Tuberculosis classification system (US) As of April 2000, the American clinical classification system for tuberculosis (TB) is based on the pathogenesis of the disease. Class 0-5 are explained on pages 1391-1392
Health care providers should comply with local laws and regulations requiring the reporting of TB. All persons with class 3 or class 5 TB should be reported promptly to the local health department.
+ Classification System for TB Class Type Description 0 No TB exposureNot infected No history of exposureNegative reaction to tuberculin skin test 1 TB exposureNo evidence of infection History of exposureNegative reaction to tuberculin skin test 2 TB infection No disease Positive reaction to tuberculin skin testNegative bacteriologic studies (if done)No clinical, bacteriologic, or radiographic evidence of TB 3 TB, clinically active M. tuberculosis cultured (if done) Clinical, bacteriologic, or radiographic evidence of current disease4 TB Not clinically active History of episode(s) of TB or Abnormal but stable radiographic findings Positive reaction to the tuberculin skin test Negative bacteriologic studies (if done) and No clinical or radiographic evidence of current disease5TB suspect Diagnosis pendingTB disease should be ruled in or out within 3 months
CDC TB classification for immigrants and refugees The U.S. Citizenship and Immigration Services has an additional TB classification for immigrants and refugees developed by the Centers for Disease Control and Prevention (CDC).CDC Immigration Requirements: Technical Instructions for Tuberculosis Screening and Treatment. October 1, 2009. Classifications, see pages 21-22. The B notification program is an important screening strategy to identify new arrivals who have a high risk for TB.Revised CDC TB Classification system for overseas screening of immigrants and Refugees with Class B1/B2 TB Conditions . State of Wisconsin, Department of Health Services, Division of Public Health, International Health and Respiratory Disease Unit, Bureau of Communicable Diseases and Emergency Response. September 29, 2009. Accessed 2011-07-27. + United States Immigrant/Refugee TB Classification - revised 2009 Class Description None No TB Classification (Normal) A TB with positive sputum smear (considered infectious; requires a waiver to enter US) B1 Overseas evidence of TB with negative sputum smear (considered non-infectious; includes pulmonary and extrapulmonary); includes "old healed TB" and previously treated TB B2 Latent TB Infection (LTBI) defined as tuberculin skin test ≥ 10 mm B3 TB contact
See also list of notifiable diseases Tuberculosis radiology for CXR details Tuberculosis diagnosis
References