Chest
Tuberculin Skin Testing: The State of the Art
Section snippets
ANTIGENS
Old tuberculin was produced and used by Robert Koch in 1890 in Germany. He had tried it unsuccessfully as a therapeutic agent, but it proved useful as a diagnostic tool. It is prepared from heat-stabilized cultures of tubercle bacilli filtered and evaporated to 10 percent of original volume. It is a crude product which contains some extraneous agents to which people may react. This may confuse the issue of infection as when a reactor to OT is found and one is not sure if the individual tested
MULTIPLE PUNCTURE TESTS
Several multiple puncture tests are commonly used. They can have as their antigen PPD or OT: Heaf uses PPD, Sterneedle uses PPD, Monovac uses OT, Tine uses OT with PPD recently introduced and available, Aplitest uses PPD. The reaction size to these tests is of little significance because the dosage is not controlled. In most instances, strong doses of OT or PPD are used. Therefore, reactions might be cross-reactions to nontuberculous mycobacteria. It is claimed by several of the manufacturers
MANTOUX TEST
This is the standard tuberculin test which, if positive, is taken as the definition of tuberculous infection. The advantages and disadvantages are listed in Table 3. The antigen is given in a single dose plastic syringe with a No. 26 or smaller gauge needle. Even though the material is Tween stabilized to keep it from being adsorbed through the glass, it should not remain in the syringe longer than one hour prior to testing. Intracutaneous injection of 0.1 milliliters PPD is given into the skin
FACTORS AFFECTING TUBERCULIN STATUS
The major factor related to infection is known to be close contact with a bacteriologically-positive case of tuberculosis.7 We recently showed8 several other factors related to skin test reactivity and the expected reactor rate in a large urban population. Related to positivity were race, socioeconomic status, age and sex, in that order. We showed in a study population of 61,321 individuals with 51,441 analyses (Table 5) that 12.5 percent were positive reactors: men 13.27 percent, women 12.2
THE BOOSTER EFFECT
The booster effect has been studied recently by the National Center for Disease Control.13. A boosting phenomenon in serial tuberculin testing has been reported for at least 30 years. Basically on a sequential test, some persons show a marked increase in the size of their tuberculin reaction which may not be due to tuberculous infection either recently or in the far distant past.14 These marked increases have been attributed to a variety of causes related to the administration of tests, but it
BCG
BCG is the bacillus of Calmette and Guerin which was derived from a strain of Mycobacterium bovis attenuated through years of serial passages and cultures at the Pasteur Institute in Lille, France. It was first administered to human subjects in 1921. There are many BCG vaccines available in the world today. All are derived from the original strain, but they vary in immunogenicity, efficacy and reactogenicity. Variation probably has been the result of genetic changes in the bacterial strains,
REFERENCES (18)
- et al.
Radiation protection guidance to federal agencies for diagnostic x-rays
Fed Reg
(February 1, 1978) Frost revisited: The modern epidemiology of tuberculosis
Am J Epidemiol
(1975)American Thoracic Society: Diagnostic standards and classification of tuberculosis and other mycobacterial diseases
(1974)American Thoracic Society: The tuberculin test
(1974)Tuberculin negative? (Editorial)
N Engl J Med
(1972)Diagnosis of tuberculosis today
Comp. Therapy
(1977)- et al.
An analysis of 3,485 tuberculosis contacts in the city of Edinburgh during 1954-1955
Am Rev Tuberc
(1958) - et al.
Tuberculous infection in a large urban population
Am Rev Respir Dis
(1978) - et al.
The influence of a history of a previous test on the prevalence and size of reactions to tuberculin
Am Rev Respir Dis
(1977)
Cited by (0)
Supported in part by the Pulmonary Academic Award #K07 HL 00124-05 of the National Heart, Lung and Blood Institute.