Cases of monkeypox continue to crop up around the world. According to the World Health Organization (WHO), at least 27 countries, mainly in Europe and North America, have confirmed cases. Other reports have found confirmed cases in more than 30.

The situation isn’t necessarily going to evolve into a pandemic, but there are some worrying signs. Perhaps the main point of concern is that not all cases appear related, and some isolated cases have no clear connection to an existing outbreak. This points to a tracing problem, and suggests that many linking cases are going undetected.