TB Flashcards
a. Infectious disease caused by Mycobacterium tuberculosis
b. Lungs most commonly infected
TB
Risk factors for TB
a. Poor, underserved, and minorities
b. Homeless
c. Residents of inner-city neighborhoods
d. Foreign-born persons
e. Living or working in institutions
f. IV injecting drug users
g. Overcrowded living conditions
h. Poverty, poor access to health care
i. Immunosuppression
j. Advanced age
Resistance to 2 of the most potent first-line anti-TB drugs (isoniazid and rifampin)
Multidrug Resistant Tuberculosis (MDR-TB)
resistant to any fluoroquinolone plus any injectable antibiotic
Extensively drug-resistant TB (XDR-TB)
Several causes of drug resistance
i. Incorrect prescribing
ii. Lack of public health case management
iii. Nonadherence
iv. Lack of funding for education and prevention
Etiology of TB
a. Spread via airborne droplets, 1 to 5 (micrometers)
i. Can be suspended in air for minutes to hours
What influences transmission?
Number
Concentration
Length of time for exposure
Immunity
Aerophilic (oxygen-loving)—has affinity for lungs
Can spread via lymphatics & grow in other organs
M. Tuberculosis
Bacteria are inhaled, inflammatory response occurs; if adequate immune response (body is fighting it on its own) infection does not progress to disease
Primary TB Infection
active disease within 2 years of infection
Primary TB
Reactivation TB (post-primary) disease occurs
greater than 2 years after infection; infectious
i. Infected (positive skin test) but not active disease
ii. Asymptomatic
iii. Noninfectious—can’t transmit
Latent TB infection
Latent TB infection: may develop active TB later; what could cause it?
Immunosuppression, diabetes, aging, pregnancy, stress, chronic disease
i. Takes 2 to 3 weeks to develop symptoms
ii. Characteristic initial:
Late:
Pulmonary TB
Dry cough that becomes productive
Dyspnea & hemoptysis
Acute, sudden presentation of TB symptoms
i. High fever
ii. Chills, generalized flulike symptoms
iii. Pleuritic pain
iv. Productive cough
v. Crackles and/or adventitious breath sounds
Mantoux test
Tuberculin Skin Test (TST)
Greater than 10 mm induration (positive test)
high risk
Greater than or equal to 15 mm induration (positive test)
low risk
Greater than or equal to 5 mm (positive test)
immunocompromised
Infectious for first 2 weeks after starting treatment if sputum +
Restrict visitors & limit public exposure
Hand & oral hygiene
Two phases of treatment
- Initial (8 weeks to 3 months): 4 drugs (below)
2. Continuation (18 weeks): 2 drugs (isoniazid and rifampin)
b. Initial 4-drug regimen: REMEMBER “RIPE”
Rifampin
Isoniazid
Pyrazinamide
Ethambutol
All urine/blood/sweat will be what with treatment?
Orange
major side effect for 3 of 4 first-line drugs
Non-viral hepatitis, liver function tests should be monitored
MDR-TB (Multi-drug resistant TB) treatment
ii. Initial: Five drugs for at least 6 months
iii. Continuation: 4 drugs for 18 to 24 months
i. Nonadherence is major factor in MDR-TB and treatment failures
ii. Provide drugs and watch patient swallow
Directly observed therapy (DOT)
Physical symptoms
i. Productive cough (collect sputum for AFB in early morning), night sweats, fever, weight loss, pleuritic chest pain, abnormal breath sounds
Acute care of TB
i. Airborne isolation
1. Single-occupancy room with 6 to 12 airflow exchanges/hour
2. Health care workers wear high-efficiency particulate air (HEPA) masks; fit tested
ii. Immediate medical workup: chest x-ray, sputum smear and culture
iii. Appropriate drug therapy
Ambulatory care
ii. Monthly sputum cultures
1. Two consecutive negative cultures = noninfectious
