The World Health Organization (WHO) has declared a public health emergency of international concern due to an ongoing outbreak of mpox, formerly known as monkeypox, in Central and West Africa. This marks the second time in two years that such a declaration has been made, highlighting the outbreak’s severity. On August 15, health officials in Sweden reported the first known case of mpox outside Africa, indicating the strain currently driving the outbreak.
Understanding Mpox
Mpox is an infectious disease caused by a virus related to smallpox. The virus typically circulates among animals, such as rodents and monkeys, in Central and West Africa, occasionally making the jump to humans and causing localized outbreaks.
Two primary lineages of mpox exist: clade I and clade II. Clade I is associated with more severe disease and a higher risk of mortality. The ongoing outbreak is linked to a subtype of clade I, known as clade Ib, while the previous global outbreak from 2022 to 2023 was driven by clade II.
Experts have stated there is currently no evidence suggesting that clade Ib poses a greater risk than the original clade I strain.
Current Case Numbers
As of August 13, the Africa Centres for Disease Control and Prevention reported over 17,000 suspected cases across the continent. The agency noted these figures are likely underrepresentative due to challenges in surveillance and testing.
In the Democratic Republic of the Congo alone, there have been 15,664 reported cases and 537 fatalities this year, surpassing the total cases recorded in 2023, according to the WHO.
Geographic Spread of Mpox
The outbreak originated in a small mining town in the Democratic Republic of the Congo and has since spread to at least 11 other countries in Africa, including four nations—Kenya, Rwanda, Burundi, and Uganda—that had not previously reported cases of mpox. Additionally, instances of mpox have been identified in Sweden.
Survival Rate and Symptoms
While over 99.9% of those infected with clade II survive, outbreaks involving clade I have a mortality rate of up to 10%. Vulnerable populations, including children and immunocompromised individuals, face an increased risk of severe illness.
The first symptom of mpox typically manifests as a rash that begins as a flat sore and progresses to a blister. This rash usually appears on the face before spreading to other areas of the body, including the hands and feet. Accompanying symptoms may include fever, headache, muscle aches, fatigue, and swollen lymph nodes. Symptoms generally appear within one week of infection but can arise anywhere from one to 21 days after exposure, and some individuals may remain asymptomatic.
Transmission of Mpox
Mpox spreads through close contact, primarily skin-to-skin interactions such as kissing, touching, or sexual contact. The virus can also be transmitted via respiratory droplets or contact with contaminated materials like bedding or medical supplies. Individuals remain contagious until their sores have healed completely.
Transmission can also occur through contact with infected animals via bites, scratches, or when hunting or consuming these animals. The current outbreak has predominantly affected young adults and children, differing from trends in previous outbreaks.
Treatment Options
Treatment for mpox focuses on managing symptoms and preventing complications, including secondary infections. Although some antiviral medications developed for smallpox have been utilized for mpox, recent trials have indicated that certain antivirals may not be effective against clade I. Individuals diagnosed with mpox are advised to self-isolate and follow strict hygiene practices.
Vaccination Against Mpox
An mpox vaccine is available, providing optimal protection after two doses. Additionally, smallpox vaccines may offer some level of protection against mpox, although their effectiveness against the current variant is not yet confirmed.
Vaccination is recommended primarily for those at high risk of exposure. For individuals outside of affected areas, the risk of contracting mpox remains low. Current vaccine availability in Africa is limited, with estimates suggesting a need for up to 10 million doses.
