Question

For full credit) In your own words, explain what the 2 step TST is and why it is used? (References still required)

Answer 1

Ans-

The two-step tuberculin skin test is used to detect the individuals with past tuberculosis infection.

The person who diminished skin test reactivity. This procedure will reduce theboosted reaction is later interpreted as a new infection.

Two step TST-

Tuberculin Skin Test (TST) is a screening method developed to evaluate an individual’s with past history status for active Tuberculosis or Latent TB infection.

A 2-Step TST are recommended for initial skin testing of adults who will be periodically retested, such as healthcare workers.

A 2 step means as two TST’s done within 1 month of each other.

Step 1-Visit 1)Day 1. Visit 2)Day 3

Step 2)Visit 3)Day 7-21. Visit 4)48-72 hours after the second TST placement.

Why to 2 step TST is done-

Single step TST is give Negetive response.also induced inamstic response.2step TST gives possitive response.

Some people infected with M. tuberculosis may have a negative reaction to the TST. if many years have passed since they became infected. They may have a positive reaction to a subsequent TST because initial test stimulates their ability to react to the test.

This is commonly referred to as the Booster phenomenon.For this reason, the “two-step method” is recommended at the time of initial testing for Individuals who may be tested periodically (e.g., health care workers).