Studies of TB among Mentally Ill Patients

It is unlikely that psychiatric illnesses constitute a risk factor for LTBI or TB disease. However, many individuals with such conditions are also at risk for TB due to living in overcrowded, impoverished neighborhoods, living in shelters or other congregate settings, engaging in substance use, being HIV+, and originating from countries where TB is endemic. Few studies have examined TB risk and/or prevalence in persons with mental illness. Dr. Colson and colleagues conducted TSTs and examined risk factors in a cohort of continuing treatment clients. Of 71 participants, 12 (17%) were TST positive. Seven risk factors for LTBI were examined. Those with LTBI were more likely to be immigrants and to be above the study group's median age of 32.

Dr. Colson is also extending this inquiry in a larger, representative sample of persons with mental illness. Dr. Evelyn Bromet of SUNY - Stony Brook has assembled a sample of all the individuals experiencing their first psychotic episode in a suburban New York county over 10 years. Approximately 695 participants have been followed for up to 10 years as part of this longitudinal study. Of 282 participants responding to a health factors questionnaire, 210 reported having received a TST. Of these, 14 (6.7%) reported testing positive. Further analyses will examine associations between positive skin tests and risk factors.