Scientists from the United States, Europe, and Africa believe that the evolution of the virus, the severity of illness, and the ways the virus spreads remain an “unknown,” which hinders efforts to control the outbreak.
According to researchers, the new variant of the monkeypox virus (mpox) known as clade 1b is spreading in the Democratic Republic of the Congo and neighboring countries, evolving faster than expected and often occurring in areas lacking the resources to implement monitoring and disease prevention measures.
Monkeypox patient in the Democratic Republic of the Congo. (Source: Getty Images/TTXVN).
Scientists from the United States, Europe, and Africa argue that such mutations mean that the evolution of the virus, the severity of illness, and the ways the virus spreads remain uncertain, thus hindering efforts to control the outbreak.
Monkeypox has been reported in several African countries since 1970. However, it was not until decades later that the scientific and public health communities paid attention to the disease, following a global monkeypox outbreak that forced the WHO to declare a global health emergency from July 2022 to May 2023. This is the highest alert level issued by the WHO for an outbreak.
Subsequently, on August 14, the WHO declared a global public health emergency due to the outbreak of mpox in African countries, with the emergence of the clade 1b variant raising global concerns for its rapid spread and higher risk of mortality.
Clade 1b is a variant of the endemic clade 1 strain of the monkeypox virus. The clade 1 strain is transmitted through contact with infected animals and has caused outbreaks in the Democratic Republic of the Congo for decades.
The illness typically causes flu-like symptoms and pus-filled sores. Though usually mild, it can still pose fatal risks or lead to serious complications for many cases, especially in children, pregnant women, and those with weakened immune systems, such as individuals living with HIV.
According to the WHO, since the beginning of the year, the Democratic Republic of the Congo has reported over 18,000 suspected cases of the endemic clade 1 strain and the clade 1b variant, along with 615 fatalities.
Last month, there were 222 confirmed cases of the clade 1b variant in four African countries.
The Swedish health agency confirmed its first case of clade 1b variant infection on August 15. This also marks the first case outside Africa of this new monkeypox virus variant.
Then, on August 22, Thailand confirmed what is known as the first case in Asia of the clade 1b variant of the monkeypox virus. This is also the second confirmed case of clade 1b outside Africa.
Dr. Dimie Ogoina, an infectious disease expert at the Niger Delta University Teaching Hospital in Nigeria and Chair of the WHO Emergency Response Committee on Monkeypox, expressed concern that the virus appears to be mutating and generating new strains.
Dr. Ogoina stated that without a clear understanding of how the virus is changing, the medical community will struggle to address issues related to transmission, disease severity, and risk factors.
Gene sequencing of clade 1b variant cases, which the WHO estimates emerged in mid-September 2023, indicates that they carry a mutation known as APOBEC3 (an enzyme belonging to a protein family).
According to Dr. Miguel Paredes, a researcher studying the evolution of the monkeypox virus at the Fred Hutchinson Cancer Research Center (USA), the monkeypox virus typically mutates slowly, but mutations driven by APOBEC could accelerate the virus’s evolutionary process.
Dr. Paredes noted that all cases of monkeypox transmitted from person to person show signs of the aforementioned APOBEC mutation, indicating that the monkeypox virus is mutating slightly faster than researchers had predicted.
Dr. Salim Abdool Karim, an epidemiology researcher in South Africa and Chair of the Monkeypox Advisory Committee of the African Centers for Disease Control and Prevention (CDC), stated that clade 1b and clade 2b variants can essentially be regarded as sexually transmitted diseases. Most cases of the clade 1b mutation are seen in adults.
The virus can also spread through close contact with infected individuals. This may explain why many children are contracting the clade 1b variant, especially in Burundi and in refugee camps in eastern Democratic Republic of the Congo, where poor sanitation and crowded living conditions may facilitate rapid disease transmission.
However, many countries in Africa also lack the necessary equipment to monitor and track the outbreak.
Many countries in Africa also lack the necessary equipment to monitor and track outbreaks. (Source: Reuters)
Scientists monitoring monkeypox outbreaks in Africa report that they even lack sufficient chemicals for diagnostic testing. Meanwhile, the clade 1b variant can easily “slip through” even these testing methods.
Additionally, about 50% of cases in eastern Democratic Republic of the Congo, where the clade 1b variant is circulating, are diagnosed by physicians without confirmation through testing.
Therefore, researchers are calling on countries and international and regional organizations to urgently implement research efforts and response planning, including vaccination strategies; otherwise, controlling and preventing the outbreak will face significant challenges.
