april edition 2020
Is the Coronavirus Crisis a Testing Crisis?
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In fact, on March 21st the government claimed that 50 thousand tests had been bought, yet only until April 9 their arrival was confirmed. Similarly, the clinical laboratory Abbott was supposed to receive a portion of them on April 6 to start widespread testing in its facilities. The tests never arrived. During the first week of April, the National Health Institute (INAS) announced they had reached their maximum capacity. Now, the government has referred to the over 47 thousand “fast tests” donated by South Korea and Japan as the kickoff to accurate testing. However, this is far from reality. But why?
With the sudden ups and downs in the numbers of COVID-19 infections, how can one hold any expectations regarding the progression of the infection?
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Despite fears of an “unbeatable” virus, the inexactitude with which the data regarding the novel coronavirus is presented to us is rather the result of ineffective clinical testing and data collecting. Right now Colombia is only starting to gather a roughly sufficient quantity of diagnostic tests for the virus. Also, the available tests are not the most accurate ones. Combining these two factors, it makes sense both health experts and the population in general fear an unprecedented, sudden outbreak in infections.
In the first place, it is a known fact that the healthcare system in Colombia is not precisely among the most efficient. According to health experts, the best way to prevent an outbreak of the virus is to do as many tests as possible - ideally screening more than a 10 thousand people for every million people. Only through testing the infected individuals can be rapidly isolated, preventing further infections and saturated hospitals However, as of April 2nd, only 939 tests were done for each million people in Colombia a day.
Yet still, the Health Ministry has announced there won’t be massive testing. Though this may sound nonsensical, the decision is coherent with the low capacity of the health system. Massive testing would require coordinated efforts from all clinical laboratories of the country, all under strict supervision regarding their contingency and biosecurity conditions. However, there is neither sufficient budget nor sufficient administration organization to undergo such high testing output. As well, it would be counterproductive to trust in the results of massive but inaccurate tests, as there has been no certainty about the quantity and quality of the tests that have been arriving.
There are different ways to test for the coronavirus: through molecular or imaging methods. The latter are the most accurate ones (indicating infection correctly 98% of the time), but as they require massive specialized x-ray equipment, they become too expensive and time-consuming for the needed efficient testing. For another part, there are 3 molecular tests: rtRT-PCR, antigen-based, and antibody-based. The first identifies the genetic material of the virus. An enzyme mixed with cells of the respiratory tract (collected in nose swabs) of the patient binds to the virus RNA pieces (as COVID-19 has RNA instead of DNA) and, if present, makes DNA pieces from it, which are then copied multiple times to be detectable. This method identifies infections correctly 87% of the time.
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The other two tests are protein-based. They identify the presence of the antigen (unique recognition pieces of a virus, especially membrane proteins) or antibody for coronavirus (proteins the body makes to identify and attack an antigen) in the individual’s blood. As the antigen tests directly identifies the virus in the body, it is much more accurate than the antibody test. Additionally, the antibody production in the human body is not immediate: the fastest antibodies form up to significant concentrations in the blood at least 7 days after the infection. This means that a recently infected person could take the antibody test and still appear as not infected. These false negative cases are common with antibody tests.
The accuracy of antibody tests has been found to be as low as 76%, which means up to 24% of infected cases can go unnoticed, unattended, and yielding further infections. Nonetheless, their low cost and short processing time have made public entities still prefer them over trustworthy testing. In fact, the thousand of “fast tests” that arrived in Colombia are antibody-based.
Evidently, the inefficient healthcare administration across the country and the inaccurate tests on which health institutions rely on definitely set low expectations for appropriate contingency of the novel coronavirus. Even if the 17 thousand daily tests projected by the Health Ministry were done, there would (or should) still be major doubt around the accuracy of the results. For now, however, the best we can do is stay at home, social distance, and think critically about information presented in the media
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By Alejandra Durán, 10B