The rise in diphtheria cases across South Africa has renewed concerns about this deadly yet preventable disease.
With nine confirmed fatalities reported this year alone, the National Institute for Communicable Diseases (NICD) is urging parents and guardians to urgently review their children’s vaccination records ahead of the approaching school holidays and the long Easter weekend, a time when families commonly travel and engage in activities together.
Diphtheria is a contagious, severe, vaccine-preventable illness, usually associated with a sore throat, fever, and large swollen glands in the neck. This is sometimes called a “bull neck”, and on examining a patient, the doctor will see a characteristic adherent membrane over the tonsils and the throat. This is sometimes called a “pseudomembrane”.
NICD spokesperson Vuyo Sabani said that since mid-June 2024 to March 23, 2025, 40 cases of diphtheria caused by a bacteria called toxigenic Corynebacterium diphtheriae have been confirmed in the country.
This includes 15 respiratory diphtheria cases in the Western Cape, two in Gauteng, three in Mpumalanga, and one probable case in Limpopo.
The NICD reported that the Limpopo case presented symptoms consistent with respiratory diphtheria, but laboratory confirmation is pending.
Breakdown of the diphtheria cases from 2024 to March 23, 2025:
- The first six months of 2024 saw two reported cases of respiratory diphtheria, one in Kwa-Zulu Natal and one in the Western Cape.
- During July and September 2024, a cluster of three respiratory diphtheria cases and seven asymptomatic contacts who tested positive for toxigenic C. diphtheriae were identified in a community located in Cape Town's Western Sub-District, Western Cape Province. Two additional sporadic respiratory diphtheria cases were reported in Cape Town, with no links to the cluster.
- The Western Cape has seen a significant rise in diphtheria cases since November 2024. In Cape Town, 12 respiratory diphtheria cases and 12 asymptomatic contacts have tested positive for toxigenic C. diphtheriae. This includes a cluster of one respiratory diphtheria case and 12 asymptomatic contacts linked to a correctional facility in Cape Town.
- Gauteng reported one confirmed respiratory diphtheria case and one asymptomatic contact who tested positive for toxigenic C. diphtheriae during week two of 2025 (week starting January 13, 2025).
- A report based on data collected by the NICD up to March 16, 2025, stated that there were two new laboratory-confirmed cases of toxigenic respiratory diphtheria, both from Mpumalanga, one of whom has died. One probable case from Limpopo who died was linked to a case in Mpumalanga.
Sabani stated that 19 individuals exhibited symptoms, while 21 were asymptomatic carriers identified through contact tracing.
He said that more than 78% of cases have been in adults over the age of 18.
“Of the symptomatic cases, it is important to note that nine individuals have died, with a case fatality ratio of 27% (9/33) since the beginning of 2024.
“Adults who have not had a diphtheria vaccine in the last 10 years are urged to seek vaccination at a clinic or with their usual healthcare provider. Pregnant women are advised to get the vaccine with each pregnancy to protect the baby from diphtheria, tetanus, and pertussis.”
Sabani said that if diphtheria is not treated early, the disease causes difficulty in breathing and can lead to complete blockage of the airway and death.