Immune System

Question 1

Humoral defects

Susceptible to what bacteria, viruses, protozoa

Answer 1

Bacteria
Staph, strep, haemophilus influ, moraxella catarrhalis

Viruses: enteroviruses

Protozoa: Giardia

Question 2

Cellular immunity

Susceptible to what organisms

Answer 2

Bacteria: Mycobacterium, listeria spp

Viruses: CMV, HSV, measles, RSV adenovirus

Fungi: Candida, aspergillus

Protozoa: Pneumocystis

Question 3

Neutrophil defect

What organisms typically cause disease

Answer 3

Gram +, gram -

Aspergillus, candida

Question 4

Complement defects

What organisms

Answer 4

Neisseria

Staphylococcus

Question 5

Viral causes of encephalitis

Frequent

Rare

Answer 5

Enterovirus
HSV 1 and HSV 2
Varicella zoster
Measles, mumps
Influenza 

Rare: adenovirus, rubella, EBV, arenaviruses (japanese B encephalitis), rabies, mycoplasma

Question 6

Role of steroids in meningitis

Answer 6

Improves deafness in Hib meningitis

Lowers mortality in Step pneumoniae meningitis ( no effect seen in neisseria or Hib subgroups)

Question 7

Rate of deafness after meningitis

Answer 7

5%

Question 8

Acute haematogenous osteomyelitis

Most common age groups & the bacteria seen
Destruction of growth plate in which group

Answer 8

Neonate: GBS, S aureus, E Coli
Femur or humerus
Multifocal in 20-40%
Usually with S.A

Infant: S aureus, strep pneumoniae, Hib, GBS, GAS, K kingae
Single long bone metaphysis

Child: staph aureus, strep, E. coli, K kingae, Salmonella

Sickle cell: salmonella, strep pneumoniae, staph aureus, gram neg
Diaphysis rather than metaphysis affected

Question 9

Kawasaki differential dx

Answer 9

TSS (staph or strep)
Staph scalded skin 
Scarlet fever 
Enterovirus
Adenovirus 
Measles 
Parvovirus 
EBV
CMV
Mycoplasma pneumoniae 
Rickettsiae
Leptospira spp

Question 10

Non-criteria features of Kawasaki

Answer 10

Arthritis 
Aseptic meningitis 
Pneumonitis
Uveitis
Gastroenteritis
Meatitis
Dysuria
Otitis

Question 11

Proportion of Kawasaki developing aneurysm

Proportion of CAA that regress within 5 y

Mortality rate

Answer 11

20-40%

50% regress within 5 y

3.7%

Question 12

Infective endocarditis
- native valves: organisms

• prosthetic valves

Answer 12

Strep viridans (mutans, sanguis, mitis)
Staph aureus
Enterococcus ( S faecalis, Strep Bovis)

Staph epi, staph aureus, strep viridans

Question 13

Brucellosis

Gran stain
Transmission
Incubation
Sx

Dx

Rx

Answer 13

Brucellosis
Gram neg bacilli
Zoonotic, ingestion of unpasteurized milk
Incubation 1-4w

Fever, night sweats, anorexia, wt loss myalgia, lymphadenopathy, HSM
Endocarditis & Osteomyelitis

Blood culture, paired serology
Doxycycline & rifampicin

Question 14

Lyme disease
Where
Transmission from
Skin sign
Clinical features 3w later
Late features

Answer 14

US, Europe, UK
Spirochaete borrelia burgdorferi
Transmission from ticks

Bullseye lesion expands to 15cm diameter
Fever, headache, malaise, neck stiffness

3-5w later: CN palsies, meningitis, arthralgia, myalgia, headache

Late: recurrent arthritis, neuropathy & encephalopathy

Question 15

Listeriosis 
Gram stain
Incubation 
Source 
At risk
Features of illness

Answer 15

Gram positive bacillus
3-70d
Raw vegetables & meat, soft cheese, meat pate
Fetus, neonate, immunocompromised, pregnant women, elderly

Flu like
Meningoencephalitis, septicaemia
Asymptommatic

Amoxicillin

Question 16

Leptospirosis 
Source
Incubation 
Illness 
Second phase

Treatment

Answer 16

Urine of rats, dogs, livestock
Swimming in contaminated water or direct contact
1-2 weeks
Biphasic:
Fever, rigor, headache,malaise, conjunctivitis

Aseptic meningitis, uveitis, myalgia, lymphadenopathy, vasculitic rash

Penicillin
Or doxycycline

Question 17

TB
Time from infection to positive mantoux
Defects in what cytokines predispose to infection
Rate closely exposed who develop infection
Rate of infected who develop disease

Risk of disease highest for how many months

Answer 17

2-12w
Interferon gamma, IL-12
30%
5-10%
Highest risk within 6 months

Question 18

Gohn focus

Answer 18

Pulmonary macrophages ingest bacteria and mount a cellular immune response

Primary infection controlled over 6-10weeks
Pulmonary foci latercalcify : gohn focus

Question 19

Neonatal contact with maternal TB
Separate if…
Treatment
Test (when, what)

Answer 19

High risk
Separate if mother is smear positive or has abnormal cxr
Treat for 3 mo with isoniazid then test mantoux and do cxr
Stop if negative
Continue further 3 mo if positive mantoux, negative disease
Triple therapy if disease present

Question 20

TB chemotherapy

Answer 20

Pulmonary and non-pulmonary (except meningitis)
Isoniazid & rifampicin for 6 mo
First 2 mo with pyrazinamide and eitherethambutol or steptamycin

Same but 12mo total

Question 21

Atypical mycobacterium
Source
Acquired by
Clinical presentations

Dx

Rx

Answer 21

Soil, food, water, animals
Ingestion, inhalation, inoculation
Disseminated in immunodeficiency and HIV

Lymphadenitis, pulmonary infection, cutaneous infections, osteomyelitis (rare)

Culture or PCR
Mantoux may be weakly positive

Excision of LN
2x drugs for other forms

Question 22

Parvovirus 
Incubation 
Infectious period
Presentation 
Complications

Answer 22

1 week
Until rash appears

Very erythematous cheeks, then erythematous macula papular rash trunk & extremities, fades with central clearing giving a lacy or reticular pattern

Aplastic crisis in chronic haemolytics
Aplastic anaemia
Arthritis, myalgia
Congenital hydrops

Question 23

HHV-6
Other names for illness
Clinical presentation
Complications

Answer 23

Roseola infantum
Exanthem subitum

High Fever without focus
Day 3-4 fever stops and macular/papular rash appears, lasts 1-3d
Febrile convulsions (often day 1)

Question 24

TRAPS

Length of fever episode
Associated symptoms
Inheritance
Amyloidosis?

Answer 24

1-3w

Abdominal pain 
Pleuritis
Rash
Myalgia 
Orbital oedema 

AD

Amyloidosis in 10-15%