A research group of the Ministry of Health, Labor and Welfare has decided to start a large-scale fact-finding survey in December in order to investigate the spread and causes of olfactory disorders that make people feel no odor due to infection with the new coronavirus.

The research is conducted by a research group of the Ministry of Health, Labor and Welfare created by Professor Takaki Miwa of Kanazawa Medical University.

It has been reported that the new coronavirus has an olfactory disorder that makes it impossible to smell as one of the symptoms, but detailed investigations have not been conducted in Japan so far.

In order to understand the actual condition of olfactory disorder caused by the new coronavirus, the research group uses a test kit to evaluate the olfactory function of more than 1000 infected people who are undergoing medical treatment at medical institutions nationwide, and the state of olfaction. Is to find out how it changes.

In addition, we will investigate the psychological effects such as the stress of persistent olfactory dysfunction for a long period of time.

It has been pointed out that the cause of olfactory disorder caused by the new coronavirus is not only inflammation of the mucous membrane of the nose, which is also seen in normal colds, but also inflammation of cells involved in olfaction and a part of the brain that recognizes odors. ..

In the study group, we want to connect to the survey results are summarized, the development of the understanding and treatment of the cause to the prospect of March next year.

Takaki Miwa, chief professor of Kanazawa Medical University, who is the representative of the research group, said, "This survey will give us a detailed understanding of how many patients will have sequelae and how long they will last. I think I'm worried that it won't heal, but I want to find an effective treatment and use it as an opportunity to eliminate my anxiety. "

Patients suffering from a life that does not smell

Although the symptoms of infection with the new coronavirus are relatively mild, many people continue to have sequelae.

Of these, some people with persistent olfactory dysfunction who do not feel the odor have difficulty feeling the taste, have a poor quality of life, and are mentally depressed.

A woman in her 50s, who was infected with the new coronavirus in August, stopped smelling a few days after her runny nose and fever.

At that time, I was diagnosed with mild illness and was hospitalized for a week, and after that, the test was negative, but even after nearly four months, the odor has not returned.

After seeing an otolaryngologist near her home, the woman began to go to a university hospital in Tokyo, but the odor did not recover, her mental instability continued, and she had tinnitus. Since I couldn't sleep, I started to go to the psychosomatic medicine department.

With the support of her husband and children, the woman gradually became calm mentally, but because she couldn't enjoy eating, she lost about 10 kilograms at one point.

The woman said, "I was diagnosed with mild illness at the time of my illness, and I thought it would be cured someday, so I didn't expect it to be cornered by the time I went to psychosomatic medicine. It's a disease that should never be underestimated." I am.

In addition, a man in his twenties who continues to have olfactory dysfunction almost four months after being infected with the new coronavirus cannot return to work in earnest due to sequelae, and continues to receive medical treatment at home. I will.

When the man was infected in late July, he had fever, coughing, and dullness, but the symptoms of the new coronavirus were mild, and he was treated at the hotel for more than two weeks.

However, after a while, I noticed that I didn't feel the smell, and even after the test was negative, my sense of smell continued to be impaired.

Even now, I can understand the taste a little, but the smell has hardly returned, and even when I walked around the city, I could not understand the smell of my favorite yakitori and coffee, and I felt lonely saying "I was deprived of the enjoyment of life." It is said to be.

The man had just started working at a company in Tokyo from April, and after finishing medical treatment at the hotel, he was aiming to return to work by gradually increasing the number of times he went to work after September. In addition to his olfactory dysfunction, his general malaise and suffocation did not improve as expected, and he is forced to recuperate at home from this month.

The man said, "I thought that it would be cured in about a month or two after the onset, so I couldn't keep up with my feelings, and I was forced into both my mind and body. I firmly accepted my physical condition and concentrated on treatment. I want to do it. Corona will change my life, so I want you to take proper precautions. "

At the clinic that sees patients with sequelae

The clinic in Shibuya-ku, Tokyo provides medical care to patients suffering from the aftereffects of the new coronavirus.

In March, the clinic was accepting medical examinations for patients suffering from sequelae, and about 50 patients visited the clinic a day. So far, there are over 400 people.

According to Dr. Koichi Hirahata, of the 181 patients diagnosed with sequelae since last month, 75 are men and 106 are women.By age group, 2 under 10 years old, 10 teenagers, and 20s. There are 30 people in their 30s, 47 people in their 30s, 60 people in their 40s, 24 people in their 50s, and 8 people in their 60s, and many younger generations who are said to have relatively mild symptoms when infected also receive medical examinations. It means that it is.

The most common symptom complained by patients is malaise in 95.6%, followed by depression in 84.7% and poor thinking in 83.5%.

In addition, 70.1% complained of suffocation, 48.8% had hair loss, 32.8% had olfactory dysfunction without smell, and 21.9% had dysosmia without taste.

A man in his twenties who visited the clinic had relatively mild symptoms when he was infected with the new coronavirus in July due to fever and coughing, but even after recovering for nearly four months, his whole body became sluggish. It means that symptoms such as suffocation and olfactory dysfunction continue.

The man was instructed to take care of his diet and nutrition to improve his olfactory dysfunction by complaining to the director in detail.

Dr. Hirahata said, "Even if the symptoms of the new corona itself are mild, some people have long-lasting sequelae. It is easy to feel anxious about when the sequelae will heal. Especially, olfactory dysfunction reduces the quality of life such as losing the enjoyment of eating. It's easy to get depressed mentally. Anyway, it's important for medical personnel to listen carefully and proceed with treatment while being close to the patient. "

Sequelae in 27% after 4 months

According to a follow-up study conducted by the National Center for Global Health and Medicine on people who recovered after being infected with the new coronavirus, about 27% of the 63 people who were able to hear about 4 months after the onset of the disease, 17 people. It means that there were aftereffects.

Some people had multiple symptoms, but the specific symptoms were

▽ shortness of breath in about 11% in 7 people,

▽ malaise and dysgeusia in 6 people each in about 10%,

▽ cough. Was about 6% for 4 people,

and about 2% for 1 person with dysgeusia.

In addition, of the 58 additional surveys, 9 males and 5 females, which is almost a quarter, had alopecia about two months after the onset.

How far does the olfactory disorder work?

The exact cause of the olfactory dysfunction caused by infection with the new coronavirus is still unknown.

The olfactory dysfunction caused by infection with the new coronavirus has been reported to be 40% to 80% of infected people in overseas studies, although it varies depending on the survey, and it is reported in women rather than men. Many, more in Europe and America than in Asia.

In addition, it is said that 60% to 80% of people who have symptoms are cured in about 2 weeks, while 10% to 20% of people who have symptoms last for more than a month.

On the other hand, in Japan, surveys by the National Center for Global Health and Medicine have reported symptoms in 15.1% of infected people, but the details are still unknown.

Also, the cause is unknown.

According to Rumi Ueba, a specially appointed lecturer at the University of Tokyo Hospital, who is one of the members of the research group and is familiar with olfactory problems, olfactory disorders can occur not only with the new coronavirus but also with normal colds. That is.

The mechanism is that inflammation of the mucous membrane of the nose may be the cause, inflammation may occur in nerves that sense odors, and inflammation may occur in a part of the brain that processes odor information called the olfactory bulb. is.

It is believed that this mechanism also exists in olfactory disorders caused by the new coronavirus.

According to a study by Dr. Ueba and his colleagues, the presence of a protein called "ACE2" that serves as a foothold for infection with the new coronavirus in the mucous membrane of the human nose, and the virus entering cells through the mucous membrane of the nose Is confirmed.

"Smell is one of the five human senses, and if it is lacking, QOL = an important problem that impairs quality of life. In the future, the mechanism by which the new corona virus will infect and cause symptoms," said Ueba. I would like to study in more detail and find treatment targets. "