CDC Warns of Deadlier Mpox Strain Spreading in Congo

Health officials in the United States are sounding alarms over a potential resurgence of mpox, an infectious disease formerly known as monkeypox, as global Pride events approach. The Centers for Disease Control and Prevention (CDC) has issued warnings about a more lethal strain of the virus that is currently spreading in the Democratic Republic of the Congo (DRC), where it has led to nearly 20,000 infections and approximately 1,000 deaths since January 2023. This situation raises concerns about the virus's potential to spread beyond Africa, echoing the global outbreak that began in 2022.

The mpox virus exists in two main genetic groups, or clades. The Clade I strain, which is prevalent in the DRC, has a significantly higher mortality rate—between 1.4% and 10%—compared to the Clade II strain that caused the 2022 outbreak, which had a mortality rate of less than 0.2%. The CDC has emphasized the need for urgent global action to contain the virus, particularly as the DRC has reported an unprecedented number of suspected Clade I cases. While the 2022 outbreak primarily affected gay and bisexual men, the current situation in the DRC shows a shift in transmission dynamics. Recent evidence suggests that Clade I is now spreading among adults through sexual contact, particularly among sex workers and their clients. This change in transmission patterns has raised alarms among health experts, who fear that the virus could easily cross borders, especially given the transient nature of populations in mining and urban areas.

In the U.S., the CDC is urging individuals at highest risk to get vaccinated, as vaccination rates among those most vulnerable remain low. Despite the availability of a two-dose vaccine that has shown effectiveness of up to 90%, fewer than one in four Americans at risk have received both doses. The agency is working to engage advocacy groups and social media influencers to promote vaccination within the LGBTQ+ community, which was heavily impacted during the last outbreak.

The DRC's ongoing epidemic is compounded by a lack of resources and healthcare infrastructure. Many suspected cases are diagnosed based solely on symptoms, as testing capabilities are limited. This has led to concerns that the virus could evolve further, particularly with the emergence of a new variant known as Clade Ib, which has mutations that allow it to spread more efficiently among humans. The World Health Organization has called for countries to reassess their testing procedures to ensure they do not miss cases of this new strain.

Historically, mpox has been endemic to Central and West Africa, with sporadic outbreaks occurring for decades. The first human case was recorded in 1970, and the virus is related to smallpox, sharing similar symptoms such as fever, swollen lymph nodes, and rash. The 2022 outbreak marked a significant shift, as it spread rapidly outside of Africa, leading to tens of thousands of cases globally. As the CDC prepares for a potential resurgence in the U.S., it is also supporting efforts in the DRC to control the outbreak. Experts emphasize that addressing the epidemic in Africa is crucial to preventing a global health crisis. "It’s much better to help them get this outbreak under control before it spills over into other areas and becomes more of a global risk," said a CDC official, highlighting the interconnectedness of global health.

The situation serves as a stark reminder of how infectious diseases can transcend borders, underscoring the importance of global surveillance and vaccination efforts. As health officials continue to monitor the situation, the call for coordinated action has never been more urgent, with the hope that lessons learned from past outbreaks will guide effective responses to this evolving threat.