Which patients should receive Zika testing?
Zika testing should be done on pregnant patients with possible exposure to Zika, based on a travel history to an area where Zika is present or sexual contact with someone at risk for or with known Zika infection. The type of testing to be done depends on two important factors:
- Does the patient have symptoms?
- When was the patient exposed?
- Once you have the specific information about the patient's exposure, call the State Epidemiologist, at the Georgia Department of Public Health (DPH) at 404-657-2588.
What will the DPH want to know?
You can use this worksheet in data collection.
- Basic information includes patient date of birth, address, contact information and the specifics of their exposure
- Any office member can call the State Epidemiologist to confirm testing; the State Epidemiologist does not need to speak to a physician.
What types of tests are run on patients exposed to Zika?
https://www.cdc.gov/zika/hc-providers/index.html
- rRT-PCR (real time reverse transcription- polymerase chain reaction) can detect the active Zika RNA virus in body fluids like blood, urine or amniotic fluid.
- Done on patients with active symptoms or positive IgM testing
- Both blood and urine samples will increase detection rate
- IgM antibody can detect previous infection
- Primarily done on asymptomatic patients with exposure greater than 2 weeks prior to testing
- There may be cross reactivity with other flaviviruses. Your lab may test for other flaviviruses such as Dengue to help understand which infection is present.
- IgM antibody take time to form and the test is recommended after at least 2 weeks following exposure.
- PRNT (plaque reduction neutralizing test) is used to quantify the neutralizing antibody for a virus
- Done to help understand equivocal testing or to confirm antibody testing with negative rRT-PCR results
This page has more information the guidelines and testing.
How will a patient receive the results of testing?
Testing may take 4 to 6 weeks. The Department of Public Health will send a copy of the testing results to the physician who requested the test.
What referrals will a pregnant patient with positive Zika viral testing need?
- Maternal Fetal Medicine
- Consider referring to a perinatologist as growth ultrasounds are recommended and to facilitate discussion of further testing and management of pregnancy
- Amniocentesis may be offered though the efficacy has not been proven as negative amniotic fluid testing does not rule out fetal infection
- Infectious Diseases
- Can help with diagnosis and doing additional or follow-up testing as needed
- There may be other infections and these can be managed and followed by their service
- Pediatrics
- Establishing an early partnership with a pediatrician prepared for long term follow-up is important. You can also contact Children’s Healthcare of Atlanta, choa.org.
- Neonatology
- Will be needed if any fetal anomalies are found
- Consider antepartum consultation to help patients with expectations at delivery and possible NICU care
Will exposed patients need repeat testing?
Yes. If there is an on-going risk of exposure such as intimate partner contact or repeat travel, then testing should be repeated.
- Repeat testing should be done in the first and second trimester
- Note that men infected with Zika may carry the virus in seminal fluid for 6 months and ongoing condom use is an important prevention strategy.
http://www.cdc.gov/condomeffectiveness/male-condom-use.html
What kind of outcomes should a patient expect?
Pregnancy outcome data is not fully known but complete counseling about potential for fetal anomalies and pregnancy options should be considered.
- National U.S. data is available: https://www.cdc.gov/mmwr/volumes/66/wr/mm6623e1.htm
What risks does a Zika-infected pregnant patient pose to the public?
Any person recently infected with Zika has virus in their blood and, if bitten by an Aedes mosquito, could lead to spread of virus. Pregnant patients may stay viral positive for many weeks. They should be counseled heavily to:
- Use mosquito repellents. See the CDC’s list of recommended mosquito repellants.
- Stay indoors as much as possible
- Have others "tip and toss," which eliminates standing water and helps decrease mosquito population around homes
- All patients should be made aware of how they can help prevent spread of this disease
http://www.cdc.gov/zika/vector/index.html
Should Zika-infected pregnant patients expect to have testing on the delivered baby?
- Yes, the neonate will be screened by blood and possibly by urine testing
- Cord blood may be obtained as well, but the results of cord blood testing can be confusing as there may be maternal contamination; for this reason, neonates will need blood draws.
- Cord blood banking and donation will not be available
http://www.cdc.gov/zika/hc-providers/test-specimens-at-time-of-birth.html
What does the delivering provider need to know about delivery of a Zika-infected pregnant patient?
Use standard protocol for delivery. Contact the DPH for instructions on possible specimen collection.
If my patient miscarries is there any further testing?
- Products of conception can be sent for testing
- Patients should be followed until viral load is negative to better understand and counsel on public health risks