The World Health Organisation has declared that the monkeypox outbreak, which has infected more than 17,000 people in at least 75 countries, is a public health emergency of international concern. Here, Professor Chloe Orkin, Professor of HIV medicine at Queen Mary University of London and Barts Health NHS Trust, explains some of the key things you need to know about the disease and its impact. Prof Orkin talks through the disease's symptoms and treatment, what might have caused it to spread internationally, and the need to destigmatise public health messaging about the disease.