Owl’s recollection is that this observation came out very clearly from Tim Spector’s innovative work in re-purposing his research to create a symptom tracking phone app, weeks ago (formal peer reviewed paper already published 11 May).
The relatively slow (to Owl) take up of this, demonstrates the difficulty the Government will have in selecting and applying key findings from a fast expanding body of relevant research.
The Government really will have to “Stay Alert”!
Loss of sense of smell has been added to the list of symptoms that should prompt people in the UK to self-isolate for suspected coronavirus.
Experts said this morning that tens of thousands of cases of Covid-19 were being missed because the government still only recognised a fever and a cough as symptoms, and from now on loss of smell and taste will also be classed as a danger sign.
People will be told to be alert to food losing its flavour because smell and taste are so closely connected.
However, officials signalled that they would not add other signs such as fatigue to the symptom list because these would be too easily confused with other conditions.
Jonathan Van-Tam, the deputy chief medical officer for England, said that adding loss of sense of smell would only pick up 2 per cent more cases and defended a decision not to change advice earlier, saying experts needed time to be sure the problem appeared early enough in the disease to be useful.
The loss of sense of smell, medically known as anosmia, has been widely reported by people suffering from Covid-19, with anywhere from 10 to 50 per cent of patients thought to be affected. It is common with a range of respiratory infections because of the way the virus clusters in the nose.
Anosmia can last for weeks after infection, but people will only be told to isolate for seven days. Those living with someone who experiences anosmia will be told to isolate for 14 days.
Professor Van-Tam said: “The way we are describing anosmia is clinically in terms of its technical definition, loss of or change in your normal sense of smell. But in terms of public messaging, we do understand that smell and taste are very closely linked in a neurological sense. Patients who experience loss of sense of smell can also experience loss of sense of taste, and therefore from that perspective the messaging will explain that to the public.”
He said the red flag symptoms of cough or fever picked up 91 per cent of cases and that government calculations suggested adding anosmia would take that to 93 per cent. “In other words, it’s a very small addition, which we’ve taken time to be sure about.”
However, he added: “Clearly we are moving into an era, thankfully, where we have much, much lower disease activity in the UK, as signalled by the prime minister’s initiatives to gradually begin to ease lockdown. The test-and-trace strategy is absolutely part of a strategy moving forward. At a time when disease activities are going to be lower in the UK, we hope for the foreseeable few months, it is going to be even more important to keep it that way, by picking up all the cases we can.”
Many European countries and the United States have already added anosmia to official symptoms of coronavirus but in Britain senior doctors had worried that it was subjective. However, after considering the question since March 27 scientific advisers on the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag) have now recommended a change.
Professor Van-Tam said that “this has been quite a difficult piece of science because there’s a distinction between can anosmia occur with Covid-19 versus whether it occurs early to be a useful help in detecting cases”.
He added: “It’s not just about whether anosmia exists. It’s about what role it plays in identifying cases, and that’s taken time to work through.”
Although he said Nervtag had been looking at other symptoms reported by Covid patients, he suggested that the group concluded it would not help to add them to the official lists. “We’re looking for things that are not so common and so non-specific that actually they would just cause more confusion,” he said.
“Fatigue, for example, on its own — people can report fatigue for any number of reasons. It’s a genuine symptom of Covid, but it doesn’t really serve a purpose in terms of helping us pick out cases.”
Tim Spector of King’s College London, who runs a Covid-19 symptom tracker app, has said that 14 different symptoms had been shown to be linked to a positive test for coronavirus.
He told BBC Radio 4’s Today: “At the moment people are being told to go back to work if they’re a care worker and they’ve got something like loss of sense of smell or severe muscle pain or fatigue — things which we know are related to being swab positive. This country is missing them all and [not only] underestimating cases but also putting people at risk.”
Professor Spector estimated that “we’re probably missing at the moment between 50,000 and 70,000 people who are infected”, urging ministers to “get in line with the rest of the world and make people more aware. There’s no point telling people to be alert if they don’t know the symptoms.”
People in Scotland who find they cannot detect scent or enjoy the taste of food should ring NHS 24 on the 111 number for advice and may be sent for a coronavirus test.
Dr Nicola Steedman, interim deputy chief medical officer for the Scottish government, said: “It is one of those symptoms that usually people do notice when they have got it. They will notice all of their food is tasting different.”
She said there was no scientific evidence on what people should smell or eat to check for anosmia, but suggested a curry or garlic-flavoured dish might serve as a barometer.
She said adding this symptom to those that would cause cases to be tested and isolated would be beneficial when lockdown measures were eased.