The spread of the rare virus could “accelerate” in summer, the UN health body’s top official in Europe warns Europe should expect a wave of monkeypox cases in the coming months, according to Hans Kluge, the World Health Organization’s top official on the continent. “As we enter the summer season… with mass gatherings, festivals and parties, I am concerned that transmission [of monkeypox] could accelerate,” Kluge said on Friday. The number of the infected could rise because “the cases currently being detected are among those engaging in sexual activity,” and many don’t recognize the symptoms, he added.