"Monkeypox" has been reported one after another mainly in Europe and the United States.
More than 5,000 people have been confirmed infected worldwide.
Infected people have also been confirmed in South Korea, Singapore, and Taiwan.
There is a risk that it will enter Japan, and vaccines and therapeutic drugs are being prepared.
WHO = The World Health Organization has said that it is not a "public health emergency" at this time, but will it be an infectious disease that requires caution like the new Corona in the future?
How should we respond?
I have summarized what I have learned so far (as of July 4, 2022).
"Trends in the spread of infection will continue" WHO Secretary-General
"The trend of the spread of monkeypox is likely to continue. I'm worried that the virus will settle and move to children, immunocompromised people, pregnant women, etc." WHO Secretary-General Tedros said at a meeting on June 29. I showed a feeling.
The number of people confirmed to be infected with monkeypox continues to increase.
According to the summary of the CDC = Centers for Disease Control and Prevention in the United States, as of July 1, 5,783 infected people have been confirmed in 52 countries and regions where monkeypox has not been established.
The increase in infected people is particularly remarkable in Europe.
By 1 day, more than 4,500 cases have been confirmed in 31 countries and regions in WHO's European region.
Of these, about 10% were hospitalized for treatment or isolation, one was treated in the intensive care unit, and no one died.
In addition to a statement released on the 1st, WHO is rapidly expanding, with approximately 90% of the world's infected cases reported from the European region and the number of reported cases tripled in approximately two weeks. Since female and child cases are also being reported, we called on each country to strengthen measures.
Be wary of seeing off “public health emergencies”
Prior to this, on June 23, WHO convened an urgent committee of national experts to discuss whether the spread of the infection would be an "international public health emergency." , I have decided that it is not an emergency at this time.
Experts said that the urgent committee discussed "more understanding of how the infection spreads," "difficulty in tracking people who come into contact with infected people," and "evaluation of vaccination strategies." That is.
On top of that, the urgent committee continued to closely monitor the situation and collect more information as it is unusual for the infection to spread so much in countries and regions where "monkeypox" has not been established and may continue to spread. He advised that we should soon determine if we need to revisit our conclusions.
WHO states that the overall risk of monkeypox is "moderate" globally, but raised it to "high" in the European region in a June 27 report.
"Monkeypox" with a characteristic rash In this infection
Monkeypox is a disease caused by infection with the "monkeypox virus," which is similar to the smallpox virus.
According to the National Institute of Infectious Diseases and WHO, the incubation period of monkeypox virus is usually 7 to 14 days, and after the incubation period, fever, headache, swollen lymph nodes, myalgia, etc. continue for 1 to 5 days. After that, a rash appears.
The rash typically begins on the face and spreads throughout the body.
It gradually swells and becomes blisters (blisters), scabs appear, and it heals within 2 to 4 weeks after the onset.
In many cases, it is mild and recovers spontaneously, but it may cause complications such as pneumonia and sepsis, and it is said that the younger the age, the more severe it may be.
However, the appearance of monkeypox that is spreading this time is different.
According to the materials issued by WHO after the emergency committee, the case where the rash is limited to a part such as the genitals and the area around the anus, and the case where the rash appears before fever etc. are characteristic of this spread of infection. That is.
There are almost no cases of hospitalization.
The "basic reproduction number", which indicates how many people are infected from one patient when all people are not immune, is 0.8, which is not so much compared to the new coronavirus, which is said to exceed 2. It is not very infectious.
According to the analysis in the Netherlands, the incubation period from infection to onset is 8.5 days on average, and according to the analysis in the United Kingdom, the onset interval is one infected person and the next infected person. It is estimated to be 9.8 days on average.
In addition, although 10 cases of health care worker infections have been reported so far, at least 9 cases were not work-related infections.
What is the infection route?
Monkeypox is generally transmitted by being bitten by infected animals such as mice and squirrels, or by touching blood, body fluids, or rashes.
It has also been pointed out that anyone can be infected by contact with the infected person's rash, body fluids, scabs, bedding or clothing used by the patient, or by being exposed to flying shots at a short distance.
WHO states that "close contact can infect anyone," and that many of the patients identified in previous studies had sexual contact between men.
Some experts suggest that the infection may have spread through large-scale events held throughout Europe.
On the other hand, patients who are considered to be so-called "community-acquired infections" and female patients whose infection route cannot be identified have been confirmed, and it is necessary to be cautious without considering it as a disease of a specific group of people.
And anyone who has had close contact with a person with monkeypox is at risk of getting infected, saying, "No one should be treated unfairly because of illness."
WHO encourages people with symptoms to be tested and to avoid close contact with others and seek medical attention.
ECDC = Centers for Disease Control and Prevention in Europe said that "the possibility is very low", and if human-to-human transmission continues, it will eventually be transmitted from human to animal, and it is possible that it will spread among animals and become established in Europe. I'm pointing out.
Origin of the "monkeypox" name and previous infections
Monkeypox was named after its first discovery in 1958 in cynomolgus monkeys at a facility where primates from around the world were gathered to produce the polio vaccine.
However, the natural host carrying this virus under normal conditions is thought to be a reservoir, not a monkey.
WHO is currently considering changing the name "monkeypox".
Human transmission was first identified in the current Democratic Republic of the Congo in 1970, and is still frequent in Africa.
It is said that different strains of virus are spreading in West Africa such as Nigeria and Central Africa such as the Democratic Republic of the Congo.
The monkeypox virus found in Central Africa is more likely to become more severe, with case fatality rates ranging from a few percent to 10%.
On the other hand, it is said that the virus of West African strain, which is relatively low in pathogenicity, is currently spreading in various countries such as Europe.
In 2003, the virus was introduced into the United States through small animals imported as pets from Africa, and 71 people were infected with monkeypox.
In recent years, all cases confirmed outside Africa have a pattern of onset of returnees from Nigeria, and several cases have been confirmed annually.
No one has died outside Africa.
What are vaccines and remedies?
The once vaccinated smallpox vaccine is highly effective against monkeypox, and according to WHO, it is as effective as 85% to prevent monkeypox infection.
However, smallpox was eradicated from the earth in 1980 as a result of active vaccination, and the last vaccination in Japan was in 1976, when I was a child at that time. People in their late 40s and older are vaccinated and may be immune to monkeypox.
In Japan, there is a vaccine for smallpox, which is said to be highly effective and has few side reactions, and is stockpiled nationally as part of counterterrorism measures.
However, it has not been approved as a vaccine for monkeypox, and the Ministry of Health, Labor and Welfare has conducted a "specific clinical study" to investigate the safety and efficacy of the drug, targeting the families of patients with close contact at the National Center for Global Health and Medical Sciences in Tokyo. We have prepared a system for inoculation.
At the subcommittee made up of infectious disease specialists of the Ministry of Health, Labor and Welfare held on June 29, the target of infectious disease was
▽ medical personnel such as doctors and nurses in charge of hospitalization of
patients ▽ staff of health centers that transport patients
▽
It is reported that it is also being considered to extend it
to the person in charge of the local health research institute that conducts the inspection .
In the United States, Canada, and the United Kingdom, smallpox vaccination has begun as a countermeasure against monkeypox infection.
Initially, people who had direct contact with health care workers and patients were targeted for vaccination, but in the United Kingdom and the United States, the target has been expanded to include people who have had sexual contact between men and an unspecified number of people. People who have had sexual activity are also targeted.
However, due to the low supply of vaccines, there are situations where vaccines are in short supply.
In New York, where expanded vaccination began on June 23, 1000 vaccine reservations were filled up that day.
The US government announced on June 28 that it will supply approximately 300,000 doses of vaccine to medical institutions across the United States within a few weeks.
The EU is also accelerating the movement to secure vaccines, including the announcement that it will purchase 110,000 new vaccines.
Regarding therapeutic agents, administration in clinical studies is being considered in Japan.
The drug used is a drug called "Tekobirimat" developed by an American pharmaceutical company as a treatment for smallpox, and is approved in Europe as an antiviral drug for monkeypox.
In addition to being able to be administered to patients as a "specific clinical study" at the National Center for Global Health and Medical Research, it is being considered for introduction to medical institutions in metropolitan areas other than the Kanto region.
However, according to WHO, etc., there is a limit to the amount of medicines that can be distributed, and in many cases, symptomatic treatment is used.
No report in Japan
According to the Ministry of Health, Labor and Welfare, no monkeypox infections have been reported in Japan since 2003, when the data was started.
Monkeypox is designated as "Class 4 infectious disease", which is the same as rabies under the Infectious Diseases Control Law, and the doctor who diagnosed it must report the outbreak to the health center.
Currently, one monkeypox has been confirmed not only in Europe and the United States, but also in South Korea, Singapore, and Taiwan, which are close to Japan.
The Ministry of Health, Labor and Welfare sends administrative communications to prefectures, etc., reports any suspicious patients, and requests that they be hospitalized at designated medical institutions.
Since the monkeypox virus can be examined by PCR from the liquid contained in the blisters in the same way as the new coronavirus, the National Institute of Infectious Diseases as well as the local health laboratories of each local government have established an inspection system. It is being advanced.
“Not a level that generally requires attention”
We spoke with Professor Shigeru Morikawa of Okayama University of Science, a former director of the Department of Veterinary Sciences at the National Institute of Infectious Diseases, who has been studying "monkeypox" about the latest infection status and countermeasures.
Q. How do you evaluate the current status of infection?
A. The number of infected people in the world exceeds 5,000, but most of them are men, and the current situation is that the infection continues to spread due to close contact between men.
It means that it is not the situation that infected people are appearing one after another without knowing it at all.
Q. WHO has forgotten the declaration of "Public Health Emergency of International Concern"
A. The number of patients is increasing and the number of countries where it is occurring is increasing, but for now it is appropriate. I think that it was decided that it was not an emergency because the spread of infection could be controlled and converged if it was dealt with.
For example, if a virus mutates and spreads from person to person without your knowledge, it would be applicable, but I think it is appropriate to judge that this will not be the case at this point.
Q. However, the risk is "high" in the European region.
A. The number of patients in the UK exceeds 1000, Germany is rapidly increasing to approach 1000, and Spain has more than 800. increase.
There is also a risk of infection for family members living with the patient and hospital staff, so it is thought that the alert level has been raised.
Q. How do you see the infectivity and pathogenicity of the virus?
A. It is thought that the number of infected people will decrease and converge if appropriate measures are taken against those who have spread the infection.
However, there is a risk of infecting other people before symptoms such as a rash appear, and I think that the infection is spreading before many people are aware of the symptoms.
It has been pointed out that the "poxvirus", which contains the monkeypox virus, may become more infectious and pathogenic as the virus adapts to the animal if infection continues.
The monkeypox virus this time is also transmitted from person to person, but if this continues for a long time, it may become a virus that flies like smallpox and infects normally, and there is a risk that the pathogenicity will become stronger. There may be.
Q. Regarding the status of virus gene analysis, etc.
A. It has been pointed out that the monkeypox virus this time has about 50 mutations compared to the virus detected in the United Kingdom in 2018.
It is believed that the monkeypox virus has a high mutation rate, but it is not known whether it is directly related to the spread of the infection.
Q. Is there a risk of influx into Japan?
A. It is highly likely that infected people will enter the country during the incubation period and the infection will be reported.
However, at the moment, it is not so easily infected except for close contact, so it is not at a level that requires attention by the general public.
In Japan, there is almost no risk of getting infected by being exposed to flying.
I don't think you need to be too scared.