Risk of Zika virus-associated birth defects in congenital confirmed cases in the Brazilian Amazon

• Main Authors: Consuelo S de Oliveira, Haroldo José de Matos, Francisco Luzio de Paula Ramos, Ana Yece das N Pinto, Priscila Nathyelly dos S Graim, Vivianne de Paula R Guimarães, Luna Thaís S Gomes, Emilene M. F Serra, Ana Cecília Cruz, Alessandra Leal, Daniele F. Henriques, Juliana A. Lima, Maura V. Anjos, Eliana V. Pinto, Alana W. de Souza, Pedro Fernando da C. Vasconcelos
• Format: Article
• Language: English
• Published: Pan American Health Organization 2020-09-01
• Series: Revista Panamericana de Salud Pública
• Subjects: zika virus infection; microcephaly; pregnancy complications; infectious; brazil
• Online Access: https://iris.paho.org/handle/10665.2/52652
• ISSN: 1020-4989; 1680-5348

Objective. To establish the risk of microcephaly in neonates born to women infected with ZIKV during pregnancy. Methods. A cohort of laboratory-confirmed ZIKV cases of congenital infections (109 mothers infected during pregnancy and 101 newborns) among 308 suspect cases was followed in Belem, Pará, Brazil, from October 2015 to December 2017. Results. A microcephaly risk of 1.98% (95% CI 0.54-6.93%) was found, or 2 cases among the 101 neonates infected with ZIKV during pregnancy. 72% of the pregnant women had ZIKV infection confirmed by RT-qPCR during gestation. Conclusions. Results showed a low incidence of ZIKV-associated birth defects, stillbirth, and miscarriage, which contrasts with previous studies in other Brazilian regions. Previous exposure to yellow fever vaccine and/or multiserotype DENV infection could be implicated in the protection from ZIKV congenital infection.