Term
What organism causes tuberculosis? |
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Definition
Mycobacterium tuberculosis, can also arise from pulmonary tuberculosis, miliary tuberculosis, scrofula, meningeal tuberculosis, TB of bones or joints |
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Term
Describe Mycobacterium tuberculosis |
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Definition
Obligate aerobe, acid-fast bacilli, transmission via inhaled respiratory droplets, ingested by alveolar macrophages, lymphatics and hematogenous spread |
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Term
What are the different definitions of tuberculosis? |
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Definition
Primary tuberculosis, latent tuberculosis, multi-drug resistant tuberculosis (MDR TB), extensively drug resistant tuberculosis (XDR TB) |
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Term
How does tuberculosis progress after a primary infection |
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Definition
If the immune response is adequate -> latent TB, if it is inadequate -> primary TB |
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Term
What population is at highest risk for TB? |
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Definition
HIV patients, prisoners, homeless, foreign born, immunocompromised, < 4 age |
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Term
How do you perform a tuberculin skin test? |
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Definition
Intradermal injection of 0.1ml PPD (purified protein derivative) that is read within 48-72 hrs. |
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Term
What determines a positive TB test? |
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Definition
>15mm for patients without any risk for TB, >10mm for at medium risk, >5mm for high risk patients |
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Term
When would you retest for TB in cases of positive results? |
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Definition
If they have recently been tested for TB in |
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Term
What might yield a false positive tuberculin skin test? |
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Definition
Bacillus Calmette Guerin (BCG) vaccine or non-tuberculous mycobacteria |
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Term
What might yield a false negative tuberculin skin test? |
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Definition
Improper technique, less than 12 weeks since infection, malnutrition, advanced age, lymphoreticular malignancies, corticosteroid therapy, chronic renal failure, HIV infection |
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Term
What is QuantiFERON - Gold? |
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Definition
Blood test of blood mixed with antigens and incubated for 6-24 hrs, uses IFN-gamma to measure reactivity to antigen in LTBI, recommended for initial and serial testing of LTBI and may be used instead of TST |
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Term
What are the advantages of QuantiFERON-Gold over TST? |
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Definition
Single patient visit, no booster phenomenon, less reader bias, BCG vaccine has less effect, less reactivity with non-tuberculous mycobacteria |
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Term
What are the disadvantages of QuantiFERON-Gold over TST? |
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Definition
Blood must be processed in 12 hrs, limited labs, limited in cases of immune compromised |
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Term
What is the path of treatment for a positive TST? |
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Definition
CXR, if normal treat for latent TB, if abnormal evaluate for active TB |
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Term
What are symptoms of non-pulmonary TB? |
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Definition
Altered mental status, cranial nerve palsy, seizures, monoarticular joint swelling, painless lymphadenopathy |
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Term
What is the differential diagnosis for pneumonia symptoms? |
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Definition
Bacterial pneumonia, fungal infection, lung CA, lymphoma, or Wegener's |
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Term
How would you confirm a diagnosis of TB? |
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Definition
Clinical suspicion leads to chest x-ray, acid-fast staining, culture, and nucleic acid amplification assays |
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Term
Describe the sputum of TB positive patients |
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Definition
3 consecutive morning sputums, acid fast bacilli smear (AFB) yields 5,000-10,000 bacilli per ml, however does not eliminate diagnosis of clinical suspicion is high. Can be used for cultures and nucleic acid amplification |
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Term
What is the function of isoniazid in first line treatment against tuberculosis? |
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Definition
Peripheral neuropathy, hepatitis, pyridoxine (Vit B6) supplementation |
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Term
What is the function of rifampin and rifapentine in first line treatment against tuberculosis? |
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Definition
GI upset, hepatitis, will color urine and secretions |
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Term
What is the function of ethambutol in first line treatment against tuberculosis? |
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Definition
Optic neuritis, red-green color discrimination/visual acuity |
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Term
What is the function of pyrazinamide in first line treatment against tuberculosis? |
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Definition
Hepatitis, hyperuricemia, not used in pregnancy |
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Term
What are the drugs used in first line defense against tuberculosis? |
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Definition
Isoniazid, rifampin/rifapentine, ethambutol, and pyrazinamide. Acronym: FIRE-P |
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Term
What are the drugs used in second line defense against tuberculosis? |
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Definition
Aminoglycosides, polypeptide, flouroquinolones, thiomides, serine analogue, and P-aminosalicylic acid. Acronym: APFTSP = a place for the stupid people |
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Term
What is the key to not developing treatment resistance? |
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Definition
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Term
What actions, other than treatment, should you follow through on in incidences of tuberculosis? |
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Definition
Report to local and state public health authorities, directly observe therapy (health care worker observes the patient ingest medicine in cases of drug resistant TB and intermittent therapy) |
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Term
Rifamycins interact with what drugs or conditions? |
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Definition
Antiretrovirals, azoles, macrolides, anticoagulants, hormones, anticonvulsants, hyperglycemics, hyperlipidemics, cardiovascular agents, and psychotropic agents |
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Term
How would you treat latent TB? |
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Definition
9 months of isoniazid and 4 months of rifampin |
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Term
What are the indication sofr prophylaxis with isoniazid? |
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Definition
Now TST conversion over past 2 yrs, PPD+ contacts of patient with active TB, has HIV, or unknown duration in patient <35yrs, PPD- contacts of patient with active TB, patient w/X-ray evidence of inactive TB who were not adequately treated |
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Term
Describe the treatment schedule for TB? |
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Definition
6-9 month reigments, start with 4 drug therapy of isoniazid, rifampin, pyrazinamide, and ethambutol for 2 months, then 4 months of isoniazid and rifampin, can vary based on contraindications and initial cultures/smears |
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Term
What would you monitor while a patient undergoes tuberculosis treatment? |
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Definition
Bilirubin, liver enzymes, BUN, creatinine, CBC< visual acuity, red/green color acuity, audiometry, sputum smear and cultures |
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Term
How do you control transmission of TB? |
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Definition
Airborne infection isolation rooms with HEPA filter, UV-germicidal radiation, and local exhaust ventilation, respirator masks w/non powered particulate filter |
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Term
What modifications to treatment do you have in pediatric patients with TB? |
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Definition
Ethambutol runs the risk of decreased visual acuity |
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Term
What modifications to treatment do you see with pregnant women with TB? |
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Definition
No streptomycin, pyridoxine prevents neuropathy when taking isoniazid |
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