California has had two infants born recently with Zika-related microcephaly after their mothers contacted the virus while overseas, according to the California Department of Public Health.
The CDPH said the two women were infected with the Zika virus after spending time in a country where the virus is endemic.
While mosquitoes that can carry the virus have been found in 12 California counties, there is no evidence these mosquitoes are transmitting Zika in the state at this time.
"This is a sobering reminder for Californians that Zika can cause serious harm to a developing fetus," said CDPHDirector and State Health Officer Dr. Karen Smith. "We join the Centers for Disease Control and Prevention in urging pregnant women to avoid travel to areas with known Zika transmission. Pregnant women who must travel to one of these areas should strictly follow steps to prevent mosquito bites and speak with a health care provider upon return."
The Zika virus was confirmed in Stanislaus County in June when a 19-year-old man came down with the virus after traveling to the Caribbean. The Merced County Department of Public Health confirmed earlier this week that two residents had tested positive for the virus and are believed to have been infected while traveling overseas.
Most of the people sickened in the U.S. came into contact with the virus while overseas, but recently four cases have been confirmed to have originated in Florida, according to the Centers for Disease Control and Prevention.
Zika is carried by the Aedes aegypti mosquito, which is known to be in the San Joaquin Valley. The CDC says this type of mosquito is an aggressive day biter, but also known to bite at night.
Most people testing positive for Zika will have mild to no symptoms. The most common symptoms include fever, rash, conjunctivitis (red eyes), and joint pain and begin three to seven days after being bitten.
Severe illness requires supportive care at a hospital. There is no vaccine or cure for Zika.
The virus is of most concern to pregnant women or women considering getting pregnant in the near future. The virus has been linked to miscarriages and severe birth defects.
"Zika virus can also be transmitted to sexual partners by both males and females. Both men and women of childbearing age should take precautions if they have recently traveled, or plan to travel, to a location where Zika is spreading," Dr. Smith said.
The CDPH stated the agency has a team of experts across several fields working in conjunction with local public health departments, vector control agencies and the medical community to respond aggressively and timely to the emerging threat of Zika virus.
The CDPH is actively monitoring all pregnant women with Zika infection in California, and is collaborating with local health departments to provide assistance to families with infants born with Zika-related birth defects to ensure they receive appropriate medical care. Infants born to mothers with confirmed infections will be monitored for one year.
As of July 29, CDPH has confirmed 114 travel-associated Zika virus infections in 22 counties. A total of 21 infections have been confirmed in pregnant women.
People traveling to areas with known Zika transmission should take steps to avoid mosquito bites:
• Use insect repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol for long-lasting protection. If using sunscreen and insect repellent, apply sunscreen first and then the repellent. Pregnant women and women who are breastfeeding should choose an EPA-registered insect repellent and use it according to the product label. Do not use insect repellent on infants less than two months of age.
• Wear long-sleeved shirts and long pants.
• Use air conditioning or window and door screens to keep mosquitoes outside.
If mosquitoes may come indoors, sleep under a bed net.
· Reduce the number of mosquitoes outside by emptying standing water from containers, such as flowerpots and buckets.
Sexually active adults who travel to areas with Zika transmission should use condoms or other barriers in order to avoid getting or passing Zika during sex. Couples planning pregnancy should speak with a health care provider about a safe time to wait before trying to get pregnant.