23/09/2026
Diphtheria: Causes, Symptoms, Prevention and Treatment
Diphtheria is a serious and potentially life-threatening infectious disease caused mainly by the bacterium Corynebacterium diphtheriae. It commonly affects the nose, throat and tonsils, where the bacteria can produce a toxin that damages tissues and other organs.
1. Causes
Diphtheria is caused primarily by toxigenic strains of Corynebacterium diphtheriae.
It spreads from an infected person through:
Respiratory droplets from coughing or sneezing.
Close contact with an infected person.
Contact with contaminated objects or surfaces, less commonly.
Contact with infected skin lesions in cases of cutaneous diphtheria.
People who are unvaccinated or inadequately vaccinated are at greatest risk.
2. Symptoms
Symptoms usually begin 2–5 days after infection, although the timing can vary.
Common symptoms include:
Sore throat
Mild fever
Weakness and tiredness
Swollen glands in the neck
Difficulty or pain when swallowing
Hoarseness
Difficulty breathing
Nasal discharge
A thick grey or white membrane over the tonsils, throat or nose
The membrane can obstruct breathing and should not be forcibly removed, because this can cause bleeding and further complications.
Severe disease can cause:
Airway obstruction
Myocarditis (inflammation/damage of the heart)
Abnormal heart rhythm
Nerve damage or paralysis
Kidney complications
Death
3. Prevention
The most effective prevention is vaccination.
Important preventive measures include:
Routine childhood immunization with diphtheria-containing vaccines such as DTP-containing vaccines.
Completing all recommended vaccine doses and boosters.
Maintaining good hand hygiene.
Covering the mouth and nose when coughing or sneezing.
Avoiding close contact with people suspected of having diphtheria.
Promptly identifying and treating infected individuals.
Close contacts may require preventive antibiotics and vaccination, depending on public-health assessment.
4. Treatment
Diphtheria requires urgent medical attention and often hospital care.
Treatment may include:
Diphtheria antitoxin (DAT): neutralizes circulating toxin and is particularly important when toxin-mediated disease is suspected.
Antibiotics: commonly penicillin or erythromycin, depending on clinical circumstances and local guidelines.
Airway and breathing support if the throat membrane obstructs breathing.
Monitoring for heart and neurological complications.
Isolation to reduce transmission.
Vaccination if the person's immunization status is incomplete or uncertain.
Testing and management of close contacts.
Important: Anyone with suspected diphtheria should be taken to a healthcare facility immediately. Treatment should not be delayed while waiting for laboratory confirmation when clinical suspicion is high.
Key message
Diphtheria is preventable through vaccination and treatable when recognized early. A person with a severe sore throat, difficulty breathing/swallowing, swollen neck, or a grey/white membrane in the throat needs urgent medical evaluation, particularly if they are not fully vaccinated.
