Section 696.APPENDIX C   Summary of the Interpretation of Tuberculin Skin Test Results

1.         An induration equal to or greater than 5 mm is classified as positive in the following:

·                      Persons who have had recent close contact with persons who have active TB.

·                      Persons who have been diagnosed with HIV infection or who have risk factors for HIV infection but whose HIV status is unknown.

·                      Persons who have fibrotic chest radiographs consistent with healed TB.

2.         An induration equal to or greater than 10 mm is classified as positive in all persons who do not meet any of the above criteria, but who belong to one or more of the following groups having high risk for TB:

·                      Injecting-drug users known to be HIV seronegative;

·                      Persons who have other medical conditions that have been reported to increase the risk for progressing from latent TB infection to active TB disease.  These medical conditions include diabetes mellitus, conditions requiring prolonged high-dose corticosteroid therapy and other immunosuppressive therapy (including bone marrow and organ transplantation), chronic renal failure, some hematologic disorders (e.g., leukemia and lymphomas), other specific malignancies (e.g., carcinoma of the head or neck), weight loss equal to or greater than 10% below ideal body weight, silicosis, gastrectomy, jejunoileal, bypass;

·                      Residents and employees of high-risk congregate settings;  prisons and jails, nursing homes and other long-term residential facilities for the elderly, health-care facilities (including some residential mental health facilities), and homeless shelters;

·                      Foreign-born persons who have recently arrived (i.e., within the last 5 years) from countries having a high prevalence or incidence of TB;

·                      Some medically underserved, low-income populations, including migrant farm workers and homeless persons;

·                      High-risk racial or ethnic minority populations, as defined locally; and

·                      Children less than 4 years of age, or infants, children, and adolescents exposed to adults in high-risk categories.

3.         An induration equal to or greater than 15 mm is classified as positive in persons who do not meet any of the above criteria.