Treatment for TB Infection
The reason for treating a patient with asymptomatic tuberculosis infection is that there is a 5% risk for developing TB during the first year after infection and an additional 5% risk for developing TB over a lifetime. Also, treatment of asymptomatic TB infection is much simpler than treating tuberculosis.
The size of induration (swelling) and the clinical setting affect the likelihood that a positive PPD skin test represents a real infection. For instance, 5 mm of induration is significant in someone who has had recent contact with active TB, but not in a person without risk factors. The main indications for preventive therapy for tuberculosis-infected patients include the following:
- PPD > 5 mm in the following patient groups:
- Adults and children with HIV infection
- Close contacts with infectious cases of TB
- Patients with fibrotic lesions on chest x-ray
- PPD > 10mm in the following patient groups:
- Adults and children at risk for developing TB
- Intravenous drug users
- Immigrants from countries where tuberculosis is prevalent
- Members of racial and ethnic minorites with an increasing incidence of tuberculosis
- Medically underserved persons
- Residents of long term care facilities, including prisons, mental institutions, and nursing homes
- Patients with silicosis
- Post-gastrectomy patients
- Post-jejunoileal bypass patients
- Malnutrition
- Diabetes
- Chronic renal failure
- Immunosuppressive therapy (e.g., transplant patients)
- Workers in health care facilities, hospital microbiology laboratories, schools, and daycare facilities
- Children under age 4
- Patients over age 35 with an increase > 15 mm in the area of PPD over 2 years
- Patients under age 35 with an increase > 10 mm in area of PPD over 2 years
- Patients with HIV infection exposed to an active case of TB, regardless of PPD reaction
Isoniazid TB Treatment
Treatment lasts 6 months in an adult without HIV, 12 months in an adult with HIV, and 9 months in children. This drug has side effects.
Rifampin TB Treatment
This is the second most commonly used drug. Generally, the course of therapy with rifampin is 6 to 12 months. If a patient has been exposed to multidrug-resistant Mycobacterium tuberulosis, individualization of drug therapy is required. Side effects have been noted with this drug.
