PUTRAJAYA, April 21 — Datuk Dr Noor Hisham Abdullah said today that the Ministry of Health (MOH) has not ascertained if asymptomatic coronavirus disease (Covid-19) patients can infect others.

In a press conference here, the Health director-general pointed out that the SARS-CoV2 virus that causes Covid-19 was still novel and required further study before its characteristics could be determined.

“[With] regards to the population base, yes, we know there are asymptomatic (cases) but this is a new virus, so we need to learn a lot about this new virus. The behaviour of (the) virus, whether they respond to antibodies.

“As I have told you, the first, second, third and fourth cases that we detected, cases detected from the index case in Singapore, they were asymptomatic. But because they had positive contact with an index case, when it’s close contact, the chances of them being positive is about 30 per cent. So that’s very high,” he said.


Dr Noor Hisham said that this was why such patients are ultimately treated as Patient Under Investigation (PUI).

However, he said that in cases where an asymptomatic person had no close contact with those who have symptoms, it is still not known if they can be contagious.

“But now the question is, they have no close contact, and they have no symptoms. What about asymptomatic people in the community? The answer is, we don’t know, unless we do a study to screen one community for example. We test the antibody or antigen of the community, then only we can see the response.


Dr Noor Hisham said data on the virus and the disease was still inconsistent as there were not enough conclusive studies on both at this time.

“The question is whether they can transmit the infection to others. So this again, we need to fall back on data, whether there is enough data to show that asymptomatic patients can actually transmit the disease. So this is something that again, we have conflicting reports.

“Asymptomatic, perhaps they may have the virus, but whether they can transmit to others, is still to be studied and to be proven,” Dr Noor Hisham added.

He previously said over 80 per cent of Malaysia’s Covid-19 patients were either asymptomatic or only displayed mild symptoms.