News Article

The Accuracy of COVID-19 Tests

By Miriam Bello | Wed, 04/22/2020 - 12:49

Test, test, test” is what Tedros Adhanom, President of WHO, has said that countries must do to reduce contagion. According to a study made by The Lancet scholars, testing is one of the most important tools to slow and reduce the spread and impact of a virus. It enables isolation of infected cases to provide medical treatment and resources more efficiently. The data generated by testing also helps understanding the pandemic and the risks for a certain population and its different groups. Test leads to building an effective outbreak response.

There are two common COVID-19 tests: polymerise chain reaction (PCR) tests or serologic tests. WHO has said PCR is the most reliable test for COVID-19 as it detects the presence of the virus, indicating that the person is currently infected. Serologic tests tell who has been infected as they measure antibodies, so results are mostly to measure the spreading rate of the virus and how far has it gone. A serologic test will determine who has the antibodies to be somehow immune to the virus. Both tests, however, are key to determine the reach and effects of COVID-19. While one detects the actual presence of the virus, the other test helps with data to analyze its resistance, spread and damages.

Taking advantage of both testing options has put some countries on a safer place than others. Germany, for example, has bet on massive testing to detect the virus early and avoid further spreading. The country has the capacity of doing 160,000 diagnosis tests per week. South Korea is another massive tester; the country does around 10,000 daily tests. Iceland has been the major tester among all countries, having the most successful response to protect citizens from COVID-19.

Countries common response when their infection rates have gone highly up is to start spreading and doing massive tests: it happened with Switzerland and the Czech Republic and mainly in the US, which has quadrupled its testing capacity in just one week. But every country is different; France and the UK, despite having growing rates of contagion have not shown the same initiative on increasing tests administration. In Latin America, Chile and Costa Rica have the most remarkable numbers of test of the region.

Up to date, Mexico is one of the countries with the lowest numbers on COVID-19 test applications and it is only allowing testing for people who present highly suspicious symptoms. Why is Mexico not doing massive COVID-19 tests? Since March, Deputy Minister of Health, Hugo López-Gatell said that Mexico was not going to follow this pattern as “the method is not totally useful.” López-Gatell says it is not scientifically proved that testing helps to contain the virus. He pointed that some Asian countries registered 2,000 tests per million people while Italy did 1,000 per million and it still was the country with the highest rates of contagion at the time. López-Gatell has said to the Mexican media that “there is an important stock of tests in public facilities” and that more are expected to come as the pandemic advances. Since the beginning of April, Mexico has been receiving donations from China to confront COVID-19 that also include tests.

Miriam Bello Miriam Bello Senior Journalist and Industry Analyst