An epidemiologic evaluation of leprosy in New York City.

Leprosy is a transmissible disease that is propagated from human to human. At the US Public Health Service hospital, New York City, the number of new leprosy cases per year during the 1970s was about three times greater than in the previous decade. This review of our 100 most recent leprosy patients shows that 60% were of the lepromatous and borderline lepromatous type. Ninety-nine of the patients were foreign born, originating in more than 26 countries. This emphasizes that, at this time, the leprosy problem in New York City is almost exclusively a reflection of immigration patterns. The majority of the patients were asymptomatic at the time of entering the United States. The average latent period from entering the United States until onset of symptoms was 4.8 years, with a range of 0 to 38 years. These figures emphasize the need for physicians to be aware that leprosy can occur as long as five to 40 years after emigration from endemic areas. For all types of leprosy, the average lag from the onset of symptoms to the time of diagnosis was 29.0 months (range, 0 to 245 months). Our experience indicates that a program of urban leprosy treatment using available drugs and supportive care is feasible.