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Research Article

Vol. 7 No. 1 (2003)

Risk Factors for Tuberculosis Conversion in a State Prison

  • Robert Hung
  • Steven Shelton
  • Gary Rischitelli
November 7, 2020


A case-control study determined the risk factors for latent tuberculosis (TB) conversion among Oregon Department of Correction (ODOC) inmates from July 2000 - July 2001. The first objective was to identity the converters. These were inmates who tested negative for the Purified Protein Derivative (PPD) skin test on entry and subsequently tested positive on annual testing. The second objective was determining the risk factors for conversion by comparing the converters with randomly selected controls. The Correctional Information System (CIS) and Mental Health databases were accessed to obtain health and demographic information. With ninety-nine percent of PPD positive inmates on anti-tuberculosis medications, nearly all male inmates who tested positive from July 00-01 (n = 307) were identified through the ODOC pharmacy records. A medical chart review (276 of 307 or 90%) separated the converters (n = 72) from the reactors who tested positive on entry (n = 123) and the prior positives on medications (n = 81). The conversion rate was 5.0 per 1,000 person-years. Differences between the cases (converters) and controls were analyzed using multivariate logistic regression. The converters were 6 times more likely to be Latino (p < .005) vs. Caucasian, over 19 times less likely to live in medium vs. minimum (p < .001) or maximum vs. minimum (p < .001) security prisons, and over 5 times less likely to live in a medium vs. low (.012 < p < .031) or high vs. low (.002 < p < .007) density prison. They had 1.4-1.5 times fewer PPD skin tests (.002 < p < .009) and lived in 1.5-1.7 times fewer prisons (.005 < p < .017). Age, education, county of incarceration, number of incarcerations, and number of visitors were not found to be significant variables. The results revealed a low conversion rate compared to other U.S. prisons. Prison health officials should consider performing two-step skin testing in order to distinguish the booster phenomenon from intramural conversion.


  1. Centers for Disease Control. World TB Day 2003- Global Fact Sheet. The Impact of Tuberculosis Worldwide.
  2. CDC Core Curriculum on Tuberculosis. What the Clinician Should Know. 4th edition, 2000.
  3. Braun MM, Truman, BI, Maguire B. Increasing incidence of tuberculosis in a prison inmate population: association with HIV infection. Journal of American Medical Association, 261:393-7, 1989.
  4. Tuberculosis Control Program. Annual Report, 1994. Trenton, NJ: New Jersey Department of Health, 1995.
  5. CDC. Probable transmission of multi-drug-resistant tuberculosis in a correctional facility - California. Morbidity & Mortality Weekly Report, 42: 48-51, 1993.
  6. Prevention and Control of Tuberculosis in Correctional Institutions: Recommendations of the Advisory Committee for the Elimination of Tuberculosis. Morbidity & Mortality Weekly Report, 38(18): 313-325, 1989.
  7. CDC: Controlling TB in Correctional Facilities. Atlanta, GA: U.S. Department of Health and Human Services, 1995.
  8. CDC. Reported Tuberculosis in the United States, 2002. Atlanta, GA: U.S. Department of Health and Human Services, 2003.
  9. Oregon 2002 Community TB Profile. Oregon TB Control. HIV/STD/TB Program. Dept. of Health Services, 2003.
  10. Ending Neglect: The Elimination of Tuberculosis in the United States. Lawrence Geiter, ed. Committee for the Elimination of Tuberculosis in the United States. Division of Health Promotion and Disease Prevention. 292, pages, 2000.
  11. MacIntyre CR, Kendig N, Kummer L, Birago, S, Graham N. Impact of Tuberculosis Control Measures and Crowding on the Incidence of Tuberculous Infection in Maryland Prisons. Clinical Infectious Diseases, 24: 1060-70, 1997.
  12. March F, Coll P, Guerrero RA, Busquets E, Cayla JA, Prats G. Predictors of tuberculosis transmission in prisons: an analysis
  13. using conventional and molecular methods. Acquired Immunedeficiency Syndrome, 14: 525-535, 2000.
  14. Bellin EY, Fletcher DD, Safyer SM. Association of Tuberculosis Infection With Increased Time in or Admission to the New York City Jail System. Journal of American Medical Association, Vol. 269, No. 17, 1993.
  15. Oregon Department of Corrections Statistics, 2000-2001. 15. Spencer SS, Morton AR. Tuberculosis Surveillance in a State Prison. American Journal of Public Health, 79(4): 507-9, 1989.
  16. Johnsen, C. Tuberculosis contact investigation: Two years experience in New York City correctional facilities. American Journal of Infection Control, 21: 1-4, 1993.
  17. Hoft DF, Tennant JM. Persistence and Boosting of Bacille Calmette-Guerin-Induced Delayed-Type Hypersensitivity. Annals of Internal Medicine, 131: 32-36, 1999.
  18. Menzies R, Vissandjee B, Rocher I, Germain, Y. Annals of Internal Medicine, 120: 190-98, 1994.


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