Cases of cutaneous diphtheria in New Zealand: implications for surveillance and management

Diphtheria is an acute bacterial illness caused by toxigenic strains of Corynebacterium diphtheriae (C. diphtheriae). We describe two epidemiologically-linked cases of skin infections from which toxigenic C. diphtheriae was isolated, and discuss implications for diphtheria surveillance and management in New Zealand.

A public health investigation was undertaken to identify and manage close contacts of the index case. National and international guidelines on the surveillance and management of cutaneous diphtheria were reviewed, and data on toxigenic C. diphtheriae isolates identified in New Zealand from 1987-2009 were examined.

The index case was an adult male who developed a cutaneous infection after being tattooed in Samoa. A wound swab taken from the infected tattoo grew a toxigenic strain of C. diphtheriae (var gravis). A secondary case of toxigenic cutaneous diphtheria was identified in a household contact. Instances of respiratory diphtheria associated with toxigenic cutaneous lesions have been reported in the literature. The review of surveillance data revealed inconsistencies in the notification of toxigenic strains of C. diphtheriae isolated from cutaneous sites.

These cases are an important reminder that diphtheria remains a threat in New Zealand. All cases with toxigenic C. diphtheriae isolated from a clinical specimen, regardless of the site of infection, should be notified to a Medical Officer of Health.