Taiwan defends relatively limited COVID-19 testing

Swab test is performed at Taiwan Taoyuan International Airport

TAIPEI (CNA) — Amid doubts over the relatively low number of COVID-19 tests being done by Taiwan, Vice President Chen Chien-jen (陳建仁) has defended Taiwan’s practices, saying large volumes of tests are only needed when sources of infection cannot be traced.

As of March 18, Taiwan had conducted 20,014 tests for the new coronavirus disease, compared to 307,024 by South Korea, raising questions over whether Taiwan’s testing has been aggressive enough.

Health Minister Chen Shih-chung (陳時中), who heads the Central Epidemic Command (CECC), on Saturday turned down a call for conducting more COVID-19 tests as many people have requested getting tested at their own expense.

Chen contended that such a practice could increase the number of “false negative” cases.

In a Facebook post Monday, the vice president, an epidemiologist by profession, said the prevalence of the new coronavirus disease is under 1 per 100,000 people in Taiwan, and “only a few cases have unknown sources,” to explain why Taiwan has not conducted more COVID-19 tests.

Instead, he said, Taiwan has concentrated its testing of those who have come in contact with infected patients and those categorized as highly vulnerable to COVID-19.

“Such a practice guarantees that the tests are proper and efficient and in line with cost/benefit principles,” the vice president said.

To defend Taiwan’s process, Chen Chien-jen showed data for 13 countries that have conducted more than 15,000 tests to date on how many tests they have done, the number of positive cases found and the prevalence of the disease in those populations.

According to Chen Chien-jen, the figures generally showed that “the lower the rate of positive tests, the broader the coverage of tests of potentially infected people.”

Of the 13 countries, Taiwan had five positive results out of every 1,000 tests conducted, trailing only 0.8 positive tests per 1,000 in the United Arab Emirates and 1.2 positive tests per 1,000 in Russia.

In terms of the number of people per 100,000 population found to be infected by COVID-19, Taiwan had the second lowest ratio at 0.45 infections per 100,000 people, behind Russia’s 0.14 infections per 100,000 people among the 13 countries, the vice president said.

Chen Chien-jen acknowledged, however, that the correlation between positive test rates and infection rates per 100,000 people was not absolute, pointing to statistics from France, Belgium and South Korea.

In all three of those countries, roughly 16 people per 100,000 population were infected with COVID-19, but their positive test rates varied greatly.

While 27.9 out of every 1,000 tests came back positive in South Korea, the figure was 80.9 positive tests per 1,000 in Belgium and 167.4 positive tests per 1,000 in France.

The figures suggest that more tests in South Korea and Belgium were done on people who were not infected while in France more tests were done on people who were infected, the vice president said.

In defending his position on Saturday, Chen Shih-chung said more testing “might not only not help efforts to stem the outbreak, it could even create a quarantine loophole.”

He argued that those with “false negative” tests could move about without taking precautions, thinking they were free of the virus, while infecting others.

According to the CECC, COVID-19 tests are currently performed on “high-risk” subjects, divided into two groups. One consists of those who have come in contact with people from foreign countries who had respiratory symptoms and a fever.

The other consists of people with pneumonia or who have a fever and respiratory symptoms after returning from countries on the highest risk travel warning list.