European Centre for Disease Prevention and Control (ECDC) Jul 9 2025 Despite a steady decline in reported cases following a large outbreak in 2022, diphtheria is still being reported in Europe, with the number of cases higher than before 2020. An ECDC Rapid Risk Assessment issued today highlights how ongoing circulation of diphtheria caused by Corynebacterium diphtheriae ( C. diphtheriae ) may affect some populations who are more vulnerable to infection and recommends tailored public health