THE accuracy of Covid-19 tests depend on the period of infection at the time samples are taken, director-general of health Dr Noor Hisham Abdullah said. 

Noor Hisham explained that the RTK-Antigen (RTK) tests can usually detect the viral load of an infected patient between three and seven days, while the reverse transcription-polymerase chain reaction (PCR) can detect infections as early as the second day. 

“Therefore, the accuracy of RTK and PCR tests depend on the period of infection when a sample is taken,” the health DG said. 

Noor Hisham’s explanation comes after public complaints of obtaining different test results using the aforementioned test kits. 

Noor Hisham said that the RTK tests are recommended for individuals who are symptomatic or are in a high-risk group if asymptomatic.

He said that the approved RTK test must have at least 95% sensitivity, leaving a 5% possibility of a false negative result. 

“The ministry has approved the use of RTK as an alternative method of testing for Covid-19 other than PCR. 

“RTK helps to facilitate detection and control of Covid-19 infection because this method is simple, easy, and inexpensive and can be performed in the field or at point-of-care testing (POCT). 

“The test process is fast and results can be obtained within 20 to 30 minutes,” he said in a statement today. 

Noor Hisham said that the PCR test remains the “gold standard” for detecting Covid-19 infections. 

He said the PCR traces the presence of nucleic acid (viral genetic material) and has a sensitivity of 99.9%.

“In this case, the PCR requires sophisticated lab equipment, higher costs, trained staffers and a longer waiting period of between six and 24 hours,” he said.

Noor Hisham urged everyone to report their RTK self-test results via MySejahtera and update the status with the Home Assessment Tool. 

He asks those that tested positive to adhere to the latest quarantine standard operating procedures.

He said self-reporting helps the ministry in getting a clearer picture of community infections. – March 6, 2022.