gram negatives

Question 1

why is Hib so virulent in younger kiddos?

Answer 1

< 2 y unable to mount antibody response to polysaccharide capsule even after invasive infection

Question 2

what major group of patients is Hib particular bad in?

Answer 2

functional or true asplenia - spleen plays important role in immunity against encapsulated bacteria

Question 3

Treatment of: 
Hib
pertussis
N.meningitidis
non-typhoid salmonella
bartonella

Answer 3

Hib = ampicillin
pertussis = azith/clarith
N.meningitidis = ceftriaxone
non-typhoid salmonella = 3rd gen ceph
bartonella = azith

Question 4

moraxella catarrhalis mostly causes what kind of infections

Answer 4

otitis media/sinusitis

Question 5

pertussis - describe the bacteria morphology

Answer 5

Gram negative pleomorphic bacillus

Question 6

classic progression of pertussis

Answer 6

1. catarrhal: 1-2 weeks nonspecific
2. paroxysmal: 2-8 weeks of cough with whoop
3. convalescent phase

Question 7

complications of pertussis

Answer 7

a. Apnoea
b. Seizures
c. Refractory pneumonia
d. encephalopathy

Question 8

antibiotics in pertussis: do they help?

Answer 8

reduce infectivity, but not great evidence they alter course of disease

Question 9

who requires Abx prophylaxis for pertussis

Answer 9

close contact whilst index infectious +
within 14 days +

for child: anyone <3vax or <6mo
for adult: 3rd trim pregnancy /HCW / childcare worker

Question 10

efficacy of pertussis vaccine

Answer 10

85%

remember immunised can get pertussis, just mild form

Question 11

clinical manifestations of meningococcal disease

Answer 11

1. sepsis with progressive non-blanching petechial/purpuric rash
2. meningo-encephalitis
3. rarer: pneumonia / septic arthritis / pharyngitis / myocarditis
   4.

Question 12

prophylaxis Rx for Hib and N.meningitidis contacts

Answer 12

rifampicin!

Question 13

non-typhoid salmonella: non-enteritis manifestations in 3 very specific populations

Answer 13

i. Reactive arthritis (HLA B27 +ve individuals)
ii. Osteomyelitis (sickle cell disease)
iv. Toxic megacolon (IBD)

Question 14

1st and 2nd most common cause of childhood OM

Answer 14

staph aureus

kingella kingae

Question 15

burkholderia from what region

Answer 15

NT

Question 16

pseudomonas causes what skin lesion

Answer 16

ecthyma gangrenosum: haemorrhagic pustules that evolve into necrotic ulcers.

Question 17

clinical manifestations of shigella

Answer 17

dysentery - bloody stool
neuro sx inc. tonic clonic seizures (esp in children)
SIADH
HUS
reiter syndrome

Question 18

weird risk factor for cholera

Answer 18

blood group O

Question 19

GBS in children - a/w WHICH organisms

Answer 19

1. **camypolobacter jejuni **
2. Mycoplasma pneumoniae
3. CMV
4. EBV

Question 20

rice water diarrhoea =

Answer 20

= cholera, from flecks of intestinal mucous in stool

Question 21

cholera incubation period vs time to deydration/severe electrolyte imbalance

Answer 21

incubation hours to 3 days

but dehydration can happen within 4-12h of first diarrhoea/vomiting

Question 22

complications of campylobacter jejuni (4)

Answer 22

1. GBS
2. reactive arthritis
3. erythema nodosum
4. toxic megacolon

Question 23

campylobacter jejuni from where?

Answer 23

contaminated poultry/ raw milk , farm animals

and puppies!

Question 24

yersinia causes symptoms like what two conditions

Answer 24

1. appendicitis

2. KD

Question 25

types of E.Coli and type of diarrhoea

Answer 25

STEC (EHEC): shiga-like toxin > causes HUS + bloody diarrhoea
ETEC: watery diarrhoea, no blood
EIEC: invades the cell > bloody
EPEC: only infects <2yo, no blood. can stunt growth
UPEC: causes UTIs