Western Europe is experiencing its biggest diphtheria outbreak in 70 years, primarily affecting vulnerable groups such as migrants and homeless people, new research revealed Wednesday.
Diphtheria is a highly contagious bacterial infection that targets the respiratory system, causing symptoms like sore throat and fever. For those unvaccinated, it can be deadly in about 30 percent of cases, with children at higher risk, according to the World Health Organization.
The surge began in 2022, with an unusual rise in cases caused by the bacterium Corynebacterium diphtheriae across several European countries, especially among recent migrants, a study published in the New England Journal of Medicine found.
That year, the European Centre for Disease Prevention and Control (ECDC) recorded 362 cases. Thanks to contact tracing and screening efforts, the outbreak was largely controlled, but occasional infections have continued.
Since early 2022, Europe has seen a total of 536 cases and three deaths.
Analysis of patient samples from ten countries showed 98 percent of cases were male, averaging 18 years old, with nearly all being recent migrants.
“The outbreak, which mostly affected migrants from Afghanistan and Syria, did not originate in their home countries but rather during migration journeys or within their accommodations in Europe,” said a joint statement from France’s public health agency and the Pasteur Institute.
The genetic similarities of bacterial strains across different countries point to a “recent point of contact, outside the country of origin” as the source of the outbreak.
Although precise affected areas remain unclear, a genetic link between the 2022 strain and one detected in Germany this year suggests the bacteria “continues to circulate quietly in Western Europe,” the statement added.
Vaccination remains highly effective against diphtheria. Researchers urged European countries to boost immunisation programmes and improve protection for vulnerable populations.
They also called for greater awareness among healthcare providers and those working with migrants and homeless communities, along with increased access to vaccines and antibiotics.