The World Health Organization (WHO) does not have evidence that the monkeypox virus has mutated, a senior executive at the United Nations agency said in a briefing on Monday morning, noting the infectious disease that has been endemic in West and Central Africa has tended not to change.
Dr. Rosamund Lewis, head of the smallpox secretariat, which is part of the WHO Emergencies Program, told the briefing that mutations tend to be typically lower with the monkeypox virus, although genome sequencing of cases will help inform understanding of the current outbreak.
Most of the more than 100 suspected and confirmed cases in a recent outbreak in Europe and North America have not been severe, said Maria Van Kerkhove, the WHO’s emerging diseases and zoonoses lead, and technical lead on COVID-19.
“This is a containable situation,” she said, particularly in Europe. “But we can’t take our eye off the ball with what’s happening in Africa, in countries where it’s endemic.”
Outbreaks described as atypical
On Monday, Denmark announced its first case, Portugal revised its total upwards to 37, Italy reported one further infection and Britain added 37 more cases.
The outbreaks are atypical, according to the WHO, occurring in countries where the virus does not regularly circulate. Scientists are seeking to understand the origin of the cases and whether anything about the virus has changed. Monkeypox has not previously triggered widespread outbreaks beyond Africa, where it is endemic in animals.
The WHO is asking dermatology and primary health-care clinics, as well as sexual health clinics, to be alert to potential cases. Van Kerkhove said she expected more cases to be identified as surveillance expands.
Dr. David Heymann, a leading adviser to the WHO and former head of the WHO’s emergencies department, told The Associated Press that the unprecedented outbreak of monkeypox in Europe and North America was a “random event.” The leading theory to explain the spread of the disease was sexual transmission at raves held in Spain and Belgium, he said.
In a separate briefing held Monday afternoon by the U.S. Centers for Disease Control and Prevention (CDC), health officials said some of the cases being seen in North America, however, predate the events in Europe. They stressed the outbreak is still in its early stages.
U.S. health officials said Monday that they knew of one confirmed case, in the state of Massachusetts, and four probable cases — two in Utah, one in Florida and one in New York City. All were men who had travelled outside the U.S. Many — but not all — of the people who have been diagnosed in the current monkeypox outbreak have been men who had sex with men
“Remember, infectious diseases don’t care about borders or social networks,” said Dr. John Brooks, a medical epidemiologist with the CDC. “Some groups may have a greater chance of exposure right now, but by no means is the current risk of exposure to monkeypox exclusively to the gay and bisexual community in the U.S.”
CDC officials said that the U.S. is in the process of releasing some doses of the Jynneos vaccine for use in monkeypox cases, noting there are more than 1,000 doses in the national stockpile. They also said they expect that level to ramp up very quickly in the coming weeks.
Virus spread through close contact
The virus does not usually spread easily between people, but it can be passed through close person-to-person contact or contact with items used by a person who has monkeypox, such as clothes, bedding or utensils.
“By nature, sexual activity involves intimate contact, which one would expect to increase the likelihood of transmission, whatever a person’s sexual orientation and irrespective of the mode of transmission,” said Dr. Mike Skinner, a virologist at Imperial College London.