For the first time, a more serious strain of mpox has been found in the United States.

The U.S. has detected a strain of mpox disease that officials have not previously seen there, the Centers for Disease Control and Prevention said Friday — specifically in California.

The case was confirmed by lab testing from California’s health department. The illness: The patient caught it after travel to East Africa, where the clade I strain has been circulating. The individual received treatment in San Mateo County before being released. That person is recovering at home, the CDC said on Saturday.

The strain poses a low risk to the general public, according to the CDC. Travel-related casual contact is not likely to be significantly high risk for mpox transmission, it said.

The agency recommends limiting close contact with infected individuals and contaminated surfaces and objects, which can include clothing, bedding or toothbrushes. It stated that those eligible, should also be vaccinated.

In the early days of this year, mpox was declared a public health emergency of international concern by the World Health Organization.

The disease is zoonotic– caused by animals; and endemic, or regularly occurring in Central and West Africa. The WHO recently shortened the name, which was previously called monkeypox, due to critics saying that name caters to racist stereotypes while also falsely suggesting that monkeys are primary carriers of said disease.

Mpox is divided into two types based on reference strains (clade I and clade II). They look the same, but clade I diagnoses have tended to be more lethal and severe. According to the CDC, its impact has been less severe in Central and East Africa during the current clade I epidemic.

Mpox has been known to cause a rash on the hands, feet, chest, face or genitals. The time of onset of symptoms may range from 3 to 17 days.