People who have tested positive for Covid-19 or who have symptoms will now have to self-isolate for 10 days, rather than seven, the UK government has said in a move that aligns the country with the World Health Organization’s advice.
The decision by the chief medical officers is a response to concern at the rising numbers of infections in Europe and anxiety over what may happen in the winter when people are indoors far more, and is not based on new evidence, it has emerged.
Although 10 days is now be the minimum period of self-isolation, anyone with symptoms other than a cough or loss of sense of taste or smell, which can last longer, should not mix with others until they have recovered.
Scientists have known for some time that a small number of individuals will remain infectious for as long as seven to nine days, even though most people will no longer transmit the virus after a few days of illness.
Dr Tom Wingfield from the Liverpool School of Tropical Medicine, said the statement “brings the UK into line with guidance from WHO and many other countries, some of whom advocate up to 14 days isolation.
“We are seeing increasing Covid-19 cases in Europe and the UK, where local spikes and outbreaks are leading to reimposition of local lockdown measures. Therefore, this change of advice from the CMOs, aimed to reduce coronavirus transmission, is particularly timely and welcome.”
He warned, though, that families would need extra help if they would set to lose income or have difficulties shopping for food and essentials for longer.
Dr Julian Tang, honorary associate professor in respiratory sciences at the University of Leicester, said: “The evidence for this 10-day rather than seven-day cut-off has been around for some months already – and more and more studies confirm this.
“There have been concerns about the former seven-day isolation cut-off for sometime now – because it just didn’t tally with the evidence. Finally, now it does.”
Prof Peter Openshaw from Imperial College London and the British Society for Immunology welcomed the extension to 10 days, “given some hints of resurgence”.
It is clear people are most infectious just before and a couple of days after they show symptoms, he said, but recent work has shown they may have infectious virus up to nine days after the onset.
“We are now in a critical stage of controlling the disease. Keeping infection rates low is vital and extending the period of isolation to 10 days brings us in line with some other European countries. It seems to be a sensible precaution to keep pressure on the virus while other measures to control the spread of Sars-CoV-2 are developed,” he said.
In a statement, the four chief medical officers for England, Scotland, Wales and Northern Ireland, said: “In symptomatic people Covid-19 is most infectious just before, and for the first few days after symptoms begin. It is very important people with symptoms self-isolate and get a test, which will allow contact tracing.
“Evidence, although still limited, has strengthened and shows that people with Covid-19 who are mildly ill and are recovering have a low but real possibility of infectiousness between seven and nine days after illness onset.
“We have considered how best to target interventions to reduce risk to the general population and consider that at this point in the epidemic, with widespread and rapid testing available and considering the relaxation of other measures, it is now the correct balance of risk to extend the self-isolation period from seven to 10 days for those in the community who have symptoms or a positive test result.
“This will help provide additional protection to others in the community. This is particularly important to protect those who have been shielding and in advance of the autumn and winter when we may see increased community transmission.”