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The loss of taste and smell could be crucial warning signs in “hidden carriers” of the novel coronavirus, experts have revealed.

The British Association of Otorhinolaryngology — which represents ear, nose and throat specialists — says the loss of senses often appears in patients who show none of the earlier known symptoms.

“In young patients, they do not have any significant symptoms such as the cough and fever, but they may have just the loss of sense of smell and taste,” the association’s president, professor Nirmal Kumar, told Sky News.

The association said in a statement that anosmia or hyposmia — the medical terms for the loss of smell — have particularly been noted in COVID-19 hotspots around the globe.

“There have been a rapidly growing number of reports of a significant increase in the number of patients presenting with anosmia in the absence of other symptoms,” the statement says. “Iran has reported a sudden increase in cases of isolated anosmia, and many colleagues from the US, France, and Northern Italy have the same experience.”

In Germany, almost two-thirds of patients have reported losing their sense of smell, while in Korea almost a third have even in “otherwise mild cases.”

“These patients may be some of the hitherto hidden carriers that have facilitated the rapid spread of COVID-19,” they added.

If wider known, the loss of senses could force carriers into quarantine earlier, slowing the spread, the association hopes.