Mantoux Test (Tuberculin PPD Skin Test)
The Mantoux test, also known as the Tuberculin Skin Test (TST), is a screening test used to detect infection with Mycobacterium tuberculosis, the bacteria that cause tuberculosis (TB). It involves injecting a small amount (0.1 ml) of purified protein derivative (PPD) tuberculin just under the skin of the forearm. After 48 to 72 hours, the test site is checked for a localized skin reaction (induration), which indicates exposure to the TB bacteria.
Reasons for performing the Mantoux Test
This test is mainly ordered to:
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Diagnose TB exposure or infection in people at risk.
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Evaluate immune response to TB in individuals, including those who have received the BCG vaccine.
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Screen individuals with symptoms or risk factors for TB, such as persistent cough, fever, weight loss, or contact with active TB cases.
- As part of a travel medical checkup
Patient Preparation/Instructions
No special preparation is required before taking the Mantoux test. Patients should ensure that they can return to the lab within 48 to 72 hours to have the test site examined.
Typical Reference Values
Interpretation of the skin induration size (measured in millimeters) depends on the individual’s risk factors:
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An induration of 5 mm or more is positive in high-risk individuals (e.g., HIV-positive, recent contacts of TB cases).
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An induration of 10 mm or more is positive for those with moderate risk factors (e.g., healthcare workers, recent immigrants from high-prevalence countries).
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An induration of 15 mm or more is positive in persons with no known risk factors for TB.
Redness around the site (erythema) is not considered in the evaluation.
Note: In Kenya, since most people have had BCG vaccination, the test is expected to be mostly positive. This indicates (partial) immunity to the TB-causing bacteria.
Time it Takes to Get Results
Results are typically available within 3 days after the test administration when the test site is examined.
How to Order the Test
To order the Mantoux test via Labtestzote in Nairobi, Kenya:
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Click the add to cart button above and complete checkout
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Schedule an appointment and visit one of Labtestzote’s partner laboratories in Nairobi to have the test administered.
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Return to the laboratory site after 48 to 72 hours for the reading and interpretation of the test.
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Receive your results online or directly from the laboratory.
Labtestzote ensures quick, reliable testing conveniently available across Nairobi and Kenya.
Further Reading and Resources
