A case of mpox clade I has been found in Sweden, the first case of the more severe strain outside of Africa, Swedish authorities said on Aug. 15.
The unidentified patient stayed in an African country where there has been an outbreak of mpox clade I, the Public Health Agency of Sweden said in a statement.
“The case is the first case caused by clade I that has been diagnosed outside the African continent,” Olivia Wigzell, director-general of the Public Health Agency of Sweden, told reporters in a briefing. “The affected person has also been infected during a stay in an area in Africa where there is a large ongoing outbreak of mpox clade I.”
Experts, including the agency, say clade I causes more severe cases than clade II.
A clade II subvariant was previously responsible for about 300 cases in Sweden.
The Public Health Agency of Sweden declined to disclose the African country to which the new patient traveled, but said the person has a confirmed infection and has received care.
The person sought medical assistance in the Stockholm region.
Swedish health authorities said they’re confident that health care and infectious control personnel are prepared to handle mpox cases. They said they’re coordinating with regional infection control units.
Mpox, formerly known as monkeypox, is a virus that was discovered in 1958 among monkeys. The first case among humans was identified in 1970 in the Democratic Republic of Congo.
Symptoms include rash, fever, and swollen lymph nodes. They usually start within several weeks of exposure and last for several weeks.
Mpox spreads through close contact with people who have mpox and a rash, contact with objects and fabrics that have been used by a person with mpox, and sexual contact involving a person with mpox, according to the National Foundation for Infectious Diseases in the United States.
Vaccines exist that can prevent mpox, but there are no treatments currently available.
Most people who contract mpox recover, according to the U.S. Centers for Disease Control and Prevention and other health authorities. A small number of cases have led to death.
In Africa this year, more than 15,600 cases and 537 deaths have already been reported, according to the World Health Organization.
Worries stem from the spread of a strain known as clade Ib. The subvariant of clade I has been spreading from Congo to countries that have never reported mpox cases, including Burundi, Kenya, and Uganda.
Mpox has been found in 13 African countries, according to the Africa Centers for Disease Control and Prevention, with cases up 160 percent and deaths up 19 percent so far this year compared with the same period of time in 2023.
The European Centre for Disease Prevention and Control said on Aug. 15 that it would issue an updated assessment of the risk posed by the mpox outbreak in Africa. It hasn’t commented on the case in Sweden.
The European Union agency said on July 29 that the risk to Europe from clade I was very low and that there was no evidence that clade I was spreading outside Africa.
The U.S. Centers for Disease Control and Prevention said on Aug. 15 that the risk to Americans from the African outbreak is very low, based on the limited number of travelers between central Africa and the United States.
The agency said people should consider receiving a vaccine to protect themselves. Other methods of preventing infection include avoiding people who have mpox symptoms, not coming into contact with wild animals in areas where mpox is circulating, and not eating meat from wild animals.
