Tuberculosis Screening Tests
Tuberculosis skin test (TST) (formerly known as PPD)
- Tubersol or Aplisol can be purchased through your medical supply chain.
- Ten or 50 dose vials, once opened must be used within 28 days.
- Requires skill to apply intradermally and read results properly.
- Patient must have two office visits.
- Sensitive test and inexpensive.
- See the CDC TST poster.
Two-step skin testing
- Two TSTs done within a 12-month period.
- Apply the first test and read at 48 to 72 hours, and if test is 0 mm (negative), apply the second step one to three weeks after the first step was read.
- If the first test result is ≥ 10mm (positive), do not apply the second step. Send for a two-view (PA and lateral) chest x-ray (CXR), then follow the CDC Latent Tuberculosis Infection (LTBI) Guide.
Blood assay for Mycobacterium tuberculosis
- Excellent choice for screening people who may have received BCG vaccination (does not react to M. bovis BCG, only M. tuberculosis).
- Check to see if covered by insurance, otherwise the test can be expensive.
- Sensitive and specific for M. tuberculosis.
Positive Screening Results
- Send for a two-view (PA and lateral) CXR.
- If you have questions about the results of the test or CXR, hold the treatment until you call the Health Department.
Treatment of Latent Tuberculosis Infection
- Three possible treatment regimens.
- CDC—Latent Tuberculosis Infection: A Guide for Primary Health Care Providers.
- CDC—Recommendations for Use of an Isoniazid-Rifapentine Regimen with Direct Observation to Treat Latent Mycobacterium tuberculosis Infection.
Do You Suspect Active Tuberculosis?
- Report within 24 hours to the Health Department.
- If you decide to order sputum cultures for tuberculosis, first read Order Sputum AFB for Providers.
- The Health Department can facilitate sputum specimen testing by the Washington State Public Health Laboratory (PHL).
Assessing Your Agency or Facility for Tuberculosis Screening Needs
- Facilities must assess their own level of tuberculosis risk.
- To assess your risk, use Appendices B & C in Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Healthcare Settings.
- This assessment requires that you include data on local, state and national active tuberculosis.
Questions? Contact Cowlitz County Health & Human Services at (360) 414-5599.