This current Disease Outbreak News on the multi-country monkeypox outbreak is an update to the previously published Disease Outbreak News of 4 June, with updated data, some further detail on clinical description of cases, measures to increase the safety of gatherings, and again provides summaries of guidance, including on vaccination.
Outbreak at a glance
Since 13 May 2022, cases of monkeypox have been reported to WHO from 28 Member States across four WHO regions (the Region of the Americas as well as the European, Eastern Mediterranean, and Western Pacific Regions) where monkeypox is not usual or has not previously been reported (Figure 1). In addition, since the beginning of the year, there are 1536 suspected cases reported from eight countries in the WHO African Region, of which 59 cases have been confirmed and 72 deaths reported.
The continuous detection of the virus and deaths reported in some countries in the African Region highlight the need to better understand the source, transmission dynamics and provide people with the information and support they need to protect themselves and others in a range of different contexts.
While epidemiological investigations are ongoing, most reported cases in the newly affected countries have presented through sexual health or other health services in primary or secondary health care facilities with travel history to countries in Europe and North America rather than to countries where the virus is known to be present. In the countries that have long experienced monkeypox, more analysis is needed to understand the ongoing and new sources of infection.
The sudden and unexpected appearance of monkeypox simultaneously in several regions without direct immediate travel links to areas that have long experienced monkeypox suggests that there may have been undetected transmission for several weeks or longer.
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 many countries in widely disparate WHO geographical areas.
Description of the outbreak
As of 8 June, 1285 laboratory confirmed cases and one probable case have been reported to WHO from 28 countries in four WHO Regions where monkeypox is not usual or had not previously been reported. This represents an increase of 505 laboratory confirmed cases since the previous Disease Outbreak News on 4 June 2022 when 780 cases were reported. As of 8 June 2022, there have been no associated reported deaths in these four Regions.
Of the cases reported in these regions, the majority (87%) of confirmed cases are from the WHO European Region (1112). Confirmed cases have also been reported from the Region of the Americas (153), Eastern Mediterranean Region (14) and Western Pacific Region (6). The case count fluctuates as more information is reported and becomes available daily and data is verified under the International Health Regulations (IHR 2005) (Table 1).
To date, the clinical presentation of monkeypox cases associated with this outbreak has been variable. Many cases in this outbreak are not presenting with the classically described clinical picture for monkeypox (fever, swollen lymph nodes, followed by rash concentrated on the face and extremities). Atypical features described include: presentation of only a few lesions or even just a single lesion; lesions that begin in the genital or perineal/perianal area and do not spread further; lesions appearing at different (asynchronous) stages of development; and the appearance of lesions before the onset of swollen lymph nodes, fever, malaise or other symptoms. The modes of transmission during sexual contact remain unknown; while it is known that close physical contact can lead to transmission, it is not clear what role sexual bodily fluids, including semen and vaginal fluids, play in the transmission of monkeypox.
The situation is evolving and WHO expects that there will be more cases of monkeypox identified as surveillance expands in all regions and countries.
Figure 1. Geographic distribution of cases of monkeypox reported to or identified by WHO from official public sources, between 13 May and 8 June 2022, 5 PM CEST
In addition to the cases reported from or identified in newly affected countries, WHO continues to receive updates on the status of ongoing monkeypox outbreaks and newly reported cases in countries [1] in the African Region through established surveillance mechanisms (including Integrated Disease Surveillance and Response). Since the beginning of 2022, 1536 suspected cases with 72 deaths were reported from eight countries as of 8 June 2022; 59 confirmed cases were reported from six countries during this same period (Table 2). This now includes cases from Ghana that had not previously reported human cases. Although an outbreak of monkeypox in the United States of America in 2003 was linked to small mammals which been imported from Ghana. Laboratory strengthening in countries that have long experienced monkeypox is a priority to enable confirmation of suspected cases.
The case fatality ratio seen in the African Region underlines the need for support for all elements of the response including but not limited to, awareness-raising, risk communication, surveillance, diagnostic and laboratory support, and research and analysis in the Region. WHO is providing guidance and reporting forms to countries that have long experienced monkeypox as well as countries that have newly been affected.
Public health response
WHO continues to support sharing of information. Clinical and public health incident response has been activated to coordinate comprehensive case finding, contact tracing, laboratory investigation, clinical management, isolation, and implementation of infection prevention and control measures. Genomic sequencing of viral DNA, where available, is being undertaken. Several European countries (Belgium, Finland, France, Germany, Israel, Italy, the Netherlands, Portugal, Slovenia, Spain, Switzerland, the United Kingdom of Great Britain and Northern Ireland) and the United States of America have published full-length or partial genome sequences of the monkeypox virus found in the current outbreak. While investigations are ongoing, preliminary data from polymerase chain reaction (PCR) assays indicate that the monkeypox virus genes detected belong to the West African clade. Two types of vaccines (ACAM-2000 and MVA-BN) are being deployed by some Member States to serve as prophylaxis for close contacts. Others may hold supplies of other types of vaccines (e.g., LC16).
Interim guidance is being or has been developed to support Member States with raising awareness, surveillance, laboratory diagnostics and testing, case investigation and contact-tracing, clinical management and infection prevention control, vaccines and immunization, and risk communication and community engagement.
Source: World Health Organization