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Istituto Superiore di Sanità
EpiCentro - Epidemiology for public health
Epidemiology for public health - ISS

Diphtheria is an acute infectious disease caused by the bacterium Corynebacterium diphtheriae. After entering the body, this infective agent releases a toxin that can damage or even destroy organs and tissues. These organs vary depending on the type of bacterium involved: the most common one affects the throat, nose and sometimes tonsils; another type, mainly present in tropical regions, causes skin ulcers. More rarely, the infection affects the vagina or conjunctiva.


Diphtheria can affect people of all ages, but most often strikes unvaccinated children. In temperate climates, it tends to occur during the winter months.

Publication date: 15 January 2021