In brief
A case of the Clade I strain of mpox in California marks the first detection in the US of this emerging variant, which is linked to ongoing outbreaks in Central and Eastern Africa. Health officials emphasize the need for vigilance as symptoms and transmission patterns evolve.
California has confirmed its first case of mpox, formerly known as monkeypox, involving a novel Clade I strain that is part of a recent outbreak. The California Department of Public Health (CDPH) stated that the individual infected is currently isolating at home and had returned from Africa. This case is linked to the ongoing Clade I mpox outbreak occurring primarily in Central and Eastern Africa.Mpox was previously declared a global health emergency by the World Health Organization earlier this year. The CDPH noted that historically, Clade I has been associated with more severe illness compared to the more commonly circulated Clade II, which has been present in the United States since 2022. However, the severity of recent Clade I infections may not be as pronounced as previously observed.The mpox virus, belonging to the same family as smallpox, is primarily transmitted from animals to humans but has now adapted to spread between individuals. Initial symptoms of the infection generally include fever, malaise, headaches, back pain, and swelling, with a rash developing afterward that can be quite itchy or painful. Although the infection typically resolves on its own within a duration of 14 to 21 days, it can be severe and even fatal in vulnerable populations, such as young children.Historically, mpox has been endemic to tropical rainforests of West and Central Africa, particularly in the Democratic Republic of Congo (DR Congo), which has witnessed significant fatalities in recent outbreaks. Vaccination remains a key tool to control outbreaks, but it is often limited to those at known risk or in close contact with confirmed cases.
