The South Africa National Institute for Communicable Diseases (NICD) report two additional laboratory-confirmed cases of toxigenic diphtheria, both from Western Cape.
Between 29 December 2025 and 29 March 2026, 12 confirmed cases of respiratory diphtheria and two asymptomatic carriers of toxigenic C. diphtheriae, detected during contact tracing, have been identified in South Africa. All cases and carriers were from the Western Cape.
The median age for cases of confirmed respiratory diphtheria was 28 years (range: 7-36 years), with 75% (9/12) being 18 years and older. The overall case-fatality ratio (CFR) among confirmed respiratory diphtheria cases was 8% (1/12). The only diphtheria-related death occurred in a child aged 0–9 years.
In addition this year, one cutaneous toxigenic diphtheria case was reported from Gauteng.
Respiratory diphtheria is a vaccine-preventable illness caused by toxigenic C. diphtheriae (and more rarely C. ulcerans or C. pseudotuberculosis), and can occur in persons of all ages.
The clinical presentation includes the following signs and symptoms:
-
sore throat
-
low-grade fever
-
AND an adherent membrane of the nose, pharynx, tonsils, or larynx – the membrane is greyish-white and firmly adherent to the tissue
-
AND/OR enlarged glands in the neck (bull neck)
-
toxin-mediated systemic signs including myocarditis, polyneuropathy and renal damage
Treatment includes antibiotics (azithromycin or penicillin) to clear the organism from the throat and prevent onward transmission, and diphtheria anti-toxin (DAT) to neutralise unbound toxin. The dosage of DAT is determined by the duration and severity of illness. Treatment, contact tracing and chemoprophylaxis should be started prior to laboratory confirmation. Early administration of DAT may be life-saving and should not be delayed in cases with a high index of suspicion.
Robert Herriman
outbreaknewstoday.substack.com
