Chickenpox Exclusions

Question 1

When should children with chicken pox be excluded

Answer 1

If they are ill and require more care than what can provided by school or child care personnel

Can return as soon as feel well enough to participate normally in all activities

Question 2

What does the AAP recommend?

Answer 2

Children with uncomplicated varicella may return when the rash has crusted or in immunized people without crusts, until no new lesions appear within a 24-hour period

Question 3

What is the benefit of a more relaxed exclusion criteria

Answer 3

Less cost to parents, less missed work, less paying for alternative care

Question 4

Can you get VZV from any other host other than humans?

Answer 4

No

Question 5

What is the incubation period for chicken pox?

Answer 5

14-16d (range 10-21d)

Question 6

When are you contagious with chicken pox?

Answer 6

24-48h before onset of the rash

Question 7

How is chicken pox transmissible?

Answer 7

Airborne leading to replication in the nasopharynx/URT and open skin lesions

Question 8

How can you diagnosis chicken pox

Answer 8

PCR - DNA - secretion day before rash onset, max concentration day 1 of rash

Question 9

What is the correlation between high viremia and severity of clinical course

Answer 9

Higher viremia is associated with more severe clinical course - prolonged fever, more vesicles

Question 10

What is the NACI recommendation on chicken pox vaccination

Answer 10

12-18mo

Second dose at kindergarten

Question 11

When do children get chicken pox

Answer 11

50% by age 5, 90% by age 12yo

Question 12

What is breakthrough disease?

Answer 12

Varicella-like illness occurring >42d after immunisation
Usually atypical
usually in immune-compromised individuals
Less contagious than normal VZV

Question 13

What is the prevalence of breakthrough disease

Answer 13

3.1% with 1 dose of vaccine

Question 14

What has changed with 2 dose vaccination programs

Answer 14

Decrease in incidence, hospitalisation, outbreaks

Increase in case patients aged 10-14, 15-19

Question 15

Is pre-camp varicella susceptibility and exposure complete?

Answer 15

No

Question 16

Is zoster infections a risk for VZV transmission?

Answer 16

Yes - as there are immunocompromised, sub-vaccinated, or unvaccinated children around who can get VZV from zoster lesions

Question 17

What are the recommendations for camp and VZV

Answer 17

1. All personnel should provide complete history of VZV disease, immunisation
2. List of potentially susceptible individuals should be made, and available to staff
3. Susceptible campers and staff should be offered the vaccination
4. Camps should review exclusion policies, taking immune state of campers and staff into consideration
5. If there are immunocompromised conditions at the camp - campers or staff with active VZV or VZV exposure in the past 21d should be excluded