Tuberculosis Flashcards
Are local health authorities required to report TB cases?
Yes!
What happens when you report TB to local health authority
Then it can be VOLUNTARLY reported to the national reporting level if they meet the case definition
Which location in canada has the highest RATES of TB?
The northern territories-> massively highe rrate per 100,000
is a vaccine avaliable for TB?
Yes! but not commonly recommended, Canada reccomends BCG (TB vaccine) for individuals at high risk coming from TB endemic areas or infants in high-incidenece settings.
NOT recommended for prophylaxis for HCW travelling to endemic areas
Recomended for infants born in canada who are traveling to endemic areas short after ARRIVAL in that high incidence country
Do you do a skin test before vaccine?
For infants >6months of age, do a skin test prior to vaccination and DOCUMENT
2-6 month olds should assess risk of skin test before doing
Who is BSG reserved for in Canada for now?
Inuit and on reserve fist nations children born to mothers who tested negative for HIV prenatally
Classic symptoms of pulmonary TB disease
chronic cough of at least 2-3 weeks in duration -> Initially dry cough but afer several weeks to months will become productive
Fever and night sweats are common but may be abscent in very young and old
What would indicate advanced pulmonary TB?
Hemoptysis, anorexia, weight loss, chest pain and other symptoms are generally manifestations of more advanced disease
Usual first line diagnostic test for suspected TB?
Chest radiography
Typically se a triad of classic signs
Infiltrates in upper lobels or superior egment of lower lobes
Volume loss - TB is destructive and fibrotic in nature
Cavitation - Seen at a later stage depending on immune response
Is chest Xray definitive?
No need microbiology reports after
Gold standard TB lab test?
Microbology
how many sputum cultures are recommended?
at least 3 should be collected
Can TST find active TB?
not really, it cant differentiate between latent and active. You might just have a chest cold but latent TB infection
Why do you test for latent TB?
So that you can identify people at risk of developing ACTIVE TB. Dont test everybody, only those who would benefit from treatment
Name the two tests acceptable for latent TB identification?
TST (Tuberculosis skin test)
IGRA (interferon gamma release assay)
Which is more specific TST or IGRA?
(in regards to individuals with BCG vaccine history
IGRA
When do you do both a TST and IGRA?
> 18YOs where you suspect TB, but IGRA should not be used in place of microbiology
Standard treatment regiment for ACTIVE TB in canada?
Isoniazid, rifampin, pyrazinamide and ethambutol
When can you change therapy from first line?
When drug susceptibilities come back you can stop ethambutol if all other drugs work
How long to use pyrazinamide?
First two months of treatment
Standard therapy duration
6 months
when to increase duration to 9 months of treatment?
risk factors for relapse such as persistent presence of cavity on the chest x-ray after 2 months, if culture comes back +ve after standard duration
When to use DOT therapy? (directly observed treatment)
When risk of non-adherence is high or population group being treated has historically increased risk so of treatment failure
Does pregnancy drug regiment differ?
No same standard tetrad
Dosing changes in renal impariment?
No DOSE changes but frequency changes to ethambutal and pyrazinamide, change from DAILY to three times per week
Second line drugs for TB?
Fluroquin (moxi +levo) (400mg, 750-1000mg)
Amikacin (15mg/kg single dose daily)
What happens if you dont use isoniazide?
You must prolong to at least 12 months
What is pyridoxine?
B6! routine addition for patients with diabetes, renal failure, malnutrition, substance abuse or seizure disorders
Women who are pregnant or breastfeeding also get this
(added to isoniazide therapy for both situations)
pyridoxine dosage?
25mg
Treatment lengths
18 months if not using rifampin at all
12 months if no isoniazide
9 months if using rifampin and isonaizide
6 months maybe (depending on if patients are stable and responding to treatment) if using pyrazinamide
when to use rifabutin?
has less induction w/ CYP450 so used in HIV-infected or tranplant patients
Hematological toxicity common
What is pyrazinamide?
Bacteriocidal agent that only really works up to first 2 months
injectables that are used in canada for TB treatment
Amikacin (most common), streptomycin (not really in canada), kanamycin and capreomycin
Do you HAVE to do daily administration of drugs?
DOT therapy does allow for 5 times/week for first 2 months and 3 times weekly for continuation phase
Hepatotoxicity risk changes?
No pyrazinamaide and minimum 9 months (since no pyrazinamide is being used)
adverse effects of isoniaide?
Rash, hepatitis, neuropathy, anemia, CNS toxicities
adverse effects of rifampin
drug interactions (CYP inducer), hepatitis, flu like illness, thrombocytopenia and neutropenia
Pyranizomide adverse effects?
hepatitis, rash, arthralgias, GOUT (rare)
ethambutal adverse effects?
EYE TOXICITY (well known), rash
Current treatment for latent TB?
Isoniazide for 9 months
Alternative options for latent TB?
isoniazide for 6 months
Isonizide + rifampin for 3-4 months
Should you treated pregnant patients for latent TB?
not usually, defer till 3 months post partum
any issues treating latent TB in breastfeeding mothers?
Nope
TST results indicating latent TB
> 5mm (if HIV infection, contact w/ TB patient in last 2 years, organ transplant patient, end stage renal disease, on immunosuppresants)
> 10mm (diabetes, malnutrtion, smokers, daily alcohol consumption (>3 drinks per day) solicosis, hematological malignancies such as leukemia and lymphoma)
Latent TB who have had contact with cases of resistant TB disease recommendations
Contacts of isoniazide resistance should be treated with 4 months of rifampin (if they are not rifampin resistant)
Contacts of rifampin resistant TB but not isoniazide treated with 9 months of isoniazide
Multidrug resistance traet with combo of levo or moxifloxacin and pyranazinamide for 9 months
Pyranazinamide or ethambutol resistance just gets isoniazide for 9 months
Latent TB with hepatic dysfunction?
Rifampin better choice then isoniazide in mild
severe contraindicates rifampin, rifapentin, and isoniazide
use daily levo or moxifloxacin for 9 months instead
when to stop latent TB infection therapy?
5x upper limit of normal liver transaminases (or 3x if you start getting symptoms of liver failure ei flu like symptoms, jauncide, labile INR, encephalopathy)
I DONT THINK THIS WILL BE ON PEBC BUT HERE IS KIDDO DOSING
Past 35kg or older (>12YO) super vague dosing and canada guideline sucks
isoniazide:
<12 YO or <35KG 10-15mg/kg/day (max 300mg) better absorption on empty stomach, avoid sugars as it inactivates isonaizide (good luck getting kids to eat that lul)
rifampin 10-20mg/kg/day (max 600mg)
Pyrazinamide 30-40mg/kg/day max 2000mg
Ethambutal 15-25mg/kg/day max (1600-2500 (differs between guidelines)
pyridoxine 1mg/kg/day max 25mg (as it is in adults to avoid decreasing isozianide therapy effectiveness)
Do you use pyridoxine all the time in kiddos?
no, indicated for children on meat and or milk deficient diets, breastfed infants and nutrtionally defcient kids or HIV infections
Duration in pediatrics
same as adults
