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HANSEN’S DISEASE
DIPLOMA IN MEDICAL
SCIENCE
SCHOOL OF ALLIED
SCIENCE
WINDFIELD INTERNATIONAL
COLLEGE
HANSEN’S DISEASE
RUTH NAOMI MANUEL
SARAVANAN A/L SURESH
SRIRENUKAA A/P MARIMUTHU
INTRODUCTION
Also known as leprosy
Chronic infectionCaused by Mycobacterium Leprae & Mycobacterium
Lepromatosis
Affects skin, nerves & eyes
• Paucibacillary - 5 or less poorly pigmented numb skin patches present
• Multibacillary - More than 5 poorly pigmented numb skin patches present
Two main types of disease based on the number of bacteria present-
TYPES OF LEPROSY
1-Indeterminate leprosy-
A few hypopigmented macules
can heal spontaneously
2-Tuberculoid leprosy-
A few hypopigmented macules
some are large and some become anesthetic
(lose pain, tactile and termic sensation)
nerves become enlarged; spontaneous resolution
Borderline tuberculoid leprosy-
Lesions like tuberculoid
leprosy but smaller and
more numerous with less nerve
Enlargement nerves; this form may
persist, revert to tuberculoid
Mid-borderline leprosy-
Many reddish plaques
asymmetrically distributed, moderately anesthetic
regional adenopathy
(swollen lymph nodes)
Histoid leprosy lepromatous leprosy that
presents with clusters of histiocytes
(a type of cell involved in the inflammatory
response)
A grenz zone
(an area of collagen
separating the lesion from
normal tissue)
Lepromatous leprosy Early lesions are pale macules ;
(flat areas) that are diffuse and
symmetric
Alopecia (hair loss) ; often
patients have no eyebrows
nerve involvement
leads to anesthetic areas
& limb weakness;
progression leads to aseptic
necrosis (tissue death from lack of blood to area)
lepromas (skin nodules)
disfigurement of many areas
including the face
CAUSES• An intracellular, acid-fast bacterium• Aerobic & rod-shaped bacterium• surrounded by the waxy cell
membrane• does not form capsules, flagella, or
spores
Mycobacterium leprae &
Mycobacterium lepromatosis
• Are obligate pathogens• Are unculturable in laboratory
Due to extensive loss of genes necessary for independent
growth ;
Mycobacterium Leprae
Electron Micrograph
Acid Fast
Gram Staining
MODE OF TRANSMISSION
Person to person-leprosy spread from person to
• through infected respiratory
droplets• Through close contact with the affected person
Genetics• Parents of someone with
leprosy• Children of someone with
leprosy
The extent of exposure
Environmental conditions
• Poor hygiene condition
PATHOGENECITY (VIRULENCE FACTOR)
Iron utilization
• Help the pathogen acquire nutrients for growth• NRAMP proteins
• Allow transportation of iron into the macrophage for survival
Waxy
exterior
• Allows intake into the macrophage and into some dendritic cells in which it can survive
Macropha
ge invasion
• Prevent phagosome and lysosome fusion to avoid degradation
• Bacteria are absorbed into the phagolysosome
Schwann cell invasion
Major target of Mycobacterium leprae
To access the cells, Mycobacterium leprae gets
into the lymphatic system and the blood vessels
Mycobacterium leprae binds to the Schwann cell via laminin-binding protein
The bacteria will enter through the vascular
epithelium into the cell
Drug resistance
Allow it to continue to survive despite
antimicrobial presence
PATHOGENESIS
Mycobacterium leprae
has a difficult time
replicating outside of host cells
It is a very slowly
replicating bacteria that can take up to 13 days
Leprosy - bacterial replication inside intracellular vesicles • macrophages,
Schwann cells, & endothelial cells
CELL BINDING
Bacteria binds to receptors on the host cell surface
In neural Schwann cells, the phenolic glycolipid-1 (PGL-1) or LBP21 receptor on M. leprae binds to the α-2 side chain of laminin-2 & α-dystroglycan receptor(1)
Presence of the histone-like protein Hlp, secreted by M. leprae, enhances Schwann cell binding
Facilitates phagocytosis by the classical complement pathway
Once binding has occurred, M.
leprae is taken into the host cell by phagocytosis
and is encapsulated by
a phagosome
Survive phagosome-lysosome fusion & live long
enough to replicate
Replication will take
place
SIGNS & SYMPTOMSLeprosy symptoms generally appear three to five years after a person becomes infected with bacteria
Skin lesions that are lighter than your normal skin color; lesions have decreased sensation to touch, heat, or pain and lesions do not heal after several weeks to months
Numbness or absent sensation in the hands, arms, feet, and legs
Muscle weakness
Eye problems
Skin rash
Skin stiffness
Hypopigmented Macule Deformity
Skin Lesions
EXAMS AND TESTS
Lepromin skin test • D
istinguish lepromatous from tuberculoid leprosy, but is not used for diagnosis.
Skin lesion biopsy.
Different tests can be employed in the diagnosis of different type of
leprosy
Epidemicology Triangle of Leprosy
Agent- Mycobacterui
m leprae
Environment- Transmitted by
person to person contact
Host – Infected to
human
Lab Diagnosis
Skin lesion biopsy
CBC
PCRLiver blood
Creatinine blood
Lepromin skin
Types of Skin biopsy
Shave biopsy
Punch biopsy
Exicisional biopsy
Incisional biopsy
Shave Biopsy
least invasive method.
Your doctor uses a small blade to
remove the outermost layers
of skin.
The area removed includes all or part
of the lesion.
Do not need stitches.
At the end of the procedure, medicine is
applied to the area to stop any
bleeding.
Excisional Biopsy
usually done by
a surgeon. During the
procedure, the entire lesion is
removed.
Numbing medicine is
injected into the
area.The entire lesion is
removed, going as deep as
needed to get the
whole area.
The area is closed with
stitches. If a large area is biopsied, a skin graft or flap of
normal skin may be used to
replace the skin that was removed.
Incisional Biopsy
CBC ( Comp
lete Blood
Count )
Most commonly ordered
blood tests.
The complete
blood count is
the calculation of the cellular (formed
elements) of blood.
Determined by
special machines
that analyze
the different compone
nts of blood in less than a minute.
To measure
of the concentra
tion of white blood
cells, red blood
cells, and platelets
in the blood.
PCR (Polymerase
Chain Reaction)
PCR recombined
DNA technology
have allowed for
development of genes M.leprae
Used in biopsy
samples , blood and
tissue section
Liver
blood test.
Most
common
ly performed
blood
tests.
Can be
used to
assess
liver functions or liver injur
y.
An initial step is a
simple blood test to determine the
level of
certain liver
enzymes
(proteins) in the
blood.
But when the liver
is injured for any
reason,
these enzymes are
spilled
into the
blood
stream.
Creatinine blood test.
If the kidney become impaired
, the creatinine level rise due to
poor clearance of creatinine by the
kidney.
Found to be a fairly reliable indicator of
kidney function.
Elevated creatinine level
signifies impaired
kidney function.
Lepromin skin test
Used to determine what type of leprosy a person has.
A sample of inactivated leprosy-causing bacteria is injected just under the skin, usually on the forearm, so that a small lump pushes the skin up.
The lump indicates that the antigen has been injected at the correct depth.
The injection site is labelled and examined 3 days, and again 28 days, later to see if there is a reaction.
Medication
Surgical care
Treatment
Medication
Dapsone
RifampinClofazimine
Dapsone
Bactericidal
Mechanism of action is the prevention of
formation of folic acid, inhibiting
bacterial growth
Part of a 2-drug regimen for treatment
of paucibacillary leprosy; part of a 3-
drug regimen for treatment of
multibacillary leprosy
Rifampin
For use in combination with at least 1 other antituberculous drug.
Inhibits DNA-dependent bacterial RNA polymerase.
Cross-resistance may occur. Treat for 6-9 months or until 6 months have elapsed from time of negative sputum test.
Clofazimine
Epidemiology
The number of new cases of leprosy per year (incidence) also
fell from approximately
720,000 in 2000 to about 300,000 in
2005
Since then this has stabilised, with an
estimated 230,000 new cases reported in 2010. The highest numbers of new cases in 2010 were
reported from India, Brazil, Indonesia, the
Democratic Republic of Congo, and Ethiopia
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