The United Kingdom has confirmed two additional cases of clade Ib mpox. Both patients live in the same household with a person who tested positive shortly after travel to several African countries. This makes them the first locally transmitted clade Ib mpox cases in the WHO European Region, and the first outside Africa since a Public Health Emergency of International Concern was declared for a second time in August 2024. 

“The overall risk to the general population in the United Kingdom and wider region remains low, but local transmission of clade Ib mpox should be the impetus for health systems across our region to heighten their surveillance measures and prepare for rapid contact tracing of suspected and confirmed cases,” said Dr Hans Henri P. Kluge, WHO Regional Director for Europe. “People who suspect that they may be infected must also be encouraged to come forward for testing, care and prevention of further transmission, free from stigma and discrimination.”

Mpox spreads between people primarily through close physical contact, including sexual contact. Coming into contact with virus-contaminated objects, such as bedding or clothing, is also implicated, and respiratory droplet spread to those in close contact may also occur in certain circumstances, but the latter is not deemed a common mode of transmission.

Measures to reduce the risk of contracting mpox, especially during travel to countries experiencing outbreaks, include avoiding close, skin-to-skin contact, including sexual contact, with anyone who has symptoms, keeping your hands clean, and receiving the vaccine if it is offered. WHO guidance on mpox vaccination remains unchanged at this time. Where available, mpox vaccines – effective against both clades – should be prioritized for at-risk groups, including those who are more likely to come into close contact with people who are infected, such as health workers and people with multiple sexual partners, including men who have sex with men.

If you have mpox, regardless of clade, your health-care provider will advise you on what to do while you recover. Follow national advice on whether you should recover at home or need care in a health facility. If you are advised to isolate at home, protect those you live with as much as possible by isolating in a separate room, avoiding sharing clothes, bedding, towels and utensils, ensuring good ventilation in the home, and getting all household members to wash their hands and disinfect surfaces frequently. 

Clade II mpox caused the 2022 outbreak in the WHO European Region, primarily affecting men who have sex with men. Meanwhile, clade Ib mpox has been widely circulating in the Democratic Republic of the Congo in recent months, and has been reported in Burundi, Kenya, Rwanda, and Uganda, with imported cases to Germany, India, Sweden, and Thailand. 

The emergence of new pathogens is a byproduct of our interconnected world, and it is not unexpected that close, high-risk contacts of an infected person may also become infected with mpox. However, like for any evolving disease outbreak, this uncertainty does pose a risk. 

Therefore, it is essential that we remain vigilant to detect and respond to suspected cases and combat stigma, false information, and fear, which can often hinder response efforts and discourage people from seeking testing or care. Countries seeing new or increasing cases must also share information quickly, fully and transparently, allowing others to take appropriate actions to halt the spread of mpox.

“I commend the United Kingdom for its prompt action to detect and control this cluster, with clear and transparent communication to ensure timely reporting, and data sharing,” continued Dr Kluge. “Once again, I urge all 53 member states of the WHO European Region to follow the WHO Standing recommendations and enhance surveillance to detect clades I and II of mpox, issue sound public health advice, and strengthen access to vaccines and antivirals. It is also crucial to provide support to close household contacts of people who have been infected. WHO discourages any trade or travel restrictions because of mpox.” 

Based on our experience with mpox, we know what works: strong surveillance to identify cases, isolation and treatment of infected cases, contact tracing and close monitoring of contacts, clear risk communication that addresses fear and stigma, and regular sharing of data. 

“Now is the time to apply these measures widely, engaging affected communities and preventing onward transmission,” concluded Dr Kluge. “WHO/Europe stands ready to support Member States, including through the recently launched Pan-European Network for Disease Control, currently chaired by the UK Health Security Agency. Together we can stop the spread of mpox.” 

This news release was published by the World Health Organization on November 5, 2024.