Zika Virus Information for Medical Providers

Published on . Last modified on December 9, 2016

Current Situation (August 12, 2016)

There is ongoing transmission of Zika virus in parts of Central America, South America, and Oceana/Pacific Islands.  Please see the Centers for Disease Control and Prevention’s website for a current list of affected countries.  In addition, there have been cases of locally acquired Zika virus in the Mexican states of Chiapas, Guerrero, Jalisco, Michoacan, Nayarit, Nuevo León, Oaxaca, Sinaloa, Tabasco, Veracruz, and Yucatan. 

Zika virus is transmitted to people by Aedes mosquitos.  To date, there has been no local transmission of Zika virus in California.  However, the Aedes mosquitoes that carry the Zika virus can be found in California.  Zika virus can be passed from mother to baby during pregnancy.  Spread of the virus through blood transfusion and sexual contact have been reported and is being investigated.  

There have been increased reports of microencephaly and fetal demise among mothers who were infected with Zika virus while pregnant.  Most people infected with Zika virus are asymptomatic.  If symptoms develop, the most common are fever, rash, arthralgia, headache, and conjunctivitis.  Symptoms usually begin 3 to 7 days after being bitten by an infected mosquito and last several days to a week.  Treatment is limited to supportive care. 

Recommendations for Health Care Providers

  • Advise pregnant women and women trying to become pregnant to consider postponing travel to affected areas.  Pregnant women who must travel should use insect repellent containing DEET, picaridin, IR3535, oil of eucalyptus, or para-menthanie-diol.  Other precautions such as wearing long-sleeved shirts and pants and using mosquito bed nets are also recommended.
  • Advise pregnant women who have a sex partner who lives in or has traveled to a region with Zika virus transmission to either abstain from sexual contact with their partner or use a condom correctly and consistently during each sexual encounter for the duration of their pregnancy.
  • Promptly report suspected cases to the Monterey County Health Department’s Communicable Disease Unit (phone: 831-755-4521; fax: 831-754-6682).
    • Communicable Disease Unit staff will facilitate testing.  At least 2 mL of serum in a red top tube or at least 1 mL of CSF are required.  
    • Criteria for testing suspected cases include fever AND rash, arthralgia, and/or conjunctivitis, AND travel to one of the countries or Mexican states listed above in the 14 days prior to symptom onset. Dengue and chikungunya virus infection should also be ruled out in these patients.
  • Consider offering serologic testing to asymptomatic pregnant women who have traveled to one of the affected countries or Mexican states listed above within the last 2 to 12 weeks. 
    • Please complete the Request for Zika Screening Form and fax it to 831-754-6682 to start the process of requesting testing.
    • The Communicable Disease Unit (phone 831-755-4521) will facilitate testing if California Department of Public Health testing criteria are met.  At least 2 mL of serum in a red top tube are required.
    • Keep in mind the accuracy of serologic testing in asymptomatic individuals is limited.  Zika virus cross-reacts with related flavivurses, and negative serologic test results cannot definitively rule out Zika virus infection.
    • Pregnant females who may have been exposed to Zika virus during sexual intercourse with a symptomatic sex partner are also eligible for serologic testing.
  • Monitor pregnant women with a travel history to an affected country during pregnancy irrespective of serologic test results for signs of microencephaly or brain calcifications in the baby pre- and post-delivery.
  • If caring for an infant born to a mother who traveled to an affected area during pregnancy, refer to the CDC’s interim guidelines for evaluation and testing of infants with possible congenital Zika virus infection.
  • For questions about management of women of reproductive age with possible Zika virus exposure, please refer to the CDC’s interim guidance for health care providers caring for women of reproductive age released on March 25, 2016.  It provides recommendations on counseling women and men with possible exposure who are interested in conceiving.
  • Please see the CDC’s Preventing Transmission of Zika Virus in Labor and Delivery Settings for questions about infection control during delivery if a woman is suspected of having Zika virus infection.

For Additional Information

For additional information about Zika virus, please contact the Communicable Disease Unit at 831‑755‑4521, the Monterey County Public Health Laboratory at 831-755-4516, or visit the CDC’s website.