Between 1 January 2024 and 9 March 2025, 31 confirmed cases of respiratory diphtheria and 38 asymptomatic carriers of toxigenic C. diphtheriae, detected during contact tracing, have been identified in South Africa. The majority of confirmed cases and carriers (93%, 64/69) were from the Western Cape, comprising 28 respiratory diphtheria cases and 36 asymptomatic carriers. The median age of cases of confirmed respiratory diphtheria was 31 years (range: 3–51 years), with 77% (24/31) aged over 18 years and the case-fatality ratio was 23% (7/31).
Highlights:
- Since the last situational report (week 9), the following updates are included in this report:
o No new laboratory-confirmed cases of toxigenic respiratory diphtheria
o Two asymptomatic carriers of toxigenic C. diphtheriae, one from the Western Cape and one from Mpumalanga - Appropriate public health responses have been initiated for each case
Information for clinicians
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 (Figure 2) – 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.
