A. Test is read before 48 hrs.
B. 6-9 mm induration shows maximum chances of developing TB.
C. A positive test does not indicate that the person is suffering from disease..
D. New cases are more likely to occur in tuberculin negative person than those who already are tuberculin reactors.
The test shown in the picture above represents Montoux test.
Montoux test is carried out by injecting one tuberculin unit (1TU) of PPD in 0.1 ml on the flexor surface of forearm (PPD RT 23 with Tween 80)
- A positive test indicates that patient is infected with M. tuberculosis. It does not however prove that the person is `suffering’ from the disease – Park
- Studies indicate that 92% of new cases occur in persons who already are tuberculin reactors.– Park
- 6-9 mm induration does not indicate high chances of developing tuberculosis. Infact patients with 25 mm induration have more chances of developing tuberculosis than those with 6-9 mm induration –