Mantoux test

Mantoux test

The Mantoux test (or Mantoux screening test or Tuberculin Sensitivity Test or Pirquet test) is a diagnostic tool for pre-symptomatic tuberculosis. In the ordinary test the subject is given a intradermal injection of a standard dose of tuberculin, with the aim of eliciting a skin reaction two to three days later. A positive reaction ('Mantoux positive' or 'significant') is marked by a induration and erythema of the skin. A induration of more than 10 mm from 10 Tuberculin units (0.2 ml, the tuberculin is also called purified protein derivative (PPD) and the test a PPD skin test) indicates either past or present exposure to tuberculosis or a past BCG vaccination. a negative reaction is a induration of less than 5 mm.

Certain people recently infected may not react to the test. Also the elderly or immunocompromised may not show a reaction. False positive results may also occur from 'atypical', non-tuberculous forms of mycobacteria such as avian.

Tuberculin is a glycerine extract of the tubercule bacilli. It was announced in 1890 by Robert Koch. The test is named after Charles Mantoux, a French physician who developed on the work of Koch and Clemens von Pirquet to create his test in 1907.

In contrast, a Heaf test is usually performed before a BCG vaccination for tuberculosis is issued to determine if a subject is already immune, whereas a Mantoux test is sometimes performed to rule out a case of TB. In any case, the results of a Mantoux test are ready within 48-72 hours, whereas the Heaf test is read a week later.