Losing the ability to smell and taste is added to the review list for Covid-19. That was the demand of doctors in the US on Sunday.

The American Academy of Otolaryngology said symptoms of anosmia, or lack of ability to smell and dysgeusia, or lack of taste, should be used to identify potential infections such as Covid-19.

"Anosmia, in particular, has been seen in patients who have tested positive for coronavirus with no other symptoms," said a statement on the academy's website. These symptoms "require serious consideration for the isolation and testing of these individuals," the statement continues.

It has long been known that the sudden loss of ability to smell, or the anomaly, can be linked to various airway infections.

"Coronaviruses previously described are thought to account for 10-15% of cases. Therefore, it is not surprising that the novel Covid-19 virus would also cause anosmia in infected patients. Now, there is good evidence from South Korea, China and Italy, that a significant number of patients infected with Covid-19 have developed anosmia, "the statement said.

However, fever, cough and respiratory problems continue to be the predominant symptoms of Covid-19.