Zika Virus Guidelines

Prevention

Travel Advisories

Updates on areas with ongoing Zika virus transmission are available online. Mosquitoes that spread Zika virus usually do not live at elevations above 6,500 feet (2,000 meters). People who live in or visit areas above this elevation are at a very low risk of acquiring Zika virus from a mosquito unless they visit or travel through areas of lower elevation. ^[43]  

Prevention of Mosquito Bites

The CDC recommends that all residents of and visitors to areas where Zika virus is spreading take the following steps to prevent mosquito bites ^[43] :

• Cover exposed skin by wearing long-sleeved shirts and long pants.
• Use insect repellents that are registered with the Environmental Protection Agency (EPA) and contain DEET, picaridin, oil of lemon eucalyptus, para-menthane-diol, or IR3535. Always use as directed.
• Use permethrin-treated clothing and gear (boots, pants, socks, tents).
• Stay and sleep in screened-in or air-conditioned rooms.
• Sleep under a mosquito bed net if air conditioned or screened rooms are not available or if sleeping outdoors.
• Mosquito netting can be used to cover babies younger than 2 months in carriers, strollers, or cribs to protect them from mosquito bites.

Prevention of Sexual Transmission

The CDC recommends the following for the prevention of sexual transmission of Zika virus ^[44] :

• Pregnant women with male sex partners who live in or have traveled to an area with active Zika virus transmission should use barriers against infection during sex or abstain from sex for the duration of the pregnancy. 
• Couples planning to concieve in which a partner had confirmed Zika virus infection or clinical illness consistent with Zika virus disease or travels to an area with risk for Zika virus transmission should consider using barrier methods against infection or abstain from sex, as follows:

  • Men with Zika virus infection/travel, for at least 3 months after onset of illness (symptomatic) or last possible exposure (asymptomatic or travel)
  • Women with Zika virus infection/travel, for at least 2 months after onset of illness or last possible exposure (asymptomatic or travel)
  • Both partners with Zika virus infection/travel, for at least 3 months after onset of illness in male partner (symptomatic) or last possible exposure (asymptomatic or travel)
• Couples planning to conceive with 1 or both partners with ongoing exposure (live or frequently travel to an area with risk for Zika virus transmission) 

  • Discussion with healthcare provider on risks and possible health effects of Zika on baby and protection strategies from Zika virus. 

​Virus Transmission by Blood and Blood Components 

On May 12, 2021, the US Food and Drug Administration (FDA) stopped recommending that blood establishments test donated blood for Zika virus (ZIKV). The FDA withdrew its July 2018 guidance titled, “Revised Recommendations for Reducing the Risk of Zika,” after it determined that ZIKV is not a “relevant transfusion-transmitted infection” (RTTI) because it “no longer has sufficient incidence and/or prevalence to affect the potential donor population.” ^[45]

Licensed blood establishments that stop testing donated blood for ZIKV are required to report this change, the date testing ended, and “corresponding changes to the circular of information” to the FDA in the yearly report under 21 DFR 601.12(d). ^[45]

The CDC offers the following recommendations for Zika virus testing in non-pregnant patients ^[32] :

• Zika virus nucleic acid amplification test (NAAT) should be performed on serum collected ≤7 days after symptom onset.
• Zika virus IgM antibody testing should be performed on NAAT-negative serum specimens and serum collected >7 days after onset of symptoms. 
• For serum specimens collected < 7 days after onset of symptoms, the combination of a negative NAAT result and negative IgM antibody testing suggests the patient did not have a recent flavivirus infection. 
• For specimens collected from 7 days to 12 weeks after onset of symptoms, a negative IgM antibody result to Zika virus rules out recent infection with either virus, and testing for other etiologies should be considered.
• If Zika virus IgM antibody testing is positive without a positive NAAT,a plaque reduction neutralization test (PRNT) titer ≥10 against Zika virus with negative PRNTs against dengue and other flaviviruses is evidence of recent Zika virus infection. Negative PRNT titers against Zika virus in a serum specimen collected >7 days after illness onset rule out infection.

Preconception 

The CDC makes the following recommendations to individuals considering conception after exposure to the Zika virus ^[46] :

• Women with travel to an area with Zika outbreak or risk for Zika should wait at least 2-months after symptom onset or after return from travel before attempting conception.
• Men with travel to an area with Zika outbreak or risk for Zika should wait at least 3 months after symptom onset or after return from travel before attempting conception.
• Both partners with travel to an area with Zika outbreak or risk for Zika should wait at least 3 months after symptom onset of male partner or after return from travel before attempting conception.

Asymptomatic women and men who reside in an area with active Zika virus transmission and are planning to become pregnant should discuss the risks for active Zika virus transmission with their healthcare providers, and providers should discuss their patients’ reproductive life plans in the context of potential Zika virus exposure.

Testing for evidence of Zika virus infection should be performed in persons with possible exposure to Zika virus who have 1 or more of the following symptoms within 2 weeks of possible exposure:

• Acute onset of fever
• Rash
• Arthralgia
• Conjunctivitis

Routine testing is NOT recommended for asymptomatic women or men with exposure to Zika virus who are attempting conception.

Pregnant Women

The CDC recommends that all pregnant women consider postponing travel to areas with active Zika virus transmission and avoid sex with someone with recent travel to Zika risk area. ^[47]

If a pregnant woman is living or travelling to an area with Zika virus transmission, they should be advised to strictly follow recommended steps to avoid mosquito bites throughout the entire day and to avoid getting ZIKV through sex by using condoms during sexual activity (oral, vaginal, or anal) or avoiding sex during pregnancy.

Pregnant women and their partner with history of travel to an area with risk for Zika or Zika outbreak, should monitor for symptoms (acute onset of fever, rash, arthralgia, conjuctivitis) and avoid sexual transmission through abstinence or use of condoms. 

Zika testing is recommended in pregnant women under the following conditions:

• Pregnant women with travel to an area with risk for Zika or sex with partner with travel or residence in area with Zika should undergo testing if symptomatic or ultrasound suggest fetus abnormalities related to ZIKV infection.
• Pregnant women who reside or frequently (daily or weekly) travel to an area with risk for Zika should undergo testing if symptomatic at any time during pregnancy or if asymptomatic during first prenatal care visit and at 2 additional regular prenatal care visits during pregnancy. 

Routine Zika testing is NOT recommended in asymptomatic pregnant women with infrequent travel-associated exposure to an area with Zika.

Guidelines on Zika testing in pregnancy by the Centers for Disease Control and Prevention are as follows ^[48] :​

Asymptomatic pregnant women:

• For asymptomatic pregnant persons living in or with recent travel to the United States and its territories, routine Zika virus testing is NOT currently recommended.
• For asymptomatic pregnant women with recent travel to  an area with risk for Zika outside the United States and its territories, Zika virus testing is NOT routinely recommended, but NAAT testing may still be considered up to 12 weeks after travel.
• Zika virus serologic testing is NOT recommended for asymptomatic pregnant women.

Symptomatic pregnant women:

• For symptomatic pregnant women who had recent travel to areas with  a risk of Zika, specimens should be collected for Zika virus NAAT testing on a serum specimen, and Zika virus NAAT on a urine specimenas soon as possible after the onset of symptoms up to 12 weeks after symptom onset. 
• Zika virus IgM testing is NOT recommended for symptomatic pregnant women.
• For symptomatic pregnant women who have had sex with someone who lives in or recently traveled to areas with  a risk for Zika, a specimen for Zika NAAT should be collected as soon as possible after the onset of symptoms up to 12 weeks after symptom onset.

The CDC's Interim Guidance for the Evaluation and Management of Infants with Possible Congenital Zika Virus Infection contains the following major recommendations ^[49] :

• All infants born to mothers with possible exposure to Zika virus during pregnancy should receive a standard evaluation at birth and at each well-child visit. A standard evaluation should include a comprehensive physical exam (including growth parameters), age-appropriate vision screening and developmental screening and monitoring, and a standard newborn hearing screening at birth, preferably using auditory brainstem response (ABR) methodology.
• Zika virus testing is recommended for infants with clinical findings consistent with congenital Zika syndrome and possible maternal Zika virus exposure during pregnancy, regardless of maternal testing results. Infants should have a head ultrasound and a comprehensive ophthalmologic exam performed by age 1 month by an ophthalmologist experienced in assessment of and intervention in infants. Infants should be referred for automated ABR by age 1 month if the newborn hearing screen was passed using only otoacoustic emissions methodology. Appropriate consultation with a developmental specialist, family support services, neurology, infectious diseases, and clinical genetics should be performed. 
• Zika virus testing is recommended for infants without clinical findings consistent with congenital Zika syndrome and laboratory evidence of possible maternal Zika virus infection during pregnancy.
• Zika RNA nucleic acid amplification testing (NAAT) of serum and urine and Zika virus IgM testing of serum should be performed within a  few days after birth (preferred) up to first few weeks to months after birth. 
• Zika virus PCR and serologic testing is recommended during the first 2 weeks after symptom onset to diagnose postnatal Zika virus disease. Serologic testing is recommended 2-12 weeks after symptom onset.
• Testing CSF for Zika virus RNA and Zika virus IgM antibodies should be considered, especially if serum and urine testing are negative and another etiology has not been identified.

Previously recommended screenings (eg, thyroid screening, complete blood count [CBC], liver function tests [LFTs], hearing screening at 4-6 months, behavioral audiology at 9-months) are not recommended because data are lacking to show that these screenings might be needed.