Interim case definition for surveillance of Zika virus infection

patient and case management case definition

An interim case definition for surveillance of Zika virus infection has been discussed with the Health Security Committee during its meeting on 17 March 2016. Formal approval of the case definition through the appropriate channels is ongoing.

Definition

Clinical criteria 

A person presenting with a rash, with or without fever and at least one of the following signs and symptoms:

  • Arthralgia or 
  • Myalgia or
  • Non-purulent conjunctivitis/hyperaemia

Laboratory criteria
Laboratory criteria for a probable case:

  • Detection of Zika specific IgM antibodies in serum

 
Laboratory criteria for a confirmed case:
At least one of the following:

  • Detection of Zika virus nucleic acid in a clinical specimen;
  • Detection of Zika virus antigen in a clinical specimen;
  • Isolation of Zika virus from a clinical specimen;
  • Detection of Zika virus specific IgM antibodies in serum sample(s) and confirmation by neutralization test; 
  • Seroconversion or four-fold increase in the titer of Zika specific antibodies in paired serum samples

Epidemiological criteria  

  • History of exposure in an area with transmission of Zika virus within two weeks prior to onset of symptoms or
  • Sexual contact with a male having been confirmed with a Zika virus infection in the past four weeks or
  • Sexual contact with a male who had been in an area with Zika virus transmission in the past four weeks
  • A list of Zika affected areas is kept updated on the ECDC website

 

Classification 

Probable case 
A person meeting the clinical criteria and the epidemiological criteria.A person meeting the laboratory criteria for a probable case.
 
Confirmed case 
A person meeting the laboratory criteria for a confirmed case.