Home Isolation For Mild COVID Infections Cut To 7 Days, But Some Could Still Be Infectious

Researchers from the University of Exeter have highlighted the importance of having a negative active virus test to ensure Covid-affected people are no longer infectious.

In India, the quarantine period for home isolation patients, who has been tested positive for COVID-19, has been reduced to 7 days from 14 days. The Ministry of Health issued the revised guidelines for home Isolation of mild/asymptomatic COVID-19 cases last month. It stated that patients under home isolation can end isolation and be discharged after 7 days from testing positive if they have no fever for 3 successive days, and that re-testing is not required after the home isolation period is over. However, a new study has said that some Covid-affected people could remain infectious for over 10 days.

One in 10 people may have clinically relevant levels of potentially infectious SARS-CoV-2 past the 10-day quarantine period, according to the study led by the University of Exeter. The study has been published in the international Journal of Infectious Diseases.

New test can tell if the virus is still active

For the study, the researchers used a newly adapted test which can detect whether the virus was potentially still active and applied it to samples from 176 people who had tested positive on standard PCR tests. They found that 13 per cent of the patients still exhibited clinically relevant levels of virus after 10 days, meaning they could potentially still be infectious. Some people continue to retain these levels for up to 68 days.

"While this is a relatively small study, our results suggest that potentially active virus may sometimes persist beyond a 10 day period, and could pose a potential risk of onward transmission," said Professor Lorna Harries of the University of Exeter Medical School, as quoted by Science Daily.

The authors suggested that this new test should be used in settings where people are vulnerable, to stop the spread of COVID-19.

While conventional PCR tests, which work by testing for the presence of viral fragments, can tell if someone has recently had the virus, they cannot detect whether it is still active, and the person is infectious. The new test, however, gives a positive result only when the virus is active and potentially capable of onward transmission.

Lead author Merlin Davies, of the University of Exeter Medical School, noted that people who continue to be infectious after 10 days could pose a serious public health risk. So, it is important to have a negative active virus test to ensure Covid-affected people are no longer infectious, he said.

The researchers are planning to conduct larger trials to investigate this further.