Mpox: History, Status and Current Control Efforts

Mpox has recently become a major theme in global news, with many speculating as to whether the virus will be responsible for the next major global pandemic. In this article, we explore the background of the mpox virus, recent outbreaks and the efforts to contain transmission so that a global surge in cases can be avoided.

Background

The #mpox virus, formerly called monkeypox, is part of the Orthopoxvirus genus. This group also includes the #variola virus (which causes smallpox), the #vaccinia virus (used in the smallpox vaccine), and the cowpox virus, among others.??

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Whilst it came to prominence in 2022, mpox is not a newly discovered virus; it was first identified in 1958 when two outbreaks of a pox-like disease occurred in colonies of monkeys kept for research. The first human case was recorded in 1970 in the Democratic Republic of the Congo (DRC) during a period of intensified effort to eliminate smallpox.?

Mpox spreads between humans through skin-to-skin contact and bodily secretions and can be transmitted from a pregnant woman to her child. The virus can also be transmitted by touching contaminated objects or through contact with infected animals. Common symptoms of mpox include a skin rash or mucosal lesions that can last 2–4 weeks, fever, headache, muscle aches, back pain, low energy, and swollen lymph nodes.?

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Mpox Epidemiology?

There are two clades of the virus, with both having tended to be endemic and limited to core regions in Africa.?

Mpox Before 2022?

Prior to 2022, mpox cases were primarily reported in parts of Central (Clade I) and West Africa (Clade II) where it is endemic. The reservoir of mpox has not yet been established, though zoonosis has occurred from contact with small mammals, such as rope and sun squirrels, giant-pouched rats, and African dormice in parts of West and Central Africa. Outbreaks are sporadic and tend to be introduced into human populations after contact with infected animals. A 2017 outbreak involving 122 confirmed or probable cases in #Nigeria, for example, is thought to have resulted from a zoonotic spillover event and subsequent human-to-human transmission.?

Almost all mpox cases occurring outside Africa were linked to international travel to endemic regions or through imported animals. The first outbreak outside Africa occurred in the USA in 2003, where 47 human cases were linked to close contact with prairie dogs that had been infected by rodents brought in from #Ghana.?

2022 – 2023, Clade II Outbreak?

Since the 2017 outbreak in Nigeria, sporadic outbreaks have been continuously reported, with 230 confirmed cases across 20 states and the Federal Capital Territory between 2017 and 2022. In May 2022, the UK Health Security Agency (#UKHSA) confirmed a case of mpox in an individual who had travelled from the United Kingdom to Nigeria and subsequently returned to the United Kingdom. The case developed a rash on 29 April 2022 and arrived in the United Kingdom on 4 May, having departed Nigeria on 3 May. Cases continued to rise in the UK between May and October, with the primary mode of transmission being intimate acts between men who have sex with men (MSM).?

Cases from this London cluster then spread to new countries and infected more individuals, leading to new clusters within high-risk groups. The chart below highlights the dates when the first cases were reported, with novel case reporting being most intense during the summer months, and the Asia and Europe regions acting as epicentres for viral transmission.?

Interactive chart showing the date of first reported mpox case in affected countries (best viewed on desktop)

In most countries, infection rates gradually began to decrease towards the end of August and early September. This was due in large part to the U.S. @Food and Drug Administration (#FDA) issuing an Emergency Use Authorization (EUA) in August 2022, which allowed Bavarian Nordic 's Jynneos vaccine to be used for the prevention of mpox disease in individuals aged 18 years and older who were determined to be at high risk for mpox.?

Interactive chart showing the date of first reported mpox case in affected countries (best viewed on desktop)

Several countries were able to quickly resolve the crisis through various interventional strategies, including:?

• Early detection and case management?
• Targeted vaccination campaigns for those at highest risk?

• Isolation of infected individuals?

• Active collaboration with healthcare organisations worldwide?

• Close cooperation with local communities?

2023 – Present, Clade Ib Outbreak?

Clade IIb cases continue to be reported, but there was a growing consensus that transmissions could be contained and that there was a thorough understanding of how to mitigate any major outbreaks.?

Towards the end of 2023, however, mpox outbreaks were common in the DRC, and observers were reporting that transmission of the virus was becoming increasingly aggressive. Deeper investigation revealed a significant increase in cases infected by Clade Ib mpox viruses. By December 2023, more than 12,500 suspected cases of Clade Ib mpox and nearly 600 deaths had been identified. This prompted observers to raise the alarm that the risk of a future outbreak was becoming increasingly likely.?

Transmission continued to increase throughout the first half of the year in the DRC, and in July, Burundi, Kenya, Rwanda, and Uganda reported Clade Ib cases that were phylogenetically linked to samples reported in the DRC.?

Owing to the increasing transmission rates, evidence of sexual transmission, and higher lethality, the Africa Centres for Disease Control and Prevention (Africa CDC) declared the escalating mpox outbreaks in Africa a public health emergency on 12 August 2024. The World Health Organization then declared the epidemic a public health emergency of international concern (PHEIC) on 14 August 2024.?

Throughout August, cases were subsequently reported in #Sweden, #Thailand, and #India.??

Community Engagement Efforts to Contain Transmission?

On 4 September, the WHO held a live conference with speakers Dr. Maria Van Kerkhove , Dr. Kai v. Harbou , Dr. Susan Nywade, Ombretta Baggio (from 红十字会与红新月会国际联合会 ), Dr. Ruben Mayorga , Dr. Omar Sued , Dr. Meg Doherty and Dr. Nedret Emiroglu . A wide range of topics regarding mpox were discussed, with particular emphasis on effective collaboration with African communities. Community protection was a core focus, and open dialogue and communication were highlighted as key factors for success.?

According to the WHO presentation, the following areas are crucial for ensuring community protection:?

• Risk communication?

• Community service delivery?

• Prevention of animal-to-human transmission?

• Community IPC and WASH?

• Public health and social measures?

• Border health and mass gatherings?

• Vaccination?

• Multisectoral action to mitigate social and economic impacts?

Trust and other emotional drivers are essential for establishing productive relationships with communities, and communication must be rooted in understanding and empathy towards these communities.??

The key challenges identified by the WHO are:??

• New countries facing mpox for the first time?

• Limited understanding of behavioural factors driving transmission?

• Stigma?

• Misinformation?

• Insufficient contextualisation of responses at provincial, national, and district levels?

Ongoing Risks??

There have been many questions raised in the public sphere surrounding the potential for mpox to become a more significant event that puts the wider public’s health at risk. While focused activities in endemic areas are helping to contain the virus, an escalation of initiatives in non-endemic countries is also helping to catch the virus early and avoid any subsequent transmission.?

There are a number of risks; however, that may dampen efforts to contain the virus and mitigate poor outcomes for infected individuals:?

• Poor access to care – issues such as inadequate infrastructure and conflict hamper the ability of critical equipment such as tests and vaccines to be made available to at-risk populations?

• Deepening endemicity – the ongoing outbreak of the clade Ib strain is likely to broaden the human reservoir of the virus, and since mpox can re-infect individuals, it will become much more challenging to eliminate the virus?

• Virus DNA mutations – with higher transmission rates and replication within populations, it is much more likely that we will see DNA mutations that lead to increased transmission ability, virulence or lethality?

• Vaccine unavailability – despite there being so few clade Ib cases outside of Africa, demand for the vaccine has surged and led to a shortage of vaccines that can be made available to the countries most burdened by mpox

Summary?

Vaccines are currently the primary prevention method to contain mpox transmission. Africa has stated that it needs 10 million vaccines for the entire continent, and several countries, including European nations, the USA, Japan, and others, have already offered assistance. Reaching the goal of 10 million vaccines is challenging and can only be achieved through global collaboration.?

The main challenge now is to focus on controlling mpox, actively collaborating with African nations to deliver vaccines to those at risk, and ensuring that people have access to medical care.??

Useful Links:??

Scientific American: How Deadly Is Mpox, What Vaccines are Effective, and Other Questions Answered ??

Espa?a donará a áfrica el 20% de sus reservas de vacunas contra la mpox (Spanish) ??

Germany to donate 100,000 mpox vaccine shots to contain outbreak in Africa ??

WHO mpox factsheet ??

CDC mpox Factsheet ??

BBC Health Check: The Race to Distribute mpox Vaccines

UN News, Mpox: What you need to know about the latest public health emergency ??