MENDEL-MANTOUX TEST

INDEX

1. Introduction

2. Procedure

3. Results

Introduction• Also known as the tuberculin

sensitivity test.• Screening tool for tuberculosis (TB)• Uses a Purified protein derivative (PPD)

tuberculin, a precipitate of glycerol molecules obtained from filtrates of sterilized and concentrated cultures of TB.

Procedure• A standard dose

consists of an intradermal injection of 0.1 ml solution for injection in the inner surface of the forearm

• Test is read 48 to 72 hours later.

• A person who has been exposed to the bacteria is expected to mount an immune response.

• The reaction is read by measuring the diameter of induration (palpable raised, hardened area) across the forearm in millimeters.

Erythema should not be measured

Results

Classification of reaction

Induration of 5 mm – 9 mm

• Persons with recent contacts with a TB patient

• Persons with nodular or fibrotic changes on chest X-ray consistent with old healed TB

• Patients with organ transplants, and other immunosuppressed patients

10 mm – 14 mm• Injection drug users• Residents and employees of high-risk congregate

settings (e.g., prisons, nursing homes, hospitals, homeless shelters, etc.)

• Persons with clinical conditions that place them at high risk (e.g., diabetes, prolonged corticosteroid therapy, leukemia, end-stage renal disease, chronic malabsorption syndromes, low body weight, etc.)

• Children less than four years of age, or children and adolescents exposed to adults in high-risk categories.

15 mm or more • Persons with no known risk factors for TB

False positive result

• Those who have received a BCG vaccine. Interpreted as latent TB infection.

• May be caused by a non-tuberculous mycobacteria.

• Another source of false positive results can be allergic reaction or hypersensitivity.

False negative result

• Infectious mononucleosis• Anergy • Live virus vaccine - The test should not be

carried out within 3 weeks of live virus vaccination.

• Sarcoidosis• Hodgkin's disease• Corticosteroid therapy/Steroid use• Malnutrition• Immunologically compromised

THANK YOU