Tuberculosis classification explained

See main article: article and Tuberculosis.

Tuberculosis classification system

The current clinical classification system for tuberculosis (TB) is based on the pathogenesis of the disease.[1]

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.[2]

Classification System for TB
ClassTypeDescription
0 No TB exposure
Not infected
No history of exposure
Negative reaction to tuberculin skin test
1 TB exposure
No evidence of infection
History of exposure
Negative reaction to tuberculin skin test
2 TB infection
No disease
Positive reaction to tuberculin skin test
Negative 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 disease
4 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 disease
5TB suspect Diagnosis pending
TB 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).[3] The B notification program is an important screening strategy to identify new arrivals who have a high risk for TB.[4]

Class
No TB Classification (Normal)
Class A TB with waiver, infectious
Class B1 TB, Pulmonary
Class B1 TB, Extrapulmonary
Class B2 TB Latent TB Infection (LTBI) Evaluation
Class B3 TB, Contact Evaluation

See also

References

  1. Diagnostic Standards and Classification of Tuberculosis in Adults and Children: This Official Statement of the American Thoracic Society and the Centers for Disease Control and Prevention was Adopted by the ATS Board of Directors, July 1999. This Statement was endorsed by the Council of the Infectious Disease Society of America, September 1999 . American Journal of Respiratory and Critical Care Medicine . 1 April 2000 . 161 . 4 . 1376–1395 . 10.1164/ajrccm.161.4.16141. free . 10764337. Class 0-5 are explained on pages 1391-1392
  2. Web site: Menu of Suggested Provisions For State Tuberculosis Prevention and Control Laws. A. Mandated Reporting: 1. Required Reporters of Communicable Disease . Centers for Disease Control and Prevention.
  3. CDC Immigration Requirements: Technical Instructions for Tuberculosis Screening and Treatment. October 1, 2009. Classifications, see pages 21-22.
  4. http://www.dhs.wisconsin.gov/tb/pdf/Letter%20B1_B2%20FINAL_10_09.pdf Revised CDC TB Classification system for overseas screening of immigrants and Refugees with Class B1/B2 TB Conditions