What is mpox and why has the WHO declared it a global health emergency?

• A viral infection known as mpox is transmitted through close contact, including sexual contact.
• The symptoms include fever, chills, muscle aches, and pus-filled lesions.
• The recent increase in cases is attributed to clade 1b, a new branch of clade 1, according to the WHO.

The World Health Organization has declared mpox a global public health emergency for the second time in two years due to the spread of an outbreak in the Democratic Republic of Congo to neighboring countries.

Since the initial outbreak, new cases of the virus have been identified in countries such as Thailand, Philippines, Sweden, and Pakistan outside of the continent.

The new and deadlier strain, known as clade 1b, has been identified in many new cases in Africa and also confirmed in Thailand, causing health officials to raise concerns.

CNBC breaks down what we know so far.

What is mpox?

The viral infection known as mpox is transmitted through close contact, including sexual contact, and causes flu-like symptoms such as fever, chills, and muscle aches, along with pus-filled lesions. Although usually mild, it can be fatal.

The current strain of mpox, identified as clade 1, is more contagious and has a higher mortality rate compared to the 2022 strain, clade 2.

Most deaths resulting from the condition occur among young people, particularly children.

Why are cases rising?

The recent increase in cases is attributed to clade 1b, a new branch of clade 1, according to the WHO.

The DRC is believed to be the origin of clade 1b, which has been spreading person-to-person since its identification in 2024, often through sexual contact.

The Ebola virus outbreak in the DRC, caused by clade Ib, mainly affects adults and is spreading quickly, mainly due to sexual contact transmission and being amplified in commercial sex and sex worker networks, as stated by the health organization on Aug. 19.

Where are the cases?

In Burundi, Kenya, Rwanda, Uganda, and Thailand, instances of clade 1b have been discovered, in addition to those found in the Democratic Republic of the Congo.

Reports have indicated the presence of clade 1 in the Central African Republic, the Republic of Congo, and Sweden.

Cases related to the milder clade 2 have been reported in Cameroon, Côte d'Ivoire, Liberia, Nigeria, South Africa, the Philippines, and Pakistan.

What does the WHO declaration mean?

The WHO's highest designation, "public health emergency of international concern," aims to speed up international cooperation and public health measures to control a disease.

According to WHO Director-General Tedros Adhanom Ghebreyesus, a coordinated international response is crucial to halt these outbreaks and save lives, as he stated during the declaration on Aug. 14.

The rapid spread of a new mpox clade in eastern DRC and its detection in neighboring countries that had not previously reported mpox is very concerning, as it poses a potential for further spread within Africa and beyond.

Last week, Dr. Hans Kluge, the WHO's regional director for Europe, emphasized that Mpox is not the new Covid.

In a statement published on Tuesday, Kluge rejected comparisons between mpox and the coronavirus pandemic and stated that the risk to the general population is low.

Kluge stated that we must work together to address mpox, regardless of the location.

What are authorities doing?

The WHO is collaborating with countries and vaccine manufacturers to enhance access to vaccines for those affected by the virus.

The U.N. health agency has already released $1.45 million in emergency funds and may require additional funds in the near future. It anticipates an immediate need of $15 million for its response plan.

The Africa Centres for Disease Control and Prevention (Africa CDC) has formed a partnership with vaccine manufacturer Bavarian Nordic, which will enable the delivery of 2 million doses this year and 10 million by the end of 2025.

Bavarian Nordic announced that it is providing vaccines to countries outside of Africa and is seeking EU drug regulator approval to expand the use of its mpox vaccine for teenagers.