Diphtheria is a serious infection caused by strains of the bacteria called Corynebacterium diphtheriae which makes a toxin. The toxin attaches itself most commonly to tissues in the respiratory system and causes disease by killing healthy tissue.

Diphtheria is a serious infection caused by strains of the bacteria called Corynebacterium diphtheriae which makes a toxin. The toxin attaches itself most commonly to tissues in the respiratory system and causes disease by killing healthy tissue.