Los Angeles County
Department of Public Health
Tuberculosis Control Program
2615 S. Grand Avenue, Room 507
Los Angeles, CA 90007
Phone: (213) 744-6160
Fax: (213) 749-0926
Email: tb@ph.lacounty.gov

Criteria to Verify a Case of TB

The following criteria will verify a case of tuberculosis:

Positive bacteriologic findings of M. tuberculosis, M. bovis, M. africanum, M. canettii, M. microti, or Mtb Complex

OR

• When bacteriologic verification cannot be obtained, ALL of the following factors must be present.
  • Completed diagnostic procedures
  • Decision to give a full course of therapy with 2 or more anti-TB drugs
  • Two or more of the following:
    1. Positive Tuberculin Skin Test (TST)
    2. Positive AFB smear when a culture has not been collected or cannot be obtained
    3. Abnormal and unstable chest radiograph, such as worsening x-ray consistent with TB disease
    4. Clinical improvement with treatment, such as decreased cough, weight gain, decreased lymph node size, etc.
    5. Clinical evidence of TB such as histologic findings, abnormal CSF chemistries, significant radiographic findings (plain film, computed tomography (CT) scan, intravenous pyelography, bone scan, etc.) which are not otherwise explained.

Reference: Centers for Disease Control and Prevention and State of California