Tuberculosis in the Philadelphia Prison System: An Analysis of the Results of the Prison Screening Program. Brennan, P.J., Salmon, M.E.

Introduction: Identification and treatment of patients with active disease is the top priority of tuberculosis (TB) Control. Screening methods to identify patients with active disease are especially important when persons reside in congregate living situations where transmission is more likely, such as prisons. Four prisons, housing approximately 5,800 inmates, comprise the Philadelphia Prison System (PHS). Between 1993 and 1997, the case rate in the PHS has remained almost twice that of the rest of the City of Philadelphia. Because of this, we have been prompted to examine our surveillance data to determine whether screening and treatment protocols within PHS ensure that patients with active TB are promptly identified and rendered non-infectious.

Methods: Records of patients who were identified as active cases of TB while residing within the prison system were abstracted from SURVS-TB. These records were analyzed along certain variables using Epi-Info. In addition, patient files were pulled to review qualitative data.

Results: Between January, 1993 and January 1998, 57 cases of TB (range = 6-15) were diagnosed among inmates of PHS. Eighty-eight percent were pulmonary cases (n=50), 79% of the cases were Mantoux positive and 77% were culture positive. Further examination of the pulmonary cases revealed that 80% were culture positive. AFB sputum smears accompanied with chest x-ray results have not proven to be an adequate screening tool for identifying TB disease in this population. Of the sputum culture positive pulmonary cases (n=38), only 10 (26%) had positive sputum smears. Of the 28 smear negative, culture positive cases, 23 (82%) had chest x-rays interpreted as normal. Twenty-one of the 23 were not recognized as TB disease and were not started on a 4-drug TB regimen. All 21 inmates were released into the general prison population or released from custody before 4-drug therapy was initiated.

Conclusions: Within PHS, additional measures must be taken to ensure that inmates with active TB are promptly identified and started on appropriate therapy. This includes retrospective analysis of chest x-rays to determine the accuracy of interpretation and initiation of PCR sputum testing in the public health laboratory.