Measles infection is spreading in the country.
Measles can be transmitted through the air just by staying in the same room for a while, and when it develops, it can become severe and life-threatening, and experts are calling for caution, saying that it is a disease that should not be underestimated.
We have summarized the latest infection status, symptoms characteristics, and what to do if infection is suspected. (As of June 6)
Measles is spreading: 6 people in 10 prefectures so far
Highly infectious "measles".
A case that clearly demonstrates this was reported this year.
In April, a man in his 4s in Ibaraki Prefecture who returned from India was confirmed to be infected.
Later, a woman in her 30s and a man in his 30s in Tokyo who were on the same bullet train were confirmed to be infected.
In addition, two children who came into contact with either of the men and women have since been confirmed to be infected.
The National Institute of Infectious Diseases warns that "there is a possibility that there was contact with an unspecified number of people during the infectious period, and there is a concern that the spread of infection over a wide area in the future may occur."
According to data from the National Institute of Infectious Diseases and others, the number of infected people this year was 40 as of the 2st of last month.
The number of employees increased by 21 in one week until the 10st.
The six prefectures where infected people were reported are Ibaraki, Tokyo, Kanagawa, Niigata, Osaka, and Hyogo.
In 1, when the census began, the number of measles infections reached 2008,1 due to a large-scale epidemic in Japan.
However, in 1013, the number of cases was suppressed to 2015, and all of the cases were imported from overseas, so the Japan was recognized as being in a "state of exclusion" of measles by WHO = World Health Organization.
In 35, there were a series of reports of measles infections, and it was reported that 2019 people were infected in one year, but since the spread of the new coronavirus in 1, the level has been low due to the decrease in the movement of people to and from overseas, and it was 744 cases last year.
This year, it has already exceeded as of May.
Project Professor Tetsuo Nakayama of Kitasato University, who is familiar with measles,
said, "People returning from India have been infected up to the third infection, and we need to pay close attention to whether the infection spreads further or subsides."
"Almost certain infection just by being in the same room" Extremely infectivity
The reason why measles requires vigilance is that it is extremely contagious and can become seriously ill or cause death.
Measles is a viral infection that is transmitted by inhaling the virus in particles released by a patient coughing or sneezing.
In addition to airborne infection, it can also spread through droplets and contact, and is extremely infectious, and if you are not immune, you will almost certainly be infected just by being in the same room as an infected person.
If the people around you are not immune and no countermeasures are taken, the "basic reproduction number" that indicates how many people to spread the infection from one patient is "1 to 12", and it is said that it is much more infectious than the new coronavirus, which has been said to be about "18 to 2".
Last month, an infection was confirmed in a person who was riding in the same train on the Shinkansen, and in 2019, a part-time clerk was confirmed to be infected at a commercial facility in Osaka, and the infection spread to shoppers visiting the sales floor.
Dr. Kaoriko Taya, director
of the Kanagawa Prefectural Institute of Public Health, who has been working on measles control at the National Institute of Infectious Diseases, said, "It is a highly contagious disease that can become infected just by being together in the same place for a few minutes or for a short period of time."
What are the symptoms? There are also cases of severe illness and death
The main symptoms of measles infection include fever, cough, and rash.
According to Project Professor Nakayama, fever is characterized by going down in about two days and then rising again, rising to nearly 2 degrees Celsius, and fever lasting for about one week.
Also, since the rash does not appear until a few days after the symptoms begin to appear, it may be difficult to identify it as measles at first.
In addition, pneumonia and encephalitis are caused as complications of infection, and in some cases, they become severe.
In particular, encephalitis occurs in about 40 in 1,1000 people, and in some cases, death.
According to the CDC = Centers for Disease Control and Prevention in the United States, 1 to 1000 out of 1,3 children infected with measles will die from respiratory and nervous system complications.
"It's called a 'deadly disease.'"
Since there is no silver bullet for measles and treatment is based on symptoms, experts say it is important to prevent infection with vaccines and other means.
In 2007, the infection spread mainly to children aged 0 to 1 who had not been vaccinated in Japan, as well as teenagers and 1s who had received only one dose.
Experts also warn that even middle-aged and elderly people who have not been infected and have not been vaccinated or have only received one dose can be life-threatening if infected.
Project Professor Nakayama said, "The most serious complication of measles is encephalitis, and the initial symptom is that when you have a fever and a rash, you do not respond to calls for measles. I want people to recognize that there is no silver bullet and that this is a disease that should not be underestimated."
If you suspect that you are infected, you should contact a medical institution and see a doctor.
Women who are pregnant should be especially careful
Women who are pregnant should be especially careful.
If a pregnant woman is infected with measles, there is a high risk of complications, and the possibility of miscarriage or premature birth has been pointed out.
In addition, the vaccine to prevent infection is a "live vaccine" that weakens the virulence of the virus, and it is not appropriate to receive it if you are pregnant.
In order to prevent measles, it is important to get vaccinated in advance.
However, even if you get vaccinated without realizing that you are pregnant, the risk is considered low.
Even if you think you're cured... It can also develop encephalitis after a long incubation period
About five years after measles is cured, 5 in 10,1 people may develop a disease called subacute sclerosing panencephalitis (SSPE).
SSPE develops after a long incubation period due to infection with the measles virus that has been latent in the central nervous system.
Even though you were living well, you may suddenly be unable to perform daily activities, abnormal behavior may become noticeable, and you may die.
According to the National Institute of Infectious Diseases, it is common to become infected with the measles virus before the age of 2 and develop it around the age of 4 to 8 years after an incubation period of 6 to 10 years, but there are also cases of measles in adults.
Dr. Taya points out that "it is important to prevent measles infection by getting vaccinated."
【Link】Measles can leave you bedridden with subacute sclerosing panencephalitis (SSPE)
Beware of infection when traveling abroad
The National Institute of Infectious Diseases points out that the gradual increase in international travel, which has been restricted due to the effects of the new coronavirus, may also affect the spread of measles.
According to the WHO and CDC, measles infections are currently spreading in countries such as India and Indonesia.
Of these, the number of infected people has increased significantly in Indonesia since last year, and 1,3 suspected cases of measles have been reported in about three months from January.
Experts say that there may be cases of infection when traveling abroad and the onset of the disease after returning home, and cases in which tourists visiting Japan from abroad are infected.
In addition, if you are planning to travel abroad during this summer vacation, it is important to check your vaccination history.
If you think it's measles, contact us before you see a doctor.
The incubation period from infection with the measles virus to the onset of the disease is 10 to 12 days.
Measles spreads especially to the surrounding area when symptoms such as fever, cough, and runny nose occur, so if you suspect measles and visit a doctor, it is important to call the medical institution or public health center in advance and give instructions instead of visiting a medical institution without contact.
In addition, the Ministry of Health, Labour and Welfare has urged people to refrain from using public transportation if they have symptoms that may indicate infection.
Vaccination can almost certainly prevent it
Measles can almost certainly be prevented by vaccination.
In Japan, free routine measles vaccinations based on the Immunization Act began in October 1978.
After that, it was found that immunity could be weakened by only one vaccination at the age of one, and since June 10, the "MR vaccine" to prevent measles and rubella has been used, and it is performed twice, once at the age of one and one year before entering elementary school.
According to Project Professor Nakayama, two doses of the vaccine are more than 1% effective, and immunity lasts almost a lifetime.
Currently, a combination vaccine for measles and rubella is being administered.
According to the package insert of the vaccine, the side reactions after vaccination are listed as "1% or more" to "2006.6%" and the rash is "1% or more", although it varies depending on the manufacturer.
A survey of 1.2 million people from 2 to 95, when they were vaccinated against measles alone, found that 5% to 28% had a fever and 3% to 5% had a rash.
In addition, there were two people who developed encephalitis, but according to Project Professor Nakayama, it is unlikely to be related to vaccines, such as the detection of genes of a different type of virus from vaccines.
According to the Ministry of Health, Labour and Welfare and the National Institute of Infectious Diseases, the measles vaccination rate at the age of one has been continuously above the target of 1% since fiscal 2010, but has fallen to 95.2021% in fiscal 93.
The Ministry of Health, Labour and Welfare says that it seems that there were people who could not receive vaccination due to the pressure of medical institutions and public health centers due to the influence of the new corona, and refraining from visiting medical institutions.
For this reason, the Ministry of Health, Labour and Welfare is operating so that if you cannot be vaccinated during the regular vaccination period due to the influence of the new corona, you can treat it in the same way as regular vaccination even outside the period, and ask local governments to call for vaccination together with those who are eligible for regular vaccination.
Experts are concerned about the drop in vaccination coverage by a few points.
Dr. Taya, Director
of the Kanagawa Prefectural Institute of Public Health, said, "If a child fails to receive a vaccine at the age of one, he will not have the opportunity to receive the vaccine until before entering elementary school. If the infection spreads, there may be a shortage of vaccines, so I would like you to get vaccinated now."
I don't know if I was vaccinated ... In such a case, take an antibody test
It is generally thought that people in their 50s and older have never been vaccinated.
Since then, people in their 1s to 1990s born between April 4, 1 are considered to have received one dose as children, and those born on or after April 33, 40 are eligible for two vaccinations.
Some people are not vaccinated as children for some reason.
A reliable way to check vaccination history is to check with the Maternal and Child Health Handbook.
If you cannot check your Maternal and Child Health Handbook, you can also take an antibody test to find out.
Also, if you are infected with measles, such as a child, you may have antibodies.
You can find out if you tell your family clinic or local internal medicine that you want to check for measles antibodies.
It takes about a week to know the results, and the cost is several thousand yen, but it is certain.
Experts emphasize, "If you don't know your vaccination history, I want you to get tested right now."
In addition to measles antibodies, we also recommend that you examine rubella, mumps, and chickenpox antibodies.
And if the antibodies are not enough, we recommend that even adults get vaccinated.
The Ministry of Health, Labour and Welfare (MHLW) has recommended that people who have never had the opportunity to receive two doses of measles who have never had the opportunity to receive two doses of measles, especially those who are at high risk of contracting measles, such as medical personnel, child welfare facility staff, and school staff, who have a significant impact on others, and who plan to travel to endemic countries, We would like you to consult your primary care physician and consider getting vaccinated.
The National Institute of Infectious Diseases also believes that vaccination is the most effective way to prevent measles, and urges people who have a lot of contact with tourists, medical personnel, and people who plan to travel abroad to see if they are experiencing measles outbreaks to check their vaccination history.
Nakayama: "We don't know where and who can get measles, and since there is no cure and it can be life-threatening, it is quite important to prevent it with a vaccine. Considering that you can be infected with measles, the side effects of the vaccine are not severe, and I think the benefits are quite high when applied to measles. The number of measles cases is decreasing, and the fear of natural transmission is diminishing, but I want people to reaffirm the horror of measles."