First US Case of New Mpox Variant Detected Following Traveler’s Return from Africa

By the staff at Ice Network.

US health officials have confirmed the first domestic case of a new mpox variant in a Northern California resident recently returned from eastern Africa, where the strain was initially identified in the Democratic Republic of Congo (DRC). According to the California Department of Public Health, the patient is isolating at home, showing signs of improvement, and poses a low risk to the public. Health officials are tracing close contacts as a precaution.

Mpox, a viral infection related to smallpox, is endemic in several African regions and often transmitted through bites from infected animals like rodents. Typical symptoms can include fever, chills, and body aches, with more severe cases resulting in lesions on the face, hands, and other areas. Previously known as monkeypox, the virus spread widely in 2022, with the majority of cases in gay and bisexual men. However, the newer variant detected in the DRC in early 2023, classified as clade I, appears to spread through close physical contact, including sexual transmission.

This clade I variant differs from the clade II mpox variant that caused a global outbreak in 2022 and 2023, where cases were largely mild. Clade I has historically been more severe, with fatality rates between 3% to 11% in earlier outbreaks. However, recent cases have been less severe, with fatalities dropping to around 1% when patients receive appropriate medical care. The CDC reported Saturday that, although clade I mpox cases outside Africa have shown mild symptoms and no associated deaths, the variant’s historically higher risk underscores the need for vigilance. In the US and other countries with advanced healthcare systems, death rates for this new variant are expected to remain low.

Since the re-emergence of mpox in 2023, over 3,100 cases of the clade I variant have been reported, primarily in Burundi, Uganda, and the DRC, according to the World Health Organization (WHO). African health officials, anticipating further outbreaks, estimate that the continent needs at least 10 million vaccine doses to contain the virus, particularly among high-risk groups like children and pregnant women.

While the recent US case represents the first confirmed infection of this new mpox variant domestically, similar cases have surfaced among travelers in Germany, Sweden, the UK, and India. The Africa CDC noted that the outbreak in the DRC is showing signs of stabilization.