[ad_1]
NEW YORK • As coronavirus cases continue to rise around the world, many countries are doubling down on testing policies that can allow or deny entry to travelers attempting to travel across international borders.
But an unusual new testing policy, announced by China late last month, baffled health experts.
It requires inbound travelers to present negative results from an antibody test, which can neither reliably rule out infection nor prove that a person is not passing the virus to others.
“I don’t understand why they’re doing this,” said Dr. Krutika Kuppalli, an infectious disease doctor at the Medical University of South Carolina.
“This appears to be their method of security theater.”
The strange guidelines, experts said, appeared to reflect an outdated understanding of the ways the virus and the immune system interact.
In the spring, several companies attempted to commercialize antibody tests as a potential diagnosis of active infection.
Some (but not all) later mitigated or withdrawn these advertisements as researchers gathered more information on the timing of the antibody response to the virus, which does not activate until levels of the pathogen decrease.
The guidelines of the Centers for Disease Control and Prevention describe positive antibodies as a generally poor indicator of the presence of active viruses in the body.
Previous iterations of Chinese policies stipulated that travelers should only test negative with a “nucleic acid test,” a tool that hunts for the genetic material of the coronavirus.
Most of the available tests that meet this requirement are based on a laboratory technique called a polymerase chain reaction, which can enter the virus even when it is present at very low levels in the body.
But as the coronavirus continued to spread to countries such as the United States, Britain, Ireland and Russia, Chinese health officials worried that some foreign travelers might escape the diagnostic flaws.
Mainland China reported 18 new cases of Covid-19 on Friday – all imported – compared to eight cases the day before, the country’s national health authority said yesterday.
Mainland China’s total confirmed cases now stand at 86,325, while the death toll remains unchanged at 4,634.
The city of Hong Kong yesterday announced stricter restrictions on social distances, reporting three new cases transmitted locally, one of which is of unknown origin.
The new rules, which will come into force from tomorrow until November 26, envisage halving the capacity of the restaurant and bar and reducing the number of diners at the restaurant’s tables to four by six.
NYTIMES, REUTERS, BLOOMBERG
[ad_2]
Source link
