Emergency Central is a collection of disease, drug, and test information including 5-Minute Emergency Medicine Consult, Davis’s Drug, McGraw-Hill Medical’s Diagnosaurus®, Pocket Guide to Diagnostic Tests, and MEDLINE Journals created for emergency medicine professionals. Explore these free sample topics:
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- Tuberculosis (TB) is an infectious disease with protean manifestations, causing significant global morbidity and mortality.
- Infectious droplet nuclei are inhaled through the respiratory tract.
- Bacteria are dispersed through coughing, sneezing, speaking, singing.
- Primary TB/latent TB infection (LTBI):
- Initial infection occurs when organisms enter the alveoli, become engulfed by macrophages, and spread via regional lymph nodes to the bloodstream.
- Patients are usually asymptomatic.
- May be progressive/fatal in immunocompromised hosts.
- Positive reaction to purified protein derivative (PPD) indicates past exposure or infection.
- Negative PPD does not rule out active TB.
- May progress to active TB (5–10%).
- Reactivation TB:
- LTBI becomes active TB.
- Systemic (15%) and pulmonary (85%) symptoms.
- TB affects about one-third of the world's population (90 million new cases in the past decade worldwide, with about 30 million deaths).
- Centers for Disease Control and Prevention (CDC) statistics from 2011 show TB in US at an all-time low.
- TB rates in US have continued to decline since 1993.
- Increase in US foreign-born cases
- Still an estimated 10–15 million people are infected in US alone.
- Infection with Mycobacterium tuberculosis, a slow-growing, aerobic, acid-fast bacillus resulting in disease.
- Humans are the only known reservoir.
- Recent TB epidemics:
- HIV-infected patients
- Multidrug-resistant TB (MDR-TB)
- Extensively drug-resistant TB (XDR-TB):
- High mortality, few effective drugs