Definitions for Case Inclusion - Zika

Attachment R. DEFINTIONS FOR cASE INCLUSION IN us zIKA pregnancy REGISTRY

Maternal Case classification	Laboratory evidence in woman OR infant	US Pregnancy Registry
Confirmed	Detection of ZIKV (culture, viral antigen, RNA) OR ZIKV IgM positive with ZIKV neutralizing antibody titers ≥4-fold higher to titers against dengue or other relevant flaviviruses	Symptomatic woman OR Asymptomatic woman OR Woman (no, probable, or inconclusive testing) with fetus/infant with laboratory evidence (confirmed) of congenital ZIKV infection*
Probable	ZIKV IgM positive AND dengue IgM negative AND no neutralizing antibody testing or ZIKV neutralizing antibody titers <4-fold difference with titers against dengue or other relevant flaviviruses	Symptomatic woman OR Asymptomatic woman OR Woman (no or inconclusive testing) with fetus/infant with laboratory evidence (probable) of congenital ZIKV infection*
Other	ZIKV IgM positive AND dengue IgM positive, equivocal, or not performed AND no neutralizing antibody testing or ZIKV neutralizing antibody titers <4-fold difference from titers against dengue or other relevant flaviviruses (unspecified flavivirus infection)	Symptomatic woman OR Asymptomatic woman OR Woman (no testing) with fetus/infant with laboratory evidence (other) of congenital ZIKV infection

* If fetus/infant has clearer laboratory evidence of ZIKV infection than mother, the mother would be classified according to the infant’s status (e.g., if laboratory results in mother indicate probable ZIKV infection but laboratory results of fetus/infant indicated confirmed ZIKV infection, woman’s pregnancy register status would be “confirmed”)