Endemic in West Africa, monkeypox was detected on Wednesday in Spain and Portugal after affecting the United Kingdom in early May.
"More than 20 suspected cases" in humans have been identified "in the Lisbon region (west), of which five have been confirmed", announced the General Directorate of Health of Portugal in a press release.
"These cases, for the majority of young people, all male, had ulcerative lesions," said the health authority.
In Spain, eight suspected cases have been reported and "have yet to be confirmed" by tests, the Spanish Ministry of Health said.
According to the Spanish and Portuguese authorities, who have triggered a national health alert, this rare disease is not very contagious between humans, has no treatment and is generally cured on its own.
Fever, headache and rashes
Symptoms of this viral illness called "monkeypox" include fever, headache, muscle aches, back pain, swollen lymph nodes, chills and fatigue.
Rashes may occur, often on the face, and spread to other parts of the body.
The World Health Organization (WHO) said on Tuesday it wanted to shed light on the cases of monkeypox, with the help of the United Kingdom where since May 6, seven cases have been identified, including four cases in people who identify as "gay, bisexual or men who have sex with men", according to the UK Health Security Agency (UKHSA).
With the exception of the first case - the infected person had recently traveled to Nigeria - the patients were infected in the United Kingdom, raising fears of community transmission.
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