Diphtheria is a contagious bacterial infection caused by strains of bacteria called Corynebacterium diphtheriae. The bacteria infect the upper airways of the respiratory system (nose and throat) and release a toxin that makes us sick. The bacteria can also infect the skin. Diphtheria is spread through close contact with others, such as coughing or sneezing next to someone. It can also be spread through sharing personal items such as drinks, cutlery, and clothing. While diphtheria is rare in Canada, it is common in Asia, the South Pacific, the Middle East, Eastern Europe, and in Haiti and the Dominican Republic. Death occurs in up to 1 out of 10 cases, with most deaths occurring in very young children and elderly persons who are unimmunized. Persons of any age can catch diphtheria. However, it is most serious in infants and very young children.