Coronavirus patients can’t infect others after 11 days of being ill even if their test still comes back positive, scientists find.
An infected person becomes contagious around two days before symptoms show, researchers from Singapore found.
They then remain contagious for between seven and ten days after they start showing signs of the disease – which include having a high temperature and a new and continuous cough.
Covid-19 ‘could not be isolated or cultured after day 11’ of the illness, researchers said.
Scientists from Singapore’s National Center for Infectious Diseases and the Academy of Medicine examined 73 patients with coronavirus.
They looked at whether the bug could be passed from them to someone else, the New York Post reported.
Positive tests in patients that still had symptoms after two weeks could be picking up sections of the bug that cannot pass the virus on to someone else.
The authors wrote: ‘Based on the accumulated data since the start of the COVID-19 pandemic, the infectious period of [coronavirus] in symptomatic individuals may begin around two days before the onset of symptoms, and persists for about seven to ten days after the onset of symptoms.’
They added: ‘Active viral replication drops quickly after the first week, and viable virus was not found after the second week of illness.’
It comes as the UK reported a further 118 coronavirus deaths, a 30 per cent drop since last Sunday’s 170, taking the total to 36,793.
The daily death figure, revealed by Prime Minister Boris Johnson at the daily press briefing this evening, is the lowest since the lockdown was put into force on March 23.
Scientists hope that their research on the disease’s ability to spread could help hospitals figure out when to send admitted patients home.