Multi-country monkeypox outbreak: situation update

The current publication of Disease Outbreak News is an update to the previously published Disease Outbreak News of 29 May and also provides short summaries of guidance, including on vaccination

Outbreak at a glance

Since 13 May 2022, and as of 2 June 2022, 780 laboratory confirmed cases of monkeypox have been reported to or identified by WHO from 27 Member States across four WHO regions that are not endemic for monkeypox virus. Epidemiological investigations are ongoing. 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 confirmation of monkeypox in persons who have not travelled to an endemic area is atypical, and even one case of monkeypox in a non-endemic country is considered an outbreak. While most cases are not associated with travel from endemic areas, Member States are also reporting small numbers of cases in travelers from Nigeria, as has been observed before.

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.

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.

WHO continues to receive updates on the situation in endemic countries.

Description of the outbreak

As of 2 June 2022, 780 laboratory confirmed cases have been notified to WHO under the International Health Regulations (IHR) or identified by WHO from official public sources in 27 non-endemic countries in four WHO Regions. This represents an increase of 523 laboratory confirmed cases (+203%) since the Disease Outbreak News of 29 May, when a total of 257 cases were reported. As of 2 June 2022, there have been no deaths associated within the current monkeypox outbreak in non-endemic countries, however, cases and deaths continue to be reported from endemic countries (see Table 2).

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.

Figure 1 and Table 1 show the geographical distribution of monkeypox cases reported to or identified by WHO between 13 May to 2 June 2022 in non-endemic countries. The majority of cases (n=688; 88%), were reported from the WHO European Region (20 Countries). Confirmed cases have also been reported from the Region of the Americas (n=80; 10%), Eastern Mediterranean Region (n=9; 1%) and Western Pacific Region (n=3; <1%). The case count fluctuates as more information becomes available daily and data is verified by WHO in accordance with the provisions of the IHR