Hours later, Spain announced the first death in Europe, although no information about the person has been released. The Ministry of Health confirmed a second death on Saturday. Spain is one of the worst affected countries, with 4,298 confirmed cases and at least 120 patients hospitalized.

At least five people have died in Africa.

[What to know about monkeypox symptoms, treatments and protection]

On July 23, the World Health Organization declared monkeypox a global health emergency, its highest warning. According to the Centers for Disease Control and Prevention (CDC), 22,485 cases have been confirmed worldwide, the vast majority outside the countries in Central and West Africa where the virus is normally found.

The WHO says the risk of the virus is high in Europe and moderate elsewhere. Cases normally start with flu-like symptoms and a rash that appears days later, according to the CDC. Infections usually last between two and four weeks.

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The most cases so far have been reported in men who have sex with men, with WHO Director General Tedros Adhanom Ghebreyesus suggesting earlier this week that they should consider temporarily reducing sexual partners as the numbers increase. Global health authorities have grappled with the risk of stigmatizing community members or downplaying the risk to the wider population.