Should those returning to work be subjected to COVID-19 tests? 2
Health workers conduct their routine swab testing for COVID-19 on their fellow hospital employees at the Sta. Ana Hospital in Manila on April 14, 2020. George Calvelo, ABS-CBN News

Should those returning to work be subjected to COVID-19 tests?

In the latest ANCX Forum, an infectious diseases expert discusses the pros and cons of COVID tests. By RHIA GRANA
ANCX | May 24 2020

As companies resume operations, we all hope to kickstart the workforce with a semblance of normalcy. Thus the million-dollar employer question: should I have my employees tested for COVID? How aggressive should we go in terms of testing? The latest ANCX Forum co-presented by Art Rocks, a group of concerned art collectors in the Philippines, will answer these questions May 26, Tuesday in a discussion over Facebook Live.

Dr. Cristobal Dumo, a Fellow of the Philippine Society of Microbiology and Infectious Diseases, says there are two types of tests that are employed by our hospitals to diagnose SARS-CoV-2. The first involves a test of viral RNA (ribonucleic acid). “The viral RNA is the nuclear material of the virus. It is amplified a million times, and if the viral RNA is present, it’s labeled positive or COVID confirmed. [This test] is very sensitive,” he says.

This test involves inserting a long swab in the nose to get some specimen. “It’s unsightly, it’s painful and few people relish the idea of being tested for viral RNA. The technology is Reverse Transcriptase PCR (polymerase chain reaction). It’s able to detect very small levels of the virus,” he adds.

A key caveat with this type of test is that while it detects the COVID-19 virus, it’s not able to distinguish if the virus is dead or alive, because dead virus contains RNA. “That’s the weakness of the PCR,” notes Dr. Dumo, who’s also a Fellow of the Philippine College of Physicians.

Should those returning to work be subjected to COVID-19 tests? 3
The Marikina government recently tested around 6000 tricycle drivers, with thousands more workers in the manufacturing industry to follow, as more industries have been allowed to re-operate under MECQ. Mark Demayo, ABS-CBN News

The second type tests the immune system; it’s called serology. “It’s a blood test but it’s very similar to your pregnancy kit. It measures the amount of antibodies [in your blood]. If a band appears, that means you have COVID-19 or you may have had COVID 19. When you get infected, for a time you don’t produce any antibodies. After some time, your immune system kicks in and develops certain types of antibodies and they show up in your blood. That’s what’s being tested by serology,” he explains.

The serology test may be rapid (you can do it at the bedside like a pregnancy test) or lab based. The more sensitive lab test is called the ELISA (enzyme-linked immunoassay) test. “This requires machines and it takes about a day or two before the result comes out, Generally, it’s far more sensitive than the RDTs (rapid diagnostic tests).


‘Testing is a small part of everything’

Dr. Dumo emphasizes that business owners need to make sure that all the hierarchy of controls are covered. These are the elements (in order of importance) that are said to be most effective in protecting the employees from occupational hazards: elimination, substitution, engineering controls, administrative controls, and personal protective equipment.

He observes that locally, a lot of attention has been focused on the use of PPEs when according to the Centers for Disease Control and Prevention’ Hierarchy of Controls—which has been used as a means of determining how to implement feasible and effective control solutions to protect workers from occupational hazards—PPE is at the bottom of the pyramid.

Should those returning to work be subjected to COVID-19 tests? 4
More effective than routine testing in ensuring safety of workers from COVID-19 is through symptom checking, says Dr. Dumo.

“The PPE is not ineffective. What we’re saying is it’s least effective. We spend an enormous amount of resources on PPEs but yung level of control nya, yung impact, is not as large as a simple elimination activity,” he says.

“When workers come in, the concept of symptom screening is the sample of elimination,” he explains. This means eliminating physical access to workers with possible symptoms of COVID, thereby allowing you to protect your remaining employees. “The question of which to test and when becomes secondary na lang kasi we always say symptom screening is much more important at this point in time than routine testing.”

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In the latest return to work guidelines issued by the Department of Health, it can be gleaned that the main focus is symptom screening, says Dr. Dumo. “Daily temperature and symptom check has to be recorded. You make sure that anyone with symptoms, travel history or exposure history has to be reported before they go to the office. Testing comes in a very, very small reminder at the end of the document—it says you do not need to test routinely but may test a representative sample of the high risk group,” he stresses.


For the full discussion, join us at the ANCX Forum Facebook watch party this Tuesday, May 26, 5pm.