The official list of coronavirus symptoms should be expanded to include loss of smell and taste, senior medics have demanded, with patients also having reported stomach pains and sore eyes.
Ordering those with an impaired sense of smell and taste to self-isolate could significantly slow the spread of the virus, the experts have said.
Currently, the government demands only that people with a persistent dry cough or a high temperature, or both, self-isolate for at least seven days to protect the wider public.
However, specialist doctors say that in recent days they have been “inundated” by a wave of patients reporting the sudden loss – usually within 24 hours – of their sense of smell and taste.
Only a minority have gone on to develop the formally-recognised symptoms of Covid-19. Those who have called NHS 111 have allegedly been told they need not self-isolate.
It is understood that the chief medical officer and Sage, the scientific group advising the government, are considering evidence of loss of smell and taste closely.
Professor Claire Hopkins, president of the British Rhinological Society, told The Telegraph that, in the absence of adequate coronavirus testing, taste and smell loss could be a powerful means of identifying the otherwise asymptomatic super-spreaders – many of them young people – who endanger others.
“I think it’s really important that we extend the criteria for which people self-isolate to include anybody with loss of taste and loss of sense of smell,” she said. “It’s critical that we identify patients who are asymptomatic to slow the spread of this disease.”
Her comments follow a recommendation on Friday by Jerome Salomon, France’s top health official, that people experiencing anosmia (the loss of the sense of smell) should contact their doctor, although Professor Hopkins said that, providing they were otherwise asymptomatic, people should simply self-isolate rather than contacting the NHS.
She said medical colleagues involved in the coronavirus response in northern Italy had told her they believed around 50 per cent of doctors had temporarily lost their sense of taste or smell.
“I’m aware that doctors on the front line in Italy, Iran and France are actively looking out for this as a sign of infection,” she said.
The symptoms have been seen in previous coronaviruses, but nearly always alongside the classic viral symptoms of coughing and high temperature.
Paul Hunter, professor in medicine at the University of East Anglia, said: “If it really is an early feature then that would be really useful to know, but it can’t be on the basis of hearsay.”
It came as a debate flared among scientists over the extent to which diarrhoea and other gastrointestinal problems are common symptoms of coronavirus.
A paper published in the American Journal of Gastroenterology found that approximately half of a sample of 204 patients admitted to hospital in Hubei province, China, were suffering these symptoms.
However, Professor Hunter said this study was likely to be an outlier and most other research suggested that, at most, around 10 per cent of Covid-19 patients are affected.
Coronavirus is hard to stop spreading because of the incubation period, the time between infection and the moment they start displaying symptoms.
The Government has been heavily criticised for the lack of testing, prompting Boris Johnson to announce last week that the number of daily tests would jump from 4,000 to 25,000.