2022–2023 mpox outbreak

An outbreak of mpox, a viral disease then commonly known as "monkeypox", was confirmed in May 2022. The initial cluster of cases was found in the United Kingdom, where the first case was detected in London on 6 May 2022 in a patient with a recent travel history from Nigeria (where the disease is endemic). On 16 May, the UK Health Security Agency (UKHSA) confirmed four new cases with no link to travel to a country where mpox is endemic. Subsequently, cases have been reported from many countries and regions. The outbreak marked the first time mpox had spread widely outside Central and West Africa. There is evidence that the disease had been circulating and evolving in human hosts over a number of years prior to the outbreak.

On 23 July 2022, the Director-General of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, declared the outbreak a public health emergency of international concern (PHEIC), stating that "we have an outbreak that has spread around the world rapidly, through new modes of transmission, about which we understand too little". A global response to the outbreak included public awareness campaigns in order to reduce spread of the disease, and repurposing of smallpox vaccines. In May 2023, the World Health Organization declared an end to the PHEIC, citing steady progress in controlling the spread of the disease.

As of 20 January 2024, there have been a total of 93,275 confirmed cases and 177 deaths in over 113 countries.

Mpox is a viral infection that manifests a week or two after exposure with fever and other non-specific symptoms, and then produces a rash with lesions that usually last for 2–4 weeks before drying up, crusting and falling off. While mpox can cause large numbers of lesions, in the current outbreak, some patients experience only a single lesion in the mouth or on the genitals, making it more difficult to differentiate from other infections. In infections before the current outbreak, 1–3 per cent of people with known infections have died (without treatment). Cases in children and immunocompromised people are more likely to be severe.

Mpox spreads through close, personal, often skin-to-skin contact. The disease can spread through direct contact with rashes, or body fluids from an infected person, by touching objects and fabrics that have been used by someone with mpox or through respiratory secretions. Given the unexpected and vast geographical spread of the disease, the actual number of cases is likely to be underestimated. While anyone can get mpox, to date the majority of confirmed cases outside of the endemic regions in Africa occurred in young or middle-aged men who have sex with men (MSM) who had recent sexual contact with new or multiple partners. On 28 July 2022, the WHO Director-General advised MSM to limit exposure by reducing the number of sexual partners, reconsidering sex with new partners, and maintaining contact details to allow for epidemiological follow-up. The Centers for Disease Control and Prevention has emphasized the importance of reducing stigma in communicating about the demographic aspects of mpox, specifically with regards to gay and bisexual men.