ZIKA VIRUS UPDATE
C. Halter, CNM
- Zika virus (ZV): member of the Flavivirus family (ex. Dengue/Yellow Fever)
- Transmission : Aedes mosquito bites; mother to fetus; sexual transmission; blood transfusions; lab exposure
- Incubation period: 3-14 days
- 1 in 5 people will exhibit symptoms
- Symptoms: acute onset of fever, arthralgia, rash, non-purulent conjunctivitis
- Adverse effects: rare association with Guillain-Barre syndrome
Effects in Pregnancy
- Pregnant women may or may not develop symptoms and do not appear to suffer worse symptom manifestation.
- ZV has been found in pregnancy tissues of all three trimesters, including MAB tissue, amniotic fluid, term infants and the placenta
- Adverse outcomes: SAB/MAB; IUFD; microcephaly, neurological or eye deficiencies
- Unknown: rate of transfer from mother to fetus; viral load required for fetal defects
One study found that 1-13% of fetuses exposed to ZV in first trimester will develop microcephaly. An additional study from the 2016 Brazil outbreak suggests that 29% of all pregnancies infected with ZV regardless of trimester will develop IUGR, microcephaly or result in fetal demise.
Serum and urine tests for real-time RT-PCR, IgM and plaque reduction neutralization tests (PRNT).
No specific treatments are recommended other than supportive- fluids and acetaminophen. Aspirin and NSAID use should be avoided until Dengue and Chickungunya viruses are ruled out.
- Wear long sleeves and pants.
- Use mosquito nets or stay in air-conditioned rooms.
- Treat clothes and nets with permethrin.
- Safe to use approved insect repellants containing DEET in pregnancy.
- Do not travel to areas of ZV transmission- keep updated by checking CDC travel warnings.
- If partner or patient travels to areas of transmission and remain asymptomatic, it is considered ok to begin attempting conception 8 weeks after travel.
- If a male partner has symptoms of ZV, it is currently recommended to abstain from conception for 6 months (as of 8/3/16).
- If a female partner has symptoms of ZV, it is recommended she abstain from conception for 8 weeks.
- It is NOT recommended that asymptomatic individuals be routinely tested for ZV infection.
- To prevent sexual transmission either abstinence should be practiced or strict condom use should be encouraged for any sexual encounter or sexual activity.
PRENATAL/POSTNATAL CARE- ACOG RECOMMENDATIONS
- All pregnant women should be assessed for ZV exposure at every prenatal care visit
- Assess for symptoms
- Travel history for patient and partner(s)
- Testing: described below
- Positive ZV infected women per lab results: refer to perinatology and/or infectious disease specialist
- Serial ultrasounds every month
- After delivery: placenta and cord samples should be sent to lab for immunohistochemical staining and RT-PCR; for fetal demise, any fetal tissues should be sent in addition to placenta and cord
- Breastfeeding: no evidence of transmission through breast milk; patients may continue to breastfeed
- Reporting: All positive or equivocal laboratory samples should be reported to the Health Department.
- CDC Pregnancy Registry has been created for US ZV cases for additional surveillance.
- Additional information on infected patients will be required – including adverse outcomes
For additional questions regarding positive/equivocal lab results
Providers may call the CDC: 770-488-7100
Additional Information for Patients
Available Monday -Friday 8am-5pm in English and Spanish
MotherToBaby – 1-866-626-6847
Text questions to – 855-999-3525
Areas with Zika. Centers for Disease Control. Retrieved on August 9, 2016. http://www.cdc.gov/zika/geo/index.html
For Healthcare Providers. Centers for Disease Control. Retrieved on August 7, 2016. http://www.cdc.gov/zika/hc-providers/index.html
Practice Advisory on Zika Virus. The American College of Obstetricians and Gynecologists; Society for Maternal Fetal Medicine. August 3, 2016. http://www.acog.org/About-ACOG/News-Room/Practice-Advisories/Practice-Advisory-Interim-Guidance-for-Care-of-Obstetric-Patients-During-a-Zika-Virus-Outbreak?IsMobileSet=false