Representational image.

COVID-19 patients do not pose a threat of spreading the disease after 11 days, according to a recent study by researchers in Singapore.

According to a joint study conducted by the National Centre for Infectious Diseases (NCID) and the Chapter of Infectious Disease Physicians, Academy of Medicine, Singapore, the novel coronavirus ‘could not be isolated or cultured after day 11 of illness.’

The study examined 73 patients infected with Covid-19.

“In a local study from a multicenter cohort of 73 COVID-19 patients, when the Ct value was 30 or higher (i.e. when viral load is low), no viable virus (based on being able to culture the virus) has been found,” the study stated.

“In addition, virus could not be isolated or cultured after day 11 of illness,”it added.

“Based on the accumulated data since the start of the COVID-19 pandemic, the infectious period of SARS-CoV-2 in symptomatic individuals may begin around 2 days before the onset of symptoms, and persists for about 7 – 10 days after the onset of symptoms,” the study said.

It also stated that active viral replication drops quickly after the first week and viable virus was not found after the second week of illness despite the persistence of PCR detection of RNA.

The latest findings may have implications on the country’s patient discharge policy. The discharge criteria are currently based on negative test results rather than infectiousness.

Out of the total 31,068 Covid-19 patients in Singapore, 13,382 have been discharged from hospitals and community facilities