origin, transmission… Four questions about this disease

Monkeypox, several cases of which have been detected in Europe and North America, is a rare disease originating in Africa which is generally cured spontaneously. Its transmission can also “be stopped in non-endemic countries”, said a senior official of the health organization on Monday. While several cases have been detected in recent days around the world, including one in France, here are some answers to questions shared by many French people.

What is this disease?

Close to smallpox, it is however to this day considered much less serious and less contagious. Monkey pox (“monkeypox” in English) or “simian orthopox virus” is a disease considered rare, known in humans since 1970, identified for the first time in the DRC (formerly Zaire). “The identification in May 2022 of clusters of monkeypox in several non-endemic countries [où la maladie ne circule pas, NDLR] without a direct link with travel to an endemic area is atypical”, according to the WHO.

Monkeypox is an infectious disease that is caused by a virus transmitted to humans from infected animals, most commonly rodents. But the virus was first discovered in 1958 in a group of macaques that were being studied for research purposes, hence its name, Inserm explains.

The incubation can generally range from 5 to 21 days and the symptoms resemble, in less serious, those of smallpox (fever, headaches, muscular pains…) during the first five days. Then appear rashes (on the face, the palms of the hands, the soles of the feet), lesions, pustules and finally scabs. Since 1970, human cases of monkeypox have been reported in about ten African countries. In the spring of 2003, cases were also confirmed in the United States, marking the first appearance of this disease outside the African continent.

How is it transmitted?

Infection in initial cases results from direct contact with blood, body fluids, or skin or mucous membrane lesions of infected animals. In the current state of knowledge, secondary transmission – i.e. human-to-human – requires close and prolonged contact between two people, and occurs mainly via saliva or pus from skin lesions formed during infection.

Several experts have pointed out that while this virus can be caught during sexual activity, it is not a sexually transmitted disease. This transmission could be due to intimate and close contact during sexual intercourse and not by the sexual intercourse itself. UNAIDS has warned of homophobic and racist slippages, sometimes seen in comments on monkeypox, which could “quickly undermine the fight against the epidemic”.

How serious?

Monkeypox, as hitherto known, usually heals spontaneously and symptoms last for two to three weeks. Severe cases occur more frequently in children and are related to the extent of exposure to the virus, the patient’s medical condition and the severity of complications.

The lethality rate of the disease varies from 1 to 10% depending on the variant (there are two), rates observed in endemic areas, in countries with a failing health system. But proper medical care greatly reduces the risk, and most people recover spontaneously. In countries where the disease has been identified recently, the cases observed are mostly mild and there are no deaths recorded.

Is there a treatment?

There are no specific treatments or vaccines against monkeypox, but we can stem the multiplication of cases, explains the WHO. It has been proven in the past that the anti-smallpox vaccination then had an efficiency evaluated at 85% for the prevention of monkeypox. 1st and 2nd generation vaccines have not been used for the general population since 1984, due to the eradication of smallpox.

A third-generation vaccine (non-replicating live vaccine, that is to say that does not replicate in the human body) has been authorized in Europe since July 2013 and is indicated against smallpox in adults. It also has marketing authorization in the United States for the prevention of smallpox and monkeypox.