Leprosy in Toronto: an analysis of 184 imported cases

Leprosy is a rare but serious mycobacterial infection. Immigration from areas where the disease is endemic has resulted in the importation of leprosy into countries where it is not endemic and where physicians and health care workers have little or no experience in diagnosis and therapy. In this study we characterized leprosy patients seen in a tropical disease unit that manages most of the reported leprosy cases in Canada.

We reviewed the clinical records of all 184 leprosy patients who were referred to the Tropical Disease Unit at Toronto General Hospital between 1979 and 2002 and abstracted demographic and clinical information.

Patients were more likely to be male (122 or 66.3%) and of Indian (44 or 23.9%), Filipino (49 or 26.6%) or Vietnamese (37 or 20.1%) origin. Patients experienced symptoms for a mean of 4.8 years before referral to the Tropical Disease Unit. Most had no family history of leprosy (152/172 or 88.4%). Most patients presented with either borderline tuberculoid (80 or 43.5%) or borderline lepromatous (37 or 20.1%) disease. On average, patients presented with 5.8 skin lesions. Upper- and lower-extremity nerve dysfunction was common at presentation, with up to one-third of patients demonstrating either sensory or motor loss. A significantly greater lag time to presentation was observed in patients who emigrated from low-prevalence regions (p < 0.001).

Leprosy is a chronic infectious disease that is associated with serious morbidity if left untreated. Leprosy is uncommon in developed countries, but it is important for physicians to have a high index of suspicion when a foreign-born patient presents with chronic dermatitis and peripheral nerve involvement.