June 06, 2025
Bulletin interne de l'Institut Pasteur
A study published in the New England Journal of Medicine (NEJM) reveals that the largest diphtheria epidemic in Western Europe for 70 years, which broke out in 2022 among migrants and in 2023 spread to other vulnerable populations in several European countries, is the result of contaminations occurring during migratory travel or in destination European countries, and not in the countries of origin. However, the geographical area and conditions of these initial contaminations are still unknown. A genetic link has also been established between the strain that circulated during the 2022 epidemic and an epidemic that occurred in Germany in 2025, suggesting that the bacterium has been circulating silently in Western Europe. While demonstrating the effectiveness of vaccination programs for the general population, this research, carried out by an international team including researchers from the Institut Pasteur and epidemiologists from Santé publique France, underlines the importance of maintaining a high level of vigilance and public health support dedicated to diphtheria (vaccination, screening, clinical examination) among vulnerable populations in Western Europe.