Mycobacterium ulcerans infection in North Queensland: the 'Daintree ulcer'

As the third most common mycobacterial infection in the world after tuberculosis and leprosy, Mycobacterium ulcerans is a major health and development problem that has become the focus of a World Health Organisation (WHO) initiative seeking to reduce the burden of this disease. The Daintree River catchment in north Queensland is an endemic focus for Mycobacterium ulcerans infection, known locally as the 'Daintree Ulcer'. The aim of this study is to analyse the changing pattern of the disease over the last 44 years in the region.

The study is a descriptive review of all human cases where infection had been acquired in an endemic region of far north Queensland. Demographic information, lesion characteristics, management and outcomes were recorded in a database.

Over the period there were 92 cases of M. ulcerans infection. The average age was 41.7 years and 56.7% were male. There was distinct clustering of cases in several defined locations in the area. Most cases (90%) presented with ulcers, and all but three patients were treated surgically. Excision and skin grafting was more commonly used in the period between 1964-1988. Excision alone was the most common treatment used thereafter. Earlier recognition and smaller lesion size is thought to have contributed to the change in surgical practice.

Ulcers caused by M. ulcerans infection are a distinct clinical entity in tropical North Queensland. Early recognition, diagnosis and prompt surgical intervention has minimised morbidity associated with this disease.