Zika Virus Testing in St. Louis Area

The purpose of this communication is to address any questions or concerns regarding Zika virus testing in the Saint Louis area.

Zika virus is acquired by the bite from an infected Aedes species of mosquito, and by sexual transmission from an infected partner. Patients at risk for infection are those who 1) have a travel history to an area in which Aedes mosquitoes are endemic and where Zika virus transmission is occurring  (ie. South or Central America, Caribbean, South Florida – the geographic range is slowly expanding) or 2) have had sex with a partner who has recently traveled to such an area. About 1 in 5 people infected with Zika virus become symptomatic. Characteristic clinical findings are acute onset of fever with maculopapular rash, arthralgia, or conjunctivitis. Other commonly reported symptoms include myalgia, headache, retro-orbital pain and vomiting. Clinical illness is usually mild with symptoms lasting for several days to a week. Severe disease requiring hospitalization is uncommon and death is very rare. Guillain-Barre syndrome is an uncommon complication of Zika virus infection. Infection during pregnancy is associated with substantial risk for severe fetal abnormalities, including microcephaly.  There currently is no treatment or vaccine available for Zika virus.

Current CDC recommendations to prevent congenital Zika Virus Disease are for pregnant women to 1) avoid traveling to areas where Zika virus is being transmitted, and 2) avoid unprotected sexual activity with partners who have traveled to areas where Zika virus is being transmitted.

Testing Recommendations:

On July 29th, 2016, the Centers for Disease Control (CDC) issued updated guidelines for the testing for Zika virus. These guidelines recommend testing pregnant women with a history of travel to an endemic area and symptoms consistent with Zika virus infection. The updated guidelines also state that testing should be performed in pregnant women with travel to endemic areas but without symptoms of infection.  Given the potential for sexual transmission, the CDC’s most recent recommendations Interim Guidance for Prevention of Sexual Transmission of Zika Virus also suggest testing in all patients at risk from sexual transmission.

In summary, testing is recommended for symptomatic patients with infection risk and asymptomatic pregnant women with infection risk. Testing is not currently recommended for asymptomatic non- pregnant patients, regardless of infection risk.

How to send Zika testing:

At this time, all testing for Zika virus for patients residing in Missouri is performed by the Missouri state laboratory and the CDC. Testing typically requires serum (for PCR and serology) as well as urine (for PCR). Two red top tubes and one urine specimen should be collected for submission. Specimens for testing should be sent to the Missouri Department of Health first for tracking and notification purposes. The Missouri Department of Health should also be contacted regarding all suspected cases. This allows them to vet appropriate testing and notify other potentially exposed individuals ASAP.  The order of contact is as follows:

-State epidemiologist: (573)751-6113 M-F 8AM-5PM

-Epidemiologist on call: 800-392-0272

Samples sent by Barnes Jewish Hospital will be sent by the chemistry laboratory send out department. The microbiology laboratory medicine resident should be contacted to help coordinate this (747-1320, option #3).

Samples for testing will need to be sent to the state lab along with 2 completed forms:

1) Virology Test Request Form for the Missouri State Public Health Laboratory and 2) CDC form 50.34. Information regarding how to access and fill out these forms is given on the last page of this document.  Importantly, the ordering physician should list themselves as the “intermediate submitter” not the “primary submitter”.

Due to the issues with serology the state lab and CDC needs at least 2 mls of serum to perform all the necessary tests, so two red top tubes should be sent to ensure there is enough serum for complete testing. Due to the testing requirements, it may take weeks to get serology results.

Zika virus causes an initial viremia which typically persists in blood and urine for about 8 days following infection. During this time PCR based tests are usually positive whereas after this time serology is the best way to make the diagnosis.  Unfortunately serologic testing cross reacts with many other flaviviruses. False positives can occur in patients with current or past West Nile, Chikungunya, Dengue and Yellow fever. Even people who have had the yellow fever vaccine may cross react.


Neil Anderson, M.D.

Assistant Professor of Pathology & Immunology, Washington University School of Medicine

Assistant Medical Director, Clinical Microbiology

Barnes Jewish Hospital

Hilary M. Babcock, M.D., M.P.H.

Associate Professor of Medicine, Infectious Disease Division

Medical Director, BJC Infection Prevention and Epidemiology Consortium

Medical Director of Occupational Health (Infectious Diseases) Barnes-Jewish and St. Louis Children’s Hospitals

Missouri Physicians’ Instructions for Completing Zika Test Request Forms

Two forms are required to submit specimens for Zika virus testing.  Please complete and print both forms and send with specimen(s) being tested.  Testing by the Centers for Disease Control and Prevention (CDC) will be delayed if any of the following information is missing: symptoms (if applicable), symptom onset date (if applicable), date of return to U.S. for asymptomatic pregnant women, specimen collection date, travel history (locations and travel start/end dates), patient name and address, and submitter name and address. Delays will also occur if submitted specimens have not been screened by a state or local public health agency epidemiologist.

Facilitation of testing for Zika virus is a component of the Missouri Department of Health and Senior Services’ response to the introduction of this virus into the tropical Americas. In addition to giving medical providers information they need to diagnose and manage patient illness, test results also produce important data that can lead to a better understanding of the spectrum of Zika virus illness and help public health practitioners assess and reduce the risk of local transmission.

Specimens should be sent to the Missouri State Public Health Laboratory (MSPHL) in Jefferson City via the MSPHL courier system.  View a list of drop-off locations in Missouri, by county. For information on specimen packaging and shipping, please call the laboratory at 573-751-3334 during regular business hours (Monday – Friday, 8:00AM to 5:00PM). After regular hours and on weekends, call 800-392-0272 for assistance.

Please follow these instructions for obtaining copies of the forms:

Form 1: Virology Test Request Form for the Missouri State Public Health Laboratory

  1. Visit  Virology Additional Tests
  2. Scroll down to Test Request Forms, click the link that says “Virology Test Request Form.”
  3. Select “CDC Referrals” from the list of test form options.
  4. From the drop-down list, choose the name of your facility and press “Select.”
  5. A fillable PDF form will open and your facility’s information (name, address) will be pre-populated; complete the remainder of the form. If your facility is not here, choose any facility, delete pre-populated data, and proceed.

-> Under the “Test(s) Requested” section, please select the following:

Under Serology, mark “CDC Referral” and type/write in “Zika virus.”

  1. Print completed form and send with the specimen(s) being tested.

Form 2: CDC Specimen Submission Form 50.34

  1. CDC Specimen Submission Form
  2. Page 1: In the top left corner in the “Specimen Origin” field, select “Human.”
  3. Page 1: Under “Laboratory Examination Requested” in the “Test order name” field, select “Arbovirus Serology.”
  4. Page 1: Leave the “Suspected Agent” field blank – you will specify this later in the “Brief Clinical Summary” field at the top of page 2. Leave “Date Sent to CDC” blank – this will be completed by the MSPHL.
  5. Page 1: Complete the “Patient Information” and “Specimen Information” sections:

Date of birth, symptom onset date (if applicable), date of return to U.S. for asymptomatic pregnant women, and specimen collection date are required fields.

  1. Page 1: Top right column – leave the “State PHL” section blank; the MSPHL will complete this section upon receipt.
  2. Page 1: Under “Original Submitter,” enter facility (Barnes Jewish Hospital)
  3. Page 1: “ Intermediate Submitter”  – enter point of contact (the requesting physician).
  4. Page 2: Under “Brief Clinical Summary,” enter “Zika virus testing.” Also include in this section signs, symptoms, and underlying illnesses as well as any past infections with other flaviviruses such as West Nile, dengue, yellow fever and/or with chikungunya virus.
  5. Page 2: Check the applicable “State of Illness.” “Type of Infection” and Therapeutic Agents” are optional.
  6. Page 2: Complete the entire “Epidemiologic Data” section. “Travel History” and “Dates of Travel” are required fields. “Relevant Immunization History” should be completed if patient has been vaccinated for flaviviruses such as yellow fever, dengue, and/or Japanese encephalitis virus.
  7. Print the completed form and submit (along with Form 1) with the specimen(s) being tested.