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進入《TAIPEI TIMES》 Experts endorse Delta strategies
People walk past figures painted on a building in Taipei on Saturday last week. Photo: CNA
RAPID VERSUS PCR: A study showed that rapid antigen tests are more useful than PCR tests if the purpose is to screen for people who pose a higher risk of infection
By Chiu Chih-jou / Staff reporter
The SARS-CoV-2 Delta variant is more infectious than others, but is also more detectable, National Taiwan University Hospital （NTUH） experts said yesterday, affirming a policy of three tests for everyone who arrives in Taiwan.
The Delta variant, which was first detected in India, has spread to at least 96 countries, while the number of young people it has infected is four to five times more than the Alpha variant, Department of Laboratory Medicine deputy director Chang Sui-yuan （張淑媛） told an online news conference hosted by NTUH vice superintendent Kao Jia-horng （高嘉宏）.
Clinical observations show that the Delta variant causes more severe infections and fewer asymptomatic cases, Chang said, adding that infections develop faster and antibody treatments are less effective on them.
Generally, it takes about 18 days for Delta variant infections to become less contagious, defined as when a patient’s virus cycle threshold value exceeds 30, she said.
At a meeting last week hosted by the Central Epidemic Command Center （CECC）, medical experts debated whether a 14-day mandatory quarantine for arrivals should be extended, but the conclusion was that it should not, as virus tests can easily detect Delta variant infections, Chang said.
The CECC’s policy is that everyone who enters Taiwan must undergo three tests, the first upon arrival, once during quarantine and once at the end of their quarantine, with genome sequencing to be performed if a positive result is returned.
Such a strategy is likely to curb the spread of the Delta variant in Taiwan, Chang said.
Department director Chou Wen-chien （周文堅） said an NTUH study showed that rapid antigen tests are more useful than polymerase chain reaction （PCR） tests if the goal is to screen for people who pose a higher risk of infection.
However, the precision of rapid tests is affected by many factors, including how advanced an infection is, the part of the body from which samples are collected, and sampling methods and quality, Chou said.
Rapid tests conducted every three days can provide more information about the prevalence of infections and curb the spread of the virus by swiftly spotting positive cases, said Chen Yee-chun （陳宜君）, director of the hospital’s Center for Infection Control.
By comparison, PCR testing — which is not universally accessible — requires a professional and takes more time, Chen said.
While the effectiveness of the two testing strategies are somewhat similar, an overall strategy should be determined after considering the tools, logistics and the expected outcome, she said.
The availability of equipment and whether costs are covered by individuals, insurance firms or the government should also be taken into account, she said.
新聞來源：TAIPEI TIMES
