A rare case of toxigenic diphtheria tonsillitis resistant to penicillin causing sepsis and death

Diphtheria is a rare, contagious and potentially life threatening acute bacterial infection caused by toxigenic and non-toxigenic strains of Corynebacterium diphtheriae. Australian public health immunization initiatives have resulted in near complete eradication. An unimmunized 22-year-old female presented to the Emergency Department of the Princess Alexandra Hospital with a 6-day history of a sore throat despite previous oral and intravenous antibiotic therapy. Examination and investigation revealed diffuse pseudomembranous coating of her upper aerodigestive tract and tracheobronchial tree. Biopsy confirmed Corynebacterium diphtheriae and sensitivity testing demonstrated penicillin-resistance. Unfortunately, she progressively deteriorated despite maximal antimicrobial therapy and succumbed to the infection on day six of admission. This is the first documented Australian death from toxigenic Corynebacterium diphtheriae since 1992 and the first reported case of penicillin-resistance. Immunization is fundamental in preventing diphtheria-related morbidity and mortality. Clinicians must now be wary of emerging penicillin-resistance.