A multi-country outbreak of monkeypox outside endemic areas has been ongoing worldwide since the beginning of May with Europe as the main affected area.
Germany and Spain are among the European countries with the most reported cases of monkeypox. Two articles published in Eurosurveillance describe the epidemiology of monkeypox and sources of transmission in the Madrid region in Spain and in Germany, with focus on Berlin.
Mass Gatherings as Main Source of Transmission in Madrid Region
Martínez et al.  analysed the data of 508 confirmed monkeypox cases in the Madrid region. The majority of reported cases are men who identify themselves as men who have sex with men (MSM) and who have had condomless sex or sex with multiple partners within the 21 days before onset of symptoms.
In the beginning of the Madrid outbreak, many people attended the same sauna in the city centre which was temporarily closed by the public health authorities as a precautionary measure.
The Maspalomas Gay Pride in Gran Canaria was also considered as a source of transmission for many of the confirmed cases in Madrid, in the Canary Islands as well as other European countries  based on the high number of sexual partners reported by those who attended the event.
In addition, meeting people on dating apps following private encounters or parties was also reported from many cases and thus may also play an important role in the transmission of monkeypox.
Authors also speculate that the number of cases will increase during the next weeks, given the ways of transmission and the fact that most of the contacts are unknown.
From Travel-Associated to Local Transmission in Germany
Selb et al.  analysed 521 confirmed cases of monkeypox in Germany. At the start of the outbreak, half of reported cases had likely acquired their infection while travelling abroad. However, from 23 May 2022 onwards, cases with locally acquired infection were more frequent in Germany, with the highest incidence in Berlin.
In Berlin, 353 monkeypox cases have been reported, 73% identifying themselves as men who have sex with men. The majority of them had no travel history, indicating that they acquired monkeypox in Berlin, mentioning visits to clubs, bars and private parties. For those who had a travel history, the Maspalomas Gay Pride on Gran Canaria was the most frequently mentioned destination.
Monkeypox Mainly Spreading in MSM Communities
Both Martínez et al. and Selb et al. discuss that most confirmed cases in Berlin and Madrid are among men identifying as MSM. According to Selb et al. this may also explain the shift from travel-associated to local transmission in Berlin, as the city “has one of the largest MSM populations in Germany and is a major international hotspot of the MSM community”.
In Madrid sexual activities have played a key role in transmission according to Martínez et al. who state that “together with the predominant location of the rash in the genital, perineal or perianal area and the presence of lymphadenopathy in the inguinal region, indicate that close physical contact during sexual activities has been highly involved in the transmission of the infection in this outbreak.”
Based on their findings, both articles conclude that in order to minimise and effectively manage the ongoing monkeypox outbreak, it is important to further actively work with risk groups and to spread non-stigmatising, targeted information and recommendations for populations at risk, especially MSM.