In 2022, Europe skilled the most important diphtheria outbreak within the area in 70 years, and authors writing yesterday within the New England Journal of Drugs have traced the outbreak pressure to recognized migration routes and migrant communities in European international locations—and never essentially to sufferers’ international locations of origin.
Furthermore, the authors establish a genetic hyperlink between the 2022 pressure and an epidemic in Germany this yr, suggesting the bacterium that causes the illness is circulating undetected in Western Europe.
362 circumstances in 10 nations
Mass vaccination had largely eradicated diphtheria in Europe, and between 2016 and 2020, an annual common of 27 diphtheria circumstances brought on by Corynebacterium diphtheriae had been reported within the European Union and European Financial Space (EU/EEA), in response to a information launch from the European Centre for Illness Prevention and Management (ECDC).
However from January to November 2022, 362 circumstances had been recognized in 9 European international locations: Austria, Belgium, France, Germany, Italy, Norway, the Netherlands, Spain, Switzerland, in addition to the UK. These sickened had been largely migrants who had relocated to Europe: Germany (118 sufferers) and Austria (66 sufferers) had the biggest case counts.
The median age of the sufferers was 18 years on the time of information assortment; 176 sufferers (48.6%) had been 16 to twenty years of age, and 355 (98.1%) had been male, the authors wrote. The overwhelming majority of the sufferers (96.1%) had a latest migration historical past, shut contact with migrant populations, or a latest date of entry into the reporting nation. Roughly half of all sufferers (48.1%) had been reported to be residents of a migrant middle.
Most migrants from Afghanistan, Syria
A complete of 19 international locations of origin had been reported amongst case-patients; 222 sufferers (83.5%) had been reported to have originated from Afghanistan or Syria. As well as, 28 transit international locations had been reported
“Though a number of sufferers migrated from Africa or by japanese Europe, most adopted a migration route by the western Balkans,” the authors wrote.
Of 436 sufferers with scientific information, 268 (77.5%) had cutaneous diphtheria, 53 (15.3%) had respiratory diphtheria (11 [3.2%] had a pseudomembrane), and 9 (2.6%) had each respiratory and cutaneous signs. Isolates collected from sufferers confirmed 4 genetic clusters.
Individuals who left their residence international locations with out the illness contracted diphtheria on their option to the vacation spot nation the place they had been identified.
“Our evaluation illustrates that intently associated diphtheria clones had been detected in a number of European international locations, which tells us that individuals who left their residence international locations with out the illness contracted diphtheria on their option to the vacation spot nation the place they had been identified,” mentioned Andreas Hoefer, PhD, at ECDC and one of many co-authors of the examine.
Case counts dropped considerably by the spring of 2023.
“The rise within the variety of C. diphtheriae infections noticed amongst migrants in western Europe within the second half of 2022 was seemingly halted by response measures, however some ahead transmission within the reporting international locations was noticed in 2023,” the authors wrote.
Nevertheless, because the ECDC reviews, in April 2025, Germany confirmed a diphtheria outbreak brought on by a C. diphtheriae sequence kind that was initially linked to the 2022 outbreak and was additionally detected in a number of circumstances in 2023.
“In keeping with the data from Germany, diphtheria circumstances had been reported amongst folks experiencing homelessness, an older grownup and an unvaccinated baby,” the ECDC mentioned. “Following this latest outbreak sign from Germany, ECDC is in shut contact with EU/EEA Member States and can replace its threat evaluation and suggestions primarily based on the brand new information.”
In keeping with a press launch from the Pasteur Institute, a complete of 536 circumstances, together with at the least 3 deaths, have been reported in Europe because the begin of the 2022 epidemic.
Isabelle Mother or father du Châtelet, unit supervisor at Santé publique France, which helped fund the examine, mentioned, “The examine reveals how vital it’s to make sure that diphtheria immunization ranges are updated, notably for weak inhabitants teams, comparable to migrants, and that diphtheria poses a threat particularly amongst homeless folks, injecting drug customers, unvaccinated people and aged folks with pre-existing diseases.’
