A handful of monkeypox cases have been reported or are suspected in Britain, Portugal, Spain, and the U.S.
The outbreaks are raising alarm because the disease mostly occurs in west and central Africa, and only very occasionally spreads elsewhere.
Here's what scientists know so far.
Monkeypox is a virus that causes fever and a distinctive bumpy rash. There are two main strains.
猴痘是一种会引起发烧和明显丘疹的病毒 。主要有两种毒株 。
The Congo strain is more severe, with up to 10% mortality, the West African strain has a fatality rate of 1%.
Jimmy Whitworth is a professor of international public health at the London School of Hygiene and Tropical Medicine.
It usually starts with fever and headache. People feel pretty miserable and tired. They can get swollen glands.
该疾病最初症状通常是发烧和头痛 。人们会感到非常疼痛和疲惫 。他们的腺体会肿大 。
And then this typical rash develops, which is sort of pustular in form. And that's usually what's infectious.
然后出现典型皮疹，形成脓疱 。这时通常就具有传染性了 。
The virus was first found in monkeys in 1958, hence the name.
But rodents are now seen as the main source of transmission.
The virus spreads through close contact, both in spillovers from animal hosts and, less commonly, between humans.
Transmission this time is puzzling experts.
That's because a number of the cases in the UK have no known connection with each other. Only the first case reported on May 6 had recently travelled to Nigeria.
这是因为英国的一些病例彼此之间没有已知的联系 。只有5月6日报告的第一个病例最近去过尼日利亚 。
The UK and U.S. health officials also highlighted that the recent cases were predominantly among men who self-identified as gay or bisexual.
One likely scenario behind the jump in cases is increased travel after COVID restrictions were lifted.
Monkeypox puts virologists on the alert because it is in the smallpox family, although it causes less serious illness.
Smallpox was eradicated by vaccination in 1980, and the shot has been phased out. But it also protects against monkeypox.
天花在1980年通过接种疫苗被消灭，而该疫苗也已逐步消失 。但它对预防猴痘也有作用 。
Some epidemiologists say the winding down of vaccination campaigns has led to a jump in monkeypox cases.
So this is quite alarming from a public health point of view and something that we really need to get a grip of and control as as quickly as we can.
There's no need to panic here. This is not going to spread and get into the general population and cause an epidemic like the corona virus has.
现在还没有必要恐慌 。这种病毒不会像新冠那样传播、感染普通人群并引发大流行 。