Chest infections

Question 1

Pathogenesis of TB

Answer 1

Infects macrophages
- resistant to oxidative burst

–> long time latent infection

Reduced protection with impaired TH-1 response

Question 2

Increased risk of TB reactivation?

Answer 2

HIV +++

Long term prednisone - >15mg for >1 month
Immunosuppression and immunomodulation

Question 3

Isolation for treatment of TB?

Answer 3

2 weeks at least

Longer if ongoing AFB positive or ongoing cough

Question 4

Paradoxical reactions and TB?

Answer 4

Deterioration of lesions while on therapy
Similar to IRIS

Continue anti-TB therapy, corticosteroids, and aspirations

Question 5

Quantiferon gold assay?

Answer 5

Whole blood to TB antigens
Measure cytokine response

Does not differentiate latent and active TB
Less false positives with BCG and atypical mycobacteria

Question 6

Different kinds of MAC lung infections

Answer 6

Nodular:

• Elderly white females
• RML
• Smear negative, culture positive

Fibronodular cavitating

• Male smokers
• Smear postive

Question 7

Treatment of MAC infections?

Answer 7

Clarithromycin
Rifampicin
Ethambutol

Question 8

Antibiotics for CAP?

Answer 8

Mild CAP = amoxyl or doxy

Moderate CAP = Ben pen + doxy

Severe CAP = Ceftriaxone + azithromycin

Question 9

Aspiration Pneumonia treatment?

Answer 9

Most are pneumonitis not pnuemonia

No longer metronidazole first line
Only if poor oral hygiene or EtOH or lung abscess or empyema

Question 10

Pertussis diagnosis and treatment?

Answer 10

Ongoing cough, no fever

Pertussis PCR = diagnosis

Treat with azithromycin or bactrim
Vaccinate

Question 11

Risk factors for severe flu

Answer 11

Pregnancy
Immunosuppressed
Obese
Asthma
Low IgG2

Question 12

What is antigenic shift?

Answer 12

Genetic reassortment = new strain = no immunity –> pandemic

ONLY INFLUENZA A

Question 13

What is antigenic drift?

Answer 13

Mutations- in Ha and NA proteins –> annual epidemic

Question 14

Cause of meningococcus?

Transmission?

Answer 14

Neisseria meningitis

Transmission via respiratory route

Question 15

Clinical syndromes of meningococcus?

Answer 15

Bacteraemia without sepsis
Miningococcaemia without meningitis
Meningitis
Meningo-encephalitis

Question 16

Treatment of meningococcus?

Answer 16

Ben pen 1.8gms 4 hrly for 1 week

Question 17

Chemoprophylaxis for neisseria meningitis?

Answer 17

Eradicate asymptomatic carriage

Ceft or cipro or rifampicin

Question 18

Pneumococcal meningitis?

Answer 18

Associated with head trauma, CSF leak and dural tears

Treatment:

• Ben pen
• Vanc and ceft if resistant
• Steroids

Question 19

Which infections need droplet precautions?

Answer 19

> 5 nanos

Influenza
Neisseria meningitis
Pertussis

Question 20

Which infections need airbourne precautions?

Answer 20

<5 nanos

Varicella
Measles
TB
MERS-CoA
Ebola