(REUTERS) - The state of Florida in United States on Wednesday announced that three pregnant women who had travelled outside the United States tested positive for Zika virus.

In efforts to protect their privacy, the state is not revealing the names or locations of these women.

Zika has been greatly associated with the birth defect microcephaly and Guillain-Barre, a rare syndrome where the immune system attacks nerves.

Microcephaly is a neurological disorder which results in babies born with abnormally small heads, causing severe developmental issues and sometimes death.

Brazil has seen 508 confirmed cases of microcephaly in newborns.