Countermeasures against “Infectious Diseases” Indispensable in the Era of Globalization
With the easing of restrictions on entry into Japan, the acceptance of foreign tourists has begun, and the day is near when Japanese will resume overseas travel. The recent spread of infectious diseases caused by the new coronavirus has made the world acutely aware of the dangers of “infectious diseases” in a society where the movement of people has become globalized. Before the ban on overseas travel is lifted in earnest, we asked experts about infectious diseases to be aware of and the importance of vaccination.
Of particular concern is the “monkeypox” epidemic that is reported daily. Monkeypox is an infectious disease similar to smallpox and has been around for some time, but until now it had been confined to outbreaks in West and Central Africa. However, since the beginning of May this year, outbreaks of monkeypox have been confirmed one after another in Europe and the United States, and monkeypox patients with no travel history have also been found.
Monkeypox causes symptoms such as fever, headache, lymphadenopathy, and myalgia that last from 1
Monkeypox” is rapidly spreading in Europe and the United States. What about vaccines? Is anyone under 45 years of age required to take precautions?
Actually, there is a vaccine for monkeypox. Dr. Kana Yamamoto of the Institute for Medical Governance, an internist and expert on overseas affairs, says, “Past data suggest that the smallpox vaccine currently manufactured and stockpiled by the CDC (Centers for Disease Control and Prevention) is at least 85% effective in preventing monkeypox, due to bioterrorism concerns. Even after contact with the monkeypox virus, if the vaccine is given as soon as possible, it has no effect,” he says.
In Japan, those 46 years of age and older are the generation in which “smallpox” (vaccination against smallpox) was performed. Therefore, they are less susceptible to monkeypox, and some data indicate that 80% of them already have antibodies to the virus.
According to a domestic survey conducted in 2004, the generation after the cessation of smallpox (currently under the age of 45) had no antibodies at all against smallpox or its allies. On the other hand, 80% of the smallpox generation had antibodies at the time of the survey. In particular, when looking at average antibody titers by generation, those currently 73 years of age and older retained strong immunity. Children have also had monkeypox deaths overseas, and in any case, the younger generation appears to be at higher risk.”
When Japanese people resume full-scale overseas travel, they will inevitably travel to and from other countries more frequently. As seen in the new corona epidemic, it is extremely difficult to determine who has been in close contact with whom when monkeypox outbreaks occur in large cities. Dr. Yamamoto suggests, “It may be necessary to prepare for emergencies by establishing guidelines such as prioritizing those under the age of 45 years, with a standard of “within 4 days and within 14 days” in the event of a close contact.
The smallpox vaccine, which is also effective in preventing monkeypox, has been stockpiled by the Japanese government as a counterterrorism measure, but it is currently not available in Japan because its use in preventing monkeypox has not been approved by the pharmaceutical industry.
Japanese have been too careless about infectious diseases and vaccination.
The importance of vaccination (vaccine) was once again recognized by the new coronary epidemic. Until now, vaccines for influenza and tetanus have been known to some extent, but those for overseas travel have not been so well known. The Ministry of Health, Labor, and Welfare lists tetanus, hepatitis A, rabies, polio, and yellow fever as vaccines that should be received for overseas travel.
Even for short-term overseas travel, information on infectious diseases and vaccines that are prevalent in the destination country must be gathered at the planning stage of the trip. Such information can be obtained from the “FORTH” quarantine station of the Ministry of Health, Labor, and Welfare, as well as from the website of the U.S. Centers for Disease Control and Prevention (CDC) and other organizations.
Dr. Yamamoto says, “Many Japanese people seem to be resistant to vaccines, but considering the risk of infection in the destination country, they should get vaccinated,” and adds , “It is better to first check the epidemic situation in the destination country and know what risks there are. If there is a vaccine that requires vaccination, get it as soon as possible,” he advises. It is well known that vaccination against yellow fever is mandatory in Africa and South America, but even in Southeast Asia, where it is easy to travel from Japan, there are many wild dogs roaming the streets, and there are risks such as rabies and tetanus.
In addition, it generally takes several weeks after vaccination for immunity to develop. Some vaccines must be administered several times at intervals, and if you do not consider vaccination as soon as you decide to travel to Japan, you may not make it in time.
In addition, “It is also important to check your “records” to understand and manage what vaccines you have been vaccinated with in the past and when you were vaccinated,” he said. He says that vaccines inoculated when he was a child may be effective for the rest of his life in the destination country. If you are planning to travel abroad in the near future, it would be a good idea to check your past vaccination records right away.
In fact, this is such a scary infectious disease. Almost 100% of people die after contracting an infectious disease.
Information on infectious diseases and vaccinations for overseas travel is detailed in “FORTH,” the quarantine station of the Ministry of Health, Labor and Welfare.
For example, completion of inoculation is required at the time of entry into tropical regions of Africa and South America. Short-term tourists are also required to present a certificate of vaccination against yellow fever. Yellow fever is a viral infection transmitted by mosquitoes and is usually fatal in only a few percent of cases, but in the absence of immunity or in an epidemic, it can reach 60 percent or more. The vaccination is valid for life, starting 10 days after inoculation. A certificate of vaccination may also be required for airplane transfers. Although it is rare for a mosquito bite to cause serious illness in Japan, it can be deadly overseas, especially in Africa and South America, so one must be very careful.
In addition, rabies, measles, rubella, chickenpox, influenza, and tetanus are “recommended vaccinations for those who need them regardless of the destination,” according to FORTH. Rabies, for example, has an almost 100% chance of causing death if contracted. Although there have been no cases of rabies in Japan, it is possible to contract rabies from all animals overseas, and the vaccine requires a high number of doses: three pre-exposure doses and six post-exposure doses. It is not uncommon for cases to occur at zoos in the destination country, so it is important to be informed about this.
The body’s immunity is also lowered during the period when you cannot travel abroad due to the coronary disaster!
Infectious diseases that spread overseas are often related to the local sanitary environment. Japan boasts one of the highest levels of sanitation in the world, but this is not always the case overseas. Dr. Yamamoto said, “It has been a long time since I traveled overseas after the coronary disaster, and I keenly felt that my immunity and resistance had declined. Please take even greater care to take care of yourself there,” he advises.
For example, “traveler’s diarrhea ” is one of the illnesses diagnosed when diarrhea occurs three or more times per 24 hours during a trip or after returning home, along with some accompanying symptoms such as fever and vomiting. It can be caused by viruses or parasites in a poor sanitary environment, contaminated raw water or seafood, undercooked food, or diarrhea caused by anxiety, stress, fatigue, or differences in eating habits due to environmental changes caused by travel. Infectious diseases can also cause severe illness.
New coronas, monkeypox, and other infectious diseases, even if not prevalent in Japan, can be life-threatening overseas. Before resuming overseas travel, it is a good idea to research infectious diseases and vaccines in your destination country once again.
Kana Yamamoto was born in 1989. Born in Shiga Prefecture. Doctor. D. in medicine from Shiga University of Medical Science in 2015. 2022 Completed graduate studies at the University of Tokyo Graduate School of Medicine. Internist at Navitas Clinic (Tachikawa), part-time physician at Yoshinobu Clinic (Kagoshima), and researcher at the Institute of Medical Governance, a non-profit organization. He is the author of the book “Anemia Great Nation, Japan” (Kobunsha Shinsho).
Information and data in this article are current as of June 3, 2022.
Interview, text, and photos (unless otherwise noted)： Aki Shikama / Aki Shikama