The WHO Director-General is hereby transmitting the Report of the second meeting of the International Health Regulations (2005) (IHR) Emergency Committee regarding the multi-country outbreak of monkeypox, held on Thursday, 21 July 2022, from 12:00 to 19:00 CEST.
The WHO Director-General is taking the opportunity to express his sincere gratitude to the Chairs and Members of the Committee, as well as to its Advisors, for their careful consideration of the issues regarding this outbreak, as well as for providing invaluable input for his consideration. The Committee Members did not reach a consensus regarding their advice on determination of a Public Health Emergency of International Concern (PHEIC) for this event.
The WHO Director-General recognizes the complexities and uncertainties associated with this public health event. Having considered the views of Committee Members and Advisors as well as other factors in line with the International Health Regulations, the Director-General has determined that the multi-country outbreak of monkeypox constitutes a Public Health Emergency of International Concern.
The WHO Director-General also considered the views of the Committee in issuing the set of Temporary Recommendations presented.
The WHO Secretariat presented the global epidemiological situation, highlighting that between 1 January 2022 and 20 July 2022, 14,533 probable and laboratory-confirmed cases (including 3 deaths in Nigeria and 2 in the Central African Republic) were reported to WHO from 72 countries across all six WHO Regions; up from 3,040 cases in 47 countries at the beginning of May 2022.
Transmission is occurring in many countries that had not previously reported cases of monkeypox, and the highest numbers of cases are currently reported from countries in the WHO European Region and the Region of the Americas.
The majority of reported cases of monkeypox currently are in males, and most of these cases occur among males who identified themselves as gay, bisexual and other men who have sex with men (MSM), in urban areas, and are clustered in social and sexual networks. Early reports of children affected include a few with no known epidemiological link to other cases.
There has also been a significant rise in the number of cases in countries in West and Central Africa, with an apparent difference in the demographic profile maintained than that observed in Europe and the Americas, with more women and children amongst the cases.
Mathematical models estimate the basic reproduction number (R0) to be above 1 in MSM populations, and below 1 in other settings. For example, in Spain, the estimated R0 is 1.8, in the United Kingdom 1.6, and in Portugal 1.4.
The clinical presentation of monkeypox occurring in outbreaks outside Africa is generally that of a self-limited disease, often atypical to cases described in previous outbreaks, with rash lesions localized to the genital, perineal/perianal or peri-oral area, that often do not spread further, and appears prior to the development of lymphadenopathy, fever, malaise, and pain associated with lesions.
The mean incubation period among cases reported is estimated at 7.6 to 9.2 days (based on surveillance data from the Netherlands, the United Kingdom of Great Britain and Northern Ireland (United Kingdom), and the United States of America (United States). The mean serial interval is estimated at 9.8 days (95% CI 5.9-21.4 day, based on 17 case-contact pairs in the United Kingdom).
A small number of cases have been reported among health workers. Investigations so far have not identified cases of occupational transmission, although investigations are ongoing.
The Secretariat noted that, although the number of cases and countries experiencing outbreaks of monkeypox appear to be rising, the WHO risk assessment has not changed since the first meeting of the Committee on 23 June 2022, and the risk is considered to be “moderate” at global level and in all six WHO Regions, except for European region, where it is considered to be “high”.
Modeling work conducted by European Centre for Disease Prevention and Control (ECDC) and the European Commission’s Health Emergency Preparedness and Response Authority (HERA) suggests that isolation of cases and contact tracing could be effective in bringing the outbreak under control. However, the operational experience gained to date in responding to this event, indicates that the implementation of such interventions in practice is extremely challenging – the identification of cases is hampered by barriers to access diagnostic testing; the isolation of cases for 21 days is difficult in the current COVID-19 pandemic-related post-lockdowns context; and contact tracing is difficult as contacts are often multiple and may be anonymous. The modeling by ECDC and HERA is suggesting that the addition of vaccination-related interventions can increase the chances of controlling the outbreak, with pre-exposure prophylaxis of individuals at high-risk of exposure appearing to be the most effective strategy to use vaccines when contact tracing is less effective, or impracticable. However, the limited data on vaccine effectiveness against monkeypox constitutes one of the limitations of the modeling work conducted. Additionally, the operationalization of such vaccination strategy presents challenges, including those related to vaccine access.
The genome sequence of the virus obtained in several countries shows some divergence from the West African clade. Work is ongoing to understand whether the observed genomic changes lead to phenotypic changes such as enhanced transmissibility, virulence, immune escape, resistance to antivirals, or reduced impact of countermeasures.
Although many species of animals are known to be susceptible to the monkeypox virus in the natural setting (e.g., rope squirrels, tree squirrels, Gambian pouched rats, dormice, non-human primates), there is the potential for spillback of the virus from humans to other susceptible animal species in different settings. To date, there is currently no documented evidence of instances of anthropozoonotic transmission available to the WHO Secretariat or its One Health partners the Food and Agriculture Organization (FAO) and the World Organisation for Animal Health (WOAH).
The WHO Secretariat also outlined the WHO response so far, and the ongoing work to develop the WHO Strategic Readiness and Response Plan for monkeypox, being its overall goal to stop human-to-human transmission.
Representatives of Spain, the United Kingdom, the United States, Canada and Nigeria updated the Committee (in this order) on the epidemiological situation in their countries and their current response efforts. With the exception of Nigeria, the remaining four countries reported that 99% of cases were occurring in MSM, and mainly among those with multiple partners.
In Spain, cases have been decreasing over the past few weeks, but it is likely the data are incomplete because of delays in reporting. Most cases have been reported in major urban areas, with very few reports of cases among females and children who had epidemiological links to MSM. Pre-exposure prophylaxis with vaccination is being offered to health workers, contacts and people living with HIV, but vaccine supplies are low.
The United Kingdom reported on a few severe cases of monkeypox (including encephalitis), and it is also planning to modify its case definition for monkeypox, to include newly recognized conditions such as proctitis. Environmental investigations have identified monkeypox virus DNA (presumed to be infectious because of moderate Ct values) on surfaces in hospitals and households. The vaccine strategy is targeted and aims to interrupt transmission through post-exposure prophylaxis and pre-exposure prophylaxis among MSM at highest risk.
In the United States, cases of monkeypox are widely distributed across the country, although most cases are concentrated in three large cities. While a few cases have occurred in children and a pregnant woman, 99% are related to male-to-male sexual contact.
In Canada, 99% of cases have occurred among MSM, and the country is taking a broad approach to pre-exposure prophylaxis, given the challenges with contact tracing; and is strongly focused on engagement with community-led organizations supporting key affected populations groups.
Nigeria recorded a little over 800 cases of monkeypox between September 2017 and 10 July 2022 and has seen at 3% case fatality ratio among confirmed cases. Cases are predominantly in men aged 31 to 40 years; there was no evidence of sexual transmission presented. The highest number of annually reported cases since 2017 has been observed in 2022.
Following the presentations, the Committee Members and Advisers proceeded with a questions and answers session for both the Secretariat and the presenting countries.
The Committee continues to be concerned about a broad range of issues, including the following: the need for further understanding of transmission dynamics; the impact of the fear of stigma on health-seeking behaviour among MSM; the potential implications on rights-based delivery of care by Ministries of Health and other authorities; the challenges related to the use of public health and social measures to stop onward transmission, including isolation, access to testing and contact tracing, particularly because of multiple anonymous contacts; planned large local and international gatherings focused on MSM and associated public and private satellite events, conducive for increased opportunities for exposure through intimate sexual encounters and subsequent amplification of the outbreak; the need for continuous evaluation of interventions may have have had an impact on transmission (e.g., one-dose versus two-dose vaccination regimens and vaccine effectiveness in general, given the apparent permucosal exposures that are causing infection in some cases); and the identification of key activities for targeted risk communications and community engagement, working in close partnership with affected communities, and providing the necessary support for community-led organizations to play their important role in the response to the outbreak.
There was particular concern about how vaccines and antivirals would be priced and distributed in the near future and made available in an equitable manner.
