Coronavirus: Patients no longer infectious after 11 days, Singapore study finds

The findings could lead to people with the virus being released from hospital earlier, even if still sick

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Covid-19 patients are no longer infectious after 11 days of getting sick, even though they still test positive, according to a new study by infectious disease experts.

A positive test "does not equate to infectiousness or viable virus," a joint research paper by Singapore's National Centre for Infectious Diseases and the Academy of Medicine, Singapore said.

The virus “could not be isolated or cultured after day 11 of illness.”

The paper was based on a study of 73 patents in the city-state.

"Scientifically, I'm very confident that there is enough evidence that the person is no longer infectious after 11 days," Prof Leo Yee Sin, executive director of the NCID, told Straits Times.

The latest findings may have implications for the patient discharge policy in Singapore and elsewhere. As in other countries, including the UAE, patients in hospital are only discharged when they test negative at least twice.

Singapore's Ministry of Health will look at whether the latest evidence can be incorporated into its patient management plan.

To date, 13,882, or about 45 per cent of the 31,068 Covid-19 patients in Singapore have been discharged from hospitals and community facilities. It reported 642 new Covid-19 cases on Saturday.

Should officials allow patients to be discharged based on time, more than 80 per cent could go home after 11 days of illness.

The remainder may need more care if they have a severe form of the illness, but they could not pass on the virus to anyone and would not need to be isolated in the same way.

The paper also makes reference to a small study of nine patients in Germany that found 'viral shedding' from the lungs or throat was very high in the first week but none by day eight.

Dr Asok Kurup, an infectious disease expert at the Academy of Medicine, said much more is known about the virus today than in the weeks after the outbreak began.

"Studies are still going on and we will get more data, but we will see the same thing as there is a great deal of science in this. So there is no need to wait," he said.

The government has been actively screening pre-school staff as it prepares to reopen pre-schools from June 2. On Friday, two pre-school employees tested positive for the novel coronavirus, bringing the total number of confirmed cases among pre-school staff to seven, according to the Ministry of Health.