The National Institute for Communicable Diseases wishes to advise members of the public to review the vaccination status of their children following an increase in diphtheria cases in the country. Since the beginning of 2025 (until 23 March), diptheria caused by a bacteria called toxigenic Corynebacterium. diphtheriae has been confirmed in 40 individuals in South Africa. Of these, 19 had symptoms, and 21 had no symptoms (asymptomatic). These asymptomatic individuals were carriers identified during contact tracing. This includes 15 respiratory diphtheria cases in the Western Cape, two cases in Gauteng, three cases in Mpumalanga and one probable case in Limpopo, not confirmed in the laboratory, but the individual had symptoms consistent with respiratory diphtheria.
More than 78% of the cases have been in adults (≥ 18 years of age). 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. Pregnant women are advised to get the vaccine with each pregnancy to protect the baby from diphtheria, tetanus and pertussis.
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”.
If not treated early, diphtheria causes difficulty in breathing and can lead to complete blockage of the airway and death. The organism also produces a toxin which affects the heart muscle, kidneys and nervous system, leading to life-threatening illness. Treatment is with diphtheria antitoxin to neutralise the toxin produced by the bacterium and appropriate antibiotics to eradicate the organism. Treatment must be given early to be effective. Doctors and healthcare workers should be on high alert for suspected diphtheria cases and are urged to report cases on the Notifiable Medical Condition app or the NICD website. Click here for more details.
The best protection against diphtheria is vaccination. Infant vaccine is given at 6, 10 and 14 weeks of age, with booster doses at 18 months, 6 years and 12 years of age. The available vaccines include Dt (diphtheria and tetanus) and Dtap [diphtheria, tetanus and acellular pertussis (whooping cough)]. Visit the NICD website for more information: https://www.nicd.ac.za/diphtheria-situational-report-week-11-of-2025/.
