Diphtheria in Europe: current problems and new challenges

Area of Science:

• Infectious Diseases
• Microbiology
• Public Health

Background:

• Diphtheria, caused by toxigenic Corynebacterium diphtheriae, historically caused epidemic waves with high mortality.
• Despite progress towards elimination in Europe by the 1980s, a major epidemic re-emergence occurred in the Russian Federation and Newly Independent States into the 1990s.

Purpose of the Study:

• To review the historical epidemiology and current global threat of diphtheria.
• To highlight the ongoing circulation of toxigenic strains and the emergence of Corynebacterium ulcerans as a zoonotic cause of diphtheria.

Main Methods:

• Literature review of diphtheria epidemiology.
• Analysis of historical and recent surveillance data.
• Review of emerging zoonotic pathogens causing diphtheria-like illness.

Main Results:

• Diphtheria epidemics have been controlled in Europe, with only sporadic cases currently observed.
• Toxigenic strains of Corynebacterium diphtheriae continue to circulate globally, posing a risk to under-seroprotected populations.
• Corynebacterium ulcerans is increasingly identified as a zoonotic agent of diphtheria, originating from companion animals.

Conclusions:

• Diphtheria remains an enduring global health threat due to persistent circulation of toxigenic strains.
• The emergence of zoonotic Corynebacterium ulcerans underscores the need for continued vigilance and surveillance for diphtheria and diphtheria-like diseases.