Corynebacterium diphtheriae, a gram-positive bacillus, is the causative agent of diphtheria which may occur in one of two forms: respiratory or cutaneous. Humans are the reservoirs of the organism. The respiratory form is caused by toxin producing strains. The cutaneous form may be caused by either toxin or non-toxin producing strains. Cases of cutaneous diphtheria are not reportable.
The respiratory form of diphtheria is characterized by the formation of a membrane in the throat and/or on the tonsils which interferes with respiratory functions. Medical treatment is dependent on the administration of diphtheria antitoxin, available only from the Centers for Disease Control and Prevention (CDC).
Diphtheria is prevented by administration of a primary series of diphtheria toxoid injections. Adults require three injections and infants require four injections. Both adults and children should receive boosters every 10 years.
Although rare in the United States, diphtheria can infect unimmunized or partially immunized travelers to endemic countries. Countries with endemic diphtheria include Africa – Algeria, Egypt, and the countries in sub-Saharan region; Americas – Brazil, Dominican Republic, Ecuador, and Haiti; Asia/Oceania – Afghanistan, Bangladesh, Cambodia, China, India, Indonesia, Iran, Iraq, Laos, Mongolia, Burma (Myanmar), Nepal, Pakistan, Philippines, Syria, Thailand, Turkey, Vietnam, and Yemen; and Europe – Albania and all countries of the former Soviet Union.
No cases of diphtheria have been reported in Indiana since 1996.