Congenital Zika Virus Infection: Role of the California Pediatrician

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Although Zika isn’t in the headlines as it was in 2016, new infections continue to be reported in California, and, thus, the need for health care providers to understand their role in caring for affected pregnant women and infants continues.  Health care providers are challenged with staying abreast of the ongoing Zika epidemic where they must learn the basics of Zika, including how to screen and test for exposure, as well as provide evaluation and follow-up care for exposed infants. Advising concerned patients has its own challenges; Zika is a complicated disease that isn’t easily explained. Though the World Health organization and Pan American Health Organization have reported a decline in the prevalence of Zika virus infection in much of the Americas, there are some areas, mostly those that experienced local Zika transmission later in the outbreak, that are seeing an increase in transmission. While Mexico experienced local transmission later than other countries, it is unclear what Zika transmission will look like this summer as their mosquito season is just beginning.  Due to California’s proximity and large travel volume to Mexico, we believe there may still be increased risk of Zika infection for those traveling to Mexico.  This article will summarize the key information about Zika including available resources for the pediatrician.

Zika in California:  California is continuing to identify new cases of pregnant women with Zika virus infection, despite state and national travel advisories recommending pregnant women avoid travel to areas with Zika transmission.  As of July 28, 2017, California had 581 reported Zika infections, including 143 in pregnant women; of 109 completed pregnancies, there were 8 liveborn infants with birth defects.  These numbers are likely an underestimate of the true number of infections in Californians.  It is unknown whether all pregnant women are asked by their prenatal care providers about Zika virus exposure.  Of those with identified exposure risk, Zika virus testing is conducted by a combination of public health and commercial laboratories.  Women and their sexual partners travel to or periodically reside in these areas for a variety of reasons (e.g., work, leisure, business, and family).  Thus, it is important that California providers are aware of the Zika recommendations for screening and testing.


Zika Transmission: Zika virus is spread to people primarily through mosquito bites from an Aedes species of mosquito (Aedes aegypti and Aedes albopictus) in areas with Zika, including common destinations such as Mexico, Central and South America, and the Caribbean.  For a full list of areas of the world with Zika, see    Zika is also sexually transmitted (vaginal, anal, and oral sex and sharing of sex toys), and 8 of the cases reported in California have been transmitted through sexual contact with sexual partners who contracted the disease through travel. Men have particularly long persistence of Zika in semen, and available evidence indicates men should practice safer sex (e.g., male or female condoms, dental dams) for at least 6 months after exposure or symptom onset, and women, for at least 8 weeks, to avoid transmission to their partner. 

Zika Signs and Symptoms: It is estimated that about 20 percent of people infected with Zika virus have symptoms. If symptoms do develop, the most common are fever, maculopapular rash, arthralgia, and/or conjunctivitis.  Myalgia or headache may also occur.  Symptoms are usually mild and develop a few days to two weeks after exposure and can last several days to a week. 

The greatest risk from Zika infection is in pregnancy which can result in miscarriage, stillbirth, and birth defects, including congenital brain abnormalities, eye anomalies, and hearing deficits.  The clinical features of congenital Zika syndrome are due to the neurologic damage from infection and subsequent intracranial volume loss. Clinical features of congenital Zika syndrome include severe microcephaly in which the skull has partially collapsed; decreased brain tissue with a specific pattern of brain damage, including subcortical calcifications; damage to the back of the eye, including macular scarring and focal pigmentary retinal mottling; congenital contractures, such as clubfoot or arthrogryposis; and hypertonia restricting body movement soon after birth.

Prevention: Pregnant women should not travel to areas with Zika virus transmission or have unprotected sex with anyone who has traveled to an area with Zika.  If women must travel, they should take steps to avoid mosquito bites and sexual exposure and women of reproductive age should be advised to prevent unplanned pregnancy:

Screening for Zika exposure: Healthcare providers caring for pregnant women and infants should ask about Zika exposure.  The Centers for Disease Control and Prevention (CDC) has developed a screening tool with questions that should be asked during each prenatal care visit and again at the first newborn visit if this information is not available to the pediatrician.  To assess if the mother had possible Zika exposure during pregnancy, three screening questions are recommended:

1.       Do you live in or do you frequently travel (daily or weekly) to an area with risk of Zika?

2.       Have you traveled to an area with risk of Zika during pregnancy or just before you became pregnant?

3.       Have you had sex without a condom with a partner who lives in or traveled to an area with risk of Zika?

Pregnant women with possible Zika virus exposure, including both symptomatic and asymptomatic pregnant women, should be evaluated for Zika virus infection. See CDPH’s Updated Guidance for Health Care Providers Caring for Pregnant Women with Possible Zika Virus Exposure (August 2, 2017) for California providers which are in accordance with CDC guidance (Interim Guidance for Health Care Providers Caring for Pregnant Women with Possible Zika Virus Exposure – United States and U.S. Territories August 24, 2017 ( that allows for application of regional trends in Zika virus transmission and travel patterns in local and state Zika guidance.


Pediatricians should ask about possible maternal and congenital Zika virus exposure for every newborn.  If there was a possible exposure, the pediatrician should ask whether the mother and infant were tested for Zika virus, and obtain test results as well as other evaluations, such as a head ultrasound, done at the birth hospital.

INFANT ZIKA TESTING AND EVALUATION: Infant management will be based on a number of factors, including maternal exposure history, maternal Zika virus test results, infant clinical findings, and infant Zika virus test results. An infant born to a woman with laboratory evidence of possible recent Zika virus infection during pregnancy should receive a comprehensive physical exam, newborn hearing screen, postnatal neuroimaging and Zika virus testing.  Infants with abnormal clinical findings suggestive of congenital Zika virus syndrome with possible maternal Zika exposure are recommended to be tested for Zika virus infection and have an extensive evaluation and follow-up.  For infants whose mothers were potentially exposed but not tested, pediatricians should have a high index of suspicion and consider Zika virus testing and further evaluation. For further details on infant testing and evaluation (including neuroimaging and ophthalmologic evaluation), visit: CDC’s websites for Healthcare Providers Caring for Infants and Children and Evaluation and Testing.


Coordination of specialty care and follow-up evaluations will be important.  Infants with no evidence of Zika virus infection or anomalies at birth should still be monitored for growth parameters and age-appropriate developmental screening as recommended by Bright Futures since the impacts of congenital Zika virus exposure on infant development are still being determined.


U.S. Zika Pregnancy Registry and Disease Reporting: Report infant follow-up data to the California Department of Public Health for submission to the U.S. Zika Pregnancy Registry.  The U.S. Zika Pregnancy Registry includes both asymptomatic and symptomatic pregnant women with laboratory evidence of possible Zika virus infection and their infants up to 1 year of age (regardless of infant test results).  Zika virus infection is a reportable condition in California (Title 17, CCR § 2500). Contact your local health department to report all pregnant women with laboratory evidence of possible Zika virus infection and their infants (regardless of infant Zika test results).  For more information, contact or call (510) 620-3151.

Breastfeeding: Although Zika virus has been detected in breast milk, no cases of Zika virus infection associated with breastfeeding have been reported, and current evidence suggests that the benefits of breastfeeding outweigh the theoretical risk of Zika virus transmission. CDC encourages mothers with Zika virus infection to breastfeed their infants.


Family Support:

MotherToBaby has free and confidential counselors, speaking both English and Spanish, available at to talk to families about Zika virus infection or diagnosis during pregnancy. 

·         Phone: 1-866-626-6847


Zika Resources

CDPH Zika webpage:


·         CDPH Evaluation and Follow-up Procedures for Suspected Congenital Zika Virus Infection

·         CDPH Zika Virus Testing FAQs

·         CDPH Outpatient Screening Algorithm-Child/Adult

·         CDPH California map of Aedes aegypti and Aedes albopictus mosquito detections   

CDC Zika pediatric resources for health care providers:

·         General website:

·         Interim Guidance for the Evaluation and Management of Infants with Possible Congenital Zika Virus Infection – August 2016

AAP Zika resources:

·         Providers:

·         Families:

March of Dimes:


California Local Health Department Communicable Disease Contacts:


Zika Care Connect (ZCC), a collaboration of CDC and the March of Dimes, provides a searchable network of healthcare specialists who care for patients affected by Zika. If you are interested in being part of the ZCC Referral Network, call the toll-free ZCC HelpLine to join.


·         Toll-free helpline for providers and patients: 1-844-677-0447

o   Monday-Friday (9 a.m. – 5 p.m. Eastern Time)

o   English and Spanish

·         Email:


Author: Eileen Yamada, MD, MPH, FAAP, CDPH, Maternal, Child and Adolescent Health Division