Mpox, a viral disease that has been around for decades, is currently experiencing a surge in cases across multiple regions. The complexity of this outbreak stems from the fact that three different variants are spreading simultaneously in different populations and locations. The most affected areas include the Democratic Republic of the Congo (DRC) and neighbouring countries, where two distinct clades of the virus, Ia and Ib, are causing significant concern. These clade strains have shown varying transmission patterns and impacts on different age groups, making the situation challenging to control.

Spread of Clade I and Its Impact

In the DRC, Clade I has been present for many years, mainly affecting children in the western and central regions. This variant typically spreads from animals to humans, with limited human-to-human transmission. However, according to a report by Science.org, the spread has now extended to the eastern parts of the country, where it primarily affects adolescents and adults, with sexual contact being the main mode of transmission. The emergence of Clade Ib, which has spread to Uganda, Kenya, Rwanda, and Burundi, has added to the concerns, especially with reports of cases in refugee camps.

Clade II: The Global Spread

The third variant, Clade II, originated in Nigeria and has been responsible for the global outbreak that began in 2022. This variant has primarily affected men who have sex with men, spreading through sexual networks. Although the initial surge in cases has subsided, the virus continues to circulate globally, with recent cases reported in Europe, the Americas, and South Africa. The varying impacts of these clades highlight the need for a nuanced approach to containment and treatment.

Mortality Rates and Transmission Differences

The mortality rates between the clades have raised questions, with Clade I in the DRC initially reported as more lethal than Clade II. However, recent studies suggest that the differences may be due to the varying conditions in the regions affected, such as healthcare access and the health status of the populations. The mode of transmission also plays a crucial role, with non-sexual transmission leading to more severe cases.

Why Is Mpox Spreading Now?

The resurgence of Mpox can be attributed to several factors, including the decline in immunity following the end of smallpox vaccination and increased human encroachment into wildlife habitats. The combination of these factors, along with population growth and increased mobility, has created an environment conducive to the virus’s spread. As researchers continue to study the virus, understanding these dynamics will be key to controlling the outbreak.