Aug 23, 2020 09:00:00

Claim that 'inexpensive and poor test' should be carried out for new coronavirus infection

The number of new coronavirus infectious diseases (COVID-19) infected worldwide per day

continues to exceed 200,000, and there is no sign that the COVID-19 epidemic will end. Regarding the issue of 'detection of infected person', which is considered to be important as a countermeasure against COVID-19, the claim that 'cheap and inferior inspection is more optimal than expensive inspection that boasts a perfect detection rate' has appeared. ..

Harvard Scientist Says We Need More Cheap,'Crappy' Tests For COVID-19. Here's Why
https://www.sciencealert.com/harvard-researchers-want-more-crappy-tests-for-covid-19

It is Michael Mina, who studies epidemiology as an associate professor at Harvard University, who claims that 'bad and cheap tests are the best'. Mr. Mina wants to reduce the scale of PCR test used for confirming COVID-19, and as a substitute, a simple test that can be diagnosed by yourself like a pregnancy test kit and gives results in about 15 minutes is common. Seeking to sell.

A simple test such as a pregnancy test kit has the problem of false negatives: 'I am actually infected, but the test result is negative.' False negatives and their antonyms, false positives, are explained in detail by the Japanese Society of Clinical Laboratory Medicine.

About false positives and false negatives of clinical tests-Japan Society of Clinical Laboratory Medicine
(PDF file) https://www.jslm.org/committees/COVID-19/20200427.pdf

However, according to Mina, a simple test such as a pregnancy test kit is optimal, even considering the problem of false negatives. The reason is that the simple test is easy to identify 'people who have released a large amount of virus'. The PCR test is extremely sensitive and can detect even infected people who have almost no infectivity. On the other hand, the simple test has low sensitivity, so infected people at such levels cannot be detected, but due to the poor sensitivity, if the simple test is caught, it can be diagnosed as 'infected person with considerable infectious power'.

Mina pointed out that the COVID-19 test in the United States demands too much precision, is expensive and takes too much time, and what is needed now is ``poor quality inspection'' that is rather cheap and does not take much time. Insist. The false negative problem is explained by the fact that it is possible to solve it by conducting multiple tests, taking advantage of the fact that poor quality tests are cheap.

Ashish Jar, director of the Global Health Institute at Harvard University, is one of the researchers who agree with Mina. Jar said, 'These tests are not really bad tests. If the amount of virus in the body is very small and the infection is not spread widely, the accuracy of the test will be low. The number of infections is very large, so the accuracy of the test will be high.From an epidemiological point of view, we would like to catch the infected person who has a large amount of virus in the body. ', and supported the benefits of cheap and poor inspection.

According to the estimation by the Center for Disease Control and Prevention in the United States, only one in 10 infected people is tested under the current test system, and the test itself is overwhelmingly lacking. According to Science Alert, a science news site that reported this problem, the development of an inexpensive simple test from 1 dollar (about 106 yen) to 5 dollars (about 528 yen) per time was at the approval stage of the US Food and Drug Administration. It seems to have stopped.