Epidemiological Update: Monkeypox in non-endemic countries – 13 June 2022 – World

Given the simultaneous occurrence of monkeypox outbreaks in non-endemic countries within and outside the Region of the Americas, the Pan American Health Organization/World Health Organization (PAHO/WHO) shares with its Member States an update on the epidemiological situation and reinforcing guidance on surveillance, laboratory, clinical management, infection prevention and control, vaccination, mass gatherings, international travel, and risk communication.

Situation summary

From 13 May to 10 June 2022, the World Health Organization (WHO) was notified of 1,423 confirmed cases of monkeypox in 31 Member States that are not endemic for monkeypox (Table 1). So far, no deaths related to the ongoing outbreak have been reported in non-endemic countries. Most cases have been identified through sexual health clinics and primary care facilities, and have included primarily, but not exclusively men who have sex with men (MSM) community.

As of 10 June 2022, most confirmed cases in non-endemic countries were reported in the European Region with 87% (n=1,243, 23 countries), followed by the Region of the Americas with 11% (n=159, 5 countries), the Eastern Mediterranean Region with 1% (n=14, 2 countries) and the Western Pacific Region with <1% (n=7, 1 country) (Figure 1, Table 1).

In all samples in which sequencing was performed and the monkeypox virus (MPXV) was identified, the West African clade was particularly identified. Most confirmed cases with a history of travel reported travel to countries in Europe or North America, rather than West or Central Africa, where monkeypox is endemic. Confirmation of monkeypox in persons who have not traveled to an endemic area is unusual and the occurrence of a case in a non-endemic country is considered an outbreak.

This is the first recorded occurrence of simultaneous monkeypox outbreaks in non-endemic countries, suggesting that there may have been undetected transmission for an unknown period, followed by recent amplifying events.

To date, the clinical presentation of confirmed cases has been varied. Many cases in this outbreak do not present the classic clinical presentation of monkeypox. These atypical clinical findings, different from the classic presentation of monkeypox, are the presence of skin lesions in the genital or perineal/perianal area, without subsequent dissemination, in a small number, and which may precede the general symptoms (fever, malaise, mylagia, etc.), as well as proctitis. Frequently, adenopathies are found. Lesions around the mouth and on the oral mucosa, similar to the classic presentation of monkeypox, have also been described.

In this outbreak, some documented cases have presented pustules and lesions at different stages of development, which is atypical compared to the known clinical presentation of monkeypox.

Most patients have received home care; very few cases have required hospitalization due to complications or severe clinical manifestations, and some cases were hospitalized for monitoring and isolation purposes. Reasons for hospitalization included symptomatic pain management and treatment of secondary infections.

In addition to cases reported in non-endemic countries, the World Health Organization continues to receive updates on monkeypox outbreaks in endemic countries in the Region of Africa through established surveillance mechanisms (Integrated Disease Surveillance and Response). From January through 8 June 2022, a total of 1,536 suspected cases, including 72 deaths, were reported in eight endemic countries. During the same period, 59 confirmed cases were reported in six of the above endemic countries.

The outbreak of monkeypox is ongoing and more cases are expected to be identified as surveillance and laboratory capacity is implemented in non-endemic countries.