lower respiratory tract

Question 1

sterile

Answer 1

mucucilliary escalator - swallows down to stomach
phagocytes
mucosal IgA

Question 2

how do infectious agents gain entry

Answer 2

inhalation
aspiration of GI tract
haemotogenous spread

Question 3

community acquired pneumonia

Answer 3

build up of fluid in the alveoli
lobar pneumonia
atypical pneumonia - psittacosis from parrots
age related organisms

Question 4

CAP neonate

Answer 4

group B streptoccocus, L monocytogenes

Question 5

CAP infant

Answer 5

encapsulated bacteria
H. influenzae (vaccine at 3)
C. trachomatis

Question 6

CAP young adult

Answer 6

Strep pneumonia

Question 7

CAP older adults

Answer 7

S. pneumonia, Legionella

Question 8

Hosptial acquired

Answer 8

occurs in patients hospitalised longer than 72 hours
gram negative bacilli (P. aeruginosa)
endogenous

Question 9

institutionalised pneumonia

Answer 9

MRSA , enteric flora, negative bacilli

Question 10

immunocomprimised

Answer 10

AIDS- penumocystitis jiroveci

CF- P.aeringinosa, Burkholderia cepacia

Question 11

lobar pneumonia (CAP)

Answer 11

discrete region of lung with fluid (lobar)
Strep pneumonia (leolancate, a haemolysis, sensitive to optochin - viridans are resistant (also in mouth))
mortality 10%
vaccine covers 13 serovars

Question 12

bronchopneumonia (CAP)

Answer 12

diffuse lung infection
staph aureus, secondary infection following viral infection
plums and custard sputum
S aureus produces b lactamases
fuscidic acid used to treat intravenously
other causes: K. pneumonia, P. aeruginosa

Question 13

necrotising pneumonia

Answer 13

S aureus strain produces Panton-Valentine Leukocydins
B barrel toxin - forms pores in immune cells
cavatating lesions - destruction of lung tissue
healthy individuals

Question 14

atypical pneumonia

Answer 14

patients present with dry, unproductive cough
chronic, flow onset, fever
no evidence on X ray - bacteria lack cell wall, obligate intracellular
not treated with b lactams
Mycoplasma pneumonia
chlyamydia pneumonia
coxiella bunette

Question 15

Legionnaires disease

Answer 15

atypical 
caused by Legionella Pneumophilia 
-gram negative bacillus 
-urine sample -antibodies found
found in stagnent waters 
initial symptoms resemble influenza
progresses into systemic infection 
consolidation in both lungs - wipe out
mortality 50%

Question 16

diagnosing pneumonia

Answer 16

clinical: CURB65 score of severity determines treatment
confusion, urea, respiratory rate, blood pressure

X ray, ultrasound (collections of pus - emyprna)

lab- microscopy 
sputum sample 
or broncho-alveolar lavage 
blood culture 
urine - antibodies

Question 17

chronic bronchitis

Answer 17

multifactorial disease
over production of mucus
haemophilus influenzae - encapsulated
X and V factor

Question 18

whoooing cough

Answer 18

vaccine in UK
bordetella pertussis (gram -ve cocci-bacillus)
mucus
toxin mediated (AB) increases cAMP
parocymysmal coughing and inhilation of breath
71% of cases in children before vaccine (18 months)
regan-lowe charcoal absorbs fatty acids in agar

Question 19

respiratory tuberculosis

Answer 19

Mycobacterium tuberculosis
escapes macrophage killing 
granulomas formed
M. bovis, M. avum 
lab diagnosis difficult - acid fast, ZN stain 
slow growth in culture
direct observation of sputum
MGIT quick
IFNy assay but immunocomprimised have none (false negative)