Zika Virus Testing Overview for Healthcare Providers

Testing Types

Nucleic Acid Amplification Test (NAAT)

Zika virus immunoglobulin (Ig) M antibody testing

Plaque reduction neutralization tests (PRNT)

Specific Patient Groups

Asymptomatic pregnant women

Symptomatic pregnant women

For symptomatic pregnant women who lived in or traveled to an area with an active CDC Zika Travel Health Notice during pregnancy OR had sex during pregnancy with someone living in or with recent travel to an area with an active CDC Zika Travel Health Notice

For symptomatic pregnant women who lived in or traveled to an area with current or past Zika virus transmission during pregnancy

• Specimens should be collected as soon as possible after onset of symptoms up to 12 weeks after symptom onset.
• Perform dengue and Zika virus NAAT testing on a serum specimen and Zika virus NAAT on a urine specimen.
• If Zika NAAT is positive, repeat test on newly extracted RNA from same specimen to rule out false-positive results.
• Perform IgM testing for dengue only.
• If dengue NAAT or IgM is positive, this provides adequate evidence of dengue infection, and no further testing is indicated.

For symptomatic pregnant women who had sex during pregnancy with someone living in or with recent travel to an area with current or past Zika virus transmission:

• Specimens should be collected as soon as possible after onset of symptoms up to 12 weeks after symptom onset.
• Only Zika NAAT should be performed.
• If Zika NAAT is positive, repeat test on newly extracted RNA from same specimen to rule out false-positive results.

Fetus with congenital Zika virus infection

Pregnant women who have a fetus with prenatal ultrasound findings consistent with congenital Zika virus infection, and:

• Zika virus NAAT and IgM testing should be performed on pregnant woman's serum and NAAT on pregnant woman's urine.
• If the Zika virus NAATs are negative and the IgM is positive, confirmatory PRNTs should be performed against Zika and dengue.
• If amniocentesis is being performed as part of clinical care, Zika virus NAAT testing of amniocentesis specimens should also be performed and results interpreted within the context of the limitations of amniotic fluid testing.
• Testing of placental and fetal tissues may also be considered (see guidance for Collecting & Submitting Placental and Fetal Tissue Specimens for Zika Virus Testing)

Symptomatic non-pregnant patient

For symptomatic non-pregnant patients living in or with recent travel to the United States and its territories:

• routine Zika virus testing is not recommended.

For symptomatic non-pregnant patients living in or with recent travel to an area with an active CDC Zika Travel Health Notice or current or past Zika virus transmission outside the US and its territories:

• Dengue and Zika virus NAATs should be performed on serum collected ≤7 days after symptom onset.  A positive NAAT result typically provides evidence of acute infection.
• Perform dengue and Zika virus IgM antibody testing on NAAT-negative serum specimens and serum collected >7 days after onset of symptoms.
• If either dengue or Zika virus IgM antibody testing is positive, and definitive diagnosis is needed for clinical or epidemiologic purposes, confirmatory PRNTs should be performed against dengue, Zika and other flaviviruses endemic to the region where exposure occurred.

Asymptomatic non-pregnant patient

• Testing for dengue or Zika viruses is not recommended.

Infant with possible congenital Zika virus infection

With a mother with possible Zika virus exposure during pregnancy:

• Collect specimens as soon as possible after birth.
• Zika virus NAAT and IgM testing should be performed on infant serum and NAAT on infant urine.
• If cerebrospinal fluid (CSF) is obtained for other purposes, NAAT and IgM antibody testing should be performed on CSF.
•  If the infant's serum is IgM non-negative and NAAT negative, but PRNT was not performed on the mother's serum, PRNT for Zika and dengue viruses should be performed on the infant serum.
• Perform PRNT on a sample collected from an infant aged 18 months or older whose initial sample collected at birth was IgM non-negative and neutralizing antibodies were detected by PRNT in either the infant's or mother's sample.