A rare case of potentially fatal diphtheria has been detected in Canterbury, in the finger of a traveller who had been in Samoa.
The 48-year-old had returned to Christchurch following a brief stay in Samoa last year.
The Institute of Environmental Science and Research said soon after the person returned they noticed their right middle finger was swollen.
A swab of the finger wound revealed diphtheria of the skin after the person had been admitted to hospital for unrelated congestive heart failure.
Because the disease can spread to the throat and bloodstream, the patient was given antibiotics and was cleared.
Nine patients in the same room, and staff, were also given antibiotics and the diphtheria vaccine and none became infected.
Immunisation in childhood and at 45 and 65 mean diphtheria is rare in New Zealand.
Four cases of skin diphtheria were diagnosed in 2014 and 2015 from infections picked up overseas.