Between 01 January 2024 and 11 May 2025, 50 confirmed cases of respiratory diphtheria, 1 probable respiratory diphtheria case, 1 case of cutaneous toxigenic diphtheria, and 44 asymptomatic carriers of toxigenic C. diphtheriae, detected during contact tracing, have been identified in South Africa. The majority of confirmed respiratory diphtheria cases (62%, 31/50) were from the Western Cape. The median age for cases of confirmed respiratory diphtheria was 26.5 years (range: 2–55 years), with 72% (36/50) being 18 years and older. The overall case-fatality ratio (CFR) among probable and confirmed respiratory diphtheria cases was 22% (11/51). Among children and adolescents under 18 years, the CFR was 21% (3/14), compared to 22% (8/37) among adults.
Highlights:
- Since the last situational report (week 18), the following updates are included in this report:
o One new laboratory-confirmed case of toxigenic respiratory diphtheria from Limpopo.
o No new asymptomatic carriers of toxigenic C. diphtheriae.
o One new laboratory-confirmed toxigenic cutaneous diphtheria from Gauteng. - Appropriate public health responses have been initiated for each case.
Information for clinicians
Clinical presentation of respiratory diphtheria
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
Patient management
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. Supportive care is primarily aimed at airway management and includes providing oxygen, monitoring with electrocardiogram and intubation or performance of a tracheostomy if necessary.
To access previous diphtheria situational reports, click here.
