Confident with test results

Barbadians are being told that they need not worry about the accuracy of the tests currently being performed in this country to diagnose COVID-19.

In recent weeks there have been concerns raised internationally about the use of serology tests, commonly referred to as antibody tests, to determine the rate of infection in some countries. The major concerns have been that there are a number of fraudulent tests on the market and that these tests, which use blood samples to detect antibodies to the COVID-19 virus to see if a person previously been infected, are less accurate on those recently exposed to the virus.

But, Acting Chief Medical Officer (CMO), Ministry of Health and Wellness, Dr. Kenneth George says there is no cause for alarm in this country, as Barbados has been and continues to use the polymerase chain reaction (PCR) tests, which directly detect the presence of the virus. This, he maintained, is considered the “gold standard”.

“We have followed the guidance of the WHO [World Health Organisation] and PAHO [Pan American Health Organisation] and that is why Barbados only recognises the PCR antigen test for COVID-19. It is the most reliable test, but there are several other tests on the market 

[including] tests for antibodies. But the antibody test we do not use,” he told The Barbados Advocate.

He explained that while such tests would show previous exposure, they do not indicate when that exposure was, which he explained, would prevent the health authorities from getting a clear picture of the situation. 

“We don’t know if it was a long standing thing or more recent infection. So for now we only use the PCR test, which remains the gold standard. Some jurisdictions have been using antibody tests but it has not been verified for use in large populations,” Dr. George stated.

The Acting CMO went on to explain that the antibody test itself will become more useful as more people get infected. 

“Antibody tests would tell you about herd immunity, but with this epidemic we haven’t started to move to herd immunity because with herd immunity we are speaking about 60 to 70 percent of the population being exposed to the virus. That tells you when large segments of your population have been exposed. The antibody test could indicate which of the small pockets haven’t been exposed to the virus. But it is not a useful test now,” he indicated. 

Additional, the Ministry of Health and Wellness official said that Barbados has also not given the green light to the use of any of at-home testing kits for COVID-19. In fact, he said such tests which use saliva or a small drop of blood to test for the virus, have not been approved as yet for large populations.

To date Barbados has performed in excess of 8100 PCR tests on both nationals and non-nationals, many of whom were tested on arrival into the country. With the country expected to welcome commercial air travel again in a few days’ time, Barbados is requiring those seeking to come into the island to have PCR tests done by labs, either International Organisation Standard (ISO), College of American Pathologists (CAP) , United Kingdom Accreditation Service (UKAS) accredited or their equivalent, at least 72 hours prior to departure. (JRT)