Zika Update: Clinical Laboratory Testing and Care of Infants with Congenital Zika Virus Infection

Moderator: Dr. Loretta Jackson Brown

Presenters: Sara E. Oliver, MD, MSPH and Kate Russell, MD, MPH

Date/Time: August 23, 2016, 2:00 - 3:00 pm ET

---

Coordinator: Welcome and thank you for standing by. All participants will be in listen-only mode until the question and answer session of today's conference. At that time you may press Star 1 to ask a question. Today's conference is being recorded. If you have any objections, you may disconnect at this time.

I would now like to turn the meeting over to Dr. Loretta Jackson-Brown. Thank you, you may begin. Dr. Jackson, you may begin at this time.

Dr. Loretta Jackson-Brown: Thank you, (Melinda). Good afternoon, I'm Loretta Jackson-Brown and I'm representing the Clinician Outreach and Communication Activity (COCA) with the Emergency Risk Communication Branch at the Centers for Disease Control and Prevention.

I'm delighted to welcome you to today's COCA Call, Zika Update: Clinical Laboratory Testing and Care of Infants with Congenital Zika Infection. You may participate in today's presentation by audio only, via webinar, or you may download the slides from our COCA webpage if you are unable to access the audio. Our webpage is emergency.cdc.gov/coca.

Free continuing education is offered for today's call. Information on how to earn continuing education will be provided at the end of the call.

CDC, our planners, presenters, and their spouses/partners wish to disclose that they have no financial interest or other relationships with the manufacturers of commercial products, supplies of commercial services, or commercial supports. Planners have reviewed content to ensure that there is no bias.

This presentation will not include any discussion of the unlabeled use of a product or products under investigational use.

At the end of the presentation, you will have the opportunity to ask the presenters questions. On the phone, dialing Star 1 will put you in the queue for questions. You submit questions through the webinar system at any time during the presentation by selecting the Q&A tab at the top of the webinar screen and typing in your question. Questions are limited to clinicians who would like information related to the Zika virus infection.

For those who have media questions, please contact CDC Media Relations at 404/639-3286 or send an email to media@cdc.gov. If you are a patient, please refer your questions to your healthcare provider.

At this conclusion of today's session, the participant will be able to interpret revised testing guidance for newborn with possible congenital Zika virus infection, discuss clinical evaluation of infants born to mothers with laboratory evidence of Zika virus infection and outline outpatient management of infants with laboratory evidence of congenital Zika virus infection with, and without, abnormalities consistent with congenital syndrome.

Today's first presenter is Dr. Sara Oliver. Dr. Oliver is an Epidemic Intelligence Service Officer in the Division of Viral Diseases at the Centers for Disease Control and Prevention. She completed a pediatric residency at Cincinnati's Children's Hospital Medical Center and a pediatric infectious disease fellowship at the University of Alabama at Birmingham. Dr. Oliver holds a Master's of Science in Public Health in Applied Epidemiology from the University of Alabama at Birmingham.

Our second presenter is Dr. Kate Russell. Dr. Russell is an Epidemic Intelligence Service Officer in the Influenza Division at the Centers for Disease Control and Prevention. Dr. Russell earned a Doctor of Medicine from Dartmouth Medical School and a Master's in Public Health from Boston University. Dr. Russell completed a pediatric residency at Duke University Medical Center.

At this time, please welcome Dr. Oliver.

Dr. Sara Oliver: Thank you so much. In today's COCA Call, we will discuss some background on the effects of Zika virus during pregnancy on the infant and updated recommendations for infant diagnostic testing and interpretation. We will also review the clinical evaluation of all infants born to mothers with lab evidence of Zika including the initial evaluation and outpatient management.

We will start with some background. Pregnant women can be infected with Zika virus through the bite of an infection Aedes aegypti or albopictus mosquito, or through sex with an infected partner-these are the most common modes of Zika virus transmission. If a woman is infected with Zika around the time of conception, the risk to the fetus is currently unknown. However, from what we know about other viral infections, infections around the time of conception can potentially lead to infections in the fetus. If a woman is infected during pregnancy, Zika virus can be passed to her fetus during pregnancy or around the time of birth.

There have been numerous reported brain abnormalities with congenital Zika virus infection which are listed on this slide. The initial birth defect detected was microcephaly. However, since then, emerging data has shown a variety of findings, mostly related to brain atrophy.

The illustration on the upper left depicts an infant with severe microcephaly compared to a baby with typical head size on the lower left. The right side of the slide shows CT scans with abnormal findings from infants with congenital Zika virus infection on the top, compared to a typical newborn head CT scan on the bottom. In the scans on the top, the arrows point to the bright white lesions of intracranial calcifications on the left and large ventricles with volume loss on the right.

In addition to microcephaly, other problems have been detected among fetuses and infants infected with Zika virus before birth, such as spontaneous abortion and stillbirth, and other infant outcomes, such as eye abnormalities, hearing impairment, limb abnormalities, seizures, developmental delay, and impaired growth.

Many questions remain, including what is the full range of potential health problems that Zika virus may cause. As well as when during pregnancy Zika virus infection imposes the highest risk to the fetus.

This slide lists what CDC is doing to learn more about Zika. First in collaboration with State, Tribal, Local, and Territorial Health Departments, CDC established the U.S. Zika Pregnancy Registry. We are working to collect information about woman with lab evidence with possible Zika virus infection during pregnancy in the United State and their infants. We hope to develop a similar system in Puerto Rico, the Zika Active Pregnancy Surveillance System. And we've established enhanced surveillance of pregnant woman with Zika in Colombia.

Zika virus disease and congenital Zika virus infection in an infant is a reportable infection and should be reported to the health department. In partnership with these health departments, the U.S. Zika Pregnancy Registry is a surveillance system for Zika-affected pregnancies and congenitally exposed infants up to one year of age in the U.S. and District of Columbia. The system is used to monitor any adverse pregnancy and fetal or neonatal outcomes, including microcephaly and other birth defects.

ZAPSS is a surveillance system constructed similarly to the U.S. Zika Registry, collecting information on Zika-affected pregnancies and congenitally exposed infants. However, this system is conducted in Puerto Rico and will follow up with exposed infants up to three years of age. ZAPSS is a collaborative activity between CDC and the Puerto Rico Department of Health.

Currently there are over 1,000 pregnant women with lab evidence of possible Zika virus infection in the United States and U.S. territories, including over 500 in the United States and the District of Columbia. Because of this, updated guidance was released to assist healthcare providers for caring for infants born to these women.

We will now discuss infant diagnostic testing and interpretation. There are many challenges with the diagnosis of congenital Zika infection. Real time reverse transcription-polymerase chain reaction (RT-PCR) detects viral RNA in body fluids such as serum, urine, cerebrospinal fluid, or tissues such as the placenta. A positive PCR can confirm congenital Zika virus infection. However, a negative PCR does not exclude infection. Viral shedding for other congenital infections including CMV and rubella can be prolonged, but the duration of viral shedding in infants with congenital Zika virus infection is unknown.

Zika virus immunoglobulin M or IgM results can be difficult to interpret because of false-positive and false-negative results. Maternal IgG can cross the placenta and because of this, neutralization testing does not distinguish maternal from infant antibodies.

Here are the current recommendations for lab testing of infants with the possible congenital Zika virus infection. Testing is recommended for infants born to mothers with lab evidence of Zika virus infection. Lab evidence for mothers includes Zika virus RNA detected in any maternal clinical specimen by PCR including serum or urine, or positive Zika virus IgM with confirmatory neutralizing antibody titer.

Testing is also recommended for infants with abnormal findings suggestive of congenital Zika syndrome with a maternal epidemiologic link suggesting possible transmission, regardless of maternal testing results. And epidemiologic links include: travel to or residence in an area of Zika virus transmission, or sex with a partner who has traveled or resided in such area.

 

So what is congenital Zika syndrome? Congenital Zika syndrome is a recently recognized pattern of congenital anomalies associated with Zika virus infection during pregnancy that includes: microcephaly, intracranial calcifications, and other brain anomalies, eye anomalies and other findings, such as club foot and contractures. Research is ongoing to further define anomalies associated with congenital Zika syndrome.

Laboratory testing for congenital Zika virus infection should include collection of several samples. Zika virus PCR should be performed on infant serum and urine. Additionally, Zika virus IgM testing should be performed on infant serum. If cerebrospinal fluid (CSF) is obtained for other purposes, PCR testing for Zika virus RNA and Zika virus IgM should be performed.

Lab testing of cord blood specimens is no longer recommended as it can yield false-positive results through contamination with maternal blood and might also yield false-negative results. Infant testing should be performed within the first two days after birth. If testing is performed later, distinguishing between congenital, perinatal, and postnatal infection will be difficult.

This is the table for interpretation of Infant Zika virus testing. A positive result in a Zika PCR from an infant sample, regardless of Zika virus IgM results, confirms the diagnosis of congenital Zika virus Infection. A negative Zika PCR, but with a positive Zika virus IgM, should be interpreted as probable congenital Zika virus infection. If both PCR and IgM testing from an infant specimen are negative, the infant is considered negative for congenital Zika virus infection; but, these results should be interpreted in the context of maternal serology, clinical findings consistent with congenital Zika syndrome, and with confirmatory neutralizing antibody testing.

The plaque reduction neutralization test, or PRNT, measures virus-specific neutralizing antibodies and is used to confirm the specificity of the IgM antibodies against Zika virus, or to rule out a false-positive IgM results. PRNT is a functional assay of neutralizing antibodies composed primarily of IgG. Since IgG crosses the placenta, however, PRNT's cannot distinguish between maternal and infant antibodies.

This diagram illustrates which infants and children should receive PRNT testing. If an infant's initial sample is PCR positive, there is no need for additional PRNTs, as congenital Zika virus infection has been confirmed. When an infant's initial testing is PCR negative but IgM positive, if PRNTs were not performed on the maternal sample, PRNTs should be performed on the infant initial sample. This is performed as a confirmatory test for the positive IgM. Additionally, PRNTs should be performed on the child once he or she is aged 18 months or older; by this time, maternal antibodies are likely to have declined.

Since an initial IgM positive test result classifies the infant as probable congenital Zika virus infection, identifying neutralizing antibodies in the child can confirm congenital infection. If the infant initially has negative Zika virus PCR and IgM, but clinical concerns remain, such as microcephaly or other CNS abnormalities without another defined etiology, PRNT can be performed once the child is aged 18 months or older to further assess for congenital Zika virus infection.

If PRNT results at 18 months are negative, the child should be considered not to have congenital Zika virus infection. If PRNT results at 18 months are positive, congenital Zika virus infection is presumed, however, postnatal infection cannot be excluded, especially for children residing in an area with active Zika virus transmission.

Molecular Zika virus testing can be performed on placental samples as well. Detection of Zika virus RNA in the placenta can confirm maternal infection, but cannot distinguish between maternal and congenital infection. Placental testing can be helpful to confirm maternal infection in circumstances where maternal testing either was not performed, performed beyond 12 weeks after exposure, or is not definitive for Zika virus. The clinical implications for an infant with Zika virus RNA detected in the placenta are unknown, especially if infant testing is negative.

For infants born to mothers with risk factors for Zika virus infection during pregnancy, but maternal testing is not performed, then maternal diagnostic testing should be performed at the time of delivery. Placental PCR testing should be considered. Infant testing should be performed if abnormalities consistent with congenital Zika syndrome are present.

If abnormalities for congenital Zika syndrome are not present, then infant testing can be deferred until the maternal test results are available. But if there are concerns with infant follow up, testing and any further evaluation can be performed prior to discharge from the hospital.

We will now move to Evaluation and Management with Dr. Russell.

Dr. Kate Russell: Thank you, Dr. Oliver. On July 21 and 22, CDC sponsored a meeting in collaboration with the American Academy of Pediatrics, entitled Clinical Evaluation and Management of Infants with Congenital Zika virus Infection. Multiple pediatric specialties, partner organizations and other federal agencies were represented.

The goal of the meeting was to gather individual expert opinion regarding evaluation and management of infants with congenital Zika virus infection to be considered in the development of CDC guidance for pediatric healthcare providers.

There were three main areas of focus, including the initial evaluation and testing of infants born to mothers with laboratory evidence of possible Zika virus infection during pregnancy, outpatient management and follow-up of infants with laboratory evidence and findings consistent with congenital Zika syndrome, and finally, outpatient management and follow-up of infants of laboratory evidence of congenital Zika virus infection, but without findings consistent with congenital Zika syndrome.

I will discuss the guidance for the initial evaluation. This flowchart can be found in the MMWR released on August 19, and I will walk through it now. All infants born to mothers with laboratory evidence of congenital Zika virus infection during pregnancy should receive a comprehensive physical exam with neurologic exam, a postnatal head ultrasound, a standard newborn hearing screening, and Zika virus testing.

A postnatal head ultrasound should be performed on all infants before discharge from the hospital, including those infants with normal prenatal ultrasound findings, because some abnormal findings associated with congenital Zika syndrome might not be readily apparent on prenatal ultrasounds.

Further evaluation depends on whether the infant has findings consistent with congenital Zika syndrome. As a reminder, congenital Zika syndrome is a recently recognized pattern of congenital anomalies associated with Zika virus infection during pregnancy, which includes microcephaly, intracranial calcifications, other brain anomalies, or eye anomalies, among others.

Infants with findings consistent with congenital Zika syndrome require additional initial evaluation and consultation with multiple specialists. A neurologist should be consulted for determination for appropriate neuroimaging and additional evaluation. An infectious disease specialist should be consulted for diagnostic evaluation for other congenital infections such as syphilis, toxoplasmosis, rubella, CMV, and others.

An ophthalmologist should be consulted for a comprehensive eye exam and an evaluation for possible cortical visual impairment prior to discharge from the hospital or within one month of birth. Endocrinology should be consulted for evaluation for hypothalamic or pituitary dysfunction, and clinical genetics should be consulted to evaluate for other causes of microcephaly or other anomalies if present.

In addition to these, consideration should be given to consulting other specialists depending on the infant's needs. An orthopedist, physiatrist, or physical therapist should be consulted for the management of hypertonia, club foot, or arthrogrypotic-like conditions, if present. Pulmonology or otolaryngology could be consulted if there are concerns for aspiration. And lactation specialists, nutrition, gastroenterology, or speech or occupational therapy should be consulted for the management of feeding issues as necessary.

In addition to these consultations, infants with abnormalities consistent with congenital Zika syndrome should have an auditory brainstem response or ABR test prior to discharge to assess hearing. Infants should also have a complete blood count and metabolic panel, including liver function tests. Family and supportive services should be provided.

This evaluation should ideally take place as soon as possible and prior to discharge from the hospital, and may be started prior to the infant's Zika virus testing results.

When testing results return, if the testing results have confirmed or probable congenital Zika virus infection, CDC has further guidance for management and follow up. If the infant testing results are negative, the evaluation for other causes of congenital anomalies should continue and the infant should receive care as medically indicated.

Infants of mothers with laboratory evidence of Zika virus infection without abnormalities consistent with congenital Zika syndrome should also undergo Zika virus testing. Infants with confirmed or probable congenital Zika virus infection should receive newborn care and receive an ABR and ophthalmology exam within one month of birth to assess for hearing loss and eye anomalies.

If the initial newborn hearing screen was performed as only otoacoustic emissions testing the infant should be referred for an ABR before one month of age. If the infant's testing results are negative for congenital Zika virus infection, infants should receive routine care.

As a reminder, healthcare providers should report information on pregnant women with laboratory evidence of Zika virus infection and their infants, regardless of infant testing results, to health departments for inclusion in the U.S. Zika Pregnancy Registry or Puerto Rico Zika Active Pregnancy Surveillance System.

Now to outpatient management. This table can be found in the supplemental material on the CDC website for healthcare providers caring for infants and children with Zika virus infection. And I'll walk through each row now.

Infants with abnormalities consistent with congenital Zika syndrome and laboratory evidence of Zika virus infection require additional follow up as outpatients. Infants with abnormal brain development can be at risk for hypothalamic dysfunction leading to pituitary deficiency, and early manifestations of endocrine dysfunction might not be detected by routine newborn screening.

Thyroid screening including measurement of TSH and either free T4 and or both total and estimated free T4 should be performed at age two weeks and again at age three months. If either of these results is abnormal, further evaluation of pituitary function should be performed by an endocrinologist.

A thorough neurologic exam should be performed at age one and two months by a primary care provider, and then as needed depending on the infant's clinical status. If not already initiated, neurology referrals should occur for any abnormalities, including sleep problems and excessive irritability.

Infants with congenital Zika syndrome should also receive a repeat ophthalmology evaluation at three months of age and repeat ABR at four to six months of age. Infants should receive routine preventive health care including monitoring of feeding, growth, and development. Standardized, validated screening tools such as Ages and Stages should be used to assess the presence of developmental delay at nine months of age as currently recommended by AAP.

Referral to a developmental specialist and early intervention services should occur as soon as possible if needed. Families should receive anticipatory guidance related to congenital Zika syndrome including concerns for development, feeding and growth, sleep, irritability, and seizure recognition. Referrals for abnormal findings should occur as clinically indicated either to a pediatric specialist or a specialist with expertise in the care of children.

Infants with abnormalities consistent with congenital Zika syndrome but negative testing for Zika virus infection should be evaluated for other causes of congenital abnormalities including other infectious or genetic causes and further managed as clinically indicated. Infants with laboratory evidence of Zika virus infection but without abnormalities consistent with congenital Zika syndrome are recommended to have additional monitoring until further information is available regarding outcomes as some sequelae of congenital Zika virus infection such as seizures, cognitive impairment, and vision and hearing abnormalities might be subtle or have delayed onset.

When testing results return as confirmed or probable congenital Zika virus infection, providers should make sure that these infants undergo an ophthalmology exam preferably within one month of birth. Providers will also need to ensure that these infants have had an ABR.

Although later development of hearing loss in infants without other clinical findings has been observed in other congenital infections, the likelihood that an infant with congenital Zika virus infection without clinical findings and with a normal newborn hearing screen will develop hearing loss is unknown. ABR testing of infants at age four to six months can be considered although the risk from possible sedation needs to be taken into account.

Infants who pass an initial ABR and without and ABR at age four to six months should be referred for behavioral audiologic diagnostic testing at age nine months. Behavioral audiologic testing is recommended because of a potential need for sedation with ABR testing in infants. The healthcare provider should closely monitor growth parameters and ensure developmental monitoring is performed by caregivers and healthcare providers in addition to age appropriate development screening at age nine months. Anticipatory guidance provided to caregivers should emphasize developmental milestones, feeding and growth, sleep, irritability, and seizure recognition. Given the current limited information on the subtle or delayed onset effects of congenital Zika virus infection, providers should have a low threshold for further evaluation or referral to specialists for infants with laboratory evidence of congenital Zika virus infection. Referrals for further evaluation or supportive services should be made for any provider or caregiver concerns.

Infants with no abnormalities consistent with congenital Zika syndrome and with negative congenital Zika virus testing should receive routine care, including monitoring of growth parameters, developmental monitoring and age-appropriate developmental screening.

Overall, families and caregivers of infants with Congenital Zika virus Infections will require ongoing psychosocial support. As a critical component of patient care and to facilitate early identification of development delays, families should be empowered to be active participants in their child's monitoring and care. Healthcare providers should work closely with parents to ensure that the care plan is consistent with their infant's needs and family wishes.

A disproportionate burden of Zika virus infection might affect families with already limited access to medical care. These families might face language, cultural, and financial barriers to care. Barriers to care for all affected infants and their families should be addressed to linkage to national, state, and local health program.

Healthcare providers should work closely with state, local, or territorial health departments to assure that the appropriate testing is ordered and interpreted correctly. If questions remain, CDC maintains a 24/7 Zika consultation service for health officials and healthcare providers. To contact this service, call the number listed here and ask for the Zika Pregnancy Hotline or email ZIKAMCH@cdc.gov.

Additional information and resources for both healthcare providers and families can be found on the CDC website.

As a reminder, the latest guidance can be found on the CDC website. The current interim guidance will be updated as more information becomes available. All of this is the work of many people. Many thanks to all of our collaborators and thank you all for listening today.

Dr. Loretta Jackson-Brown: Thank you, presenters, for provider our COCA audience with a wealth of information, we will now open up the lines for the question and answer session. Joining us for the question and answer session is Dr. Ingrid Rabe.

Dr. Rabe is a medical epidemiologist in the Division of Vector-Borne Diseases at CDC. Questions are limited to clinicians who would like information related to Zika virus infection. For those who have media questions, please contact CDC Media Relations at 404/639-3286 or send an email to media@cdc.gov. If you are a patient, please refer your questions to your healthcare provider.

When asking questions, please state your organization and also remember you can submit questions through the webinar system as well. Coordinator?

Coordinator: Thank you, and to ask a question, please press Star 1 at this time please unmute your phone and clearly record your name at the prompt. Please press Star 2 to withdraw your request. Once again, at this time please press Star 1. One moment please for the first question to come through.

Dr. Loretta Jackson-Brown: And while we are waiting for the first question from the phones, presenters, we did have a question come through the webinar. And the question is related to congenital defects in newborn as being a result of being exposed herbicides or pesticides. There's some concern that that is found in other countries and it's not necessarily related to Zika virus itself.

So our participant wants to know if there have been any reports of microcephaly in the mother's being infected with Zika in the United States and who have not had any recent travel to any other country where exposure to teratogenic elements might have occurred. Simply stated, can we definitively say that congenital defects are a direct result of Zika virus?

Dr. Sara Oliver: Thank you for the question, we're lucky to have with us Dr. Rasmussen who actually wrote the New England Journal paper on microcephaly and congenital Zika virus infection so she's going to answer this question.

Dr. Sonja Rasmussen: Thank you, Dr. Oliver. I'm Dr. Ramsmussen, I'm a pediatrician and clinical geneticist at CDC and I thank you for asking that question because I've seen that asked several times previously, especially on the internet and I think we have really strong evidence that Zika virus is the cause of microcephaly and other serious brain defects and as you heard, many other problems as well.

There are a number of pieces of evidence that we use to put together that puzzle to be able to say that Zika virus is the cause of the problems and that included information that Zika virus was actually found in the brain of babies, even Zika virus that was able to be grown later on was found in the brain of babies with Zika virus Infection.

Some of the women that had microcephaly - had babies with microcephaly had only a very short exposure, so they were only in another country for few days, and so they - if it was caused by exposure to an insecticide that would have been a very short exposure versus an infection where you come back and the damage to the baby's brain continues because the woman is infected.

Another thing is that those insecticides have been evaluated carefully, they've been used for many, many years and we haven't seen an increase in microcephaly before and both the World Health Organization and the EPA -- the Environmental Protection Agency -- have both done careful reviews looking for problems with these insecticides and have not found any evidence that they cause microcephaly.

And then finally, our scientific - our basic science colleagues have really provided us with some additional information recently. There've been now several animals models that have shown that if you expose animals, mice, and sometimes even primate models -- nonhuman primate models -- to Zika virus during pregnancy that you can replicate what we are seeing in humans. You can see defects in the baby, so we do feel confident at that. But thank you for asking that question.

Dr. Loretta Jackson-Brown: Thank you Dr. Rasmussen, and that you for joining us for the Q&A session. Coordinator, do we have a question on the phone?

Coordinator: Thank you. Our first question is from Mia Lingafelter. Your line is open.

Mia Lingafelter: Yes, I have a question regarding placental testing. Is that a swab, or a send out of the placenta?

Dr. Sara Oliver: Thank you for the question. ,So it's a pathology test, you send a specimen here and actually included in the MMWR where it talks about this is the link to the pathology form that's required. And that is also on the CDC website as well, so it explains how to get the sample here. It's an actual piece of placenta that is sent here. The PCR test is done on the piece of placenta.

Mia Lingafelter: Thank you.

Dr. Sara Oliver: Thanks.

Dr. Loretta Jackson-Brown: Coordinator?

Coordinator: Thank you. Next question from Hannah Oltine, your line is open.

Hannah Oltine: Hello, my question is related to the guidance on testing for pregnant women, so the past MMWR on recommendations for management of pregnant women talked about evaluation of women who had been exposed, or had onset of disease more than 12 weeks ago and suggested that IgM antibody testing might be considered.

However, in the new MMWR and in this presentation the guidance suggests that diagnostic testing should be performed at delivery. So I'm trying to understand and get further clarification on what testing is recommended at delivery, and why this pregnant woman would not be tested at the earliest point of evaluation.

Dr. Sara Oliver: Thank you for the question. So the hope is that the pregnant woman would be tested as soon as risk was identified. So we certainly wouldn't wait until testing at time of delivery, we would recommend that she's tested as soon as she either returns from a travel or that the risk of exposure was identified.

For mothers where testing was not performed, either the - she didn't have prenatal care, or the exposure was not identified before, those - whether maternal testing is performed or not should be taken within the context of the previously published pregnancy guidance.

And those - there will be individual cases that will have to be discussed, both with the clinician and with the local and state health departments as to what testing would be helpful based on when mom was exposed and when she is showing up for care or for delivery. And if the state or local health departments have further questions then CDC's available to discuss individual cases. So, does that answer your question?

Hannah Oltine: Yes, it just sounds like it might be an update to the previous guidance that said antibody testing might be considered if you're after 12 weeks. It sounds like there is maybe a recommendation to test as soon as a person is identified as being at risk.

Dr. Sara Oliver: Yes, that's the recommendation. Thanks.

Dr. Loretta Jackson-Brown: Presenters, staying in that same lane, we have a question from the Alabama Department of Public Health, and for a pregnant woman who had a positive exposure history to Zika, but who did not have testing and presented to a healthcare provider with a fetal death, and testing is done on the mother, but the testing is negative, is there any additional testing needed for the fetal tissue?

Dr. Sara Oliver: Thank you for the question, so the same place where I had directed previously, where it talks about sending tissue, placental tissue, to CDC, there's additional guidance for sending fetal tissue as well. So, there's - it's within the context of, you know, an individual case, and so we would generally recommend that for a specific situation that we be contacted and then can provide further instructions on what to do in that circumstance. Thank you.

Dr. Loretta Jackson-Brown: Coordinator, do we have additional questions on the phone.

Coordinator: Thank you we do. The question from Dalen Peterson. Your line is open.

Dalen Peterson: Hi yes, after reviewing the initial evaluation and outpatient management flowchart that was released with the MMWR, it talks about head ultrasounds being something that we recommend to providers, that's not something that we had routinely doing, is that something that we should, you know, push forward and ask providers to do?

Dr. Kate Russell: Yes, this is Dr. Russell, and that was new for this guidance and an update on our previous ones. We are now recommending that all infants born to mothers with laboratory evidence of Zika virus infection during pregnancy do receive a head ultrasound. So, all infants with that potential exposure should receive a head ultrasound. In most cases, that should be done prior to discharge from the hospital and will be done prior to infant testing results being available. Thank you.

Dr. Loretta Jackson-Brown: Coordinator, the next question please.

Coordinator: Next question from Maurine Corning. Your line is open.

Maurine Corning: I have two questions. My first one is it known for positive Zika pregnant women the percent of fetuses that contract the virus?

Dr. Sara Oliver: It is not at this time. We're continuing to gather information and as soon as we have more we will share it, but not at this time.

Maurine Corning: Okay. The second question is can a Zika positive pregnant woman be given any medication such as immunoglobulin during her pregnancy?

Dr. Sara Oliver: Not to modify the risk to the fetus for the Zika Virus. So there's nothing that's being recommended at this time. Again, further information will be shared as soon as anything is known.

Maurine Corning: Okay. Also, since we're in close vicinity to New York City area, if we get a pregnant woman coming into the emergency room saying that she wants to be tested because she's in an area that has, you know, certain number of cases in New York City, what do you recommend?

Dr. Sara Oliver: I would recommend that they contact the local health department and discuss the case there and whether they would recommend testing.

Maurine Corning: All right. Thank you very much.

Dr. Loretta Jackson-Brown: Coordinator, do we have another question from the phones?

Coordinator: Thank you. Next question from Mia Pho. Your line is open.

Mia Pho: All right. Thanks for taking the call. I think you may have answered my question, but to just confirm, if a pregnant woman comes to care after the 12 week window of time since her exposure, but hasn't been tested yet, then you recommend maternal diagnostic testing. Is that the same as the 2 to 12 week window testing, i.e. and IgM first and then PCR if that's negative?

Dr. Sara Oliver: The maternal testing outside of that 12 week window might be considered. And so it would be - and again in consultation with the local or state health department, and then CDC can provide further information. But I would refer to the pregnancy guidance that's previously been published.

Mia Pho: Okay.

Dr. Ingrid Rabe: Hi, this is Ingrid, is it alright.

Dr. Loretta Jackson-Brown: Please do.

Dr. Ingrid Rabe: So just to chime with that, and that was to do with (Hannah's) question as well. We do have, kind of, difficulty in terms of interpretation of test results of that time period after 12 weeks, or 12 weeks after last exposure which was the reason for, you know, suggesting that testing could be considered, but with the realization that there are limitations to what that testing can tell because that would be testing by IgM, possibly an PCR as well, and negative IgM, as well as a negative PCR, you know, that may be, that may not rule out, or does not rule out infection when the exposure has been remote.

But as indicated per the guidance that's issued now, if a woman is not, if she presents after 12 weeks is not tested at that point in time, that testing will be required at the time of infant delivery, and I think that the discussions that have been had is about a suggestion that if IgM is going to be waning over time, then you might have a better chance of even catching it that IgM if she would have tested earlier on.

But I think it is important that people are aware of the caveats of that negative test results and what that actually means, that that does not necessarily indicate that the woman was not infected. Thanks.

Mia Pho: Thank you. That makes sense. It's feasible then to test them if they're outside the window of time with the caveat understanding the limitations of the test. When a mother does deliver, you would consider retesting the mother as well as placental and infant testing.

Dr. Ingrid Rabe: Well, if the - you know, if she's been tested maybe late in the pregnancy as well, that probably would be sufficient and that's why the guidance does indicate that if she was not tested during the pregnancy to do that at the time of birth. So that, if the testing was done after the exposure the sufficient time period, then that should suffice and she would not need to be retested at delivery specifically.

But just again, to reiterate that both test results need to be interpreted with caution and I think what we've tried to indicate, and the speakers have repeated alluded to is just that we are strongly encouraging patients to speak with their local and state health departments if these scenarios arrive and certainly we are trying to provide as much assistance as we can from CDC side in terms of discussing those cases as well when the need arises. Thank you.

Dr. Sara Oliver: We would also like to reiterate given the limitations of testing that the previous pregnancy guidance also recommends serial ultrasounds for the pregnancies as well.

Dr. Loretta Jackson-Brown: So, Dr. Oliver and Russell, so staying in that lane of ultrasound, we have a question from the webinar and that's should a woman with evidence of congenital infection on perinatal sonograph deliver at a tertiary care center? And also, essentially the participant wants to know are there any other signs that a baby is symptomatic besides looking for signs of Zika syndrome. Is there anything else they can do besides - I guess thinking the ultrasound?

Dr. Sara Oliver: So as for where the mom should deliver, I think that is a discussion that needs to happen with that mother and her OB in consultation with the hospital that they would deliver at, so we don't have recommendations specifically for where somebody should deliver. It would be a local decision between the mom and her OB.

As for what else should be looked for, for symptomatic from a prior to delivery standpoint, it would be the serial ultrasounds that are recommended in the pregnancy guidance, looking for signs of microcephaly, growth restriction, things that are listed there. After the baby's born, the initial work up that's recommended, the neuro exam, the head ultrasound, the hearing, the eye exam, the evaluation that's previously discussed. Thanks.

Dr. Loretta Jackson-Brown: Wonderful. Thank you for covering that. Coordinator, do we have another question from the phone?

Coordinator: Thank you. Next question from Elizabeth Shipman. Your line is open.

Elizabeth Shipman: Yes, hi. My question is regarding the timeframe that was mentioned in the presentation for when testing should occur. It was stated that testing should happen within two days of birth, but I'm thinking that's not a particularly a feasible timeframe for testing to actually be completed.

So I'm wondering if it's more geared toward when specimens should be collected, if the point is discriminating between prenatal and postnatal, congenital infections, that sort of thing? If it's sufficient that the samples are collected within two days of birth?

Dr. Sara Oliver: Yes, thank you. We meant that the specimens should be collected within the first two days after birth. We're aware that - it's likely - the results won't be back, potentially, before the infant is discharged from the initial hospitalization. But that the samples be collected as close to within the first two days after birth as possible.

Elizabeth Shipman: Okay, perfect. I just wanted to clarify that. Thank you.

Dr. Loretta Jackson-Brown: Coordinator, next question please.

Coordinator: Next question from Tammy Cooper. Your line is open.

Tammy Cooper: Hi, I we are talking specifically about testing and care of infants, but is there a recommendation on the amount of time, post travel, for women interested in, or engaged in fertility treatment?

Dr. Kate Russell: There is information on the CDC website about recommendations for women who have traveled to wait and I believe that timing is eight weeks, however, I would refer you to the CDC website.

Dr. Loretta Jackson-Brown: Coordinator, do we have another question from the phone?

Coordinator: Thank you. Next question from Ellen Lee. Your line is open.

Ellen Lee: Hi, thank you so much for taking my call. I have a few questions, but maybe the first that I'll focus on is could you discuss a bit more the disadvantage or the issues of using cord blood, sample from cord blood for testing infants? Particularly the false-negatives testing.

Dr. Sara Oliver: Thank you. So for - to diagnose all other congenital infections, HIV, syphilis, all other congenital infections, a sample is collected from the infant. So part of the recommendation was just in an attempt to standardize diagnostics of congenital Zika virus infection the way that HIV and other diagnostic tests are done.

There have been case reports of false-positives and false-negatives obtained using cord blood samples for other congenital infections. So that is where the recommendation came from was to best determine what is going on with the infant, we wanted infant samples.

Ellen Lee: Okay. Thank you. Also, your mention about considering the testing of placental tissues in the context of, let's say, a mother whose testing status is unknown for Zika and an infant is delivered, now that seems to be a bit different from previous guidance and I know that usually to submit placental tissues to CDC for testing we need to have an infant with concerning findings or a mother who has already has laboratory evidence of Zika. So is there now a broadening of criteria for accepting placental tissues at CDC for pathology testing?

Dr. Sara Oliver: Okay, so we recommend to accept the placental testing samples here, it's done in consultation with somebody from the epidemiology team here, so the clear samples where - the clear illustrations where people - placentas are accepted is the circumstances where you mentioned.

However, the issues where we listed in the MMWR where mom's testing was either potentially either not performed , performed outside of the window, or was nonspecific, are circumstances that the accepting pathology branch takes into consideration, so it would still need to have a consult with CDC and so it's taken on a case by case basis. But those are circumstances where CDC recognizes placental testing could be helpful.

Ellen Lee: Okay, great. And I guess the last bit is about getting PRNT for infants and so I know you discussed the, sort of, algorithm for evaluating an infant, and the question of doing PRNT seems to be certainly influenced by mom's testing status. It just - so, there was a particular scenario where an infant's testing is PCR negative and IgM negative but that you might consider PRNT at the age of 18 months or older if you have any concerns for that infant.

Now it seems like even though you might be detecting maternal antibodies, that there would be potential role for PRNT earlier than that because if you saw Zika - if you saw (unintelligible) for Zika at an earlier stage, then that might be useful for the clinicians. So, I'm wondering if you might have any comment about that.

Dr. Sara Oliver: Thank you, I'll say something and then let Dr. Rabe state as well. So the problem, if it's a negative, that could be helpful, if it's a positive - done prior to 18 months, if it is a positive, then the issue becomes it would be difficult to distinguish between maternal or infant antibodies. So certainly similar to what's recommended for HIV, if a test is done at 12 months and it's negative it can be helpful, but if it's positive, you likely have to repeat again and so we recommend it at 18 months so we weren't having to potentially do multiple PRNTs on a single infant.

Dr. Ingrid Rabe: Yes, thanks very much and I as always, very thoughtful questions in terms of the practicality of that, and I think there are couple of issues even if the PRNTs are positive for Zika in the infant both may still be reflecting the Zika PRNTs in the mom. And it really not clear from the data that we have whether there's any kind of reliable quantifiable difference in the PRNT profile between infected infants and kind of passively transmitted from the mom.

So, that does make it very difficult to evaluate an infant's PRNT findings. There are, obviously, a lot studies in progress at the moment together with collaborators in other countries that are releasing a (unintelligible) of disease and we are trying to get a better handle of the laboratory performance characteristics, but at the moment it would be - it's just very difficult to pass off in terms of what you make of those infant PRNTs when they're likely a reflection of what's going on with mom at the time.

So, you know, those data that are generated may change the approach over time, but that's kind of the level of where we are right now and how much we can interpret from those findings. So, maybe there's most benefit as mentioned a negative result, but a positive result we don't have enough right now to be able to make a call based on that as to whether the congenital infection actually occurred in that interim period.

Dr. Loretta Jackson-Brown: Thank you, Dr. Rabe. Coordinator, we have time for one more question.

Coordinator: Lucy Marques, your line is open.

Lucy Marques: Hi, thanks for taking the call. I am struggling a little bit with the practicality of even the specimen collection at two days, just as a PEID specialist we've already seen patients come up from outlying hospitals that weren't tested at delivery, and that have come in for evaluation and it's like, I just was hoping that you could further elaborate a little bit more on the downfalls of not collecting the specimens in that two day window.

Particularly if you are talking about a population that resides in an area where there's no ongoing active transmission, you know, if you are testing, say at a two week period, or even in the neonatal period, what are the downfalls compared to that two day period?

Dr. Sara Oliver: Thanks, so the recommendation was two days after birth if possible, so, recognizing that it ideal, obviously there will be situations where that potentially isn't done, certainly if the baby's not stable enough in the first two days, or if they were in a location where it couldn't be obtained for some reason, there - the further out you go from birth as the last information we have regarding what a positive or negative test would be, that's why the recommendation as made.

However, especially there is some concern that if there were concerns for breast milk transmission, further testing wouldn't be able to distinguish between a congenital versus kind of a postnatally acquired, from that circumstance. However, it's - we understand that there might be circumstances where testing should be - or would be performed later.

I would like to say that given the concern for potential, even with the theoretical concern for breast milk transmission, we are still recommending that mom's be given the opportunity to breast feed, we are just saying that's a situation that could provide an additional area that might make the testing performed after the first two days of life slightly more difficult to interpret.

Dr. Ingrid Rabe: This is Ingrid, and just one other thing to add is that especially for the serologic evaluation we do also have to take into account other flavivirus activity in an area, so, you know, it's not clear at this stage how much cross activity there might be with West Nile virus for example, but if there were West Nile circulating in an area, within the month after birth, or weeks after birth even, there is the possibility for neonatal infection and that may also obscure the findings, so that's one additional consideration that we have in that as well. And again, kind of encouraging that we do our specimen collection if at all possible.

Dr. Loretta Jackson-Brown: On behalf of COCA, I would like to thank everyone for joining us today with a special thank you to our presenters Dr. Oliver and Dr. Russell, and to Dr. Rabe and Dr. Rasmussen.

The recording of this call and the transcript will be posted on our COCA webpage at emergency.cdc.gov/coca within the next few days. All continuing education for COCA calls are issued online through TCE online. The CDC training and continuing education online system at www.cdc.gov/tceonline.

Those who participated in today's COCA call and would like to receive continuing education just complete the online evaluation by September 22, 2016. Use (unintelligible) code WC2286.

Those who will review the call on demand and would like to receive continuing education should complete the online evaluation between September 23, 2016 and August 22, 2018 using (unintelligible) code WD 2286.

To receive information on upcoming COCA subscribe to COCA by going to the COCA webpage at emergency.cdc.gov/coca and clicking on the Join the COCA Mailing List.

Also, CDC launched a Facebook page for clinicians, like our page at facebook.com/cdc clinician outreach and communication activity to stay connected and get the latest updates on clinical news from CDC. Thank you, again, for being a part of today's COCA call. Have a great day.

Coordinator: Thank you for attending today's presentation. This does conclude the conference, you may disconnect at this time.

END