What is mpox, and why is this outbreak raising concerns?
On Wednesday, the World Health Organization declared the ongoing mpox outbreak in Africa a global health emergency, the highest level of alert under international health regulations. This decision follows a similar declaration by the Africa Centres for Disease Control and Prevention on Tuesday. The outbreak, driven by a more dangerous strain of the virus known as clade Ib, is spreading rapidly in the Democratic Republic of Congo (DRC) and has reached at least four previously unaffected countries in Africa. WHO Director-General Tedros Adhanom Ghebreyesus expressed concern over the “very worrying” potential for further international spread.
Dimie Ogoina, chair of WHO’s emergency committee, noted, “It was unanimous that the current outbreak of mpox is an extraordinary event.” He added that the situation in Africa may represent only “the tip of the iceberg,” indicating that the full extent of the outbreak is not yet fully understood.
Experts worldwide are closely monitoring the situation. While the immediate risk to the United States is considered low, understanding the outbreak is crucial. Here’s what you need to know:
What is mpox?
Mpox, formerly known as monkeypox, is a viral disease related to the now-eradicated smallpox virus. It spreads through close contact, such as touching, kissing, or sexual activity, as well as through contaminated materials like clothing and needles. Initial symptoms resemble flu-like conditions—fever, chills, exhaustion, headache, and muscle aches—often followed by a rash with raised lesions that eventually scab over.
What is different about this outbreak?
Mpox is classified into two genetic clades, I and II. Clade II was responsible for a global outbreak declared a health emergency from July 2022 to May 2023. However, the current outbreak is driven by clade I, specifically clade Ib, which causes more severe disease and is a newer mutation.
Dr. Daniel Bausch from FIND explained that clade Ib has evolved to be more adaptable to humans. This mutation could lead to larger outbreaks if it becomes more transmissible. The current situation is complicated by multiple overlapping outbreaks of different clades with varying transmission modes and risk levels.
How dangerous is it?
Some clade I outbreaks have had fatality rates as high as 10%, though recent cases have shown lower death rates. In contrast, clade II’s fatality rate is under 0.2%. Vulnerable groups, such as infants, individuals with weakened immune systems, and pregnant women, are at higher risk for severe disease. Surveillance is limited, and our understanding of the virus’s transmissibility and fatality may be incomplete, particularly in rural areas where diagnosing and tracking the disease is challenging.
Where is mpox found?
Historically, mpox was confined to Central and West Africa, with clade I prevalent in Central Africa and the DRC, and clade II in Nigeria. In 2022, the disease spread to Europe and North America. The current outbreak is affecting more African countries than before and recently reached Sweden, marking its first appearance outside Africa.
How can the spread be contained?
Vaccines are available but not widely accessible in Africa. The US CDC has recommended vaccination for those at high risk of mpox. The Vaccine Alliance (Gavi) has allocated up to $500 million to supply vaccines to affected regions, including the DRC and neighboring countries. A global stockpile of mpox vaccines will be established by 2026. WHO has also approved the Emergency Use Listing for mpox vaccines and is working on a regional response plan with $15 million in funding, including a $1.5 million allocation from its Contingency Fund for Emergencies.
In summary, while vaccines are crucial, addressing the outbreak will also require enhanced surveillance, diagnostics, and research to fill existing gaps in understanding.