For Healthcare Providers Banner

Testing Guidance

Dengue and Zika virus testing is recommended for:

  • Patients with a clinically compatible illness who live in or recently traveled to an area where there is risk for infection with Zika and dengue viruses.  This includes symptomatic pregnant women.

Zika virus testing is recommended for:

  • Symptomatic patients who had sex with someone who lives in or recently traveled to and area with Zika virus
  • Asymptomatic pregnant women with ongoing possible Zika virus exposure (i.e., residence in or frequent travel to an area with risk of Zika)
  • Pregnant women with possible Zika virus exposure who have a fetus with prenatal ultrasound findings consistent with congenital Zika virus infection

Zika testing is not routinely recommended but may be considered for:

  • Asymptomatic pregnant women with recent possible but no ongoing exposure to Zika virus (i.e., travelers)

Zika virus testing is not recommended for:

  • Non-pregnant asymptomatic people
  • Preconception screening

Dengue virus testing is not recommended for:

  • Individuals without a clinically compatible illness

Testing Guidance for Symptomatic Non-Pregnant Patients

For non-pregnant persons with a clinically compatible illness and a serum specimen collected within seven days of symptom onset:

  • Dengue and Zika virus nucleic acid amplification tests (NAAT) should be performed.
    • Other specimen types, including plasma, whole blood, cerebrospinal fluid, or urine may be acceptable specimens for some NAATs.
  • For symptomatic persons with possible exposure to dengue and Zika virus, a positive NAAT result typically provides adequate evidence of infection, and no further testing is indicated. However, in some circumstances, a repeat NAAT may be performed (see testing guidance) to confirm the initial result.
  • A negative NAAT does not rule out infection and dengue and Zika virus IgM antibody testing is recommended. This further testing is needed because declining levels of viremia over time and possible inaccurate reporting of dates of illness onset may result in poor NAAT sensitivity and false-negative results.
  • If both dengue and Zika virus NAATs are negative but either IgM antibody test 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.

For non-pregnant persons with a clinically compatible illness and a serum specimen collected greater than seven days after symptom onset:

  • Dengue and Zika virus IgM antibody testing should be performed on serum specimens.
  • If either IgM antibody test 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.

See the testing algorithm and test interpretations for symptomatic non-pregnant individuals pdf icon[PDF – 1 page].

Healthcare providers are strongly encouraged to read the full testing guidance: Dengue and Zika virus diagnostic testing for patients with a clinically compatible illness and risk for infection with both viruses

Testing Guidance for Symptomatic Pregnant Women

For pregnant women with a clinically compatible illness and recent possible exposure to dengue and Zika virus with a specimen collected within 12 weeks of symptom onset:

  • Specimens should be collected as soon as possible after onset.
  • The following diagnostic testing should be performed at the same time:
    • Dengue and Zika virus NAAT and IgM antibody testing on a serum specimen, and
    • Zika virus NAAT on a urine specimen.
  • A positive NAAT result on any specimen typically provides adequate evidence of recent infection. However, if NAAT is only positive for Zika virus on a single specimen and IgM antibody testing is negative, the NAAT should be repeated on newly extracted RNA from the same specimen to rule out false-positive NAAT results.
  • If both dengue and Zika virus NAATs are negative but either IgM antibody test is positive, confirmatory PRNTs should be performed against dengue, Zika, and other flaviviruses endemic to the region where exposure occurred.
  • The interpretation for IgM and neutralizing antibody test results in a symptomatic pregnant woman is similar to that for non-pregnant patients; however, because dengue and Zika virus IgM antibodies can be detected in serum for months after an infection, the specific timing of infection cannot be determined, and other factors (e.g., epidemiologic and clinical findings) should be used to assess the likelihood that the current illness was due to either dengue or Zika virus and that exposure occurred during the pregnancy.

See the testing algorithm and test interpretations for symptomatic pregnant women [PDF – 2 pages].

Healthcare providers are strongly encouraged to read the full testing guidance: Dengue and Zika virus diagnostic testing for patients with a clinically compatible illness and risk for infection with both viruses

Testing Guidance for Asymptomatic Pregnant Women

For asymptomatic pregnant women with ongoing possible Zika virus exposure (i.e., residence in or frequent travel to an area with risk of Zika):

  • Zika virus NAAT testing is recommended three times during pregnancy.
  • Zika virus IgM antibody testing is no lon­ger routinely recommended because IgM can persist for months after infection; therefore, IgM results cannot reliably determine whether an infection occurred during the current pregnancy.
  • Recommendations for the timing of Zika virus NAAT testing are at the initial prenatal care visit, followed by two additional Zika virus NAAT tests performed during pregnancy, coinciding with non-consecutive prenatal visits. Zika virus testing is not recommended for pregnant women with a previous diagnosis of laboratory-confirmed Zika virus infection.
  • Dengue virus testing is not recommended for individuals without a clinically compatible illness.

For asymptomatic pregnant women with recent possible exposure to Zika virus but no ongoing exposure (i.e., through travel or sexual exposure):

  • Zika virus testing may be considered.
    • Although not routinely recommended, testing may be considered on a case-by-case basis and in line with jurisdictional recommendations.
    • If Zika virus testing is conducted, follow algorithm for symptomatic pregnant women using timeframe from last possible exposure.
  • Dengue virus testing is not recommended for individuals without a clinically compatible illness.
  • Jurisdictions may take into account local epidemiologic considerations (e.g., seasonality, geography, and mosquito surveillance and control factors) in making recommendations for Zika virus testing for asymptomatic pregnant women with possible recent exposure to Zika virus but no ongoing exposure; therefore, testing recommendations for this group of pregnant women may differ by jurisdiction. Please contact your state, tribal, local, or territorial health department for jurisdiction specific guidance.

See the testing algorithm and test interpretations for asymptomatic pregnant women. [PDF – 2 pages]

Pregnant women with possible exposure to Zika virus and who have a fetus with prenatal ultrasound findings consistent with congenital Zika virus infection 

  • Zika virus NAAT and IgM testing should be performed on maternal serum and NAAT on maternal urine.
  • 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. It is unknown how sensitive or specific RNA NAAT testing of amniotic fluid is for congenital Zika virus infection or what proportion of infants born after infection will have abnormalities.
  • Testing of placental and fetal tissues may also be considered (see guidance for Collecting and Submitting Specimens at Time of Birth for Zika virus Testing).

Clinician Materials

Zika and Dengue Testing Algorithm for Symptomatic Non-Pregnant Patients

Zika and Dengue Testing Algorithm for Symptomatic Pregnant Women

Zika Testing Algorithm for Asymptomatic Pregnant Women

Patient Materials

Make sure to get your Zika test results

What You Should Know About Zika Virus Testing: For asymptomatic pregnant women with ongoing exposure to Zika

What You Should Know About Zika Virus Testing: For symptomatic pregnant women with exposure to Zika or dengue

What You Should Know About Zika Virus Testing: For asymptomatic pregnant women with recent exposure to Zika