Clinical
Features |
This chronic infectious disease
usually affects the skin and peripheral nerves but has a wide
range of possible clinical manifestations. Patients are classified
as having paucibacillary or multibacillary Hansen's disease.
Paucibacillary Hansen's disease is milder and characterized
by one or more hypopigmented skin macules. Multibacillary
Hansen's disease is associated with symmetric skin lesions,
nodules, plaques, thickened dermis, and frequent involvement
of the nasal mucosa resulting in nasal congestion and epistaxis. |
Etiologic
Agent |
A bacillus, Mycobacterium leprae,
that multiplies very slowly and mainly affects the skin, nerves,
and mucous membranes. The organism has never been grown in
bacteriologic media or cell culture, but has been grown in
mouse foot pads. |
Incidence |
In 2002, the number of new cases
detected worldwide was 763,917. In 2002, 96 cases occurring
in the United States were reported to CDC. In 2002, WHO listed
Brazil, Madagascar, Mozambique, Tanzania, and Nepal as having
90% of cases. |
Sequelae |
Worldwide, 1-2 million persons are
permanently disabled as a result of Hansen's disease. However,
persons receiving antibiotic treatment or having completed
treatment are considered free of active infection. |
Transmission |
Although the mode of transmission
of Hansen's disease remains uncertain, most investigators
think that M. leprae is usually spread from person
to person in respiratory droplets. |
Risk
Groups |
Close contacts with patients with
untreated, active, predominantly multibacillary disease, and
persons living in countries with highly endemic disease. |
Surveillance |
Hansen's disease is nationally notifiable
in the United States. |
Trends |
Prevalence has remained relatively
stable in the United States. Decreasing numbers of cases worldwide
with pockets of high prevalence in certain countries. |
Challenges |
Multi-drug therapy has not been
implemented in many endemic areas. Nerve damage must be recognized
and managed. Relapse rate after completion of short course
multi-drug therapy may rise. |
Opportunities |
Opportunities exist for participation
in Hansen's disease elimination activities in endemic-disease
countries, and for Mycobacterium research in the Laboratory
Research Branch of the National Hansen's Disease Program. |
|
December 2003
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