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.
Symptoms of diphtheria
- 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.
- Diphtheria-related mortality remains high (10%) even during recent outbreaks.
- Diphtheria must be treated as an emergency in order to reduce the risk of complications and death. Treatment relies mainly on the administration of diphtheria antitoxin by the intramuscular or intravenous route. Antibiotics are also used to contain bacterial growth, but they have no effect whatsoever on toxin-induced symptoms.
Epidemiology and vaccination against diphtheria
- Humans are the only natural reservoir of Corynebacterium diphtheriae. Transmission occurs through respiratory droplets and close physical contact.
- Before vaccination against diphtheria became readily available in the 1980s, it was estimated that approximately 1 million cases including 50,000-60,000 deaths occurred in low and middle income countries each year.(1)
- Diphtheria is still present in many countries and epidemics have broken out during the 1990's in Eastern Europe.(1)
- Diphtheria vaccines are produced from diphtheria toxoid, a non-toxic form of the toxin.
1 - WHO. Diphtheria vaccines Position paper; WER 2017, 92: 417-436; accessed January 2018 http://www.who.int/immunization/policy/position_papers/wer_31_diphtheria_updated_position_paper.pdf?ua=1