# 2024 mpox outbreak

On 14 August 2024, the World Health Organization declared a new outbreak for a separate and more lethal Clade I form of the mpox virus relative to the Clade II form that was predominant in the 2022-2023 mpox outbreak. Thirteen countries have presently been reported to have confirmed cases for adults and children. Vaccines for the virus were heavily limited in the countries the outbreak was announced in.

## Background

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). In the 2023-2024 outbreak the rate of death was less than 0.2 percent. 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.

### 2022-2023 mpox outbreak

In May 2022, the World Health Organization (WHO) made an emergency announcement of the existence of a multi-country outbreak of mpox, a viral disease then commonly known as "monkeypox". 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 has been 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. The disease had been circulating and evolving in human hosts over several years before the outbreak and was caused by the clade IIb variant of the virus.
In May 2023, the World Health Organization declared an end to the PHEIC, citing steady progress in controlling the spread of the disease. Relatively low levels of cases continued to occur, and as of 28 July 2024, there have been a total of 99,388 confirmed cases and 208 deaths in 116 countries.

## Epidemiology

Epidemiologists first reported on a new strain of mpox in a mining town in the Democratic Republic of the Congo (DRC), reporting that it had the potential to spread with greater ease compared to other mpox strains. The researchers theorized that the new strain underwent genetic mutations allowing it to spread easier through human transmission, due to the mining town's remote location away from animals that naturally carry and spread the disease.
The lead researcher of the new outbreak, Dr. Placide Mbala-Kingebeni, called the strain "a new phase of mpox" from the prior 2022-2023 mpox cases, due to the new strain producing more mild lesions predominantly formed on the genitals, making the strain more difficult to diagnosis compared to strains that cause chest, feet, and hand lesions. He also noted that the disease was allowed to transmit silently due to differences in their manifestations making it harder for infected people to determine if they need to seek medical attention. His research team determined the strain to be a Clade I type strain, which is historically more severe compared to the Clade II type that was predominant during the 2022-2023 mpox outbreak.

## Outbreak

In August 2024, the Africa Centers for Disease Control and Prevention (ACDC) declared that spreading mpox outbreaks in Africa had become a public health emergency and reported over 500 deaths. The organization requested the help and intervention of the international community to control the spread of the virus and to treat the infected.
In 2024, thirteen countries were reported to have confirmed cases of mpox, with over 96% of all reported cases and fatalities from the disease in the DRC, with a total of 14,000 cases reported globally and 524 reported deaths. The ACDC stated that the fatality rate of the strain of virus causing the outbreak was 3-4%, significantly higher than the <1% fatality rate during the 2022-2023 mpox outbreak. It further reported that 70% of reported cases in the DRC were in <15-year-old children, and that the demographic represented 85% of reported deaths. Epidemiologist Jacques Alonda expressed concern over the disease's spread in refugee camps in the DRC and around nations surrounding the DRC, especially considering the amount of healthcare strain the nation was suffering from due to concurrent outbreaks of cholera and measles as well as from widespread malnutrition.
The health agency of the United Nations reported that four nations in East Africa— Kenya, Burundi, Uganda, and Rwanda— had newly reported cases of the mpox strain linked to cases from the DRC.