As a part of the Zika Birth Defects Surveillance, a national effort coordinated by the Centers for Disease Control and Prevention (CDC), NYC is conducting enhanced surveillance of all births with defects included in the congenital Zika syndrome (CZS) phenotype among infants born in NYC beginning in 2016. The intent of the project is to provide background on the prevalence of these conditions, regardless of cause. The surveillance project builds on the New York State (NYS) Congenital Malformations Registry, a passive, mandatory reporting system that relies on reporting from hospitals and providers. For the Surveillance project, potential cases of Zika-related birth defects (ZBD) are identified by hospital and administrative data of birth records with one or more of the International Classification of Diseases, 10th Revision (ICD-10) diagnostic codes associated with CZS.1 The list of included diagnostic codes was specified by the NYS registry following guidance established by CDC. Full medical record chart abstraction of the birth hospital visit of potential cases is then conducted applying further inclusion guidelines to identify ZBD cases. Recent reports of late presentation of birth defects consistent with CZS suggest that some cases are being missed due to identification and diagnosis of the condition after birth.2 As one component of a broader strategy to obtain a more accurate surveillance count, we seek to identify potential ZBD cases first diagnosed in the 6-month postpartum period using Medicaid claims data.

Objective:

To assess the use of Medicaid claims data to conduct surveillance for cases of Zika-related birth defects identified after birth among infants born in New York City (NYC).