scientists shows that the rule may have little impact on the spread of the UK’s new strain of coronavirus.
Starting Monday in the UK, passengers must have a negative Covid-19 test within three days of boarding a flight to the US.
A CDC press release on Thursday welcomed the new changes.
“Today President Trump is taking another step to protect the health of the American people,” the statement said.
According to researchers from the CDC Covid-19 Response Team, testing three days before a flight may not do much – but it only reduces the risk of the virus spreading by 5 to 9%.
Dr. Paul Offit, an infectious disease specialist at the University of Pennsylvania, said the new test requirement was “like putting up a chain link fence to keep a mosquito out.”
The CDC regulation recognizes that “tests do not rule out all risks”, but when combined with other measures such as self-monitoring for symptoms, masks and distancing can “make travel safer”.
A federal official told CNN that the new order is just one layer in a layered approach to curb the spread of the new variant, which appears to be easier to transmit than other coronavirus strains.
In March, the CDC halted travel by foreigners from the UK, reducing travel from the UK to the US by 90%, from about 30,000 to 3,000 passengers a day, the official said.
Additionally, the CDC has recommendations for international travelers, including getting tested one to three days before the flight and three to five days after the trip, and staying home seven days after the trip, even if they are negative.
Covid-19 tests often lack recent infections, so someone can test negative and actually become infected because they don’t give off enough viruses to be detected.
“A lot of people are missing 72 hours before a flight,” said Dr. Peter Hotez, an infectious disease specialist at Baylor College of Medicine, who pointed out that the new variant appeared in the UK three months ago and is likely already in the United States.
On the other hand, tests on the day of departure can be more effective and reduce the risk of transmission by 37 to 61%, according to the November report by the CDC scientists, which is based on mathematical models and was not peer-reviewed.