Skip to main content
A Singapore Government Agency Website How to identify
Official website links end with .gov.sg
Government agencies communicate via .gov.sg websites (e.g. go.gov.sg/open). Trusted websites
Secure websites use HTTPS
Look for a lock () or https:// as an added precaution. Share sensitive information only on official, secure websites.

Government officials will never ask you to transfer money or disclose bank log-in details over a phone call.

Call the 24/7 ScamShield Helpline at 1799 if you are unsure if something is a scam.

Communicable Diseases Agency

Diphtheria

Diphtheria is a bacterial disease caused by Corynebacterium diphtheriae.

Last updated 7 November 2025

What is diphtheria?

Diphtheria is a bacterial disease caused by Corynebacterium diphtheriae. The bacteria produce toxins that destroy healthy tissues, leading to severe infections. The disease occurs worldwide.

How is diphtheria transmitted?

Diphtheria is primarily transmitted through direct deposition of infectious respiratory particles when an infected person coughs or sneezes. It can also be transmitted via contact with contaminated surfaces, such as when a person touches these contaminated surfaces and then touches their eyes, nose or mouth.

Diphtheria can also be transmitted via direct contact with open sores or ulcers caused by Corynebacterium diphtheriae.

The incubation period is typically 2 to 5 days, ranging from 1 to 10 days.

What are the symptoms of diphtheria?

The symptoms of diphtheria depend on the site of infection. It usually involves the mucous membranes. These may include:

  • Respiratory infection: Symptoms include sore throat, fever, fatigue and swollen neck glands. A coating of dead tissue (called “pseudomembrane”) can occur in the throat, making it difficult to breathe and swallow.

  • Skin infection: Usually presents with ulcers, pain, redness, swelling and rash with peeling skin.

Mucous membranes of the eyes, genitalia and ears could also be affected.

Diphtheria infection can lead to complications at the respiratory site, including severe neck swelling that may cause airway obstruction. If the toxin enters the bloodstream, it can damage tissues in other organs, leading to complications such as kidney failure, myocarditis (inflammation of the heart muscle) and polyneuropathy (nerve damage).

What are the risk factors?

Risk factors include:

  • Persons who are partially vaccinated or unvaccinated against diphtheria

  • Persons with weakened immune systems

  • Persons travelling or living in areas with ongoing transmission or outbreaks

How is diphtheria treated?

Patients are given antibiotics to treat the infection, and diphtheria antitoxin to neutralise toxin in the blood. Other treatments include those that manage and relieve the symptoms of the disease. Those who have had close contact with persons infected with diphtheria may need antibiotics for prophylaxis and vaccination if they are not previously vaccinated. Prompt and early treatment can prevent complications or death from diphtheria.

How to prevent diphtheria?

Vaccination is the most effective preventive measure for diphtheria. The diphtheria vaccination is compulsory for children in Singapore under the Infectious Diseases Act. Please refer to the National Childhood Immunisation Schedule (NCIS) for vaccine recommendation on diphtheria.

Other preventive measures:

  • Practise good personal hygiene at all times.

  • Wash your hands regularly with soap, especially before handling food or eating, after going to the toilet, or when hands are dirty from coughing or sneezing.

  • Avoid touching your face, including eyes, nose and mouth with unwashed hands.

  • Avoid sharing of food/drinks or eating utensils.

  • Wear a mask and seeking medical attention promptly when unwell.

Please refer to Health advice for travellers for additional precautions to take when travelling.