2022 monkeypox outbreak

Article

August 14, 2022

The 2022 monkeypox outbreak appears on May 7, 2022 in the UK in an individual returning from Nigeria. As of May 25, 2022, more than 300 cases of monkeypox were confirmed or suspected in Europe, America and Australia, according to the count made daily by an international team of epidemiologists. The 3rd generation smallpox vaccine MVA-BN from the Danish Bavarian Nordic (in) (IMVANEX in Europe, JYNNEOS in the United States or IMVAMUNE in Canada) sees its indication extended to monkeypox.

Virus spread

At the beginning of May 2022, three cases are first reported in the United Kingdom - probably by an imported case from a traveler returning from Nigeria -,, then 23 suspected cases in Spain and Portugal. The US public health agency, the Centers for Disease Control and Prevention (CDC), says it is concerned about community transmission beyond the UK. Cases are then confirmed in Canada and the United States, in Argentina, as well as in Italy, the Netherlands, Belgium, France, Sweden, Norway, Denmark, Germany, Switzerland, Austria , Greece, Israel and Australia. According to the World Health Organization (WHO), most cases involve male homosexual relationships, with the risk of contagion being higher in people with multiple sexual partners, while remaining "very low" in the general population. On May 23, the WHO says the spread can be stopped in countries where the virus is not yet endemic. A first genomic analysis carried out on a confirmed case in Portugal identifies the West African strain as the source of the infection and the closest known viral genomes would be those of the cases exported from Nigeria in 2018-2019 to the United Kingdom , Israel and Singapore. Another virus genome, sequenced on a patient in the United States, matches that identified in Portugal. Since then, two variants from this West African strain have been identified in Europe. In humans, the virus had never been detected outside Africa before 2003. As of May 2022, the pattern of virus spread is still misunderstood and intrigues epidemiologists as it differs from past outbreaks outside of Africa. Almost all previous epidemics could be explained by the importation of the virus by flights from Africa, or by direct exposure to infected exotic animals (the most frequent case). On May 30, Nigeria announces the first death linked to the disease. In Europe, the first death linked to the disease took place in Spain on July 29. On the same day, Brazil declared a death earlier on its soil, the first death outside the African continent. On July 23, the World Health Organization declares the ongoing monkeypox outbreak a public health emergency of international concern.

Risk Factors

Since the end of the 20th century, epidemics of monkeypox have been more frequent and have occurred in 11 African countries (mainly in the Democratic Republic of the Congo). This increase could have two explanations: a decrease in the overall immunity of the population against smallpox (a disease whose virus is similar to that of monkeypox) since the end of vaccination programs against smallpox. A clue to this explanation is that in Africa child victims of monkeypox are usually among those who have not been vaccinated against smallpox; increasing land use changes are bringing more people into close proximity to animals carrying the virus.

Risk of wildlife infection

At the end of May 2022, the British group Human Animal Infections and Risk Surveillance (HAIRS) warns that the virus could attack