LONDON — British health authorities said Friday that a nationwide monkeypox outbreak may be peaking and that the rate of growth of the outbreak has slowed.
The UK’s Health Security Agency said in a statement that there were “early signs that the outbreak is plateauing”, with 2,859 cases identified since May. No deaths have been reported. Last month, authorities estimated the outbreak was doubling in size roughly every two weeks, but the number of new infections has fallen in recent weeks.
“While the latest evidence suggests that the growth of the epidemic has slowed, we cannot be complacent,” said Dr. Mira Chad, Director of Clinical and Emerging Infections at the Health Security Agency. He said anyone who thought they might have monkeypox should skip meeting friends, socialize and avoid sexual contact.
The Health Security Agency said its latest analysis of the outbreak “shows that monkeypox continues to be transmitted primarily through interconnected sexual networks of gay, bisexual or men who have sex with men.” Over 70% of UK cases are in London.
British officials noted a small number of infections among women, but said there was not enough evidence to suggest there was a sustained spread of monkeypox beyond gay and bisexual men. 99% of all cases in the UK involve men.
Scientists who analyzed monkeypox viruses in the UK noticed a number of mutations compared to viruses circulating in Africa, but said there was no evidence that these genetic changes made monkeypox more contagious.
Experts suspect that outbreaks of monkeypox in North America and Europe may have originated in Africa long before the disease began to spread through sex at two raves in Spain and Belgium.
The World Health Organization said this week that 92% of monkeypox cases outside Africa were likely to have been infected through sex and its Director-General recently appealed to vulnerable gay and bisexual men to consider reducing their sexual partners “currently.”
To date, more than 26,000 cases of monkeypox have been reported in nearly 90 countries, with a 19% increase in the past week.
In June, British authorities they expanded them vaccination strategy, offering vaccines not only to healthcare workers treating monkeypox patients and high-risk patient contacts, but to some gay or bisexual men at high risk of contracting the virus, including those with multiple sexual partners or engaging in group sex.
Last month, the UK downgraded its assessment of the monkeypox outbreak and dropped a recommendation for contacts of monkeypox cases to self-isolate for three weeks unless they have symptoms. The change was prompted by data showing that only a small number of contacts ultimately become ill from monkeypox and a lack of evidence that the disease spreads without close, intimate or sexual contact.
On Thursday, the US declared its monkeypox outbreak a national emergency, while the WHO declared it a global emergency last month.
Monkey pox is spread when people have close, physical contact with an infected person’s lesions, clothing, or bed linen. Most people recover without treatment, but the lesions can be extremely painful and more severe cases can lead to complications such as encephalitis and death.