These are interim case definitions based on data obtained from the current epidemic in the Region of the Americas and may be subject to modifications based on advances in knowledge about the disease and the etiologic agent.
Suspected case of Zika virus disease
- fever, usually <38.5 ° C
- conjunctivitis (non-purulent/hyperemic)
- peri-articular edema
Suspected case of Zika virus disease in geographic areas without autochthonous transmission and where there are no vectors present
- in the 2 weeks prior to onset, traveled to, or resided in, a geographic area where there is known local transmission of the Zika virus or there is known vector presence; OR
- had un-protected sex, in the 2 weeks prior to onset, with a person who traveled, in the previous 8 weeks, to a geographic area with (a) known local transmission of the Zika virus or (b) and area with known vector presence.
Probable case of Zika virus disease
Confirmed case of Zika virus disease
- RNA or Zika virus antigen in any specimen (serum, urine, saliva, tissue or whole blood); OR
- Positive Zika IgM antibodies AND Plaque reduction neutralization (PRNT90) for Zika virus titers = 20 and four or more times greater than the titers for other flaviviruses; AND exclusion of other flavivirus; OR
- In autopsy specimens, detection of the viral genome (in fresh or paraffin tissue) by molecular techniques, or detection by immuno-histochemistry.
Guillain-Barré Syndrome (GBS) associated with Zika virus
Suspected case of Zika-virus-associated GBS
- resides in, or recently traveled to, an area where there are vectors for the Zika virus; OR
- has had unprotected sex with someone who resides in, or recently traveled to an area of circulation of vectors for the Zika virus;
presents the following signs and symptoms (level 3 Brighton criteria):
- Bilateral and flaccid weakness of the limbs; AND
- Decreased or absent deep tendon reflexes in weak limbs; AND
- Monophasic illness pattern; and interval between onset and nadir of weakness between 12 hours and 28 days; and subsequent clinical plateau; AND
- Absence of identified alternative diagnosis for weakness
Confirmed case of Zika-virus-associated GBS
Congenital syndrome associated with Zika virus infection
Suspected case of congenital syndrome associated with Zika virus
- Microcephaly: head circumference below -2 standard deviations for gestational age and sex, measured at 24 hours post-partum according to the standardized reference; OR
- Other congenital malformation of the central nervous system;
- traveled to, or resided in, an area where Zika virus vectors were present during her pregnancy; OR
- had unprotected sex during pregnancy with a partner who resided in, or traveled to, an area with the presence of Zika virus vectors.
Probable case of congenital syndrome associated with Zika virus
- who has intracranial morphological alterations detected by any imaging method, and not explained by other known causes; OR
- whose mother had rash during pregnancy
Confirmed case of congenital syndrome associated with Zika virus
Zika-virus-associated abortion or stillbirth
Suspected Zika-virus-associated abortion or stillbirth
- presented rash AND
- resided in or travelled to an area where Zika virus vectors were present; OR had unprotected sexduring pregnancy with a partner who resided in or travelled to an area where Zika virus vectors were present.