To describe and compare differences in the epidemiologic, clinical, and laboratory characteristics of pregnant women with confirmed or probable Zika virus infection and to compare the risk of having a neonate with laboratory evidence of Zika virus infection with that of having a neonate without evidence of Zika virus infection by maternal characteristics.
We conducted a retrospective cohort study of women with Zika virus infection who completed pregnancy in New York City from January 1, 2016 to June 30, 2017. Confirmed Zika virus infection was defined as 1) nucleic acid amplification test–detected Zika virus, or 2) a nonnegative enzyme-linked immunosorbent assay test result and a plaque-reduction neutralization test result positive for Zika virus but negative for dengue virus, or 3) delivery of a neonate with laboratory evidence of Zika virus infection. Probable infection was defined as a nonnegative enzyme-linked immunosorbent assay test result and a positive plaque-reduction neutralization test result for Zika virus and dengue virus.
We identified 390 women with confirmed (28%) or probable (72%) Zika virus infection. Fever, rash, arthralgia, or conjunctivitis was reported by 31% of women and were more common among women with confirmed than with probable infection (43% vs 26%, P=.001). Of 366 neonates born to these women, 295 (81%) were tested for Zika virus and 22 (7%) had laboratory-diagnosed congenital Zika virus infection. The relative risk (RR) for having a neonate with laboratory evidence of Zika virus infection was greater among women with fever (RR 4.8, 95% CI 2.1–10.7), tingling (RR 4.8, CI 1.7–13.7), or numbness (RR 6.9, CI 2.6–18.2) during pregnancy or the periconception period. However, the RR did not differ whether the mother had confirmed or probable Zika virus infection (RR 1.6, CI 0.7–4.1).
In New York City, a greater proportion of women had probable Zika virus infection than confirmed infection. Women with some symptoms during pregnancy or periconceptionally were more likely to have a neonate with laboratory evidence of Zika virus infection. Neonates born to women with confirmed or probable Zika virus infection should be tested for Zika virus infection.
Risk of congenital Zika virus infection may be higher among neonates born to symptomatic women; neonates born to women with confirmed and probable Zika virus infection should be tested.
Division of Disease Control and the Public Health Laboratory, New York City Department of Health and Mental Hygiene, New York, New York; the Career Epidemiology Field Officer Program, Office of Public Health Preparedness and Response, Centers for Disease Control and Prevention, Atlanta, Georgia; and the Wadsworth Center, New York State Department of Health, Albany, New York.
Corresponding author: Sally Slavinski, MPH, DVM, Division of Disease Control, New York City Department of Health and Mental Hygiene, 4209 28th Street, CN# 22A, Queens, NY 11101; email: firstname.lastname@example.org.
Supported by the Public Health Emergency Preparedness Cooperative Agreement (Grant Number: NU90TP921856) and by the Epidemiology and Laboratory Capacity for Infectious Diseases Cooperative Agreement (Grant Number: NU50CK000407-03) from the Centers for Disease Control and Prevention (CDC). Its contents are solely the responsibility of the authors and do not necessarily represent the official position of CDC.
Financial Disclosure The authors did not report any potential conflicts of interest.
For a list of members of the Zika Working Group, see Appendix 1 online at http://links.lww.com/AOG/B119.
Each author has indicated that he or she has met the journal's requirements for authorship.