Medical Groups Reiterate Opposition To Rapid Test Kits For Workers
The use of rapid antibody testing kits are not recommended because these do not accurately tell if an individual is infected with the coronavirus disease 2019.
Seven medical societies and a health advocacy group on Tuesday, May 19, reiterated their opposition to antibody testing using rapid test kits (RTKs) for coronavirus disease 2019 (COVID-19) as a requirement for returning to work.
In a press briefing, Philippine Society of Microbiology and Infectious Diseases (PSMID) president Issa Alejandria said they do not recommend the use of RTKs because these do not accurately tell if an individual is infected with COVID-19.
“We reviewed the evidence, and we think that there’s no added value in requiring rapid antibody testing for clearance to work among workers without symptoms, without history of direct contact or exposure to a suspect, probable or confirmed case,” she explained.
Alejandria pointed out that currently, the available RTKs merely detect whether or not a person has antibodies, but do not tell “whether that antibody is high enough to be protective or to neutralize the virus.”
She noted that the “sensitivity or the yield of the capacity” of RTKs is “very low at about 20 percent.” Of this percentage, some two-thirds will have false positive test results, which wrongly indicate a particular condition.
The RTKs can also generate false negative results.
In a statement, the groups said they are “deeply concerned about the high level of inaccuracies of the rapid antibody test, particularly the high prevalence of ‘false positives.’ ”
“As an example, when the test reports a false positive result, the worker is unnecessarily forced to self-isolate. After this, healthcare workers are forced to do contact tracing at a time when they are already undermanned at the frontline,” the statement read.
Once contact tracing is completed, those who came into contact with the worker are then required to undergo quarantine needlessly.
Instead of conducting RTKs, as now required by some local government units and government agencies, the groups recommend what they consider to be the “cheapest and most accurate test for fitness to return to work – the 14-day test.”
According to Philippine College of Occupational Medicine (PCOM) president Phil Pangilinan, the impact of this pandemic to employers is “very alarming.”
“Companies that are trying to recover from economic devastation are forced to suffer further by paying for costly and potentially misleading tests. The RTKs have their advantages, disadvantages and limitations,” Pangilinan said.
He stressed that these tests do not detect the virus, “thus, it is not recommended as a screening tool for early infection, let alone used to screen workers prior to return to work in the workplaces.”
As part of the testing protocols for COVID-19, all results generated by rapid test kits must be submitted to confirmatory tests using the real-time polymerase chain reaction (RT-PCR) tests.
Alejandria said the “cost-effective strategies” in fighting the coronavirus are physical distancing, wearing face mask, regular hand washing, observing cough etiquette, avoiding spitting in public, having proper ventilation, regular cleaning of toilets and pantries, and daily screening for symptoms by safety officers.
“Since there is still no effective vaccine and effective cure, the most effective intervention for now are these non-pharmacologic interventions… which are the minimum health standards,” she added.
Aside from PSMID and PCOM, the same positions were taken by the Philippine College of Physicians, Philippine Society of General and Internal Medicine, Philippine Academy of Family Physicians, Philippine Society of Public Health Physicians, Philippine Medical Association (PMA) and Action for Economic Reforms (AER).
In April, a coalition of 26 medical societies, health advocacy groups, civil society organizations and three medical doctors issued a joint statement, supporting the use of RTKs only in clinical setting, citing that evidence about its accuracy remained lacking.
According to the Stop COVID-19 Coalition, they support calls against the use of the RTKs for clinical or public health purposes within 14 days from the onset of the illness.
“We echo the call of numerous experts: rapid antibody tests should not be used outside a research setting at this time. In this time of crisis, we believe that tests and treatments should be carefully assessed before routine use, so as not to aggravate the dangers of the disease and the difficulties already faced by our healthcare system,” they said.
The coalition includes the PMA, Philippine Pediatric Society, AER, Action on Smoking & Health Philippines, ANG NARS, Asia-Pacific Center for Evidence-Based Healthcare, Framework Convention on Tobacco Control Alliance-Philippines, Southeast Asia Tobacco Control Alliance, Philippine Society of Private Midwife Clinic Owners Inc.-Davao, Consolidated Council of Health and Allied Profession and United Healthcare Organization of the Philippines, Inc.
The three medical doctors were Anthony Leachon and Rogelio Dazo Jr. as well as Jofti Villen.
Citing the pronouncement of the World Health Organization, they maintained the “lack of evidence on the accuracy of the rapid antibody test means that this must be used only in research settings, until there is enough proof supporting its use for specific indications.”
According to Dr. Antonio Dans, president of the Asia-Pacific Center for Evidence-Based Healthcare, as much as 72 percent of positive test results using the RTKs will turn out to be false positives. This means the patient is actually not infected.
“Non-COVID-19 cases will be classified as COVID-19 cases and this will lead to errors in management. Numerous non-COVID patients will be sent to COVID centers, exposing them to patients with COVID-19, and occupying scarce beds during this great time of need,” Dans cautioned.
Last April 1, the Food and Drug Administration approved the use of five RTKs in the country, but subject to confirmatory tests using the RT-PCR test to validate the finding.
FDA director general Eric Domingo also pointed out that while the RT-PCR measures the viral load of a patient, the RTKs mainly determine the antibody that a patient has, which can generate inaccurate results.
Domingo said the body takes time to develop antibodies from a bacteria or virus that a person has been infected with. If the person is tested when the antibodies are not yet developed, it may result in a false negative.
On the other hand, there can be a false positive result due to “cross reaction” with antibodies that were developed due to other bacteria or viruses previously acquired by a person.
As the national government insisted on buying RTKs in April, the Department of Health (DOH) also reiterated in April that these devices could not be used for mass testing.
In a press conference, DOH Undersecretary Maria Rosario Vergeire said the “gold standard” for COVID-19 remains the laboratory-based RT-PCR.
“We repeat – the rapid antibody test kits are not stand-alone tests. We still have to validate or confirm the results using the RT-PCR test, which remains the gold standard to diagnose COVID-19,” she stressed.
Vergeire maintained that the RTKs are “not recommended for mass testing” as provided for in DOH Memorandum Circular No. 2020-00160.
“The rapid antibody test kits are also not for self-testing. They cannot be produced over-the-counter because results are presumptive… and need confirmatory test,” she said.
As pronounced by President Duterte, she said the use of these test kits should be in accordance with DOH guidelines.
This means that only licensed doctors can prescribe and interpret the results generated by the RTKs.