#18,084
While there had been persistent warnings for years (see here, here, and here) that Mpox (formerly `Monkeypox') could one day escape the confines of central Africa and begin a world tour, it still took the world by surprise when - in the spring of 2022 - a new clade (IIb) of the virus began spreading internationally.
Although the declared global health emergency was ended after only 10 months, we continue to see sporadic infections around the globe, and a far more dangerous clade I mpox virus continues to rage in the DRC.
In November of last year, the WHO Reported the 1st Confirmed Cluster Of Sexually Transmitted MPXV Clade 1 in the DRC, warning that `The risk of mpox further spreading to neighbouring countries and worldwide appears to be significant.'
The changing epidemiology and genetic evolution of mpox clade I in central Africa has sparked a number of risks assessments over the past six months, including:
CDC HAN Advisory #00501: Mpox Caused by H-2-H Transmission with Geographic Spread in the Democratic Republic of the Congo
ECDC Risk Assessment On Transmission & Spread of Clade I Mpox From The DRC
Last March a study was published Eurosurveillance: Ongoing Mpox Outbreak in South Kivu Province, DRC Associated With a Novel Clade I Sub-lineage, which contained the first genomic analysis of samples from a previously unaffected region of the DRC (the city of Kamituga).
That study revealed a novel clade I sub-linage had emerged - most likely from a zoonotic introduction - with changes that may render current CDC tests unreliable.
In April, in Preprint: Sustained Human Outbreak of a New MPXV Clade I Lineage in Eastern Democratic Republic of the Congo, we saw a further analysis, which called for this new lineage to be named Clade Ib, and warned of its potential to spread globally.
Complicating matters, two recent studies have suggested that the effectiveness of the JYNNEOS vaccine (approved in 2019) wanes significantly between 1 and 12 months, even when a person has received two doses.
ECCMID 2024 Study: Mpox (monkeypox) Antibodies Wane Within A Year of Vaccination)
Immune response to MPXV wanes rapidly after intradermal vaccination with MVA-BN (Jynneos)
While the public appears to greet these reports with a collective yawn - public health officials are bracing for a potential surge in clade IIb this summer - and are on alert for any signs that clade I has begun to spread internationally.
On Thursday of this week the CDC published the following MMWR report on preparing for a return of Mpox. I've only posted some excerpts from a much longer report, so follow the link to read it in its entirety.
Weekly / May 16, 2024 / 73(19);435–440Jennifer H. McQuiston, DVM1; Richard Luce, MD2; Dieudonne Mwamba Kazadi, MD3; Christian Ngandu Bwangandu, PhD3; Placide Mbala-Kingebeni, MD; Mark Anderson, MD2; Joanna M. Prasher, PhD5; Ian T. Williams, PhD5; Amelia Phan, MPH6; Victoria Shelus, PhD1; Anna Bratcher, PhD7; Gnakub Norbert Soke, PhD1; Peter N. Fonjungo, PhD8; Joelle Kabamba, MD9; Andrea M. McCollum, PhD1; Robert Perry, MD10; Agam K. Rao, MD1; Jeff Doty, MS1; Bryan Christensen, PhD1; James A. Fuller, PhD6; Nicolle Baird, PhD1; Jasmine Chaitram, MPH11; Christopher K. Brown, PhD12; Amy E. Kirby, PhD13; David Fitter, MD14; Jennifer M. Folster, PhD15; Mushtaq Dualeh, MPH16; Regan Hartman, MPH2; Stephen M. Bart, PhD14; Christine M. Hughes, MPH1; Yoshinori Nakazawa, PhD1; Emily Sims, MPH1; CDC 2024 Clade I Mpox Response Team; Athalia Christie, DrPH17,*; Christina L. Hutson, PhD1,*
Summary
What is already known about this topic?
Compared with clade II monkeypox virus (MPXV), which caused the 2022 global mpox outbreak, clade I MPXV can result in more persons with severe illness and higher mortality.
What is added by this report?
The increasing number of reported suspected clade I mpox cases in the Democratic Republic of the Congo (DRC) poses a global threat for potential spread. No clade I cases have been reported in countries without endemic transmission. CDC is supporting DRC’s response and containment efforts and ensuring U.S. preparedness by increasing awareness and surveillance, expanding clade I diagnostic testing capacity, and communicating guidance.
What are the implications for public health practice?
U.S. clinicians and public health practitioners should be alert for possible cases in travelers from DRC and request clade-specific testing. Appropriate medical treatment is critical given the potential for severe illness, and contact tracing and containment strategies, including isolation, behavior modification and vaccination, will be important to prevent spread if any U.S. clade I mpox cases occur.
Abstract
Clade I monkeypox virus (MPXV), which can cause severe illness in more people than clade II MPXVs, is endemic in the Democratic Republic of the Congo (DRC), but the country has experienced an increase in suspected cases during 2023–2024. In light of the 2022 global outbreak of clade II mpox, the increase in suspected clade I cases in DRC raises concerns that the virus could spread to other countries and underscores the importance of coordinated, urgent global action to support DRC’s efforts to contain the virus.To date, no cases of clade I mpox have been detected outside of countries in Central Africa where the virus is endemic. CDC and other partners are working to support DRC’s response. In addition, CDC is enhancing U.S. preparedness by raising awareness, strengthening surveillance, expanding diagnostic testing capacity for clade I MPXV, ensuring appropriate specimen handling and waste management, emphasizing the importance of appropriate medical treatment, and communicating guidance on the recommended contact tracing, containment, behavior modification, and vaccination strategies.
Introduction
The global clade II monkeypox virus (MPXV) outbreak that began in 2022 demonstrated the pandemic potential of mpox (1). Clade I MPXV is endemic in several Central African countries, including the Democratic Republic of the Congo (DRC); clade I is generally associated with higher case fatality rates (CFRs) (1.4% to >10%) compared with clade II MPXV (0.1% to 3.6%) (1–3). MPXV can spread to persons from contact with infected wildlife, or through close, prolonged contact with persons infected with MPXV; the global clade II MPXV outbreak spread primarily via sexual contact among gay, bisexual, or other men who have sex with men (MSM) (1). During 2023–2024, DRC has reported an unprecedented number of suspected clade I MPXV infections. Neighboring countries and the global community should help support DRC’s effort to contain the virus as well as prepare for the possibility of further spread. This report describes investigation of cases in DRC, CDC’s support to DRC, and U.S. public health preparedness activities to date.
(SNIP)
Discussion
Ten years ago, the 2014 West Africa Ebolavirus outbreak demonstrated the risks associated with a delayed global response to a serious pandemic threat (9). During the 2022 clade II MPXV outbreak, the United States launched a robust domestic response based on 2 decades of smallpox preparedness; however, the global public health community missed earlier opportunities to recognize the threat and help contain clade II mpox, which was spreading person-to-person in Nigeria as early as 2016 (10).The recent increases in clade I MPXV transmission in DRC pose a new risk for global spread if the virus is not urgently contained. Reports of increased mpox in some bordering countries with endemic MPXV, including 19 confirmed cases in Republic of the Congo, reinforce this concern.†††††In the United States, clinicians and public health practitioners should be aware of clade I MPXV and request clade-specific testing for possible cases in travelers from DRC. In addition to preparing for the possibility of spread beyond DRC, support to DRC from global partners is needed as the country works to increase testing and surveillance for clade I MPXV.Although vaccines and therapeutics are not currently authorized for use in DRC, the National Immunization Technical Advisory Group in DRC recently released recommendations supporting their use as part of the country’s response. Collaboration among global public health partners is now urgently needed to assist DRC in procuring and delivering sufficient vaccine where it is most needed.
The CDC also published the following two reports on Mpox this week:
Monkeypox Virus Infections After 2 Preexposure Doses of JYNNEOS Vaccine — United States, May 2022–May 2024 May 23, 2024
Interim Clinical Considerations for Management of Ocular Mpox Virus Infection May 22, 2024
Meanwhile, on Friday the WHO published a framework for dealing with Mpox over the next 3 years.
WHO releases a strategic framework for enhancing prevention and control of mpox
24 May 2024
News release
Mpox continues to affect people around the world. A new framework released today by WHO will guide health authorities, communities and other stakeholders in preventing and controlling mpox outbreaks, eliminating human-to-human transmission of the disease, and reducing spillover of the virus from animals to humans.
Mpox is a viral illness caused by the monkeypox virus (MPXV). It can cause a painful rash, enlarged lymph nodes and fever. Most people fully recover, but some get very sick. The virus transmits from person to person through close, including sexual, contact. It also has animal reservoirs in east, central and west Africa, where spillovers from animals to humans can occasionally occur, sparking further outbreaks.
There are two different clades of the virus: clade I and clade II. Clade I outbreaks are deadlier than clade II outbreaks.
A major emergence of mpox linked to clade II began in 2017, and since 2022, has spread to all regions of the world. Between July 2022 and May 2023, the outbreak was declared a Public Health Emergency of International Concern. While that outbreak has largely subsided, cases and deaths continue to be reported today, illustrating that low-level transmission continues around the world.
Currently, there is also a major outbreak of clade I virus in the Democratic Republic of the Congo (DRC), where cases have been on the rise for decades. Since the beginning of the year, over 6500 cases and 345 deaths have been reported in the DRC. Almost half of these are among children under the age of 15 years.
The Strategic framework for enhancing prevention and control of mpox (2024–2027) provides a roadmap for health authorities, communities, and stakeholders worldwide to control mpox outbreaks in every context, advance mpox research and access to countermeasures, and to minimize zoonotic transmission.
While Mpox clade I is considerably less deadly, it continues to evolve - both in reservoir animal hosts and in humans - and new, potentially more problematic clades are always possible.
But even at today's severity, the international spread of a clade I Mpox virus would constitute a major public health crisis. One which we should be trying both to avert, and working to prepare for.
