Discharge criteria for COVID-19 revised allowing patients to leave hospital if clinically well by day 21

Patients who have been tested positive for COVID-19 in Singapore are allowed to be discharged from hospital without any further tests if they are assessed to be clinically well and no longer infectious by day 21, said Health Minister Gan Kim Yong on Thursday (28 May). As a precaution measure, these patients must self-quarantine at home or in their dormitories for another additional seven days - until day 28 - Mr Gan explained. After that, they will be permitted to go back to work. “This revised approach will allow patients who are well and not infectious to return to the community,” the Health Minister noted at a press conference. The Ministry of Health (MOH) revealed that this new revision in the discharge criteria will take effect immediately. The MOH made this decision of adopting to a new time-based discharge requirement after looking into clinical and scientific evidence gathered locally and internationally. Prior to this, patients have to test negative twice consecutively, 24 hours apart, in order to be allowed to be discharged from the hospital. However, it is important to note that this new discharge requirement will not be applied to patients with compromised immune systems as they can still spread the virus for a prolonged period.

Virus no longer viable after 11 days

As to why this decision was made, Mr Gan explained that based on a position paper by physicians from the National Centre for Infectious Diseases (NCID), it was revealed even though patients still test positive for the coronavirus, the virus is apparently not viable after 11 days of a person falling ill and it no longer has the ability to spread to others. He went on to state that the World Health Organisation (WHO) also made similar recommendation on Wednesday (27 May) where it suggested to shift from transmission-based discharge to time-based discharge for patients who are clinically well. “Patients who are clinically well can now be discharged from after 10 days from the onset of illness, plus at least three days without respiratory symptoms or fever,” Mr Gan said. He added, “As we know more about COVID-19, as a result of both global research, as well as research done locally, we will adjust our medical plan for COVID-19 patients." NCID executive director Leo Yee Sin, who was also at Wednesday's press conference by the multi-ministry task force on COVID-19, presented three local studies on the virus. The first one involved 18 COVID-19 patients, and it was found that the virus shedding is at its peak during the early onset of the illness. In another study, which looked at 766 patients, the results of the polymerase chain reaction (PCR) tests for about 30 per cent of the patients tested came out clean by day 15 of their illness. By the time they reached day 21, 68 per cent of them cleared the PCR test. Once they hit day 33, 95 per cent of them successfully cleared the tests, Prof Leo explained. As for the other study that she highlighted, researched monitored 73 patients regularly by testing them with the PCR, and sending their respiratory samples to be cultured. However, after a certain point, she noted that the researchers were not able to culture the respiratory sample. “By such time, most of the patients would reach beyond day 10, day 11 of their clinical illness,” Prof Leo remarked. She continued, “If we were to take all this scientific information together, we are confident to say that by the time they reach day 11, and by the time they reach two weeks of their clinical illness, we can no longer have any viable virus.” Although data from the studies show that COVID-19 patients are no longer infectious beyond day 10 or 11, Associate Professor Kenneth Mark, who is the director of medical services at the MOH, hinted that Singapore would still be taking an “abundance of caution” by isolating the patients for 21 days. "This is because of our commitment to the community to make sure that as we return COVID-19 infected patients back into the community, we want it to be a safe process, such that there should not be any concern for further spread of infection from these individuals to other members in the community,” he asserted. Besides Singapore, other countries like South Korea, the United Kingdom, the United States, Estonia, and Ireland have also adopted the time-based criteria to discharge COVID-19 patients. On Thursday (28 May), the MOH confirmed an additional 373 cases of COVID-19 infection in Singapore, bringing the total tally of cases in the country to 33,249.