Covid-19: public health experts demand evidence behind UK’s short self-isolation advice

Public health experts have called for the government to publish the evidence behind the UK’s guidance on self-isolation, which says that people who develop symptoms of covid-19 need only isolate for seven days.

Seven days is far shorter than the period recommended by the World Health Organization, which states that people should only end self-isolation 14 days after their symptoms have resolved.

In a letter to health secretary Matt Hancock, 25 experts from across the UK warned that the current evidence suggests a “risk of infection beyond seven days from symptom onset. This has been reported to range from day 10 of symptoms to up to 24 days after symptom onset.”

The signatories include Allyson Pollock, professor of public health and co-director of Newcastle University Centre of Research Excellence in Regulatory Science, David Hunter, professor of epidemiology and medicine at the University of Oxford, and Maggie Rae, president of the Faculty of Public Health.

In the UK, the government has advised people with either a high temperature or a new continuous cough to self-isolate at home.1 After seven days, if they do not have a temperature they can end self-isolation, even if they still have a cough—as a “cough can last for several weeks after the infection has gone.”

This is far more relaxed than WHO recommendations, which advise that people should isolate at home and should only be released once they test negative for covid-19 twice (two tests taken at least 24 hours apart), or if it has been two weeks since they last showed symptoms.

The letter has also raised concerns about the “narrow spectrum of symptoms the UK is using as an indication for self-isolation.” It pointed to several commonly reported symptoms including sore throat, fatigue, shortness of breath, and myalgia, and said, “We are aware that other countries are using a broader range of symptoms for self-isolation.”

The group has requested that the evidence base informing the UK government strategy on self-isolation—both symptoms requiring self-isolation and length of time for self-isolation—be made publicly available, and that “more granular detail be provided” on the UK testing strategy, including whether there are plans for polymerase chain reaction testing to be used to determine when people can end self-isolation.

The UK’s lack of widespread testing has been a major point of criticism, with many doctors and public health experts questioning why the government decided not to follow advice from WHO, which repeatedly told countries to “test, test, test.”2

Earlier this month, charity Sense About Science wrote to prime minister Boris Johnson3 urging him to “start publishing the government’s evolving plans for coronavirus testing.” The letter was signed by more than 100 scientists and argued that people are “frustrated and confused about the scientific and logistical challenges of testing and what the government is doing about it.”

This is not the only decision that has led to calls for transparency over evidence. After the UK medicines agencies changed their advice on ibuprofen to say that the drug can be used to treat symptoms of covid-19, professor of primary care research at the University of Southampton Paul Little highlighted in The BMJ that neither the rationale nor the evidence base for the new advice had been published.4

He said, “The whole thing should be much more explicit in order to allow sensible discussion and proper critique. I’m not cynical by nature but the thought that there might be other agendas did occur to me, but I suspect it is just that they are undervaluing the case control evidence.”

The Department of Health and Social Care did not respond to a request for a comment.