Mpox: How deadly is the virus and what treatments are available?

Mpox, previously known as monkeypox, is currently causing an outbreak in the Democratic Republic of the Congo (DRC) and neighboring countries. The increase in cases is attributed to a new variant of the virus, believed to be more deadly than the strain responsible for the global mpox outbreak in 2022. However, there are available treatments that could be beneficial.

Assessment of Mpox Fatality Rate

Research indicates that the mortality rate among individuals infected with the clade I variant of mpox, which is driving the ongoing outbreak, varies from approximately 1 to 11 per cent. Discrepancies in reported fatality rates may stem from differences in the affected populations and challenges in disease surveillance, according to Lilith Whittles from Imperial College London.

Vulnerable groups such as infants, children, and individuals with compromised immune systems, like those with HIV, are at a higher risk of developing severe and potentially fatal infections. Limited healthcare access in certain regions leads to underreporting of mpox cases, with only severe instances being identified in healthcare facilities while milder cases go undetected. Additionally, misdiagnosing mpox symptoms as other illnesses further contributes to underestimating the actual fatality rates.

Complications that can lead to death in mpox cases include sepsis, where the infection spreads to the bloodstream causing organ failure, and lung damage due to viral-induced inflammation, as explained by Piero Olliaro from the University of Oxford.

Treatments for Mpox

In the epicenter of the current outbreak in the DRC and nearby nations, specific treatments for mpox are largely unavailable. Medical professionals primarily focus on alleviating symptoms, which typically persist for two to four weeks. This includes managing fevers and headaches with medications like paracetamol and preventing bacterial infections by cleansing skin lesions, according to Jean Claude Udahemuka from the University of Rwanda.

Alternatively, in countries like the UK and US, doctors can administer the antiviral drug tecovirimat to individuals with severe mpox cases. Originally developed for smallpox treatment, tecovirimat has shown efficacy in animal studies by enhancing survival rates compared to a placebo. The drug works by targeting a protein present on both mpox and smallpox viruses, inhibiting their ability to spread.

Additional antivirals such as cidofovir, known to protect mice from lethal doses of mpox, can also be utilized in the US and UK. This medication interferes with a viral enzyme crucial for genome replication. Another treatment involves injecting VIGIV antibodies from smallpox-vaccinated individuals into mpox patients to boost immune response.

Effectiveness of Mpox Treatments

Although animal studies suggest the efficacy of these treatments against mpox, their performance in humans remains uncertain. Initial findings from a recent randomized controlled trial in the DRC indicate that tecovirimat does not expedite the healing of painful lesions in children and adults infected with the clade I variant of mpox.

However, participants receiving the antiviral exhibited a lower mortality rate of 1.7 per cent compared to the typical 3.6 per cent mortality rate in the DRC. This improvement could be attributed to the close monitoring and care provided to trial participants in the hospital setting. Continued research and development of improved treatments are crucial to combat the ongoing mpox outbreak, particularly in regions like the DRC, emphasizes Lucille Blumberg from the University of Pretoria.