Health authorities in Spain reported on Friday 23 new confirmed cases of monkeypox, mainly in the Madrid region where most infections are linked to an outbreak in an adult sauna.
The total tally in Spain has now reached 30, while23 confirmed cases have now been identified in neighbouring Portugal, where nine new cases were detected on Friday.
Madrid authorities have been working on tracing the cases mainly from a single outbreak in a sauna, regional health chief Enrique Ruiz Escudero told reporters on Friday. The word sauna is used in Spain to describe establishments popular with gay men looking for sex rather than just a bathhouse.
"The Public Health Department will carry out an even more detailed analysis... to control contagion, cut the chains of transmission and try to mitigate the transmission of this virus as much as possible," he said.
Another 18 suspected cases are under investigation in Spain, 15 in the Madrid region, two in the Canary Islands and one in Andalusia, the health authorities said.
More than 100 cases of the viral infection more common to west and central Africa have been now reported in Europe.
It is a usually mild infection, with symptoms including fever, headaches and a distinctive bumpy rash.
Twenty cases have been detected in Britain - where authorities are offering a smallpox vaccine to healthcare workers and others who may have been exposed.
The UK Health Security Agency has said a notable proportion of recent cases in Britain and Europe have been found in gay and bisexual men.
Spain is assessing different therapeutic options, such as antivirals and vaccines, but so far all cases have mild symptoms and therefore no specific ad hoc treatment has been necessary, Spanish Health minister Carolina Darias told reporters on Friday.
The Portuguese cases remain under clinical follow-up but none have been hospitalized as they are all stable, the health authority said.
Reporting by Emma Pinedo and Patricia Rua, editing by Andrei Khalip, Inti Landauro and Toby Chopra