As the novel coronavirus has spread around the globe, its hallmark symptoms have become a kind of medical mantra among health officials — fever, cough, difficulty breathing.

But mounting evidence from countries such as South Korea, China and Italy points to another symptom that may be a candidate to join the list: a newly developed loss of the sense of smell, and with it, taste.

And while the evidence still is considered anecdotal, experts in the ear, nose and throat field have begun discussing whether to add it to commonly asked screening questions.

“I think there’s something to it,” said Dr. Christie Barnes, an Omaha nose and sinus surgeon with Nebraska Medicine. “I think it may just be another question we want to start asking people.”

On Friday, the presidents of the British Rhinological Society and ENT UK, a group that represents British ear, nose and throat doctors, wrote that reports from Germany indicate that more than two out of three patients confirmed to have coronavirus disease have loss of smell, called anosmia. In South Korea, some 30% of patients testing positive report lost smell as their main symptom in an otherwise mild illness.

The two groups also wrote that asking adults with loss of smell but no other symptoms to self-isolate for seven days might help reduce the number of otherwise symptom-free people who continue to unknowingly spread the disease.

The American Academy of Otolaryngology-Head and Neck Surgery noted in a bulletin posted on its website Sunday that the loss of smell in particular has been seen in patients who have tested positive for the virus but have no other symptoms. The group proposed adding loss of smell and taste to the list of screening tools for possible coronavirus disease, or COVID-19, infection.

The presence of such symptoms in patients with no other respiratory disease, such as allergies or sinus infections, should “alert physicians to the possibility of COVID-19 infection and warrant serious consideration for self-isolation and testing of these individuals,” the group wrote.

A World Health Organization official said Monday that the agency is looking into whether the loss of smell or taste is a defining feature of the disease. But agency officials said they had not yet confirmed loss of smell or taste as a symptom.

And one German doctor warned that some people naturally have a limited sense of smell. Alerting everyone that they need to stay home if they can’t smell would cause false alarms.

Locally, Douglas County Health Department officials have noticed that some people diagnosed with the virus have experienced a loss of taste and smell.

Meanwhile, Barnes and other Omaha-area doctors say they’re notifying colleagues, including their health systems’ infectious disease physicians.

“The reason this is important,” said Dr. Andrew Coughlin, a head and neck surgical oncologist with Methodist Health System, “is that it might identify people earlier who are carriers and have no symptoms at all. If they’re in the early days before they start showing symptoms (and potentially spreading the virus), we can say, ‘Stop meeting with people and isolate yourself.’ ”

The loss of a sense of smell and taste due to a viral infection is not a new phenomenon.

Many viruses that cause common colds cause inflammation that can obstruct the nose, Barnes said. Neurons responsible for smell sit high in the nasal cavity. Allergies and chronic sinus conditions also can diminish smell.

Decreased sense of taste comes not because there’s anything wrong with the taste buds but because smell plays a significant role in people’s ability to taste.

Taste receptors in the mouth pick up only sweet, sour, bitter, salty and umami, the savory meat taste. “It’s smell that gives us flavor, the nuances between coffee and cherry and vanilla and chocolate,” Barnes said.

At the same time, the coronavirus is known to favor the upper nose, Coughlin said, a fact that comes with a potential warning for health care providers who work in that area. Fourteen people were infected after a patient in China with COVID-19 underwent a pituitary surgery. Health care workers swabbing the area for virus testing typically wear full protective gear.

“We need to be very careful doing anything in the nose,” he said.

Omaha-area hospitals already have agreed to postpone and reschedule most nonessential surgeries and medical procedures for the next 90 days in an effort to conserve critical medical supplies, prevent staff burnout and free up beds as more COVID-19 cases emerge in Nebraska.

The American otolaryngology academy, the Centers for Disease Control and Prevention and the Centers for Medicare and Medicaid Services have made similar calls.

But Coughlin said discussions are taking place across the country about whether doctors with patients who absolutely need an operation in the nose, back of the mouth or throat should be testing the patients for the virus first so they can wear the correct protective gear in the operating room.

In addition, a recent study from China also has identified digestive symptoms as a main complaint among some patients.

Adi Pour, director of the Douglas County Health Department, said at a recent press conference that local health investigators have noted such symptoms in some people with the illness. Fatigue is another.

Dr. Renuga Vivekanandan, an infectious disease doctor with CHI Health, said she would not make a coronavirus determination based on diarrhea alone. Vivekanandan said she is more concerned about fever, cough and shortness of breath in connection with the virus. Sore throats are an additional symptom, she said.

In a small percentage of cases, she said, those with the virus have diarrhea, but that usually is in conjunction with one or more of the prominent symptoms, she said. She also said she had no reason to think the virus has mutated, causing additional symptoms.

“I don’t think there’s any indication right now the virus is changing,” she said.

World-Herald staff writer Rick Ruggles contributed to this report, which also includes material from the Associated Press and the Washington Post.