1. What is monkeypox?
Also called monkeypox (simian orthopoxvirus), this disease was first detected in the 1950s, when two outbreaks occurred in colonies of monkeys used for research purposes. The first human case was reported in 1970 in the Democratic Republic of Congo (DRC).
Monkeypox is endemic to West Africa and is generally rare elsewhere in the world.
This disease, also called
smallpox, is often considered a mild form of smallpox. Recall that the World Health Organization (WHO) declared smallpox eradicated from the world in 1980.
2. What are the symptoms?
Reported symptoms consist of skin lesions on the mouth and genitals similar to those caused by chickenpox. These symptoms may be preceded or accompanied by fever, night sweats, headache, swollen glands, and joint or muscle pain.
The incubation period varies from 5 to 21 days. An infected person can be contagious five days before the first symptoms and continue to be so throughout the period when they have skin lesions.
Most patients are not hospitalized and usually the symptoms eventually resolve without treatment.
Very rare cases of serious complications may occur, however. For severe infections, there are some experimental antiviral treatments, such as tecovirimat, cidofovir, or brincidofovir.
The mortality rate for this (West African) strain of the disease is 1%. The mortality rate is somewhat higher in children and in immunocompromised people.
3. How many cases are there?
The first case of monkeypox outside of Africa was detected in the UK on May 6, according to theWHO. The infected person was returning from a trip to Nigeria.
On 23 May, some 200 cases were recorded outside Africa; on May 30, more than 250 cases.
According to a tally by researchers from the Global.health group (New window), as of June 2, 2022, there were approximately 775 confirmed cases in nearly 30 countries and approximately one hundred suspected cases. No deaths have been reported.
The countries with the most confirmed cases are: England (199), Spain (156) and Portugal (138).
Canada has around sixty cases, the vast majority in Quebec. In the province, the number of confirmed cases has increased from 25 to more than double in less than a week.
For the moment, we speak of a probable case when a person has symptoms of the virus and has had contact with a confirmed or probable case or has traveled to an area where a confirmed case had been detected. . People with no epidemiological link but showing the signs and symptoms associated with the disease are classified as suspected cases.
In Africa, 7 out of 54 African countries have reported the presence of the disease and there have been about three times more cases of monkeypox than usual. According to the Africa Centers for Disease Control and Prevention, there have been more than 1,400 suspected cases and 63 deaths in Cameroon, Central African Republic, Congo and Nigeria. Less than 50 cases have been confirmed, since testing capacities are limited in these countries.
Genetic sequencing did not show a direct link to the outbreak outside of Africa, according to health officials. The current outbreak therefore suggests that the virus has been spreading globally undetected for some time.
4. How does the virus spread?
The disease is usually transmitted from infected animals to humans, but it can also be spread by humans. It can be transmitted during close physical contact with an infected person, their clothes or their sheets.
However, some questions remain unanswered. For example, it is not known whether infected but asymptomatic people can spread the disease or whether the disease could be transmitted through the air, as is the case with measles or COVID-19. Airborne transmission is believed to be less common, but not impossible.
Several of the cases involve men who have had sex with other men, but theWHOwould like to remind you that monkeypox is not considered to be a sexually transmitted disease. The disease is believed to be transmitted through close contact and not through sexual activity itself.
5. Can monkeypox be prevented?
The smallpox vaccine is also 85% effective against monkeypox and the immunity conferred by vaccination appears to last for over 25 years.
However, routine immunization programs ended in Canada and around the world in the early 1970s.
At this time, large-scale vaccination campaigns are not recommended. Several countries, including Canada and the United Kingdom, vaccinate certain high-risk people, including those who have had close contact with people suspected of infection.
6. Why so many cases right now?
It is the first time that theWHOobserves as many cases in as many countries at the same time, elsewhere than in Africa.
In 2003, an epidemic of monkeypox hit the United States. Some 70 cases had been identified; none had led to a death.
Many scientists, however, are not surprised to see this explosion of cases around the world.
The number of monkeypox cases in Africa has been increasing for several years (New window).
From 2005 to 2007, there were less than 800 cases in the DRC. More than 2800 suspected cases were reported in 2018, then 3800 in 2019.
In 2020, nearly 6,300 cases were recorded, including 229 deaths. Cases were also increasing in the neighboring countries of Sudan and the Republic of Congo. In Nigeria, more than 500 cases have been recorded since 2017.
Researchers had also warned in 2010 (New window) that, because a large proportion of the population has never received the smallpox vaccine, the simian strain could spread beyond the Democratic Republic of the Congo.
Moreover, the majority of cases in the Republic of Congo in recent years have been young people who have never been vaccinated against smallpox.
In addition, according to these same researchers, animal migrations caused by climate change and deforestation fuel interactions between humans and animals, which facilitates the spread of viruses such as monkeypox to humans.
The high number of cases in Africa, combined with more travel since the lifting of restrictions related to the COVID-19 pandemic, may have created the ideal conditions for its rapid spread.
According to’WHO, there is no concrete evidence yet that the virus has mutated. It should be noted that these orthopoxviroses tend to be quite stable.