Infectious Lung Diseases (TB, flu, etc)

Question 1

Who should get a flu vaccine?

Answer 1

Anyone 6 months or older who does not have a contraindication.

Question 2

When should we start administering flu vaccines?

Answer 2

Before flu activity starts in the community: preferably October if possible

Question 3

What group might require 2 vaccines?

Answer 3

Children between the ages of 6 months & 8 years who are being vaccinated for the first time.

Question 4

At what type of visit should providers offer the flu vaccine?

Answer 4

At EVERY visit: office visit, hospital, etc.

Question 5

Which is more effective in adults: live attenuated virus or inactivated virus vaccine?

Answer 5

Both are equally effective in adults.

Question 6

Which is more effective in children: live attenuated virus or inactivated virus vaccine?

Answer 6

Live attenuated virus (flu mist)

According to the CDC website: “When immediately available, LAIV should be used for healthy children aged 2 through 8 years who have no contraindications or precautions (Category A). If LAIV is not immediately available, IIV should be used.”

Which is convenient so you don’t have to chase a kid around to give them a shot. :)

Question 7

The live attenuated flu virus should not be used in the following populations:

Answer 7

1) Persons aged 49 years;
2) Children aged 2 through 17 years who are receiving aspirin or aspirin-containing products;
3) Persons who have experienced severe allergic reactions to the vaccine or components;
4) Pregnant women;
5) Immunosuppressed persons;
6) Persons with a history of egg allergy;
7) Children aged 2 through 4 years who have asthma or who have had a wheezing episode within the past 12 months
8) Persons who have taken influenza antiviral medications within the previous 48 hours.

Question 8

What is tuberculosis?

Answer 8

Disease caused by bacteria of the Mycobacterium tuberculosis complex.

Usually affects the lungs but other organs can be involved in up to 1/3 of cases.

Question 9

Description of M. tuberculosis bacterium

Answer 9

#rod-shaped
#non spore-forming
#aerobic
#acid fast

Question 10

What does it mean for a bacterium to be acid-fast?

Answer 10

Once stained via Gram-staining, it cannot be decolorized with acid alcohol

Question 11

When a bacterium is acid-fast, what does that mean for antibiotic therapy?

Answer 11

Cell wall is not very permeable, rendering antibiotics less effective

Question 12

Of the new cases of TB reported to the World Health Organization in 2009, where were most located?

Answer 12

95% of them in the developing nations of Asia, Africa, Middle East, & Latin America.

Question 13

How is TB transmitted?

Answer 13

Droplets from a person with infectious pulmonary TB are aerosolized by coughing, sneezing, speaking. Remain suspended in air for several hours & are inhaled by others.

Question 14

Important determinants of likelihood of transmission

Answer 14

1) Probability of contact with infectious TB patient
2) Intimacy & duration of that contact
3) Degree of infectiousness of the case
4) Shared environment where contact happens

Question 15

What TB patient is most likely to transmit infection?

Answer 15

Those who sputum contains AFB visible by microscopy

Question 16

One of the most important factors in the transmission of TB is…

Answer 16

Overcrowding in poorly ventilated rooms (which makes sense with the developing nations TB problem)

Question 17

What is the “Ghon focus” in the context of TB?

Answer 17

Lung lesion forming after initial infection

Question 18

Lobes most commonly involved in primary TB

Answer 18

Middle & lower lung zones

Question 19

Primary TB may quickly progress to clinical illness in what populations?

Answer 19

1) Children

2) Immunocompromised

Question 20

Post-primary TB or “adult-type” TB can result from either

Answer 20

1) Endogenous reactivation of distant, latent infection

2) Recent infection

Question 21

Adult-type TB localizes to…

Answer 21

the apical & posterior upper lung segments, where high O2 tension favors bacterial growth

Question 22

With cavity formation in the lung parenchyma, what happens to the spread of TB in the lung?

Answer 22

Liquified necrotic contents of the cavities are discharged into the airways & undergo bronchogenic spread, resulting in more lesions that could undergo cavitation

Question 23

Up to 1/3 of untreated TB patients with post-primary disease…

Answer 23

…succumb to severe pulmonary TB within a few months. In the Olden Days this was called “galloping consumption”. Bonus points if you write that in a chart.

Question 24

Other patients undergo a spontaneous remission…

Answer 24

…and have a more chronic course. This was just “consumption” in the Olden Days. Doc Holliday had it!

Question 25

When TB is on the differential, how do we diagnose?

Answer 25

1) AFB microscopy
2) Mycobacterial culture
3) Nucleic acid amplification

Question 26

High points of AFB microscopy for TB

Answer 26

1) Relatively low sensitivity

2) 2-3 sputum specimens, preferably from early morning collection

Question 27

How long does it take to culture TB?

Answer 27

4-8 weeks

Question 28

How long does nucleic acid amplification for TB take us?

Answer 28

Diagnosis in just a few hours, with high specificity & sensitivity approaching that of culture.

Question 29

High points of radiography for TB

Answer 29

1) Initial suspicion for TB is usually based on the CXR of a patient with respiratory sx
2) Classic picture: upper-lobe disease with infiltrates & cavities
3) Virtually ANY CXR pattern may show up, though

Question 30

What’s the PPD skin test?

Answer 30

Subcutaneous injection of “tuberculin purified protein derivative”, which is widley used in screening for latent TB infection.

It’s unable to discriminate between active vs. latent disease.

Question 31

PPD false negatives? False positives?

Answer 31

#False negative: Immunosuppressed patients, patients with overwhelming TB
#False positive: infections with non-TB mycobacteria, BCG vaccination (a TB vaccine)

Question 32

Two goals of TB therapy

Answer 32

1) Interrupt transmission by rendering patients noninfectious
2) Prevent morbidity & death by curing patients while preventing drug resistance

Well don’t WE just have lofty goals?

Question 33

Though standard therapy is 3 drugs, there are 4 drugs considered 1st-line agents. They are:

Answer 33

1) Isoniazid
2) Rifampin
3) Pyrazinamide
4) Ethambutol

Question 34

The 4 first line TB agents are recommended based on what properties?

Answer 34

1) Bactericidal activity
2) Sterilizing activity
3) Low rate of induction of drug resistance

Question 35

Some 2nd-line drugs, used only in patients refractory to 1st-line agents:

Answer 35

1) Injectable aminoglycosides (streptomycin, kanamycin, amikacin)
2) Injectable polypeptide capreomycin
3) Oral agents (ethionamide, cycloserine, PAS)
4) Fluoroquinolone antibiotics (levofloxacin, moxifloxacin)

Question 36

Standard short-course therapy for TB is divided into 2 stages. What are they & what do they do?

Answer 36

1) Initial: bactericidal. KILL IT WITH FIRE. Kill the majority of the bacteria, resolve symptoms, patient becomes noninfectious.
2) Continuation: sterilization. PUT OUT THE HOT SPOTS. Eliminate persisting bacteria, prevent relapse.

Question 37

Standard therapy for virtually all forms of adult TB

Answer 37

2 month initial phase: isoniazid, rifampin, pyrazinamide, & ethambutol
4 month continuation phase: isoniazid & rifampin

Question 38

Who is at high-risk for isoniazid-related neuropathy? What do we give to prevent it?

Answer 38

Ppl with B6 deficiency: alcoholics, malnourished perople, pregnant & lactating women, patients with renal failure, diabetes, or HIV

Give pyridoxine (10-25 mg daily) to prevent

Question 39

Most important impediment to TB cure worldwide is…

Answer 39

…lack of adherence to treatment!

TAKE YOUR MEDS, PEOPLE. WORK WITH ME HERE.

Question 40

What is likely to happen to the bacteria infecting non-adherent patients?

Answer 40

Drug resistance!

CONGRATULATIONS, JERK.

Question 41

Patient-related factors affecting compliance

Answer 41

1) Lack of belief that illness is significant
2) Lack of trust in treatment
3) Existence of comorbidities or conditions (substance abuse)
4) Lack of social support
5) Poverty

Question 42

Provider-related factors improving compliance

Answer 42

1) Education & encouragement
2) Convenient hours
3) Provisions of incentives like meals or travel vouchers
4) Direct observation of treatment
5) Provision of fixed-drug combo products

Question 43

Monitoring for TB therapy response:

Answer 43

1) Sputum examined monthly until cultures are negative
2) With recommended regimen, 80% have negative sputum cultures by end of 2nd month
3) By 3rd month, virtually ALL patients should be negative

Question 44

Patients with cavitary disease & positive sputum culture by the end of 2 months require…

Answer 44

…extended treatment

Question 45

If sputum culture is still positive by ≥ 3 months of treatment, suspect:

Answer 45

1) Treatment failure & drug resistance or

2) Poor adherence to therapy

Question 46

Is a CXR useful at the end of TB treatment?

Answer 46

Yes, but not for diagnosis of cure. It may be useful for comparative purposes should the patient later develop recurrent symptoms months or years later.

Question 47

The high points of monitoring patients for drug toxicity in TB treatment

Answer 47

1) Most common adverse reaction: hepatitis
2) Educate patients about sx; discontinue treatment & see provider promptly
3) Baseline liver function tests for everyone before treatment (YOU get LFTs! YOU get LFTs! EVERYONE gets LFTs!)
4) Monthly monitoring in: older patients, hx of hepatic disease, daily alcohol users, & the immunosuppressed.

Question 48

Is the BCG TB vaccine recommended for general use in the US? Why or why not?

Answer 48

No, because of

1) low risk of transmission in US
2) Unreliability of vaccine
3) Impact on the TB skin test

Question 49

Reading a PPD: Size considered positive for different groups

Answer 49

HIV-infected or immunosuppressed: ≥ 5mm
Close contacts of TB patient: ≥ 5mm
Fibrotic lesions on CXR: ≥ 5mm
Ppl infected ≤ 2 yrs: ≥ 10mm
Ppl w/ high risk conditions: ≥ 10mm
Low risk ppl: ≥ 15mm