The U.S. Centers for Disease Control and Prevention issued a health alert on Monday for a more dangerous strain of mpox, also known as monkeypox, that was detected in the United States in recent days.
No additional mpox cases in the United States have been discovered as of Nov. 18, according to the CDC alert. Local and state health agencies are still investigating additional contacts.
The infected person has displayed “relatively mild illness and is recovering,” which the CDC said is “consistent” with recent clade I mpox cases. Health authorities say that clade I is considered a more aggressive form of mpox than clade II, which spread across the world and the United States in 2022 and 2023. A more recent outbreak in Africa centered in the Democratic Republic of Congo has been driven by the clade I strain, prompting declarations of emergencies across the continent earlier this year.
Between Jan. 1 and Nov. 15 of this year, about 12,000 mpox cases have been confirmed in Eastern and Central Africa, leading to at least 47 deaths, according to the CDC.
Countries with large numbers of cases include the Democratic Republic of Congo, the Republic of the Congo, Uganda, Rwanda, Burundi, and the Central African Republic. Other countries that have reported cases of the clade I strain include Germany, Sweden, the UK, India, Thailand, Kenya, and Zimbabwe. “Data from affected countries indicate that a large proportion of clade I mpox cases among adults were associated with heteros.