Spain was investigating a cluster of monkeypox infections on Saturday, while several other countries recorded first cases of the disease including Switzerland and Israel.
Spanish authorities are investigating whether parties on the tourist island of Gran Canaria have been the source of several monkeypox infections, according to healthcare sector sources.
Around 80,000 people from Spain and other countries attended the Maspalomas Gay Pride festival that took place on May 5-15.
Men from Madrid, Italy and the neighbouring island of Tenerife who have tested positive for the virus are said to have participated in the festival celebrations.
Most monkeypox cases reported so far involve men who have had sexual contact with other men.
On Friday, the authorities had closed a Madrid gay sauna identified as a possible place of infection.
Spain has so far recorded 30 cases of monkeypox. There are a further 23 suspected cases, media reported on Friday.
In neighbouring Portugal, 23 cases have been confirmed, according to the Público newspaper.
The disease continued its spread in other countries, with the Swiss authorities also confirming a first case, of a person who likely came into contact with the virus abroad.
Israel also identified a case of monkeypox, with the man being isolated in Ichilov Hospital in Tel Aviv, according to the Health Ministry.
Two further cases in Germany
Meanwhile two further cases were confirmed by the Berlin health authority on Saturday, a day after Germany recorded its first case.
The Berlin health authorities said they were tracing the contacts of the two people and that lab sequencing would establish whether the virus strain was West African or Central African.
Germany's first case was confirmed just a day earlier, a man who came to Bavaria from Portugal via Spain, although it was not initially clear whether he was infected in either of those countries.
The man, a 26-year-old Brazilian in the city of Munich, has the milder West African of the two known virus variants, according to a genome analysis by the Bundeswehr Institute of Microbiology. The Bavarian Health Ministry announced the findings on Saturday.
So far, none of the European cases has been registered as the more severe Central African variant.
In the western German state of North Rhine-Westphalia, meanwhile, the authorities were following up on indications that several people may have come into contact with the monkeypox virus, a Health Ministry spokesperson said.
"The situation is being closely observed; doctors as well as healthcare authorities are being asked for increased vigilance," the spokesperson said.
Germany's Robert Koch Institute disease control agency considers the risk to the general public in Germany to be low. It expects further cases in Germany, but not a wave of infections.
"According to current knowledge, close contact is required for transmission of the pathogen, so it can currently be assumed that the outbreak will remain limited," the institute wrote on its website.
Two cases in the Netherlands
In the Netherlands, the authorities are now to require all suspected cases of monkeypox to be reported as the disease continues to spread.
Two cases have been identified in the Netherlands, and the national health service said any cases of the disease must be registered, to facilitate contact tracing.
Multiple clusters of monkeypox have recently been reported in countries where the disease is not usually found, including the United States and Britain.
The virus generally occurs in Central and West Africa, often in proximity to tropical rainforests, and is considered endemic in the Democratic Republic of Congo, where it was first discovered in humans in 1970.
The illness can be transmitted from person to person through air droplets, close bodily contact or sharing contaminated linens or objects.
The virus usually causes symptoms similar to smallpox, but milder. Severe cases can lead to fatality, however.
Smallpox has been considered eradicated worldwide since 1980 after a major vaccination campaign.
Experts suspect that the pathogen that causes monkeypox circulates in rodents - monkeys are so-called false hosts. According to the World Health Organization (WHO), previous cases of monkeypox were usually linked to travel to areas in West and Central Africa.
According to the WHO, monkeypox has appeared more frequently in Nigeria in recent years. Since 2017, a total of 558 suspected cases have been reported there. Of those, 241 have been confirmed and eight people have died.