KUCHING: Using the Antigen Rapid Test Kits (RTK-Ag) to screen for COVID-19 is adequate to determine if a person is infected or not, especially in a situation when daily cases are very high and widespread.
Universiti Malaysia Sarawak (Unimas) Faculty of Medicine and Health Sciences public health expert Associate Professor Dr Helmy Hazmi said in such a situation, RTK had advantages over Reverse Transcription-Polymerase Chain Reaction (RT-PCR) tests.
“RTK is portable, easy to perform, thus does not require a trained person, and less expensive than the PCR and provides result ‘while you wait’. To put into context, the price of one PCR test costs between 10 and 20 RTKs, depending on the brand.
“Therefore, in a massive outbreak situation, RTK is an important tool for people with suspected COVID-19 to know quickly if they are infected or not, so that they can self-isolate, receive treatment and inform close contacts immediately,” he told New Sarawak Tribune.
He said RTK was almost as good as the PCR testing, if it was used correctly according to the manufacturer’s instructions.
“The accuracy of the RTKs is high as the Medical Device Authority (MDA) places a very high standard on the RTK selection and the quality of the RTKs sent to them for validation.”
Helmy said RTK were useful during the peak in Sabah after the state election in 2020, where it helped the health authorities to decide who should be isolated there and then.
The use of RTKS helped tremendously to overcome the lack of testing issues, especially before the vaccine was given.
On the ‘false’ positive or ‘false’ negative results, the health expert explained that results from RTK were subject to many variables too – whether food was taken before the test or if a deep cough was performed.
“Besides, the saliva needs to be collected adequately and the result must be read after 15 minutes and not an hour later – to name some of the reasons for variations in the result.
“When the disease occurs widely in the community – or high in prevalence, if one tests positive with the RTK, the chance for the test to be truly positive is high. This is related to the increase in the test’s predictive value as the disease prevalence increases.
“While for those who tested negative on RTK while their PCR returned a positive result, it depends again on the time the sample was collected. Initial early collection might yield low viral particles and return a negative RTK result as the spike protein might be negligible in amount, but the RNA can be amplified and return as positive in the PCR test,” he explained.
Helmy advised the public that instead of waiting for the PCR result, everyone should actually limit their movements and isolate themselves if they had viral fever symptoms, including cough and runny nose.
He said as Malaysia would be shifting towards an era of simpler or relaxed standard operating procedures (SOPs) next month, the public must be honest in their reporting of their COVID-19 positive results in the MySejahtera app.
Last week, Health Minister Khairy Jamaluddin urged Malaysians to reduce reliance on Reverse Transcription-Polymerase Chain Reaction (RT-PCR) tests and shift towards Antigen Rapid Test Kits (RTK-Ag) to screen for COVID-19 as the country entered a transitional phase into endemicity on April 1.
He said the RTK-Ag tests were sufficient to detect positive cases with higher infectivity rates, compared to the RT-PCR tests that were more sensitive.
