In recent weeks, the outbreak of disease can be said to be one after another. The new crown epidemic continues to spread, the acute hepatitis of unknown cause is still developing, and the monkeypox epidemic has reappeared in Europe and the United States. .
From May 13 to May 21, 92 confirmed and 28 suspected cases have been reported in 12 countries around the world where monkeypox virus is not endemic, according to WHO data. According to the British Broadcasting Corporation (BBC), Israel, Switzerland and Austria have also reported confirmed cases of monkeypox in the past two days, and the number of countries reporting confirmed cases in this round has increased to 15.
(Monkeypox cases reported to WHO in non-endemic countries from 13 to 21 May 2022 at 13:00 / Source: WHO)
Monkeypox is a rare viral zoonotic disease that occurs mainly in remote areas of Central and West Africa near tropical rain forests. Europe and the United States and other countries, and most of the patients have no history of travel to Africa? How can this disease be prevented? Could monkeypox virus cause a new pandemic?
“Too long to read” version:
1. Monkeypox virus and smallpox virus belong to the genus Orthopoxvirus of the Poxviridae family. The symptoms of monkeypox patients are similar to those observed in smallpox patients in the past, but the clinical severity is less severe. With the complete eradication of smallpox in 1980, monkeypox became the most serious orthopox virus.
2. In general, monkeypox does not spread easily from person to person. In past cases, monkeypox has mainly been transmitted from animals to humans, with humans contracting the disease through bites, direct contact, or consumption of improperly handled meat from infected animals. In this outbreak, there has been community spread of monkeypox.
3. People with monkeypox are contagious when they develop symptoms, and close physical contact with a symptomatic person is the highest risk of human-to-human transmission of infection.
4. Monkeypox is a self-limiting disease. Symptoms usually last 2-4 weeks. Most people recover or are cured. of people at risk of more severe monkeypox symptoms and death.
5. Although monkeypox outbreaks have been detected in 12 non-monkeypox endemic countries and territories, WHO considers the possibility of a large monkeypox outbreak to be low.
Monkeypox virus is a ‘close relative’ of variola virus
You may be at a loss when it comes to monkeypox, but you know it when it comes to smallpox.
Smallpox is one of the oldest and deadliest infectious diseases, once known as “Death’s faithful accomplice.” In the 18th century, more than 150 million people in Europe were killed by smallpox; in the 20th century, smallpox caused the death of 300 million to 500 million people. According to historians, smallpox has caused more than 10% of global deaths for thousands of years.
Smallpox is mainly transmitted through inhalation of droplets or direct contact. After infection with smallpox, a large area of fluid-filled blisters will appear on the human body from the inside to the outside. 30% of smallpox patients will be infected with smallpox. This terrifying disease afflicts death, and even those who survive will leave permanent sunken scars on their faces, commonly known as pockmarks.
Fortunately, with the invention and popularization of vaccinia vaccination, by 1980, the 33rd General Assembly of the World Health Organization officially declared that human beings had completely eliminated smallpox, and this was the only human being so far infected with smallpox. Completely eradicated infectious diseases.
Since monkeypox virus and variola virus belong to the genus Orthopoxvirus of the Poxviridae family, the symptoms of monkeypox patients are similar to those observed in smallpox patients in the past, but the clinical severity is less severe. With the eradication of smallpox in 1980, monkeypox became the most serious orthopox virus.
(Rash on the hands of monkeypox patients / Source: WHO)
Although known as the monkeypox virus, it is not limited to primates. Rodents can also transmit monkeypox virus.
The earliest human monkeypox was identified in 1970 in a 9-year-old boy in the Democratic Republic of the Congo (formerly Zaire), and most cases have been reported since then in the Congo Basin and West Africa. In tropical rain forests, monkeypox cases were confirmed in the United States until the spring of 2003, the first reported cases of monkeypox outside the African continent, and most of the patients had close contact with imported pets infected with African rodents.
The monkeypox virus has two distinct branches, the Congo Basin (also known as the Central African branch) and the West African branch. Monkeypox, which is caused by the Congo Basin clade virus, has a reported mortality rate of up to 10.6%, while the West African clade virus, which usually causes less severe disease, has a case fatality rate of 3.6%.
Fortunately, while this year’s monkeypox outbreak is the largest to date outside of endemic areas, it has been confirmed that these infections are all West African branches and are currently There were no deaths.
Human-to-human transmission of monkeypox virus has occurred
In general, monkeypox is not easy to develop between people andspread between people. In past cases, monkeypox has mainly been transmitted from animals to humans, with humans contracting the disease through bites, direct contact, or consumption of improperly handled meat from infected animals.
The monkeypox outbreak has attracted attention because of the widespread human-to-human transmission of the monkeypox virus. Eight of the original nine patients in the UK had no history of travel to Africa, suggesting community transmission. WHO speculates that this may be due to a decline in immunity to orthopoxviruses after the cessation of smallpox vaccination.
(Photo source: Figure Worm Creative)
People with monkeypox are contagious when they develop symptoms, mainly due to close contact with infected respiratory secretions (prolonged face-to-face contact), skin lesions (rashes, from Skin damage, fluid, pus, or blood, scabs are especially contagious) or items such as clothing, bedding, towels, and utensils that have been contaminated with the virus.
Canker sores or lesions can also be contagious, meaning the virus can be spread through saliva, so people who have been in close contact with an infectious person, including health workers, family members and Sexual partners are at greater risk of infection.
In addition, monkeypox virus can be transmitted from a pregnant person through the placenta to the fetus, or from an infected parent to a child through skin-to-skin contact during or after birth.
It is not known whether monkeypox can be transmitted by asymptomatic people, or whether monkeypox can be specifically sexually transmitted, in people with symptoms Close physical contact is the highest risk of human-to-human transmission.
Be vigilant with these symptoms
The incubation period (the time interval between infection and onset of symptoms) for monkeypox is usually 6 to 13 days, but it can be 5 to 21 days.
Infection can be divided into two periods:
Invasion period (duration 0-5 days)
Characterized by fever, severe headache, swollen lymph nodes, back pain, muscle aches, and weakness.
Rash
The rash begins 1-3 days after a fever, usually starts on the face and spreads to other parts of the body, ranging from a few to several thousand lesions. The rash changes and goes through different stages, eventually forming a scab, which then falls off.
(image of a single rash lesion / source: UKHSA)
Monkeypox is a self-limiting disease. Symptoms usually last 2-4 weeks. Most people recover or are cured. And people with underlying immune deficiencies may face more severe monkeypox symptoms and risk of death.
If you have recently traveled to affected areas in Africa (Benin, Cameroon, Central African Republic, Democratic Republic of Congo, Gabon, Côte d’Ivoire, Liberia, Nigeria, Republic of Congo, Sierra Leone and South Sudan) , or have had close contact with monkeypox patients/infected animals, and the above suspected symptoms appear, please go to the hospital’s dermatology department or infectious disease department for treatment in time.
Will there be a massive outbreak of monkeypox?
Although monkeypox outbreaks have been detected in 15 non-monkeypox-endemic countries and territories, WHO considers the likelihood of a large monkeypox outbreak to be low.
On the one hand, the infectivity of monkeypox virus is relatively low. According to the previous transmission pattern, compared with respiratory viruses such as new crown and influenza, monkeypox virus requires close contact between people before it can spread. , R0 (the average number of people contracting the disease from an infected person) is consistently less than 1.
Monkeypox virus, on the other hand, is a large (200 to 400 nm) DNA virus whose structure and replication, mutational capacity are easier to monitor, and what we know about monkeypox Decades-based research is well-prepared to deal with monkeypox outbreaks.
(Source: Reference [7])
However, it is important to be vigilant that this monkeypox outbreak is inconsistent with previous transmission patterns. Monkeypox has been found in many non-monkeypox-endemic countries. The cases are all “atypical” cases.
Is there a new mutation in the monkeypox virus, a “super-spreader”, or increased mobility across borders? It is still unknown.
There is currently no widely available vaccine against monkeypox, but historical research suggestsSmallpox vaccine is 85% protective against monkeypox, but since the eradication of smallpox in 1980, widespread vaccination against smallpox has been stopped in countries around the world.
For the treatment of monkeypox, there is currently no specific medicine. The clinical treatment is mainly symptomatic and supportive. In 2022, the European Medical Association (EMA) developed an anti-smallpox called tecovirimat. Viral drugs, which can be used to treat monkeypox, but are not yet widely available.
In terms of prevention, everyone should go to monkeypox endemic areas with caution and avoid contact with possible sick animals (such as monkeys, woodchucks, squirrels, etc. from the epidemic area) or monkeypox patients. Do not eat or handle game. Once suspected symptoms are found, you need to seek medical attention immediately for isolation.
Editor: Dr. Chunyu
References:
[1]WHO, https:https://www.who.int/emergencies/disease-outbreak-news/item/2022-DON385
[2] Lu Yaru, Wang Lei, Chang Xiaowei. History of the demise of the cold noodle killer “smallpox” [J]. Chinese Medical Humanities, 2022, 8(04): 66-68.
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[3]UN News, https://news.un.org/en/story/2022/05/1103502
[4]UKHSA, https:https://www.gov.uk/guidance/monkeypox
[5]WHO, https:https://www.who.int/news-room/fact-sheets/detail/monkeypox
[6] Gong Zhenyu, Gong Xunliang. Investigation on the outbreak of monkeypox in Nigeria from 2017 to 2018: responding with the concept of one health of humans and animals [J]. Disease Surveillance, 2020, 35(02):184.
[7]Di Giulio, et al., (2004). Human monkeypox: an emerging zoonosis. The Lancet Infectious Diseases, https:https://doi.org/10.1016/S1473- 3099(03)00856-9