Screening

High-risk individuals

Immunocompromised individuals (particularly HIV positive)

Immigrants from high prevalence countries

Malnourished, homeless, and those living in overcrowded and substandard housing

Alcoholics

IV drug users

Chronic systemic illness, such as diabetes

Residents of long-term care facilities, including nursing homes and prisons

Ongoing potential contact with cases of active TB, such as health care providers and prison guards

Exceptions to annual screening

Documented positive TB skin test in the past

Prior treatment of a positive TB skin test

Skin testing

Administer Mantoux test (0.1 ml of purified protein derivative [PPD] containing 5 tuberculin units)

Read 48-72 h later

Measure induration, not erythema

Measurement should be one number that is measured in the greatest transverse plane

Classification of positive PPD

PPD induration ≥5mm

Group

HIV-positive persons

Recent contact with individuals with active TB

Chest x-ray changes consistent with old, healed TB

Patients with suppressed immune systems

≥10 mm

Patients who are non-immunosuppressed, with the risk factors above

Children and adolescents exposed to adults at high risk

TB skin test converters (increase of) >10 mm induration within a 2-year period

≥15 mm

All other persons

Limitations

False positive

Previous BCG vaccination

Infection with nontuberculous mycobacteria

False negative

Patients who are immunocompromised

Recent infection (1.5-3 months required to develop adequate cellular immunity)

Treatment considerations

Rule out active TB using chest x-ray, symptom review, and/or sputum collection

Once active TB is ruled out, administer INH 300 mg p.o. qd ×9 months for chemoprophylaxis. Perform baseline hepatic function testing and neurologic examination prior to initiating INH treatment and monthly thereafter. Pyridoxine 10 mg p.o. qd may be given concurrently as prophylaxis for neuritis

INH is contraindicated in active liver disease and pregnancy

Referral to the health department for chemoprophylaxis is recommended to ensure adherence and to monitor for medication-related side effects

All suspected and confirmed cases of tuberculosis should be reported promptly to local and state public health authorities

Referral to appropriate agencies and specialists for further management should be made when active disease is detected/suspected