Leprosy in the United States, 1971-1981

Area of Science:

• Epidemiology
• Infectious Diseases
• Public Health

Background:

• Leprosy (Hansen's disease) is a chronic infectious disease primarily affecting the skin, peripheral nerves, upper respiratory tract, eyes, and testes.
• While historically associated with endemic regions, changes in global migration patterns impact disease distribution.

Purpose of the Study:

• To analyze the trends and characteristics of leprosy cases reported in the United States between 1971 and 1981.
• To understand the proportion of indigenous versus imported cases and the timing of diagnosis for imported cases.

Main Methods:

• Retrospective analysis of reported leprosy cases in the United States from 1971 to 1981.
• Categorization of cases into indigenous and imported, with further analysis of diagnosis timing for imported cases.

Main Results:

• A total of 1,835 leprosy cases were reported, with only 10% being indigenous.
• Since 1977, an increase in reported cases was observed, driven by imported cases linked to immigration from leprosy-endemic areas.
• In 75% of imported cases, leprosy was diagnosed after immigration, with onset often occurring within 12 months but extending up to 10 years post-entry.

Conclusions:

• The rise in leprosy cases in the US is significantly influenced by immigration from endemic regions.
• A substantial proportion of imported leprosy cases are diagnosed domestically, highlighting the need for increased medical and public health preparedness.
• Effective diagnosis, treatment, and long-term follow-up strategies are crucial for managing leprosy in the context of diverse populations and widespread resettlement.