Reporting All Cases of Varicella - Minnesota Dept. of Health

Reporting All Cases of Varicella

As of Jan. 1, 2013, all cases of varicella (chickenpox) are required to be reported to the Minnesota Department of Health (MDH).

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Why is case-based reporting of varicella important?

What varicella cases should be reported?

What is the clinical presentation of varicella?
Will reported varicella cases be entered into MIIC?
How should cases be reported
?
What information should be reported?
Why can't providers rely on laboratories to report varicella cases?

Why is case-based reporting of varicella important?

Case-based reporting of varicella will provide the data needed to assess the changing epidemiology of varicella and evaluate the effectiveness of current immunization strategies. It will also provide greater opportunity to implement exposure follow-up for high-risk contacts and outbreak control measures.

What varicella cases should be reported?

  • Clinically diagnosed cases (without laboratory confirmation) seen by a provider in a health care setting,
  • Clinically diagnosed cases based on symptoms relayed by phone to the provider by the patient or parent/guardian, and
  • Laboratory-confirmed cases.

It is important to report all of the above cases so that MDH can adequately assess the incidence of varicella. Cases not seen by a provider but diagnosed by phone are thought to currently represent a large proportion of total cases. MDH will collect data on how the case was diagnosed, as well as differentiate phone diagnosed cases from those that are seen by a provider and/or are laboratory confirmed.

What is the clinical presentation of varicella?

The CDC case definition for varicella is: an illness with acute onset of diffuse (generalized) maculopapulovesicular rash without other apparent cuase.

Vaccinated ("breakthrough") cases may have a milder and atypical clinical presentation, with macules and papules but few or no vesicles.

Will reported varicella cases be entered into MIIC?

Cases that meet the clinical case definition and are confirmed by laboratory testing or by an epidemiologic link to another case will be entered into the Minnesota Immunization Information Connection (MIIC) by MDH staff. This documentation may subsequently be used as evidence of immunity to varicella. Upon provider request, clinically diagnosed cases that meet the CDC case definition but are not confirmed by laboratory testing or an epidemiologic link to another case will be entered into MIIC by MDH.

How should cases be reported?

Cases may be reported through any available method for reporting communicable diseases, including:

Varicella cases should be reported within one working day (Monday through Friday) so that public health interventions may be implemented in a timely manner.

What information should be reported?

  • Information reported should include the basic information included on the MDH Yellow Disease Report Card ("Yellow Card").
  • Cases should be reported specifically as varicella (rather than varicella-zoster).
  • Providers should state if the patient information was obtained by a phone conversation from the patient or parent rather than by a clinic visit, and report varicella vaccination and/or disease history. MDH may contact providers for additional information. MDH may also interview cases or parents/guardians to obtain additional information including disease severity, as well as to identify and respond to any public health concerns.

Why can't providers rely on laboratories to report varicella cases?

Provider reporting is needed because:

  • Laboratory testing does not distinguish varicella (chickenpox) from zoster (shingles).
  • False negative results may occur, especially in mild cases of breakthrough disease (in fully- or partially-vaccinated cases).
  • Currently, laboratory testing is not performed on most varicella cases. It is important to report cases that are not laboratory-confirmed to determine the true incidence of varicella.
Updated Friday, November 20, 2015 at 10:37AM