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[KISTI과학향기]Monkeypox with an unfamiliar name, is it okay this summer?

COVID-19 and other zoonotic diseases are prevalent. It is an unfamiliar disease called monkeypox. The disease was first reported in the Democratic Republic of Congo in Central Africa in the 1970s and settled as an endemic disease in Central and West African countries.

After the first confirmed case was reported in the UK in May, there are now more than 10,000 confirmed cases of monkey pox worldwide in 65 countries (US Center for Disease Control and Prevention, as of July 13). Considering the number of people traveling back and forth between land and sky roads during the holiday season, the number of unconfirmed cases could be much higher. Korea is also managing the quarantine system more strictly as a Korean national who entered from Germany was confirmed as the first confirmed case. What is monkeypox and how does it spread? Let’s take a look at the symptoms of infection and the measures taken after infection.

◇Monkeypox, a zoonotic infectious disease that affects both monkeys and humans

Although the name of monkey pox is unfamiliar, it is likely that you have heard of the disease called chickenpox at least once. If you are infected with the varicella-zoster virus, you may have a low fever, itching all over your body, and blistering, which usually subsides naturally over time. Meanwhile, cowpox and smallpox, which have similar names to chickenpox, cause similar symptoms in cattle and humans and leave traces on the skin. All symptoms seem to originate from the same causative organism, but the latter two are caused by a species called smallpox virus.

As you can guess from these circumstances, ‘monkey pox’ appeared in monkeys with symptoms similar to chickenpox. In 1958, researchers in Copenhagen first observed symptoms in laboratory monkeys. Twelve years later, a child infected in the Democratic Republic of Congo was confirmed, and it became clear that monkey pox was a zoonotic disease that infects both animals and humans.

Monkeypox is a zoonotic disease that affects not only monkeys but also humans.  (Source: pixabay)

Human-to-human infection mainly occurs through contact with the blood of an infected person, body fluids flowing from blisters, or mucous membranes. It can be spread through micro-aerosols containing the virus, but unlike the COVID-19 virus, droplet infection is not common. This is why there is no need to worry about whether the spread of monkey pox will spread to a global situation as much as the COVID-19 pandemic, while being on the alert for a new infectious disease.

◇Coronavirus and other mutation patterns

The virus that causes monkeypox belongs to the same genus Orthopoxvirus as the smallpox virus. The infected person has a high fever and pain all over the body such as headache and muscle pain. Blisters develop all over the body with a lag of one to four days after the fever rises, and unlike chickenpox, which mainly spreads to the body, it is characteristic that it progresses to the limbs. Swelling of lymph nodes, such as the armpits, is also different from chickenpox.

Monkey smallpox is characterized by blistering after a fever.  The rash progresses in the order of blisters, pus and scabs.  (Source: CDC, USA)

Monkey smallpox has different symptoms depending on the mutant species. According to the World Health Organization (WHO), among the monkey pox viruses, the West African type has mild symptoms, and the fatality rate (the ratio of deaths among confirmed cases) is only about 1%. Monkeypox, which is currently spreading, is believed to be caused by the West African type, which has a low fatality rate.

Recently, after the delta mutation and omicron mutation, the Corona 19 virus has also appeared BA4 and BA5, which are sub mutations of omicron, and countries are raising their quarantine boundaries again. If so, wouldn’t the monkeypox virus also unwittingly cause damage due to the unexpected emergence of mutants? It is a question worth thinking about. However, first of all, it is good to remember that monkeypox virus is a DNA virus with a stable structure, unlike coronavirus. Unlike RNA viruses, which change their genetic material quickly through interaction with the host, DNA viruses are less likely to cause immediate mutation because they are already well-organized.

The appearance of monkey pox virus particles (blue) observed with an electron microscope.  (Source: NIAID)

However, the spread of the epidemic outside of Africa appears to be related to multiple strains of the DNA virus over many years. A team led by Professor Andrew Lambout of the University of Edinburgh, UK, who analyzed the virus of a monkey pox confirmed in 2022, said that the genetic analysis results were very similar to the virus of small-scale cases of monkey pox that occurred in Singapore, Israel and the United Kingdom in 2017. The researchers also noted that the 2022 virus differed by 47 bases from the 2017 virus. This can be interpreted as the result of acquiring a new mutation in the interaction with the human immune system in the 2017 virus, which infected humans at a higher level than normal mutation frequency.

Since monkeypox has been an endemic disease in Africa for a long time, countermeasures are also in place. If symptoms are suspected, PCR test can confirm the presence of infection, and antiviral drugs can be prescribed to prevent severe progression. The WHO has also announced that the previously developed smallpox vaccine is effective in preventing about 85% of this monkey pox. The risk of this summer’s monkeypox virus causing immediate chaos like the coronavirus seems low. However, it is necessary to put the two trends side by side in that frequent collisions between humans and other species are accelerating the change of species.

Written by Miseon Maeng, Science Columnist