Overview and Testing Algorithm: Asymptomatic Pregnant Women

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Overview and Testing Algorithm: Asymptomatic Pregnant Women

A separate testing algorithm is available from the CDC specifically for asymptomatic pregnant women meeting epidemiological criteria (refer to the image on the right).
The following is a summary of the testing algorithm for asymptomatic pregnant women:
  • Serum and urine collected from a pregnant woman within 14 days of her travel or exposure should be tested for Zika virus by rRT-PCR method. If the test is negative, a second serum specimen should be collected between 2 and 12 weeks following return from travel and the specimen should be tested by an antibody detection method (Zika MAC-ELISA). If the Zika MAC-ELISA is negative on the second follow up serum specimen, no further testing is necessary. If the test is positive or equivocal on the second follow up serum specimen, the specimen should be forwarded for confirmation by PRNT testing.
  • If serum from a pregnant woman first presenting 2-12 weeks following travel, exposure, or living in areas of ongoing transmission, the serum should be tested for Zika antibody using an antibody detection method (Zika MAC-ELISA). If positive or equivocal, rRT-PCR should be performed on the serum and urine. If rRT-PCR is positive for Zika virus, the patient is considered positive for Zika virus and no further testing is required. However, if rRT-PCR is negative, PRNT should be performed for confirmation of Zika MAC-ELISA result.
It is important to note that If testing of CSF from a symptomatic individual is desired, the specimen(s) must be submitted alongside a patient-matched serum specimen. A Zika virus rRT-PCR positive result from any specimen is indicative of a Zika virus infection. CSF should be tested by rRT-PCR if collected within the first week following onset or by antibody detection methods, if collected after seven days post onset of symptoms.
Although amniotic fluid testing by rRT-PCR may be considered following onset of symptoms in a pregnant woman, the optimal time to perform amniocentesis is unknown. It does appear that amniocentesis performed ≥15 weeks of gestation is associated with lower rates of complications than those performed at earlier gestational ages, and early amniocentesis (≤14 weeks of gestation) is not recommended.
The CDC however recommends that the patient-matched serum (and urine) submitted alongside these other specimens should be tested according to the method(s) recommended for the time point post-onset indicated in the testing algorithms.

CDC algorithm for testing of asymptomatic pregnant women