Some groups of doctors in the Philippines warn against the use of COVID-19 rapid test kits to screen employees returning to work.
Dr. Issa Alejandria of the Philippine Society of Microbiology and Infectious Diseases (PSMID) said, “The sensitivity or the yield of a positive test (of an antibody test) is very low (at) about 20%. And among that 20%, 2/3 will be false positive.”
“Mataas ang false positive (There is a high possibility of false positive).”
Alejandria noted their claims are based on previous studies.
“These tests do not detect the virus, (but) just the antibodies produced,” explained Philippine College of Occupational Medicine (PCOM) President Dr. Phil Pangilinan, who also does not recommend using rapid tests as a COVID-19 screening tool.
The World Health Organization and the Department of Health also prefer polymerase chain reaction (PCR) based tests than rapid antibody tests, which require blood samples instead of throat swab samples.
A rapid test kit could detect whether a person has an active COVID-19 infection (IgM positive) or if he or she has recently recovered from the disease.
DOH earlier warned the public the rapid test kit may not detect the virus in the first few days of infection because it takes time for the body to develop antibodies.
COVID-19 rapid test kits not recommended as screening tool
Alejandria also said COVID-19, who already recovered from the virus, could test positive in the antibody test.
The doctors also discussed during the virtual briefing how having many false-positive cases would be crucial to the country.
“After this, healthcare workers are forced to do contact tracing at a time where they are already undermanned at the frontline. Once contact tracing is completed, those who came into contact with the worker are then required to get quarantined unnecessarily,” the Philippine Medical Association (PMA), the Philippine College of Physicians (PCP), the Philippine Society of Microbiology and Infectious Diseases (PSMID), the Philippine College of Occupational Medicine (PCOM), the Philippine Society of Public Health Physicians (PSPHP), the Philippine Society of General Internal Medicine (PSGIM), and the Philippine Academy of Family Physicians (PAFP) said in a joint statement.
On the other hand, Alejandria said a patient who has a false positive for antibodies result could give “false security” because the patient would think he or she is already immune from the virus.