United Nations (Geneva): The World Health Organisation on Monday said that so far 780 laboratory-confirmed monkeypox cases have been reported to it from 27 non-endemic countries.
The data includes cases that have been reported or identified since May 13 and as of June 2 from 27 countries across four WHO regions.
WHO assesses the risk at the global level as moderate considering this is the first time that many monkeypox cases and clusters are reported concurrently in non-endemic and endemic countries in widely disparate WHO geographical areas.
Although epidemiological investigations are ongoing, the UN's health agency said that most reported cases so far have been presented through sexual health or other health services in primary or secondary health care facilities and have involved mainly, but not exclusively, men who have sex with men (MSM).
While the West African clade of the virus has been identified from samples of cases so far, most confirmed cases with travel history reported travel to countries in Europe and North America, rather than West or Central Africa where the monkeypox virus is endemic.
The Monkeypox endemic countries are Cameroon, the Central African Republic, the Democratic Republic of the Congo, Gabon, Ghana (identified in animals only), Cote d'Ivoire, Liberia, Nigeria, the Republic of the Congo, and Sierra Leone. Benin and South Sudan have documented importations in the past.
Countries currently reporting cases of the West African clade are Cameroon and Nigeria, the WHO said.
The sudden and unexpected appearance of monkeypox simultaneously in several non-endemic countries suggests that there might have been undetected transmission for some unknown duration of time followed by recent amplifier events.
As of June 2, there have been no deaths associated with the current monkeypox outbreak in non-endemic countries, however, cases and deaths continue to be reported from endemic countries.
While investigations are ongoing, preliminary data from polymerase chain reaction (PCR) assays indicate that the monkeypox virus strains detected in Europe and other non-endemic areas belong to the West African clade.
The majority of cases were reported from the WHO European Region (20 Countries). Confirmed cases have also been reported from the Region of the Americas, Eastern Mediterranean Region and Western Pacific Region.