Recent debates on general testing
There was a fierce debate “again” in Taiwan recently on general testing for coronavirus. However, this time the problem is not about screening all citizens but all arrivals at borders, worrying about the risk of asymptomatic carriers.
Changhua County Public Health Bureau’s undisclosed testing
These series of debates began with an asymptotic teenager tested positive while isolating at home on Aug, 17. This uncovered that Changhua County Public Health Bureau has conducted undisclosed COVID-19 screenings of asymptomatic individuals for at least six months. Without notifying Taiwan’s Central Epidemic Command Center (CECC) in advance, the Health Minister and CECC head Chen Shih-Chung have asked the ethics department to investigate this hidden testing. Chen also mentioned that the purpose is not to punish Changhua officials but to find out if their actions are following a standard operating procedure (SOP). Meanwhile, a person who took the undisclosed testing revealed that he went to the hospital by himself while he was quarantined. People concern that Changhua will become a weak point in Taiwan’s coronavirus prevention efforts. But, some people still think that discovering this confirmed case may probably reduce the possibility of cross-infection in communities, it does more good than harm.
KMT’s testing plan to the 14 cities
Haven’t waited until the controversy of the Changhua County Public Health Bureau’s undiscovered screening ended, KMT, the second-largest party in Taiwan, decided to introduce the general testing plan to the 14 cities and counties it controls. KMT Deputy Secretary-General Lee Yen-Hsiu pointed out that the majority of Taiwanese support the plan for general testing. However, the health experts were divided into two sides of opinion, some have supported general screening for all arrivals at borders and praised the actions taken by Changhua official, while others criticized the Changhua official’s carelessness for allowing quarantined people leave their house for testing on his or her own. Thus, Cabinet Spokesperson Ting I-ming commented that if KMT conducts its plan without consulting the CECC, it would create panic and undermine the government’s pandemic prevention measures. Moreover, the public would be lost and confused without a unified statement to the pandemics.
Disagreement from CECC
In response to doing the general testing or not, the Health and Welfare Minister Chen Shih-Chung respond to Changhua Public Health Bureau’s undisclosed virus testing that triggered off the debate on the issue of general testing on Aug, 22. The Changhua’s officials had halted its screening program since they received the notice from the central government. Furthermore, Chen gave an explanation to state why the CECC denied carrying out the general testing at borders.
Example to illustrate the general testing
Again, Chen mentioned the estimated cost of the general border testing is approximately NT$800 million (US$27.1 million) based on the number of arrivals since Jan, 1. This may help Taiwan if this huge amount of money can turn out to be the valid measures to prevent SARS-CoV-2. But, that’s not the whole story.
Based on the official statistics and my previous post, there is no perfect screening in the world, it all causes type I and II error which is also known as a false positive and false negative. The following table demonstrates the example mentioned in CECC’s press on Aug, 22.
| True value_positive | True value_negative | Total | |
|---|---|---|---|
| Testing result_positive | 450 True positive |
12,475 False positive |
12,925 |
| Testing result_negative | 50 False negative |
237,025 True negative |
237,075 |
| Total number | 500 | 249,500 | 250,000 |
There are around 250,000 people arrived in Taiwan, assuming that the prevalence is about 0.2% and under a test of 90% sensitivity and 95% specificity. The result turns out to have approximately 13,000 people who are false positive. Since the number of Negative Pressure Isolation Rooms in Taiwan is just about 1,000 beds, it cannot accommodate such a great number of people in the hospital. Furthermore, people with and without coronavirus are in the hospital, the cross-infection was likely to happen. Besides the concern of false positive, the false-negative need to be taken into consideration, too. If the CECC announced that people with the negative result during the general testing at borders do not need to follow the restrictions of quarantine, the false-negative would probably cause community spread, like Iceland, had learned from this lesson. Those results would eventually cause the collapse of Taiwan’s health system.
My point of view
Although the central government now decides not to introduce the general testing plan, the CECC is continuously monitoring the situation and willow to undergo some sort of change due to some countries reported a resurgence of infections recently. For example, arrivals from the Philippines are now subject to compulsory PCR testing from Aug, 22. In my opinion, I believe that no one wants to live in fear of being infected by Covid-19 and I firmly believe that people with different opinions are just because they are in different perspectives to protect Taiwanese people. However, some problems still need to be answered. On the one hand, the CECC assumed that the testing tools only have 90% sensitivity and 95% specificity. But, we all know that the sensitivity and specificity of RT-PCR would theoretically be around 95% and 99% each. This underestimated accuracy will lead to overestimate the number of false-positive and negative. On the other hand, the CECC has long claimed that the government intends to achieve controlled risks. Nonetheless, it still remains potential threats that cannot be detected by the authorities, which may be a Pandora’s box for Taiwan in the future. In the end, while the controversy of general testing seems to have many aspects to discuss, I hope that Taiwan is still the successful country in battling with coronavirus and people can remain rational when decision making instead of judge others viewpoints solely based on his or her “color” (either green or blue).
Reference
- Public health experts suggest COVID-19 testing of all arrivals
- Taiwan’s Changhua conducted undisclosed coronavirus tests for six months: CECC
- Taiwan Cabinet opposes KMT plan to implement general testing for coronavirus
- Taiwan rejects general coronavirus testing for arrivals from 12 countries
- Taiwan healthcare system would collapse under general coronavirus screening: Minister
- 入境普篩壓垮醫療體系？2前衛生署長槓陳時中
- STR Network