Testing Recommendations & Health Risks During the Periconceptional Period
Zika virus testing is performed at CDC, at several state and local health departments, and at some commercial laboratories. Several lab tests are available to help determine if a person is infected with Zika virus disease. Healthcare providers should contact their state and local health department to facilitate testing. See the Testing for Zika Virus webpage for information on how to obtain Zika testing.
Testing Recommendations for Non-Pregnant Women and Men
Symptomatic patients: Zika virus testing is indicated for non-pregnant women and men who have possible exposure to Zika and who experience symptoms of Zika virus disease. Possible exposure is defined as living in or having recently traveled to an area with risk of Zika, or sex (vaginal, anal, oral, or the sharing of sex toys) without a condom with someone who lives in or has recently traveled to an area with risk of Zika. The most common symptoms of Zika virus disease are fever, rash, headache, joint pain, conjunctivitis (red eyes), and muscle pain.
Asymptomatic patients: Routine testing is not currently recommended for women who are not pregnant and men who have possible exposure to Zika virus but no clinical illness. However, IgM testing can be considered for asymptomatic women who are planning to conceive in the near future among those who live in or frequently travel to areas with Travel Notices (see below).
No test is 100% accurate. A test result can sometimes be negative in the setting of true infection, and the results could be falsely reassuring.
- If the IgM test is performed too early after infection when the antibody levels are not yet high enough, the results could be negative even though infection is present.
- If the IgM test is performed after the IgM has waned, the results could be negative. Similarly, if the serum or blood PCR is performed after the virus is no longer in the blood, Zika could still be present in other bodily fluids (e.g., semen). In those situations, the blood test would be negative but the person could still be infected and able to infect others.
- It is also possible for IgM test results to be positive in the absence of infection because of, for example, extended IgM persistence after infection has resolved or due to cross-reactivity of IgM test with another virus.
Preconception Testing Recommendations for Women
Preconception Zika IgM testing can be considered for asymptomatic women planning to become pregnant in the near future who live in or frequently travel to areas with a CDC Zika travel notice. Testing shortly before pregnancy can provide information that may help interpret test results in the future if a woman is exposed to Zika subsequently, during pregnancy. Positive IgM test results before pregnancy should not be used to determine if it is safe for a woman to become pregnant because the test results could have multiple interpretations. Positive test results could mean a recent infection with Zika; recent infection with a similar type of virus such as dengue, a false positive result, or a past infection with Zika. Negative IgM test results before pregnancy and a subsequent positive IgM test result during pregnancy might reflect a new Zika infection that occurred between the first and the second test or a recent Zika virus infection. Again, the positive test result during pregnancy could also be reflecting a false positive result or a recent infection with a similar virus.
Risks of Infection Before Conception and Fertility Treatment
Because Zika virus infection is a cause of microcephaly and other severe fetal brain defects, pregnancy planning in the context of the Zika outbreak is important. There is limited information available about the risk for adverse pregnancy outcomes around periconceptional Zika virus infection (defined as infection during 8 weeks before conception or 6 weeks before last menstrual period). To date, there have been no published reports of adverse pregnancy outcomes after periconceptional Zika virus infection. Infections with other viruses (e.g., cytomegalovirus, rubella, parvovirus) around the time of conception have been associated with congenital infection and adverse pregnancy outcomes, although the exact timing of infection relative to conception was sometimes uncertain.
Pregnancy after Infection has Cleared
There is no evidence that a fetus conceived after the virus has cleared the woman’s body would be at risk for fetal Zika infection. There is no evidence that prior Zika virus infection poses a risk of birth defects in future pregnancies.
No instances of Zika virus transmission during fertility treatment have been documented, but transmission through donated gametes or embryos is theoretically possible. Zika virus has been detected in semen, and sexual transmission has occurred. The US Food and Drug Administration has issued guidance [PDF – 10 pages] providing recommendations to reduce the potential transmission risk of Zika virus through donated tissues, including donated sperm, oocytes, and embryos from anonymous donors. Fertility treatment for sexually intimate couples using their own gametes and embryos should follow the testing and timing recommendations for couples attempting conception, although recommendations might need to be adjusted depending on individual circumstances.
- HAN Advisory: Prolonged IgM Antibody Response in People Infected with Zika Virus: Implications for Interpreting Serologic Testing Results for Pregnant Women (May 5, 2017)
- Donor Screening Recommendations to Reduce the Risk of Transmission of Zika Virus by Human Cells, Tissues, and Cellular and Tissue-Based Products [PDF – 75 KB] (FDA)
- HAN Advisory: Recognizing, Managing, and Reporting Zika Virus Infections in Travelers Returning from Central America, South America, the Caribbean, and Mexico (HAN, Jan. 15, 2016)
- Page last reviewed: June 14, 2017
- Page last updated: June 14, 2017
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