August 1, 2016
On July 25, 2016, the Centers for Disease Control and Prevention (CDC) issued revised guidance on Zika virus sexual transmission and clinical management for pregnant women. This letter provides a summary of those updates. In addition, on July 29, 2016 the Florida Department of Health and the CDC announced Zika virus infections in four people that were likely caused by bites of local Aedes aegypti mosquitoes. The cases are likely the first known occurrence of local mosquito-borne Zika virus transmission in the continental United States. This finding in southern Florida is not unexpected; the Virginia Department of Health (VDH) will continue to implement both human illness surveillance and mosquito surveillance activities in Virginia. VDH testing algorithms and surveillance systems are designed to have the opportunity to capture local mosquito-borne transmission of Zika virus in Virginia, in the event that it may occur. There is no evidence of local mosquito-borne transmission of Zika virus in Virginia at this time. We will continue to keep you informed of our surveillance findings.
As a result of the revised CDC guidance, the following are three key points for your awareness:
- Recommendations for the prevention of sexual transmission of Zika virus now include the possibility of sexual transmission from an infected woman.
- Changes to laboratory testing recommendations for pregnant women were made, including rRT-PCR testing within 2 weeks of onset and the importance of collecting both serum and urine from pregnant women; for newborn infants, testing infant blood, not just cord blood is recommended.
- VDH strongly recommends that providers caring for pregnant women pursue Zika virus laboratory testing through public health.
- Expands the definition of possible sexual exposure to Zika virus and prevention recommendations to include unprotected sex with any person, male or female, who has traveled to/lives in an area with Zika.
- Recommends all pregnant women with sex partners who live in or traveled to an area with Zika use barrier methods during sex or abstain from sex for the duration of their pregnancy.
- In addition to testing pregnant women who have relevant travel or mosquito exposure, recommends providers test all pregnant women who may have been exposed to Zika through sex.
- Recommends providers test any patient for Zika if they develop at least one Zika-compatible sign or symptom and report potential sexual exposure to Zika virus as defined above. Providers may consider utilizing commercial labs for their non-pregnant patients in these circumstances.
Please assess all pregnant women for possible Zika virus exposure at each prenatal care visit.
- Test pregnant women who have had possible exposure to Zika virus via travel to an affected area or sex for Zika virus infection. Please review the Updated CDC Testing and interpretation recommendations for a pregnant woman with possible exposure to Zika virus – United States. This new CDC algorithm provides more detail on which tests will be conducted based on the timing of specimen collection relative to symptom onset or exposure. Some key highlights include:
- Recommends providers test symptomatic pregnant women for Zika virus infection. Testing conducted will vary depending on the time of evaluation relative to symptom onset.
- Expansion of real-time Reverse Transcriptase-Polymerase Chain Reaction (rRT-PCR) laboratory testing for Zika RNA and extension of the rRT-PCR testing window from <1 week to <2 weeks from symptom onset in symptomatic pregnant women.
- New, additional recommendations to implement: rRT-PCR testing of serum and urine among asymptomatic pregnant women with possible exposure to Zika virus; and immediate rRT-PCR testing after a pregnant woman has a positive or equivocal Zika IgM antibody test.
- For postnatal management of pregnant women with lab evidence of confirmed or possible Zika virus infection, new emphasis on the importance of testing infant blood, rather than “infant blood or cord blood” and a recommendation that if cord blood testing is performed, results should be interpreted in conjunction with infant serum results.
- Although rRT-PCR testing for Zika virus is available through some commercial laboratories, VDH strongly recommends that providers caring for pregnant women pursue Zika virus laboratory testing through public health. Public health testing affords the opportunity for appropriate and timely combinations of rRT-PCR and serological (IgM) testing; serological testing is not available commercially at this time. Providers may contact their local health department with any questions or to request Zika virus testing. Please collect both serum and urine specimens for this testing.
- Please see the updated VDH Public Health Zika Testing Algorithm. Key changes include:
- Expansion of testing to any pregnant women potentially exposed to Zika virus by sex, regardless of her or her partner’s symptoms.
- Expanded list of birth defects that are relevant to requesting Zika virus testing in infants.
- The number of symptoms required for testing for non-pregnant persons who did not travel but had possible sex exposure decreased from three symptoms to at least one.
Thank you for continuing to provide your patients with information about the actions they can take to prevent Zika virus exposure, including awareness of CDC travel advisories, avoidance of mosquito bites, household steps to reduce mosquito habitats, and steps to prevent sexual transmission. Please visit the VDH Zika Virus website for both clinical information and tools that you may use to provide guidance to your patients. Please contact your local health department for guidance, assistance with test interpretation, and other questions you may have regarding Zika virus.
Marissa J. Levine, MD, MPH, FAAFP
State Health Commissioner