Tuberculosis Screening and Latent TB Treatment for Primary Care

Screening Recommendations for Tuberculosis in Healthcare Workers

In the May 17, 2019 MMWR, the CDC changed their recommendation on how to screen healthcare workers for TB. Here’s the short version of their recommendations:

  1. TB screening with an individual risk assessment and symptom evaluation at baseline (preplacement);
  2. TB testing with an interferon-gamma release assay (IGRA) or a tuberculin skin test (TST) for persons without documented prior TB disease or latent TB infection (LTBI);
  3. No routine serial TB testing at any interval after baseline in the absence of a known exposure or ongoing transmission;
  4. Encouragement of treatment for all health care personnel with untreated LTBI, unless treatment is contraindicated;
  5. Annual symptom screening for health care personnel with untreated LTBI;
  6. Annual TB education of all health care personnel.

Diagnosing Latent TB

If a person has a positive IGRA or TST, but has no symptoms of disease they meet criteria for Latent TB.

Treatment of Latent TB

Want to keep it simple? Treat latent tuberculosis with 4 months (120 doses) of once daily Rifampin. Dose is weight based. Adults are 10 mg/kg. Children must be age 2 years or older, their dose is 15-20 mg/kg. Rifampin (rifampicin; RIF) is formulated as 150 mg and 300 mg capsules. Max dose is 600 mg.

You can use these logs from the CDC to help the patient track their medications. CDC says that patients should be seen monthly to check for treatment-associated adverse events (systemic drug reactions, loss of appetite, vomiting, yellow eyes, tenderness of the liver, easy bruising, rash). Sounds like a good idea at least to have a telephone call with the patient each month. Don’t panic if the patient reports urine or saliva turning a reddish-orange color – it is not uncommon (although you should make sure that’s the only symptom they are experiencing).

There are great handouts and more information on the CDC website for Latent TB.


  1. Health System Costs of Treating Latent Tuberculosis Infection With Four Months of Rifampin Versus Nine Months of Isoniazid in Different Settings, Annals of Internal Medicine