This document provides information on leprosy (Hansen's disease), including its causes, signs and symptoms, transmission, diagnosis, classification, treatment, and control. It discusses that leprosy is caused by Mycobacterium leprae, affects the skin and nerves, and manifests as tuberculoid, borderline, or lepromatous forms depending on the host's immune response. Diagnosis involves clinical examination of skin and nerves as well as bacteriological examination of skin and nasal smears. Multidrug therapy including rifampicin, dapsone and clofazimine is recommended. Control relies on case detection, treatment, surveillance, and health education to prevent disability.

1. DR. MAHESWARI JAIKUMAR.
maheswarijaikumar2103@gmail.com

2. LEPROSY
• Leprosy (Hansen’s disease) is a
chronic infectious disease caused
by Mycobacterium leprae.

3. • It affects mainly the peripheral
nerves.
• It may also affect skin, eyes,
bones, testes and internal
organs.

4. • The disease manifests itself in
two polar forms.
• 1. LEPROMATOUS LEPROSY. (LL)
• 2. TUBERCULOID LEPROSY. (TL)

5. • Lying at the two ends of a long
spectrum of the disease, lying
between these two polar types
occur the borderline (BL) and
indeterminate (IL) forms
depending on the host response
to infection

7. CARDINAL FEATURES
• Leprosy is clinically characterized
by one or more of the following
cardinal features.

8. • 1. Hypopigmented patches.
• 2. Partial or a total loss of
cutaneous sensation in the
affected areas.

9. HYPO PIGMENTED PATCH

10. • 3. Presence of thickened nerves.
• 4. Presence of Acid Fast Bacilli in
the skin or nasal smears.

11. • The signs of advanced disease
are striking : presence of nodules
or lumps especially in the skin of
the face and ears, plantar ulcers,
loss of fingers or toes, nasal
depression, foot drop, claw toes
and other deformities.

12. CONTRACTURE

13. UNTREATED NODULAR
LEPROSY

15. AGENT
• The agent is Mycobacterium
leprae.
• They are acid fast bacilli, and
occur both as intracellular and
extracellular bacilli.

18. • They occur characteristically in
clumps or bundles called GLOBI.
• As many as 2 to 7 billion may be
present in one gram of leproma.

19. • As many as 2 to 7 billion may be
present in one gram of leproma.

20. SOURCE OF INFECTION
• It is generally agreed that the
multibacillary cases
(lepromatous and boderline
lepromatous cases) are the most
important source of infection.

21. PORTAL OF EXIT
• The nose is the major portal of
exit.
• Lepromatous cases harbour
millions of M. leprae in their
nasal mucosa which are
discharged when they sneeze or
blow the nose.

22. • The bacilli can also exit through
ulcerated or broken skin of
bacteriologically positive cases
of leprosy.

23. INFECTIVITY
• Leprosy is a highly infective disease
but of low pathogenicity.
• An infectious patient can be
rendered non infectious by
treatment with dapsone for about
90 days or with rifampicin for 3
weeks.

24. • Local application of rifampicin
(drops/spray) might destroy all
the bacteria within 8 days.

25. ATTACK RATES
• Despite treatment all the cases
have been infectious for long
periods, before treatment is
sought.

26. HOST FACTORS

27. AGE
• Leprosy is not particularly a
disease of children.
• An individual can get infected
any time depending upon the
opportunities for exposure.

28. • In endemic areas, the disease is
acquired commonly during
childhood.
• Incidence rates generally rise to
a peak between 10 to 20 years of
age and then fall.

29. GENDER
• Both incidence and prevalence
of leprosy appear to be higher in
males than in females in most
regions of the world.

30. • The excess of cases in males is
attributed to their greater
mobility and increased
opportunities for contact in
many populations.

31. MIGRATION
• In India leprosy was considered to
be mostly a rural problem.
• But today the disease is equally
found (due to migration of
population) both in rural and urban
areas.

32. IMMUNITY
• It is a well established fact that
only a few persons exposed to
infection develop the disease.

33. • A large proportion of early
lesions that occur in leprosy heal
spontaneously.
• Such abortive self healing lesions
suggests immunity acquired
through such lesions.

34. • A certain degree of immunity is
also probable through infections
with other related mycobacteria.
• Cell-mediated immunity (CMI) is
responsible for resistance to
infection with M.leprae.

36. • In lepromatous leprosy there is a
complete breakdown of CMI.

37. GENETIC FACTORS
• Human Lymphocyte Antigen
(HLA) linked genes influence the
type of immune response to the
infection by M. leprae.

38. ENVIRONMENTAL
FACTORS

39. • The risk of transmission is
predominantly controlled by
environmental factors. i.e., the
presence of infectious cases in
the environment.
• Humidity favours the survival of
M.leprae in the environment.

40. • M.leprae can remain viable in
the dried nasal secretions for at
least 9 days and in moist soil at
room temperature for 46 days.
• Overcrowding and lack of
ventilation within the household
favours transmission.

41. MODE OF TRANSMISSION
• Transmission occurs by:
1. DROPLET INFECTION.
2. CONTACT TRANSMISSION.
3. OTHER ROUTES.

42. DROPLET INFECTION
• Nose is the most important portal
of exit.
• M.leprae could survive outside
the human host for several hours
or days.

43. • The organisms are found in large
number in the dried nasal
secretions and they are
discharged in to the environment
as droplets.

44. CONTACT
TRANSMISSION
• Leprosy is transmitted from
person to person by close
contact between an infectious
patient and a health but
susceptible person.

45. • This contact may be direct or
indirect (contact with soil, and
fomites ; clothes, linen)

46. OTHER ROUTES
• Bacilli may also be transmitted by
insect vectors or by tattooing
needles.
• However there is no evidence that
any of these transmission routes is
important in nature.

47. INCUBATION PERIOD
• Leprosy has a long incubation
period, an average of 3 to 5 years
or more for lepromatous leprosy.
• The tuberculoid leprosy is
thought to have a shorter
incubation period.

48. • Symptoms can take as long as 20
years to appear.
• Failure to recognize early
symptoms or signs may
contribute to an assumed
prolonged incubation period in
some individuals.

49. • Some leprologist prefer the term
“latent period” to incubation
period because of the long
duration of the incubation
period.

50. CLASSIFICATION
• Leprosy is classified based on the
clinical, bacteriological,
immunological and histological
status of patients.
• Indian and Mardid system of
classification are widely used.

52. INDIAN CLASSIFICATION MARDID CLASSIFICATION
INDETERMINATE INDETERMINATE
TUBERCULOID TUBERCULOID; FLAT;
RAISED
BODERLINE BODERLINE
LEPROMATOUS LEPROMATOUS
PURE NEURITIC TYPE (no
skin lesion)

54. INDETERMINATE TYPE
• This denotes those early cases
with one or two vague hypo
pigmented macules and definite
sensory impairment.
• The lesions are bacteriologically
negative.

55. TUBERCULOID TYPE
• This type denotes those cases with
one or two well defined lesions,
which may be flat or raised,
hypopigmented or erythematous
and are anesthetic.
• The lesions are bacterologically
negative.

56. TESTING FOR CUTANEOUS SENSATION

58. BODERLINE TYPE
• This type denotes those case
with four or more lesions which
may be flat or raised, well or ill
defined, hypopigmented or
erythematous and show sensory
impairment or loss.

59. BODERLINE LEPROSY

61. BODERLINE TYPE

62. BODERLINE LEPROSY

63. • The bacteriological positivity of
these lesions is variable.
• Without treatment, it usually
progresses to lepromatous type.

64. LEPROMATOUS TYPE
• This type denotes those cases with
diffuse infiltration or numerous flat
or raised, poorly defined shiny,
smooth, symmetrically distributed
lesions.
• The lesions are bacterologically
positive.

67. PURE NEURUTIC TYPE
• This type denotes those cases of
leprosy which show nerve
involvement but do not have any
lesion in skin.
• These cases are bacteriologically
negative.

69. DIAGNOSIS
• Diagnosis is based on
1. CLINICAL EXAIMINATION.
2. BACTEROLOGICAL
EXAMINATION.

70. CLINICAL EXAMINATION
• Leprosy is diagnosable on the
basis of proper clinical
examination alone.
• This is called as “case taking”.

71. • Case taking follows a set pattern,
as follows:
1. INTERROGATION
2. PHYSICAL EXAMINATION

72. INTERROGATION
• Collection of biodata of the
patient such as name, age,
gender, occupation and place of
residence.
• Family history of leprosy.

73. • History of contact with leprosy
cases.
• Details of previous history of
treatment for leprosy, if any.
• Presenting complaint or symptom.

74. PHYSICAL EXAMINATION
• A thorough inspection of the
body surface(skin) to the extent
permissible, in good natural light
for the presence of suggestive,
or tell tale evidence of leprosy.

75. • Palpation of the commonly involved
peripheral and cutaneous nerve for
the presence of thickening and / or
tenderness.

76. • They are ulnar nerve near the
median epicondyle, greater
auricular as it turns over the
sternomastoid muscle, lateral
popliteal and the dorsal branch
of the radial nerve.

77. • Testing for (a) loss of sensation
for heat, cold, pain and light
touch in the skin patches.
• Paresis or paralysis of the
muscles of the hands and feet,
leading to the disabilities or
deformities.

78. PLANTAR ULCERS

79. DIAGNOSIS OF LEPROSY

80. BACTERIOLOGICAL
EXAMINATION
• Bacteriological examination is
done by:
1. SKIN SMEARS.
2. NASAL SMEARS.
3. NASAL SCRAPINGS.

81. SKIN SMEARS
• Material from the skin is obtained
from an active lesion and also from
one of the ear lobe by the “slit and
scrape method”.
• Conventionally two sites are
examined.

82. ARTICLES FOR SKIN SMEAR
TESTING

84. • The skin is cleaned with ether or
spirit and allowed to dry.
• A fold of skin is nipped between
the thumb and the forefinger (of
the left hand in an operator).

85. FOR SKIN SMEAR

87. • Enough pressure should be
applied to stop or minimize
bleeding.
• Holding the point of knife vertical
to the apex of the skin fold, it is
pushed into the skin to a depth of
about 2 mm or so, to reach the
dermis.

88. • A tiny incision is made 5 mm in
length.
• If blood exudes, it should be
wiped off with a small dry
cotton-wool swab.

89. • The knife blade is rotated
transversely to the line of the cut
90 degrees and the knife point is
used to scrape the first on one
side and then on the other side
of the incision 2 or 3 times to
obtain a tissue pulp from below
the epidermis.

90. • This material is transferred on to
a glass and spread over an area
of about 8 mm diameter.
• Six smears can conveniently be
made on one microscopic slide.

91. • The sites of smear should be
accurately recorded so that the
same site can be used for
successive sets of smears made
for assessing the effect of the
treatment.

92. • The wound is dressed and closed
with a piece of sticking tape
applied over the site.

93. NASAL SMEARS OR BLOW
• Nasal spray can be best prepared
from the early morning mucus
material.
• The patient is asked to blow his
nose into a clean dry sheet of
cellophane or plastic.

94. • The smear should be made
straightaway and fixed.
• Nose blowing smears are used
for assessing the patient’s
infectivity.

95. • In patients with untreated
lepromatous leprosy, nose blow
smears may show a higher
percentage of solid-staining
bacilli than skin smears.

96. NASAL SCRAPINGS
• An alternative is to use a mucosal
scrapper.
• After going in 4.5cm, the blade is
rotated towards the septum and
scraped a few times and
withdrawn.

97. • A small ball of cotton is
introduced into the nostril to
absorb any blood that may ooze
out.
Nasal scrapings are not
recommended as a routine.

98. BACTERIOLOGICAL EXAMINATION

100. BACTERIAL INDEX

101. • The BI of the patient is
calculated by adding up the
index from each site examined
and dividing the total by the
number of sites examined.

102. EXAMPLE
RIGHT
EAR
5+ LEFT EAR 5+
BACK 4+ CHIN 4+
BI = 5+5+4+4 = 18 = 4.5+
4 4
When BI is 3+ and above, at least 25 oil
immersion fields should be examined.

103. MORPHOLOGICAL INDEX
• The percentage of solid staining
bacilli in a stained smear is
referred to as Morphological
Index. (MI).

104. FOOT PAD CULTURE
• The only certain way to identify
M.leprae is to inoculate the
material into the foot pads of mice
and demonstrate its multiplication.
• This test is more sensitive than skin
and nasal smears.

105. TEST FOR DETECTING CMI
LEPROMIN TEST
The test is performed by injecting
intradermally 0.1 ml of lepromin
into the inner aspect of the
forearm of the individual.

106. • As a routine, the reaction is read
at 48 hours and 21 days.
• Two types of positive reactions
have been described.

107. EARLY REACTION
• The early reaction is known as
Fernandez reaction.
• A inflammatory response
develops within 24 to 48 hours
and 21 days.

108. • It is evidenced by redness and
induration at the site of
inoculation.
• If the diameter of the red area is
more than 10mm at the end of
48 hours, the test is considered
positive.

109. • The early positive reaction
indicates whether or not a
person has been previously
sensitized by exposure to and
infection by the leprosy bacilli.
• This reaction is similar to that of
mantoux test for TB.

110. LATE REACTION
• This is the classical Mitsuda
reaction.
• The reaction develops late,
becomes apparent in 7-10 days
following the injection and
reaching its maximum in 3 t0 4
weeks.

111. • The test is read at 21 days.
• At the end of 21 days, if there is
a nodule more than 5mm in
diameter at the site of
inoculation, the reaction is said
to be positive.

112. • The late reaction by the bacillary
component of the antigen
indicates CMI.
• Lepromin test is not a diagnostic
test. The test is a useful tool in
evaluating the immune status.

113. LEPROSY CONTROL
• Can be achieved through :
1. Estimation of the problem.
2. Case detection.
3. Multidrug therapy.
4. Surveillance.

114. • 5. immunoprophylaxis.
• 6. Chemoprophylaxis.
• 7. Deformities.
• 8. Rehabilitation.
• 9. Health education.

115. MULTIDRUG THERAPHY
• The following drugs are used in
the management of leprosy.
1. Rifampicin.
2. Dapsone.
3. Clofazimine.

117. 4. Ethionamide and
protionamide.
5. Quinolones.
6. Minocycline.
7. Clarithromycin.

118. REGIMENS OF
CHEMOTHERAPHY BY
WHO

120. CHEMOTHERAPHY
FOR ADULTS

121. FOR MULTIBACILLARY LEPROSY
• RIFAMPICIN 600 mg, once
monthly given under supervision.
• DAPSONE 100 mg daily, self
administered.
• CLOFAZIMINE 300 mg, once
monthly supervised; and 50 mg
daily, self administered.

122. • When clofazimine is
unacceptable owing to the
colouration of the skin
ETHIONAMIDE 250 to 375 mg
self administered daily doses is
suggested.

123. FOR PAUCIBACILLARY LEPROSY
• RIFAMPICIN 600 mg once a
month, supervised
• DAPSONE 100 mg (1-2 mg/kg of
body weight) daily, self
administered

125. CHEMOTHERAPHY FOR
CHILDREN (10 – 14 YEARS)

126. MULTIBACILLARY LEPROSY
• RIFAMPICIN 450 mg, once a
month, given under supervision.
• DAPSONE 50 mg, self
administered.
• CLOFAZIMINE 150 mg once a
month supervised; and 50 mg
every other day.

127. PAUCIBACILLARY LEPROSY
• RIFAMPICIN 450 mg once a
month supervised.
• DAPSONE 50 mg, daily, self
administered.
• Children under the age of 10
years should receive
appropriately reduced doses of
the above drugs.

128. DUARATION OF TREATMENT
• The treatment duration varies
according to the type of disease.
• The recommendations are as
follows

129. MULTIBACILLARY
• MB blister
packs for 12
months, within
18 months.

130. PAUCIBACILLARY
• PB blister
packs for 6
months, within
9 months.

132. COMMUNITY SENSITIZATION

133. THANK YOU