The California Department of Public Health (CDPH) is urging those traveling this holiday to protect themselves against mosquito bites in areas known for Zika.

“Pregnant women and couples considering pregnancy need to be particularly cautious because Zika virus can cause severe birth defects,” said Director and State Public Health Officer Doctor Karen Smith. “Pregnant women are urged to avoid travel to areas with known Zika transmission if at all possible. If travel is necessary, it is extremely important to take steps to prevent mosquito bites.”

Several popular tourist destinations in Mexico have seen Zika transmissions take place, including Cancun, Acapulco, Cabo San Lucas, Puerto Vallarta, Ixtapa and Mazatlan.

Mosquito deterrents such as DEET, picaridin, oil of lemon eucalyptus or IR3535 are encouraged for use by CDPH if Californians do travel to areas where Zika has been recorded.

There have been 443 cases of travel-associated Zika infections in California, though health officials say the virus has not been transmitted locally.