With global public health concerns raised to the highest level, the spread of the mpox virus has been making headlines as it has now been confirmed to be present on multiple continents.  

The World Health Organization (WHO) declared a global health emergency on Wednesday over an ongoing outbreak of a contagious new mpox variant, known as clade 1b, with the UN body’s top official, Tedros Adhanom Ghebreyesus pointing to “international concern” regarding its spread.

A day after the decision, Sweden confirmed the first case outside Africa of this strain, which studies have shown to be more contagious and potentially cause more severe symptoms.

Cases of the disease in 2024 have surpassed the number of infections last year. Over 15,600 mpox cases have been reported since the beginning of this year, while at least 500 people have died of the disease.

The Democratic Republic of Congo (DRC) accounts for more than 90% of reported infections, with over a dozen African nations also reporting cases.

Africa’s top health body, the Africa Centres for Disease Control and Prevention, has responded by declaring an emergency on the continent.  

What is mpox?

Mpox is a viral disease, formerly called monkeypox before the WHO changed its name in 2022 over complaints that it was racist and stigmatizing.

The virus is closely associated with smallpox and is divided into two broad yet distinct genetic groups called clades. Clade 1 is more widespread in Central Africa, while clade 2 is prevalent in West Africa.

The zoonotic disease can be transmitted to humans through close physical contact with an infectious person or small wild animal, or via contaminated materials.

Common symptoms include rashes or lesions, as well as a flu-like fever, head and muscle aches, back pain, general weakness, and swollen lymph nodes.

According to the WHO, mpox was first discovered in Denmark in 1958 in monkeys kept for research, while the first reported human case was in 1970, in a nine-month-old boy in the DRC.  

Why is the new strain concerning?

While most cases of mpox show mild symptoms, experts and scientists are concerned about the spread of the new type of clade 1, said to be deadlier and more contagious than an earlier variant that was responsible for an outbreak in 2022.

According to Michael Marks, a professor of medicine at the London School of Hygiene and Tropical Medicine, previous studies have shown that clade 1 tends to have a higher mortality rate of 1-10%, according to different studies, compared to clade 2, which is normally less than 1%.

“The current outbreak is the largest outbreak of clade 1 we have seen. The mortality rate is about 4%, which is in line with what has been described before for clade 1 — but as this is a very large epidemic, we are seeing a large number of deaths.”

Marks pointed out that the scale of the latest outbreak is unclear because it is difficult to determine whether the large number of cases and deaths is due to the new Clade 1 variant or because the virus is spreading primarily within specific networks, such as among sex workers.

He warned, "There is a real risk of onward transmission into surrounding countries, which could lead to further epidemics in other parts of Africa."  

Will it be more dangerous than COVID-19?

Asked whether the disease could lead to a pandemic of the scale of COVID-19, Marks said this was not likely.

“Mpox is much less transmissible than COVID so although it is likely that the current outbreak will get larger.”

“It is very, very unlikely that there will be an epidemic on the side of COVID.”

This is not the first time the WHO declared an emergency due to mpox. A previous global outbreak had erupted in 2022, but was brought under control.   

What measures can be taken?

While countries are monitoring the cases and starting to take preventative measures, the WHO says the spread of the disease can be prevented by avoiding physical contact with someone who has mpox, while vaccination can help prevent infection for people at risk

According to Marks, two main approaches are crucial in combating the disease.

The first involves identifying cases, tracing contacts, and isolating them to reduce onward transmission.

However, he notes that as the number of cases rises, contact tracing becomes increasingly challenging

“The key measure is likely to be vaccination,” Marks emphasized, highlighting that vaccines originally developed for smallpox are also effective against mpox.

He stressed that a major issue is the lack of access to these vaccines among at-risk populations in Africa.

“The priority is therefore to secure supply of vaccine to control the epidemic.”