Fever and Rash: vaccine preventable death

Question 1

What do you need to know when taking a vaccine history?

Answer 1

Immunisation UTD? = up to date

• need to know schedule and age they actually go their needles
• Where they were born, have they been overseas or had someone caring from them from overseas
• Is there an outbreak atm?

Question 2

Measles

• infectious?
• Timeline?

Answer 2

• highly
• Prodrome: 2-3 days of fever, most unwell at time of rash
  Characteristic rash day 3-7, most unwell at the time of rash

Question 3

Measles complications?

Answer 3

Common 10% secondary infection (ear infection, pneumonia, croup)
1/1000 encephalitis (15% die, 25-35% long term damage)
Rarely SSPE -7-10 years = degenerative fail nervous system disease from persistent measles infection

Question 4

Infant immunity timeline? when are they most susceptible to measles?

Answer 4

maternal antibody protection from 3-6months

Declines; window of time 6-15months where they’d catch measles if they were in contact with any cases

Question 5

Measles investigations

Answer 5

Blood culture

Lumbar puncture but give antibiotics immediately if looking dangerously unwell?

Question 6

Vaccine preventable disease that causes a non-blanching rash (purpura)

Answer 6

menicoccal disease

Question 7

sign of bacterial infection in the spinal fluid?

Answer 7

Low glucose: bacteria chomping up?

Question 8

Bacterial meningitis causes

Answer 8

S. pneumoniae
N.meningitis
Haemophilius influenzae type B now rarely seen due to vaccination
Tuberculosis

Question 9

Viral agents which can cause encephalitis and meningitis

Answer 9

e.g. herpes simplex and enterovirus

Question 10

Pathogens that can cause meningitis in newborn babies

Answer 10

Grr B strep and gram negatives

Question 11

Polysaccharide and vaccines

Answer 11

Young children (<2 years) produce very weak antibody responses to polysaccharide antigens and poor immunological memory

Question 12

Conjugate vaccines

Answer 12

polysaccharide attached to a carrier protein
taken up by B cells
Carrier protein digested and antigen presented to helper T cells
Converts a T cell independant carbohydrate antigen into a T cell dependant antigen
Good immunogenicity in those <2 yrs
Good production of memory cells

Question 13

HIB vaccine

Answer 13

Induces antibody to PRP capsule, protects against invasive disease
Initial HIB vaccines were unconjugated and poorly immunogenic
Conjugate vaccines now available
- PRP polysaccharide linked to immunogenic protein
- effective in young infant s
- Reduces or eliminates nasopharyngeal colonisaiton
- If vaccine uptake is >80% invasive disease is virtually eliminated in a pop
- Protective efficacy of vax > 98%

Question 14

Conjugate HIB vaccine in NZ

Answer 14

given at 6 weeks, 5 months and 15 months

still occasional cases, some cases seen still in un or incompletely immunised

Question 15

about: strep. pneumoniae

Answer 15

invasive disease common in children <5 esp <2 and >65

• bacteria and pneumonia
• otitis media, sinusitis
• worldwide responsible for million deaths / yr for children <5

Question 16

What is invasive pneumonococcal disease (IPD)

• in children
• in all age groups

Answer 16

pneumococci isolated form usually sterile sites - CSF (meningitis), blood (bacteremia) or pleural space / lung tissue (pneumonia)
In children
- Major cause of motility and morbidity <2 years, Most common bacterial cause of ottis media
- Commonest cause of bacterial pneumonia
- Meningococci and pneumonococci most

Question 17

Strep. pneumoniae: polysaccharide vaccine

Answer 17

Contains capsular polysaccharide from each of the 23 most common infections serotypes
- Used in splenectomy, immunosuppressed, chronic illness
Elderly (>65 yrs recommend not funded)
Not useful if < 2yrs (those who die from the disease) but confers herd immunity to this population

Question 18

Strep, pneumoniae: polysaccharide vaccine, since introduction into population have

Answer 18

97% efficacy against invasive pneumonococcal disease caused by the vaccine serotypes
10% reduction in clinical pneumonia needing hospital
30% reduction in X ray confirmed pneumonia
- some reduction in all otitis media
- less antibiotic resistant serotypes
Significant protection of those not receiving the vaccine = herd immunity

Question 19

N. meningitis

• Transmission
• serogroups
• What serotypes cause meningitis?
• What serotypes can cause epidemics

Answer 19

exclusive human pathogen transmitted by droplets from colonised upper respiratory mucosal membranes
12, based on capsular polysaccharide
90% of cases of meningitis are caused by strains belonging to serotypes A, B and C
All 3

Question 20

Significant of the polysaccharide capsule of serogroup B composed if same sugars as those found on the surface of human immature neural cells

Answer 20

Intolerant to serogroup B immunogens?

- lymphocytes that could produce antibodies to capsule are deleted during fatal development

Question 21

NZmenzB vaccine

Answer 21

Outer membrane inside capsule
Two outer membrane proteins (Por A and Por B) are the main components of the MenZ B vaccine
Antibodies to these proteins can cause complement activation and phagocytosis
Don’t produce lasting antibodies but helped to lessen epidemic in short term - no longer in production

Question 22

meningococcal vaccines available

Answer 22

meningococcal C conjugate vaccine is on the schedule in aus and Uk and can buy-in NZ
New MenB vaccine on schedule in UK - uses 4 target proteins of serogroup B strain including the NZ MenzB potion targets

Question 23

Challenges in maintaining immunisation

Answer 23

Systems
complex social media and antiimunisaiton
Shifting priorities

Question 24

Too many vaccines gives mercury poisoning?

Answer 24

Thiomersal (a preservative in vaccines converted to ethylmercury in body)
no longer given in vaccines on the national immunisation schedule, used in small amounts as an adjuvant in adults DT and some flu vaccines

Question 25

Too many vaccines might weaken the immune system

Answer 25

Number of antigens now used is less than in the original small pox vaccination