Covid-19: Test based on loss of smell, researcher says

A researcher at Otago University says people should be tested for Covid-19 even if the loss of sense of smell - anosmia - is their only symptom.

Anosmia has been added to the case definition for Covid-19, but people will only be tested if it is accompanied by acute respiratory illness.

However, Dr Mei Peng, a researcher of the sense of smell at the University of Otago, said it should be tested in the absence of other symptoms.

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"Some of the case studies have suggested anosmia is one of the first symptoms and sometimes one of the only symptoms."

She is part of a project with more than 300 researchers across more than 20 countries who are gathering standardised observational data about how and when the sensory changes happen.

Alongside some other New Zealand researchers, she has also sent out a questionnaire to people who might have been affected by Covid-19 to find out how prevalent the symptom is.

She said that while adding anosmia into the case definition was "progress", she said there was lots of anecdotal evidence that it could appear as a symptom on its own in positive Covid-19 cases.

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"I think having ansomia as the only symptom is enough for swab testing for Covid.

"We haven't gathered enough empirical data to know the prevalence of this symptom... [but] we have seen a lot of anecdotal data and case studies suggesting anosmia could be the only symptom, therefore, I think people with this symptom should be tested for Covid."

But Director-General of Health Ashley Bloomfield disagreed and said it was not yet significant enough to test on its own.

"I'm pleased and I think it's good it's been added as one of the clusters of symptoms but in and of itself it's not significant enough, or sensitive enough to be a sign for testing."