Mass Testing Should Not Be the Priority Right Now
I have an unpopular opinion. Testing is not the most important thing. The most important thing is isolating people who are probable COVID-19 cases as well as those who have had contact with them.
1| The RT-PCR will likely miss 1/3 of cases.
RT-PCR stands for real-time polymerase chain reaction, which uses tiny pieces of DNA (primers) to detect and amplify (think photocopy machine on steroids) some genetic material (viral, bacterial, human, etc.) of interest. Its extreme sensitivity is a double-edged sword: Though it's great for detecting organisms that are difficult to culture and are present in tiny amounts, it also makes it prone to contamination, resulting in false positives. A positive RT-PCR means you have the viral genetic material, but it doesn't clarify if it is dead, alive, or infectious. We rarely use RT-PCR as a test of cure, because the DNA or RNA can hang out for a long time even after someone is cured.
Knowing its potential inaccuracy, the most important thing to do with a suspected COVID-19 case is to isolate for at least 14 days. This is to ensure that while waiting for the test result and even if it is a false negative, we already break the cycle of transmission.
2| Isolating known close contacts of a positive case will preempt presymptomatic/asymptomatic patients before they develop symptoms and, hence, will break the cycle of transmission.
There are also talks of just letting the virus take its course with herd immunity. "Planned" herd immunity is irresponsible genocide. You do not willingly expose a population to a disease without giving them a means to fight or prevent it. We know too little about this virus to understand how many hundreds of thousands or millions of people will needlessly die.
Maintaining social distancing and wearing masks is okay. Gradually opening the economy is okay with proper precautions. There is no guarantee immunity from natural disease is long-lasting, or if it is even generated to a large degree by very mild disease.
The U.K. and Sweden experimented with "herd immunity" and it isn't going very well. In the Philippines where large segments of the population live with their parents and grandparents, opening schools and letting young people get infected will bring deaths to multigenerational households. The only safe way to achieve herd immunity is with a vaccine. The only way to get there while we wait with reduced casualties is to continue practicing interventions that bring the R0 down—social distancing, work from home if able, wear a mask, wash your hands. Please stop these crackpot ideas from non-epidemiologists and non-infectious diseases doctors who haven't taken care of or seen COVID-19 patients die in front of them, including young people.
3| Testing is costly.
Its limitations may also actually mislead us into thinking that some people are safe to work, or are not going to transmit even if this is not the case. It only takes one false negative case to wreak havoc on a population.
I'm okay with testing to inform us of the number of cases that we have and how well we are doing, but not at the expense of proper investment in patient care and isolation facilities or PPE.
4| We need proper protocols for testing and preventing transmission.
Let's make sure our protocols for isolation take into account the limit of testing, and focus on preventing transmission rather than holding imperfect testing as a potential savior, when it is clearly not. Targeted enhanced testing is helpful. Mass indiscriminate testing is harmful and misleading. We need to invest in proper and robust isolation facilities. Without these, testing is not going to make a difference.
This post originally appeared on Dr. Edsel Salvaña's Facebook page and has been edited by Esquire Philippines.
Edsel Maurice T. Salvana, MD, DTM&H, FPCP, FIDSA, is an award-winning infectious diseases specialist and molecular biologist at the University of the Philippines and the Philippine General Hospital. He has written and spoken extensively about HIV in the Philippines, the Dengvaxia controversy, and the COVID-19 outbreak. As a Senior TED Fellow, he is constantly seeking ways to communicate complicated scientific concepts to a lay audience, and strongly believes that this is the best way to combat pseudoscience and fake news.