2. THE MANTOUX TEST
The Mantoux test is the standard method of
determining whether a person is infected
with Mycobacterium tuberculosis.
The local skin reaction to Tuberculin Purified
Protein Derivative (PPD) injected into the skin is
used to assess the individual’s sensitivity to
tuberculin protein.
3. MANTOUX TEST
The mantoux test is given to :
• Children aged 3 months to 6 years living at
high risk environments.
• Infants and children under six years of age
with a history of residence or prolonged stay
(more than three months) in a country of high
endemic.
4. • There is a history of TB in a household contact
in the last five years.
• Those who have had close contact with a
person with known TB.
5. Administering the Mantoux test
Tuberculin PPD RT 23 SSI, 2 T.U./0.1 ml,
solution for injection:
• 1 dose = 0.1 ml contains 0.04 microgram
Tuberculin PPD.
• Store at 2°C -8°C, protected from light
1ml graduated syringe fitted with a short
bevel 26G (0.45x10mm) needle
6. Injection site
• The test is usually applied on the
middle third of the flexor surface
of the forearm, as a reaction may
be weaker near the wrist or the
elbow joint.
• It is usually applied on the left
forearm.
• Ensure adequate lighting.
• Select an area of healthy skin
which is free of muscle margins,
heavy hair, veins, sores, or scars.
• Only visibly dirty skin needs to be
washed with soap and water
7. Procedure
1)Use a 1mL syringe to
aspirate out 0.1 mL
of PPD RT 23.
2) Inject the PPD
intradermally on the volar
surface of the forearm.
Position the syringe at a
10-15° to the forearm and
insert just below the
epidermis (about 2 mm).
8. 3)Remove the needle quickly.
Do not massage or use
dressing. A well-defined bleb of
6-10mm in diameter should be
formed if injected correctly.If
the bleb is <6mm, repeat the
process 2.5cm from the first
site.
4) Mark down the site, date
and time of injection, both on
the forearm and in patient’s
record.
9. 5) After 48 to 72 hours,
read the test result by
marking down the
transverse diameter of
induration, not erythema,
by Sokal’s ballpoint
method.
6) Measure the largest
transverse diameter of
induration and note down
in millimeters
(mm).
10. READING THE MANTOUX TEST
• The reaction should be
evaluated 48-72 hours after
the injection
• Only the induration, which is
a hard, dense, raised
formation, is measured.
• The area of erythema is not
included in the
measurement.
11. • Measure the diameter of the
induration using a plastic
flexible millimetre (mm) ruler.
12. POSITIVE PPD REACTION
5 or more millimeters 10 or more millimeters 15 or more millimeters
An induration of 5 or more millimeters is
considered positive for
An induration of 10 or more millimeters is
considered positive for
An induration of 15 or more millimeters is
considered positive for
People with HIV
infection
Foreign-born persons People with no risk
factors for TB
Close contacts HIV-negative persons
who inject illicit drugs
People who have had TB
disease before
People with certain
medical conditions
People who inject illicit
drugs and whose HIV
status is unknown
Children younger than 4
years old
13. • A healthy person whose immune system is
normal, induration greater than or equal to 15
mm is considered a positive skin test.
• In most cases,people who have a very small
reaction or no reaction probably do not have
TB infection.
• Induration of less than 2 mm, without
blistering, is considered a negative skin test.
15. False-Positive PPD Reactions
Sometimes people who are not infected with M. tuberculosis will have a
positive reaction to the PPD tuberculin skin test.This is called a false-positive
reaction.
two most common reasons for false positive PPD reactions are:-
• infection with nontuberculous mycobacteria (mycobacteria other than M.
tuberculosis)
• vaccination with BCG (bacillus Calmette-Gurin).
However, the reaction is more likely to be truly caused by TB infection if any
of the following are true:
o The reaction is large
o The person was BCG-vaccinated a long time ago
o The person comes from an area of the world where TB is common
o The person has been exposed to someone with infectious TB disease
o The person's family has a history of TB disease
16. False-Negative Reactions
Some people have a negative reaction to the
tuberculin skin test even though they have TB
infection. These are called false-negative
reactions.
False-negative reactions may be caused by
• Anergy
• Recent TB infection (within the past 10 weeks)
• Very young age (younger than 6 months old)
17. Type of Reaction Possible Cause People at Risk Action to Take*
False-positive
*Nontuberculous
mycobacteria
*BCG vaccination
*People infected with
nontuberculous
mycobacteria
*People vaccinated with
BCG
*Evaluate for TB
disease if person
has TB symptoms
*Assess likelihood
of true TB
infection
False-negative Anergy
Recent TB
infection
Very young age
*HIV-infected people,
other people with
weakened immune
systems
*People infected
with M.
tuberculosis within the
past 10 weeks
*Children younger than
6 months old
*May do anergy
testing
*Retest 10 weeks
after exposure to
TB ended
*Retest when
child is 6 months
old and 10 weeks
after exposure to
TB ended
18. ADVERSE EFFECT
• anaphylactic reaction and foreign body
reaction
• Slight risk of having a severe reaction to the
test including swelling and redness of the arm,
particularly in people who have had TB or
been infected previously and in those who
have previously had the BCG vaccine
• Local reactions such as regional lymphangitis
and adenitis may also occur on rare occasions.
19. CONTRAINDICATION
• severe reaction (e.g:necrosis, blistering,
anaphylactic shock, or ulcerations) to a
previous TST.
20. reference
• http://www.immunisation.ie
• http://www.hkucoi.hku.hk/TST.pdf
• http://www.cdc.gov/tb/publications/factsheet
s/testing/skintesting.htm
• http://www.ncbi.nlm.nih.gov/
• Medical Microbiology and
Immunology,Warren Levinson,McGraw Hill
