Tuberculosis

Question 1

Factors contributing to Increase in Morbidity in TB

Answer 1

HIV/AIDS
Immigration from countries where TB was common
Transmission of TB in congregate settings
Development of mullti-drug resistant (MDR) TB

Question 2

High Risk for being exposed to TB

Answer 2

Close contacts of person known or suspected to have TB
Foreign-born persons from areas where TB is common
Visiting countries where TB is prevalent
Residents or employees of high-risk congregate settings
Health employees working with high-risk pts
Populations defined locally as having increased incidence of latent M. Tuberculosis or TB disease like medically underserved, low-income, abusers of drugs or ETOH
Children and adolescents exposed to adults at increased risk for infection or dz

Question 3

Latent TB Infection (LTBI)

Answer 3

Granulomas may persist (LTBI), or may break down to produce TB disease
2 to 8 weeks after infection, LTBI can be detected via TST or interferon-gamma release assay (IGRA)
The immune system is usually able to stop the multiplication of bacilli
Persons with LTBI are not infectious and do not spread organisms to others

Question 4

TB Disease

Answer 4

In some, the granulomas break down, bacilli escape and multiply, resulting in TB disease
Can occur soon after infection, or years later
Persons with TB disease are usually infectious and can spread bacteria to others
Positive M. tb culture confirms TB diagnosis

Question 5

Dx

Answer 5

Culture = gold standard for dx

Question 6

TB Disease Tx

Direct Observation Therapy (DOT)

Answer 6

Health-care worker watches patient swallow each dose
DOT is preferred management strategy for all patients
Can reduce acquired drug resistance, treatment failure, and relapse
Nearly all regimens can be intermittent if given as DOT
DOT reduces total number of doses and encounters
For drug-resistant TB, use daily regimen and DOT

Question 7

1st Line Drugs

Answer 7

Isoniazid (INH)
Rifampin (RIF)
Pyrazinamide (PZA)
Ethambutol (EMB)

Question 8

Tx Regimen

Answer 8

Initial phase: standard four drugs (INH, RIF, PZA, EMB) for 2 months (one excludes PZA)
Continuation phase: additional 4 months; 7 months for some patients

Question 9

Criteria for Being Noninfectious

Answer 9

They have 3 consecutive negative sputum smears,
Their symptoms have improved, and
They are adhering to an adequate treatment regimen for at least 2 weeks