A rapid outbreak of a malarial virus called Zika in Latin America and the Caribbean has prompted the Centers for Disease Control and Prevention (CDC) to issue a warning for pregnant women traveling to those regions.

This tropical disease has been linked to birth defects and manifested itself in Hawaii late last week. The CDC’s official statement included “…an abundance of caution” for pregnant women and “advised (them) to consider postponing travel to areas where Zika virus transmission is ongoing.”

More often than not the virus causes cold-like symptoms in pregnant women, but Zika can also cause microcephaly, a birth defect where babies sustain severe brain damage as a result of being born with a small head.

The disease originally turned up last May in Brazil, but has since spread rampantly to other parts of Latin America and now into the Caribbean. Brazil reports seeing an significant increase in the number of microcephaly cases last year – from an average of 200 in years prior to a whopping 3,000 in 2015. More than 3,500 cases of microcephaly were reported in Brazil between October 2015 and January 2016 alone.

These risks have become so great that Brazil officials have asked women in high Zika-transmission areas to consider delaying having children altogether.

For Americans, one should not breathe a sigh of relief as a patient in Texas has been diagnosed with Zika virus after returning home from a trip to South America. The CDC reports that 22 Americans have been diagnosed with Zika since 2007, but none of them had contracted the disease domestically.

The mosquito-borne virus’ ability to spread so quickly is cause for concern. With no current treatment for Zika, there may be a growing panic as mosquito season blossoms here in the US. Officials are quick to point out that only 1 in 5 people with Zika actually experience symptoms and they usually include a rash, fever, joint pain and conjunctivitis.

That said, officials will be looking for more effective ways to prevent mosquitos from breeding as well as tracking the disease migration as it is likely to spread northward from is South American roots.