Transcript Leprosy - Penn State York

Leprosy
Mycobacterium leprae
Quick Reference
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Environment: human, mice, nine-banded armadillo
Microorganism: Gram + rod
Spore former: NO
Motile: NO
Susceptibility: anyone
Communicability: infectious
Exposure: exposure to skin
Incubation: 2-20 years
Primary Treatment: antibiotics; multi-drug treatment
Prognosis: antibiotics keep disfigurement to a minimum
Quarantine recommended: occasionally
( This is a Small island off the Upolu coast once designated as a leper colony )
Taxonomy
Kingdom: Monera
Phylum: Schizophyta
Class: Actinomycetes
Order: Actinomycetales
Family: Mycobacteriaceae
Genus: Mycobacterium
Species: Leprea
Physiology
 The genome of the Myrcobacteria
leprae 1–8 μm long and 0.3–0.5 μm
wide
 aerobic
 nonsporeformers
 have a cell wall that is rich in longchain fatty acid esters known as
"mycolic acids" that are attached to the
cell wall through arabinogalactan
 Mycolic acids are chemically related to
wax and give the colonies their
characteristic waxy appearance, and
the cells, a tendency to clump and
resist dispersion
 Gram Positive
 all mycobacteria grow slowly with
generation times that range from 2
hours for M. smegmatis to 12 days for
M. leprae.
Diagnostic Tests
 the only methods to propagate M. leprae bacilli are
via animal infections with either 9-banded armadillos
or severe combined immunodeficiency (SCID)
mice.
 Growth of sufficient bacilli for laboratory
manipulation takes approximately one year,
inasmuch as the generation time for this organism is
approximately 14 days in animal tissues.
Incubation
 children younger than two years do not have leprosy
symptoms. In addition, people residing in nonendemic
countries who have visited a site with endemic leprosy
may develop the disease many years after the initial
exposure
 Leprosy is a chronic disease with a long incubation
period
 the incubation period is estimated to range from 2–12
years ( can be longer). Like those infected with TB, only
about 10% of those infected with leprosy go on to
develop the disease
Leprosy Symptoms
 Leprosy is also known as
Hansen's disease.
 Caused by a germ similar to that
which causes tuberculosis.
 It attacks the nerves of the hands,
feet and face.
 If left untreated can take away the
ability to move fingers, toes and
eyelids.
 It can also destroy the ability to
feel pain so those affected are
prone to injuries and burns.
 The longer the disease is left
undetected, the more likely it is
that the deformities, so often
associated with leprosy, will occur.
Latest Mortality and Morbidity Reports
Many people tend to think of leprosy as a biblical disease. The truth is that the World Health Organization (WHO) still
lists leprosy as one of the major health problems of developing countries – including India, Brazil, Africa, Nepal and
Bangladesh
WHO Region
Cases on treatment
New Cases Detected in 2002
Africa
53,888
48,248
Americas
75,686
39,939
7,899
4,665
385,458
520,632
11,335
7,154
45
34
534,311
620,672
Eastern Med.
S.E. Asia
Western Pacific
Europe
Total
Source: World Health Organization 2003
(figures shown for 110 reporting countries)
In 2002 over 610,000
people were
diagnosed with
leprosy. At that rate
the number of new
cases found this
year would be
590851
The Cure
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The good news is that today leprosy can be
cured.
A course of pills, called Multi-Drug Therapy
(MDT), cures most patients in 6 months, and
the more infectious patients within 1 year.
If treatment is started early deformities and
disabilities can be prevented and social
stigmatization avoided.
The effects can be incredibly dramatic as
the photograph below shows
References
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Mycobacterium leprae (leprosy). http://microbes.historique.net/leprae.html
BEATRICE SAVIOLA WILLIAM BISHAI. The Genus Mycobacterium—Medical. The
Prokaryotes: an evolving electronic resource for the microbiological community. ©
1991, 1994-2004 Springer-Verlag New York, LLC
Lepra. What is Leprosy. http://www.lepra.org.uk/home.asp