Expanded Availability of Testing for Exposure to Zika Virus

Overview:

Commercial labs are now able to perform Zika IgM MAC-Elisa testing.  Doctors seeking testing for patients for pregnancy planning purposes should be aware of this option.  It is still recommended that pregnant women (regardless of symptoms) or any person seeking testing for Zika virus due to symptoms after having traveled to Zika-endemic areas access testing at the ADH.

Situation:

The Arkansas Department of Health (ADH) is continuing to test symptomatic persons or any pregnant woman (regardless of symptoms) who have traveled to a Zika virus-endemic location.  Depending on the timing of symptoms or travel, we perform in-house polymerase chain reaction (PCR) tests that look for the virus itself as well as IgM testing that looks for our antibody response to the virus.

Due to limited testing resources at the ADH, we require all requests for testing to meet strict criteria before completing the test and have refused to test males who were asymptomatic or individuals who wanted testing for pregnancy planning purposes.  That is because the IgM MAC-Elisa testing (which is needed in that case) is particularly resource intensive and available only under the Food and Drug Administration’s Emergency Use Authorization (EUA).  We are glad to report that this test can now be performed by commercial laboratories.   As of last week, Quest Diagnostics has been approved to perform IgM MAC-ELISA test under the same EUA.  Other labs may soon acquire this testing capability as well.

The ADH will perform tests in our laboratory for all pregnant travelers to Zika-endemic areas and non-pregnant travelers to endemic areas with at least one of the following symptoms: rash, fever, red eyes or joint pain.  We urge providers to continue to use the ADH as the primary test provider for pregnant women exposed to the Zika virus so that we may respond quickly when additional case investigation, vector control activities, high risk obstetrical consultation, and expert pediatric evaluation are needed.   We recommend that all patients needing preconception Zika testing see their primary care provider to access commercially available tests (such as those currently available at Quest Diagnostics Laboratories).¹

The clinical criteria for testing at ADH remain unchanged:

• Pregnant travelers, regardless of symptoms, can be tested for Zika at the ADH Laboratory.
• If returning from a Zika-involved country in the last 7 days, they can receive a PCR of urine and serum for Zika, Dengue, and Chikungunya and will need an IgM test at least 14 days after return to rule out Zika.
• If returning from a Zika-involved country 8-14 days ago, they can be tested by PCR of urine for Zika and IgM of serum for Zika. They also will need an IgM at least 14 days after return to rule out Zika.
• If returning from a Zika-involved country at least 14 days ago, but not more than 6 months ago, they can be tested at the ADH by IgM of serum for Zika only.
• Non-pregnant symptomatic females or males with at least one of the following symptoms: fever, conjunctivitis, rash, or joint pain while in (or within 14 days of travel from) a Zika-endemic area can be tested.
• If within 7 days of symptoms or travel, they can receive a PCR test of urine and serum for Zika, Dengue, and Chikungunya and an IgM test for Zika.
• If within 8-14 days of symptoms, they may receive a PCR test of urine for Zika and an IgM test of serum for Zika.
• If at least 14 days but not more than 6 months since travel, they can receive an IgM of serum for Zika.
• Negative PCR tests for zika are not by themselves definitive. In all testing scenarios an IgM test 15 days – 6 months after travel is needed to definitively rule out Zika.
• At the ADH, other testing scenarios are considered on a case-by-case basis.
• Any positive or equivocal tests will require additional confirmatory testing at the Centers for Disease Control and Prevention.

To discuss testing at ADH please call 501-537-8969 and ask to speak with a communicable disease nurse.

Yours sincerely,

Dirk Haselow, MD, PhD

State Epidemiologist and Medical Director for Outbreak Response, ADH

References:

• Quest Diagnostic Laboratory Zika virus Antibody (IgM), MAC-ELISA test guidance available at (http://questdiagnostics.com/home/physicians/testing-services/condition/infectious-diseases/zika)