Childhood Viruses, Immunisation and Infection Control

Question 1

What causes measles and how is it spread?

Answer 1

Paramyxovirus

Person to person, droplet spread.
Incubation = 10-12 days
Infectivity = 4 days before rash till 4 days after

Question 2

What are the clinical features of measles and its complications?

Answer 2

Conjunctivitis, Coryza and Cough

Koplik’s spots 1-2 days before Rash + Fever

Otitis media, pneumonia and diarrhoea

Question 3

What causes Chicken pox and what is used to treat it over 14s?

Answer 3

Varicella Zoster Virus

Aciclovir

Question 4

What causes Rubella and how is it spread?

Answer 4

Togavirus, RNA virus

Droplet spread
incubation = 14-21 days
Infectivity = 7 days before rash to 4 days after

Question 5

What are the symptoms of Rubella and its main complication?

Answer 5

A mild self limiting infection, with a non specific rash

Congenital rubella syndrome (CRS)
- Before 16 weeks gestation at risk

Question 6

What test is used to determine what virus is infecting a patient?

Answer 6

Serology - IgM and IgG

PCR preferred

Question 7

What causes ‘Slapped cheek’ and what are its clinical features?

Answer 7

Parvovirus B19

A facial rash
Can cause anaemia in the immunosuppressed and in unborn foetus

Question 8

What viruses can cause diarrhoea in a child?

Answer 8

Rotavirus

Norovirus

Question 9

What viruses are suspected in a child with respiratory symptoms?

Answer 9

Respiratory Syncytial Virus 
Parainfluenza
Influenza
Adenovirus
Metapneumovirus
Rhinovirus

Question 10

What does Respiratory Syncytial Virus (RSV) cause?

Answer 10

Bronchiolitis and pneumonia in children under 1yr old

Question 11

How does Adenovirus present clinically?

Answer 11

Mild URTI - occasionally pneumonia

Conjunctivitis

Question 12

How is Rotavirus spread?

Answer 12

Faecal-oral
Low infective dose
Incubation 1-2 days

Question 13

What is the winter vomiting bug otherwise known as and how is it spread?

Answer 13

Norovirus

Foodborne, Person to person

Question 14

How does Mumps present clinically?

Answer 14

Earache and tenderness over ipsilateral parotid

Enlarged parotids with severe pain and Pyrexia

Question 15

What is passive immunity?

Answer 15

Vertical transmission of auto-antibodies from mother to foetus & breastfeeding

or Injection of human immunoglobulin
Pooled plasma transfusion
specific eg. tetanus, botulism

Question 16

What is active immunity?

Answer 16

Natural infection

or vaccination

Question 17

What are the advantages of live vaccines?

Answer 17

Single dose often sufficient to induce long-lasting immunity
Strong immune response evoked
Local and systemic immunity produced

Question 18

What are the disadvantages of live vaccines?

Answer 18

Potential to revert to virulence
Contraindicated in immunosuppressed patients
Interference by viruses or vaccines and passive antibody
Poor stability
Potential for contamination

Question 19

What are the advantages of inactivated/killed vaccines?

Answer 19

Stable
Constituents clearly defined
Unable to cause the infection

Question 20

What are the disadvantages of inactivated/killed vaccines?

Answer 20

Need several doses
Local reactions common 
Adjuvant needed 
 - keeps vaccine at injection site
 - activates antigen presenting cells
Shorter lasting immunity

Question 21

How are surgical instruments reprocessed?

Answer 21

Sterilization

- Moist heat

Question 22

How are flexible endoscopes reprocessed?

Answer 22

High level disinfection

- Chemical, delivered via washer disinfector

Question 23

Describe the infection prevention methods of disposable clinical equipment eg syringes

Answer 23

Sterilization

• γ-irradiation pre-use
• Disposal after use

Question 24

How are Central venous catheter insertion sites decontaminated?

Answer 24

Disinfection (antisepsis)

- Chemical, 2% chlorhexidine in 70% isopropyl alcohol1