Received: 7 February 2017
Accepted: 5 January 2018
First Online: 12 January 2018
: The investigators are from the Microcephaly Epidemic Research Group, Brazilian Ministry of Health, Pan American Health Organization and State Health Department of Pernambuco.
: We received permission of Pernambuco Health State Department to use the anonymous data for research purpose.
: Not applicable.
: We declare that there are no competing interests to disclose.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.