Mycobacteria Flashcards
Transmission of M. tuberculosis only occurs from a person with infectious, active TB disease (T/F)
True
Risk of developing TB disease increases by ____% each year in HIV infection individuals
5-10%
Signs of pulmonary TB include a chronic, productive cough for _______
> 2 weeks
Advanced stages of pulmonary TB can cause ____ sputum
blood-tinged
Groups that are not high risk for TB should not be tested routinely (T/F)
True
Persons at higher risk for exposure to or infection with TB include:
Close contacts of a person known or suspected to have TB
Foreign-born persons from areas where TB is common
Residents and employees of high-risk congregate settings (ex. prisons)
Health care workers who serve high-risk clients
Medically underserved, low-income populations
High-risk racial or ethnic minority populations
Children exposed to adults in high-risk categories
Persons who inject illicit drugs
For patients who are HIV positive, recent contacts of TB cases, have fibrotic changes on chest x-ray, or organ transplant/other immunosuppressed patients, the classifying tuberculin reaction is ____ mm
≥5 mm
For recent arrivals from high-prevalence countries, injection drug users, residents and employees of high-risk congregate settings, children <4 years, the classifying tuberculin reaction is ___ mm
≥10 mm
For persons with no known risk factors for TB, the classifying tuberculin reaction is ___ mm
≥15 mm
Nontuberculous mycobacteria and/or BCG vaccination may result in a false-___ TST
false-positive
Very young age (<6months), live-virus vaccination, overwhelming TB disease, and immunosuppression may results in a false-____ TST
false-negative
TST is contraindicated for BCG-vaccinated persons (T/F)
False
Boosting occurs for patients who do not respond to the initial skin test. The initial skin test may stimulate the body’s ability to react to TB
True
People with LTBI may have a positive TST when tested years after infection (T/F)
False, LTBI patients may show a NEGATIVE TST when tested years after infection, which is why they require boosting
IGRA are not approved for use in children ___ years old
<5 years old
IGRA are accurate in persons recently exposed or immunocompromised patients (T/F)
False
IGRA can differentiate between latent and active infection (T/F)
False
IGRAs are more expensive than TSTs (T/F)
True
Chest radiographs can confirm TB diagnosis (T/F)
False, cultures are the gold standard for confirming TB diagnosis
___ sputum specimens for smear examination and culture should be obtained
3
TB uses the _____ bacilli smear
acid-fast bacilli
All specimens should be cultures, even if smears are negative (T/F)
True
The Nucleic Acid Amplification Test (NAAT) is more sensitive and specific than AFB smears (T/F)
True
You do not have to run a NAAT test if you get a positive smear (T/F)
False, you should run a NAAT test on at least one sputum culture
NAAT results are available after:
A. within hours to days
B. in 10-14 days
A. within hours to days
The molecular Detection of Drug Resistance (MDDR) test can be used to detect mutations frequently associated with _____ and _____ drug resistance
rifampin and isoniazid - if positive, the test will also detect resistance
For patients whose initial evaluation suggests a liver disorder, have HIV, are either pregnant or in the immediate postpartum period (≤ 3 months), have a history of regular alcohol use, injection drug user, medications with possible interactions, you should run baseline _____ measurements for LTBI treatment
hepatic
Preferred LTBI treatment that has moderate evidence for HIV + and _ patients: _____ + ______
isoniazid + rifapentine once weekly for 3 months
Preferred LTBI treatment for HIV - patients only: _____
rifampin daily for 4 months
Preferred LTBI treatment that has low evidence for HIV + and HIV- patients: _____ + ______
isoniazid + rifampin daily for 3 months
LTBI patients receiving treatment should be evaluated every _____
month
For active TB, a single drug should be added to a failing regimen (T/F)
False, usually 2 or more drugs are added
1st line active TB therapy includes RIPE - what are the medications?
Rifampin 10 mg/kg daily, Isoniazid 5 mg/kg once daily, Pyrazinamide 20-25 mg/kg daily, Ethambutol 15-20 mg/kg daily
Things to look out for regarding rifampin include
DDIs - CYP3A4 inducer
Discoloration of secretions
Hepatotoxicity
Things to look out for regarding isoniazid include
Peripheral neuropathy
This drug for active TB treatment is the most hepatotoxic
Pyrazinamide
Which 2 active TB drugs require renal adjustments and also use lean body weight measurements?
Pyrazinamide and Ethambutol
This drug for active TB treatment is the least hepatotoxic
Ethambutol
This active TB drug can cause ocular toxicity (green color and visual acuity issues)
Ethambutol
What is usually prescribed with isoniazid at 25-50 mg/day to help in malnourished patients or those prone to neuropathy?
Vitamin B6
RIPE meds should be given with food because food increases absorption (T/F)
False, empty stomach because food decreases absorption
The regimen for TB therapy includes:
RIPE for ___ months (initial phase), then rifampin + isoniazid for ___ months (continuation phase)
2 months, then 4 months
In HIV- persons, regimen should be adjusted once drug susceptibility results are known: If isoniazid + rifampin susceptible, ____ can be dropped during the initial phase but ____ should be kept on for a total of 8 weeks
can drop ethambutol but should keep pyrazinamide for a total of 8 weeks
In HIV+ persons who are not taking any protease inhibitors (PIs) or non-nucleoside reverse transcriptase inhibitors (NNRTIs), they should be on ___-based regimens
rifampin (RIPE)
In HIV+ persons who are receiving protease inhibitors (PIs) or non-nucleoside reverse transcriptase inhibitors (NNRTIs), they should be given initial RIPE therapy with rifampin substituted with _____
rifabutin
For pregnant women with TB, what is their treatment and what should be avoided?
9-month regimen of isoniazid, rifampin, and ethambutol. AVOID pyrazinamide
Children with TB should be in most cases treated with the same regimen used for adults (T/F)
True
Children with bone and joint TB, miliary TB, or TB meningitis should be treated for a minimum of ___ months
12 months
The two most common resistant TB drugs are
isoniazid and rifampin
If isoniazid resistant, what should replace it in the therapy?
discontinue isoniazid and add LEVOFLOXACIN. Continue regimen for the entire 6 months
What kind of therapy should be considered for all patients to help with treatment adherence issues?
DOT (Direct Observed Treatment)
How often should patients be monitored bacteriologically?
Monthly until cultures convert to negative
After ___ months of therapy, positive cultures should be re-evaluated for resistance and/or nonadherence
2 months
Patients are no longer infectious with TB if these 3 criteria are met:
They are on adequate therapy, have had a significant clinical response to therapy, have had 3 consecutive negative sputum smear results
Slow growing non-TB mycobacterium (NTM) is what duration? Rapidly growing NTM is what duration?
Slow: >1 week
Rapid: within 1 week
The most common clinical presentation of NTM is pulmonary disease (T/F)
True, and often occurs when there is underlying structural airway disease
Diagnosis of NTM includes pulmonary or systemic symptoms, nodular or cavity opacities on a CT scan, and positive culture results from at least ____ separate sputum samples
TWO
There is a possibility that you may not treat NTM at all and instead, use the watch and wait method (T/F)
True
NTM requires a longer treatment duration (T/F)
True, around 12 months
