Antibody-based test kits cannot be used to diagnose Covid-19, says Health DG

PETALING JAYA: The Antibody Rapid Test Kit (RTK) for Covid-19 or serological tests that use blood samples from a finger prick cannot be used to diagnose the disease, says the Health Ministry.

Health director-general Datuk Dr Noor Hisham Abdullah (pic) said this is because the presence of antibodies are unable to validate active infections while negative results are no guarantee that the individual tested is not infected with the disease.

Dr Noor Hisham, however, said that the test can be used to conduct studies of the prevalence of the Covid-19 infection in the community or among target groups, such as the working group.

“This is in line with the World Health Organisation's (WHO) recommendation that RTK antibodies can be used in epidemiological studies.

“There is no solid evidence from scientific studies showing that people who have recovered from Covid-19 and have antibodies are protected from a second infection,” he said in a press conference on Monday (May 11).

Several parties had brought up the issue of the use of RTK antibodies at private clinics for the screening of those who were returning to work.

Dr Noor Hisham said that the test to detect the Covid-19 is an antigen-based test through Real-Time Reverse Transcription-Polymerase Chain Reaction (rRT-PCR) or the RTK Antigen test.

He said both tests require the use of nasal swabs by trained members using appropriate personal protective equipment (PPE) and laboratory equipment such as the Biological Safety Cabinet (BSC) when processing samples were taken.

The rRT-PCR detects the presence of Covid-19 in an individual's body by looking at genetic material taken from swabs.

The RTK antibody method is conducted on blood samples but only detects the presence of antibodies to the coronavirus, and not the virus itself.

Antibodies will only show up in the body after seven to 14 days of an individual being exposed to the virus.

A negative result, however, does not mean that an individual has not been infected.

As of Monday (May 11), a total of 6,726 Covid-19 infections were detected in the country, with 109 deaths recorded.