Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae. Before the introduction of routine vaccination, the disease ranked among the leading causes of infant mortality.
Following a one to five day incubation period, typical diphtheria presents as pharyngitis with pseudomembranes that can spread, obstruct the airways and eventually lead to death by asphyxia. Complications of diphtheria include potentially fatal heart and neurological disorders.


  1. World Health Organization. Immunization coverage fact sheet. Available at http://www.who.int/mediacentre/factsheets/fs378/en/, accessed June 2017.
  2. World Health Organization. Available at https://www.who.int/immunization/diseases/diphtheria/en/, last update 20 September 2018.