Tuberculosis

What is the causative agent of tuberculosis and its key characteristic?

Mycobacterium tuberculosis; acid-fast bacillus

How is tuberculosis primarily transmitted?

Airborne droplet nuclei

Only active ___________ or ___________ tuberculosis is contagious.

Pulmonary; laryngeal

What is the single strongest risk factor for progression from latent to active TB?

HIV co-infection

 What is a "Ghon complex"?

Primary site of infection + regional lymph node involvement

How is Latent TB Infection (LTBI) defined?

Immune response to TB without clinical or radiologic disease

What is the "Targeted Testing" strategy for LTBI?

Testing only those at increased risk

Which diagnostic test is preferred for most patients age 5 and older?

Interferon-Gamma Release Assay (IGRA)

For which population is the Tuberculin Skin Test (TST) still preferred?

Healthy children under age 5

An HIV-positive patient has a TST induration of 6 mm. Is this a positive result?

Yes (cutoff is ≥5 mm)

What TST cutoff is used for recent immigrants from high-burden countries?

10 mm or greater

What is the preferred 1st line treatment regimen for LTBI in most adults and children ≥2?

3HP (Isoniazid + Rifapentine weekly for 3 months)

What must be co-administered with Isoniazid to prevent side effects?

Vitamin B6 (Pyridoxine)

What is the preferred LTBI treatment for HIV-negative adults?

4R (Daily Rifampin for 4 months)

What is the most consistent clinical symptom of active pulmonary TB?

Chronic, productive cough (>2-3 weeks)

What "constitutional symptoms" are classic for active TB?

• Fever

• Night sweats

• Weight loss

• Fatigue

What causes hemoptysis in advanced TB disease?

Cavitary erosion into a blood vessel

What is the most common site for extrapulmonary TB?

Lymphatic (Scrofula)

________ is TB involving the spine (vertebral destruction).

Pott's disease

______ is hematogenous spread resulting in innumerable small (1-3 mm) nodules throughout the lungs and organs.

Miliary TB

What is the "Gold Standard" for confirming a TB diagnosis?

Culture and Drug-Susceptibility Testing (DST)

What test is now recommended as the initial diagnostic molecular test?

Rapid NAAT (e.g., Xpert MTB/RIF)

 How many sputum specimens are required for the initial diagnostic workflow?

Three specimens

An _______ smear is performed in parallel with other tests; a positive smear indicates a higher bacterial load and greater infectiousness.

Acid-Fast Bacilli (AFB)

What are the classic CXR findings for "Reactivation" TB in adults?

Upper lobe or apical infiltrates, often with cavitation

When should a hospitalized patient with a presentation compatible with TB be placed in airborne isolation?

Immediately upon clinical suspicion

What are the requirements for an Airborne Infection Isolation Room (AIIR)?

Negative pressure and HEPA-filtered exhaust

What PPE is required for healthcare workers entering a TB isolation room?

N95 or higher-level respirator

When can a TB patient be taken out of isolation?

After clinical improvement and three consecutive negative AFB smears

What is "Directly Observed Therapy" (DOT)?

A healthcare worker observes each dose being taken

How soon must TB be reported to public health authorities?

As soon as TB is suspected

What is the standard 1st line empiric treatment (RIPE)?

• Rifampin

• Isoniazid

• Pyrazinamide

• Ethambutol

What specific toxicity is associated with Ethambutol?

Optic neuritis

What is the newer "4-month" treatment regimen for drug-susceptible TB?

High-dose Rifapentine, Isoniazid, Pyrazinamide, and Moxifloxacin

How is Multi-Drug Resistant (MDR-TB) defined?

Resistance to at least Isoniazid and Rifampin

 A pregnant woman is diagnosed with active TB. Should treatment be delayed?

No; treatment is safer than untreated disease

What is "Window Prophylaxis"?

Presumptive treatment following exposure while waiting for test conversion

What is the primary cause of poor TB outcomes worldwide?

Incomplete treatment