Covid-19 patients with loss of smell and taste have high recovery rate, study says

Loss of sensory functions is more likely to indicate the confirmation of having coronavirus rather than any other respiratory syndrome, according to a recent study by UC San Diego scientists.

The study was published in the journal "International Forum of Allergy & Rhinology" where researchers claimed, those who showed early symptoms of losing taste and smell due to the virus have comparatively more chances to recover than those who showed different symptoms.

Carol Yan, an otolaryngologist and head and neck surgeon at UC San Diego Health said,  "Based on our study, if you have smell and taste loss, you are more than 10 times more likely to have COVID-19 infection than other causes of infection. The most common first sign of a COVID-19 infection remains fever, but fatigue and loss of smell and taste follow as other very common initial symptoms."

"We know COVID-19 is an extremely contagious virus. This study supports the need to be aware of smell and taste loss as early signs of COVID-19," she added.

They surveyed 1,480 patients with flu-like symptoms and concerns regarding potential COVID-19 infection who underwent testing from March 3 to March 29, this year. Within that total, 102 patients tested positive for the virus and 1,378 tested negative. The study included responses from 59 COVID-19-positive patients and 203 COVID-19-negative patients.

"Our study not only showed that the high incidence of smell and taste is specific to COVID-19 infection but we fortunately also found that for the majority of people sensory recovery was generally rapid," said Yan. "Among the Covid-19 patients with smell loss, more than 70 percent had reported improvement of smell at the time of survey and of those who hadn't reported improvement, many had only been diagnosed recently."

Sensory return typically matched the timing of disease recovery. Interestingly, the researchers found that persons who reported experiencing a sore throat more often tested negative for COVID-19.

In an effort to decrease risk of virus transmission, UC San Diego Health now includes loss of smell and taste as a screening requirement for visitors and staff, as well as a marker for testing patients who may be positive for the virus.

The findings, she said, underline the importance of identifying early or subtle symptoms of COVID-19 infection in people who may be at risk of transmitting the disease as they recuperate within the community. "It is our hope that with these findings other institutions will follow suit and not only list smell and taste loss as a symptom of COVID-19, but use it as a screening measure for the virus across the world," Yan said.