Diphtheria (pronounced "diff-THEER-ee-uh") is an infectious disease caused by a bacterium called Corynebacterium diphtheriae. It can be treated by special drugs, or by antibiotics. There is a vaccine which can prevent diphtheria. In 1942, there were 50,804 diphtheria cases in England and Wales; now there is about one case a year.
Diphtheria can cause serious problems, like: