RAT tests are continuing but the PCR is also being conducted to cross check results

Controversy over Rapid Antigen testing continues with health officials claiming that despite the RAT kits being used for random checks for the COVID19, a PCR was necessary due to inaccurate results at times being displayed by the RAT kits.

In recent weeks, health officers are conducting rapid antigen tests in Colombo as well as on the borders of the Western Province, but health officials say that if results on a RAT kit are not checked on the specified time, it can display a false positive or negative.

Further, some patients who have tested negative for the virus have later tested positive when the PCR has been conducted, leading to doubts over the accuracy of the RAT kits.

“The accuracy of RAT is about 50 percent. Which means if you have a confirmed 100 persons infected with COVID-19, only 50 people will be detected and 50 will be false negatives,” a senior health official, using the testing kits, said.

“Further, if you don’t really read the result within the first 15 minutes or 20 minutes as recommended by the producer there can be a false positive. That is bad. So the ideal test throughout is the PCR,” the official added.

However, he added the RAT kits were useful to identify the presence of the virus within a community or high rise building and if there was a cluster forming.(JAMILA HUSAIN)