A new Catalan study reveals that the deadliest variant of mpox can cause a mortality rate of over 4%

The research team, led by Dr. Oriol Mitjà, has analysed nearly 5,000 confirmed cases of the disease in the Democratic Republic of Congo. The research, driven by the Fight Infections Foundation, indicates that subvariant 1a has a higher mortality rate, while 1b is more transmissible. The study has been published in The Lancet and was made possible thanks to a crowdfunding campaign, which raised more than 35,000 euros.

A new study published in the scientific journal The Lancet, driven by the Fight Infections Foundation, indicates that the mpox subvariant 1a, formerly known as monkeypox, has a mortality rate of over 4% in the Democratic Republic of Congo (DRC).

This work, carried out by the research team of Dr. Oriol Mitjà from the Germans Trias i Pujol Hospital and the Fight Infections Foundation, provides the most comprehensive clinical description of the disease caused by variant 1 of the virus. In fact, nearly 5,000 confirmed cases have been analysed in seven provinces of the DRC between October 2023 and September 2024.

Dr. Mitjà warns: “The study provides a key tool for identifying cases and strengthening the health response. However, the DRC, with more than 100 million inhabitants, has only received 250,000 doses of the vaccine, which will be insufficient to stop the outbreak.” He adds: “Research must continue and investment in health must be increased to reverse the effects of global health disinvestment initiated by the United States.”

What are the main results of the study?

The research identifies two simultaneous outbreaks caused by subvariants 1a and 1b of the virus. Subvariant 1a is the most dangerous, with a mortality rate of over 4%. On the other hand, subvariant 1b causes fewer deaths (0.6%), but is transmitted much more easily through direct contact between people. It should be noted that variant 2, responsible for the cases in Europe and Catalonia in 2022, had a mortality rate of less than 0.1%.

According to researcher Roser Escrig, co-first author of the research: “The findings show that mpox can have a much more severe presentation than previously thought, with high rates of complications and mortality, especially in children.”

In this regard, most of those affected in the DRC are young people without prior vaccination, and nearly half are women and girls. They typically present extensive skin lesions, which can number more than 250 distributed across the body. This is a worrying figure considering that in Catalonia, with variant 2 of the disease, each patient presented an average of 10 lesions. Additionally, severe bacterial complications requiring antibiotic treatment, as well as ocular and respiratory involvement, are common in these cases.

More than 35,000 euros raised for research thanks to crowdfunding

This study was made possible thanks to a crowdfunding campaign led by the Fight Infections Foundation, which raised more than 35,000 euros to finance the research and provide technical support to the government of the Democratic Republic of Congo to help combat the disease.

In this vein, the Foundation encourages citizens to continue contributing to research through micro-donations, which are key to combating infectious diseases of the present and future.