VARICELLA (Chickenpox)

1
VARICELLA(Chickenpox)

• Maria del Rosario, MD, MPH
• WVDHHR/BPH/IDEP
• IDEP Training - February 2008

2
Objectives

• To describe the presentations of varicella.
• To describe the important aspects of reporting
  varicella.
• To review the management of varicella outbreak.

3
Is varicella reportable?

• YES,
• when an OUTBREAK occurs report IMMEDIATELY
• when DEATH results from varicella report the
  case within 1 week
• aggregate number (numerical total) report
  within 1 week

4
Who should report?

• Providers, labs, health departments, etc.
• For details see WV rule at http//www.wvdhhr.org/i
  dep/PDFs/IDEP/Reportable20Diseases_20Conditions_
  20Events_07.pdf

5
CASE DEFINITION (1)

• Clinical case definition
• Acute onset of diffuse, generalized
  maculopapulovesicular rash without any obvious
  cause.
• Laboratory criteria
• VZ IgM positive, or
• Isolate VZV, demonstrate VZV antigen by DFA or
  PCR, or
• Significant rise in VZ IgG

6
CASE DEFINITION (2)

• Probable case
• meets clinical case description but not
  lab-confirmed and not epi-linked to another
  (probable or confirmed) case
• Confirmed case
• Lab confirmed,
• OR
• Meets clinical case definition and is epi-linked
  to another case, e.g. 2 probable cases
• not routinely recommended, but is strongly
  recommended in fatal cases

7
Epidemiology

• Incubation period 10 to 21 days (average 14-16
  days)
• Infectious period 1 to 2 days before rash onset
  and continue until all lesions are crusted
  (usually 5 days)

8
OUTBREAK

• Definition
• 5 or more cases in a school or daycare facility
  within one incubation period (10-21 days, ave. 14
  days)
• 3 or more cases in a long-term care facility
  within one incubation period (10-21 days, ave. 14
  days)

9
Outbreak Management (1)

• Ascertain cases
• Confirm the occurrence of an outbreak
• Immediately notify IDEP (and regional epi)
• Initiate rapid case and contact identification
• Assure immunity among those who will be
  conducting face-to-face interview of infectious
  persons.

10
Outbreak Management (2)

• Establish preventive and control measures
• Isolation and/or quarantine
• Isolate individuals with varicella until all
  lesions have formed scabs or have crusted (about
  5 days after rash onset).
• Exposed susceptible individuals exclude from
  high-risk setting for the duration of
  communicability (10th till 21st day
  post-exposure)
• Immunization
• Disease investigators need to be immune to
  varicella
• Shingles vaccine to those gt 60 year old
• Vaccinate all susceptible exposed persons within
  72 hours (no more than 120 hours after exposure)
  - modify disease outcome
• Vaccinate all non-immune even if gt5days since
  exposure - (protection) future exposures
• 2nd vaccine dose - for those who received 1
  vaccine only

11
Outbreak Management (3)

• Establish preventive and control measures (cont.)
• Chemoprophylaxis
• VZIG give within 96 hours of exposure
• Interview cases and record in Chickenpox Outbreak
  Linelist Form. Update form as necessary.
• Alert providers, parents, school, etc. about the
  outbreak

12
Chickenpox Outbreak Line Listing Form
New (CDC requirement) for 2008
Found at http//www.wvdhhr.org/idep/a-z/a-z-varic
ella.asp under Required Forms
13
DEATH

• Probable
• A probable case of varicella that contributes
  directly or indirectly to acute medical
  complications that result in death.
• Confirmed
• A confirmed case of varicella that contributes
  directly or indirectly to acute medical
  complications that result in death.
• Laboratory testing is not routinely required but
  is indicated to confirm the diagnosis in severe
  or unusual cases

14
WVEDSS Chickenpox Death Report Form
15
AGGREGATE CASE REPORTING

• Report weekly total number of cases
• Fax report to IDEP by COB on Monday, or first
  thing Tues a.m. (if Monday is non-working
  holiday).
• Form is found at http//www.wvdhhr.org/idep/PDFs/I
  DEP/flupox_reporting_form.pdf

16
REFERENCE