Scientists who analyzed monkeypox viruses in the U.K. noted a number of mutations compared to viruses circulating in Africa, but said there was no evidence those genetic changes made monkeypox any more transmissible.
Experts suspect the monkeypox outbreaks in North America and Europe may have originated in Africa long before the disease started spreading via sex at two raves in Spain and Belgium.
The World Health Organization said this week that 92% of monkeypox cases beyond Africa were likely infected through sex and its Director-General recently appealed to vulnerable gay and bisexual men to consider reducing their sexual partners "for the moment."
To date, more than 26,000 monkeypox cases have been reported in nearly 90 countries, with a 19% increase in the last week.
In June, British authorities expanded their vaccination strategy, offering vaccines not only to health workers treating monkeypox patients and high-risk contacts of patients, but to some men who are gay or bisexual and at high risk of catching the virus, including those with multiple sexual partners or who participate in group sex.
Last month, the U.K. downgraded its assessment of the monkeypox outbreak and dropped a recommendation for the contacts of monkeypox cases to isolate for three weeks unless they have symptoms. The change was prompted by data showing that only a small number of contacts are ultimately sickened by monkeypox and a lack of evidence that the disease spreads without close, intimate or sexual contact.
On Thursday, the U.S. declared its outbreak of monkeypox to be a national emergency, WHO designated it a global emergency last month.
Monkeypox spreads when people have close, physical contact with an infected person's lesions, their clothing or bedsheets. Most people recover without needing treatment, but the lesions can be extremely painful and more severe cases can result in complications including encephalitis and death.
Follow all of AP's coverage about monkeypox at https://apnews.com/hub/monkeypox