TABLE 3.

Criteria for Tuberculin Positivity by Risk Group

Reaction ≥ 5 mm in Duration	Reaction ≥ 10 mm in Duration	Reaction ≥ 15 mm in Duration
● HIV-seropositive persons	● Recent immigrant high prevalence countries	● Persons with no TB risk factor
● Recent contacts TB case	● Injection drug users
● Fibrotic changes on chest radiograph consistent with prior untreated TB	● Residents/employees of high risk congregate settings (e.g., nursing homes, jails, etc.)
● Patients with organ transplants and other immunosuppressed persons	● Mycobacteriology laboratory personnel
	● Persons with high risk (for TB) Clinical conditions: silicosis, diabetes mellitus, chronic renal failure, leukemia/lymphoma, other select malignancies, weight loss ≥10% ideal body weight, gastrectomy/ileal bypass
	● Children younger than four years or all children/adolescents exposed to adults at high risk

Modified from MMWR 2000; 49 (No. RR-6).