2. It is a chronic infectious
disease caused by M.leprae,
an acid fast, rod shaped
bacillus.
It mainly affects the skin,
peripheral nerves, and mucosa
of the respiratory tract etc…
3. HISTORY
One of the oldest and most
dreaded disease known to
mankind.
Discovered by Dr.Gerhard
Armauer Hansen in 1873 in
Norway.
Hansen’s disease
The term leprosy was taken
from a Latin word, ‘lepra’
means scaly.
4.
5. EPIDEMIOLOGY
Age
All ages,from early infancy to very old age
Youngest age reported is 1 and half months
Sex
Both
Males more than females,2:1
Source of infection
Patient
7. MORPHOLOGY
• Slender,straight or slightly curved rods
• Size – 1-8µmx0.2-0.5 µm.
• Occurs characteristically in clumps or
bundles(globi)
• Acid fast bacilli
• Live bacilli, solid uniform structure.
• Dead appear as fragmented
with granules.
8. CULTIVATION
Not possible to cultivate – media, tissue culture
Generation time – 12–13 days[20 days]
Cultivation
Foot pad of mice
Nine-banded armadillo (Dasypus novemcinctus)
Chimpanzees
Monkeys
Slender loris
Indian pangolin
Chipmunks
Golden hamsters
European hedgehog
Adaptation in artificial media – ICRC bacillus [Indian Cancer Research Center]
14. PATHOGENESIS
Chronic granulomatous disease
Patient is the only source of
infection-nasal discharge&skin
lesion
Mostly affects the cooler parts of
the body skin, eyes and nasal
mucosa.
Incubation period- long&variable
15.
16. SIGNS AND SYMPTOMS
Skin
Discolored patches on skin
Dry skin
Painless ulcers on the soles of feet
Painless swelling or lumps on the face and ear lobes
18. LEPROMATOUS TYPE
Generalized form
Found in individuals with low resistance
Severe and prognosis is poor.
More infectious
Lepromin test – negative (CMI )
Nodular lesions on face,ear lobes,hands, feet and less
commonly on trunk.
Bacilli are shed in sweat , nasal and oral secretions
Continous bacteremia is commonly seen
19. TUBERCULOID TYPE
Localised form.
Seen in patients with high degree of resistance
Skin lesions are few- face, limb and trunk.
Consists of non elevated hypo or
hyperpigmented macular patches
Bacilli are very few & absent in tissues
Lepromin test- positive.
Diagnosis – clinical& histological findings.
20. DIMORPHOUS TYPE
Clinically resemble tuberculoid leprosy
INDETERMINATE TYPE
Neither characteristic of tuberculoid not
lepromatous type.
Lesions heals spontaneously
21. RIDLEY & JOPLING’S
CLASSIFICATION
On the basis of clinical , histopathological
and immunological findings
1. Tuberculoid(TT)
2. Borderline tuberculoid(BT)
3. Borderline(BB)
4. Borderline lepromatous(BL)
5. Lepromatous(LL)
22. WHO CLASSIFICATION
Classification depends upon number of skin
lesions and involvement of nerves
Paucibacillary
When there are ≤5 skin lesions and
no/one nerve trunk involvement.
Multibacillary
6 or more skin lesions and more than
one nerve trunk involvement.
23.
24. Complications
Complications in leprosy patients may be of two types- deformities and
allergic response ( called lepra reactions types, I and II)
Deformities
Abou t 25% of untreated cases develop deformities in due course of time
which may arise due to-(1) nerve injury leading to muscle weakness or
paralysis, or (2) disease process (facial deformities or loss of eyebrow), or
(3) infection or injury (ulcers).
Common deformities include
Face: Leonine facies, sagging face, loss of eyebrow/ eye lashes, saddle nose
and corneal opacity and ulcers
Hands: Claw hand and wrist drop
Feet: Foot drop, clawing of toes, inversion of foot, and plantar ulcers.
25. LAB DIAGNOSIS
SPECIMENS
Nasal mucosa
Skin lesions
Ear lobes
Total 6 specimens are collected .
Including 4 from skin [buttocks , chin , cheek , forehead] one from nasal
mucosa and ear lobule
Slit and scrape method[ skin cleansed with spirit in order to remove any
saprophytic acid fast bacilli
Skin is punched tightly to minimise bleeding
Cut of 5mm long is made with scalpel , wipe of blood or lymph
Bottom and sides of slit are scrapped with point of blade
26. ACID FAST STAINING
5% H2SO4
1-10 bacilli in 100 fields =1+
1-10 bacilli in 10 fields = 2+
1-10 bacilli per field =3+
10-100 bacilli per field =4+
100-1000 bacilli per field = 5+
More than 1000 bacilli, clumps& globi in every
field=6+
27. BACTERIOLOGICAL INDEX(BI)
No of total bacilli in a tissue.
BI= NO. of pluses(+) scored in all smears
Number of smears
MORPHOLOGICAL INDEX(MI)
% of uniformly stained bacilli out of the total
number of bacilli counted
30. EARLY REACTION OF
FERNANDEZ
Consists of erythema and induration
developing hours and usually remains for 3-
5 days
Is a delayed type hypersensitivity reactions
Greater than 10mm diameter after 48 hrs
considered as positive
Do not indicate active infection
31. LATE REACTION OF MITSUDA
Appears in 1-2 weeks after
injection
Reaction appears in the form of
nodule that may ulcerate
Takes few weeks to heal
Reading taking after 21 days
Nodule of more than 5 mm :
positive
Positive Mitsuda indicates
resistance to leprosy
32. ANIMAL INOCULATION
Foot pad of mice
Nine banded armadillo
Tissue from LL containing leprae bacilli
inoculated intradermally into footpad of
mouse kept at 20 degree . A granuloma
develops at site in 1-6 months
Inoculation with lepra bacilli animal
develops a generalized infection with
extensive multiplication of bacilli and
lesions resembles LL
34. AURAMINE STAINING FOR
VIABILITY
To assess the metabolic activity of m.leprae
in clinical samples
MOLECULAR METHODS
Real time PCR
For detection of M.leprae DNA from clinical
samples
For treatment monitoring