Transcript for CDC Telebriefing: Zika

Press Briefing Transcript

Tuesday, February 26, 2016 at 1:30 pm E.T.

Please Note:This transcript is not edited and may contain errors.

OPERATOR: Welcome and thank you for standing by.  All participants will be in a listen mode only.  This conference is being recorded.  We’ll be conducting a question and answer session today.  If you would like to ask a question press star then 1. I would now like to turn the conference over to Kathy Harben with the CDC Office of Communication.  Thank you, you may begin. 

KATHY HARBEN: Thank you, Karen. Thank you all for joining us for an update on the Zika virus outbreak. With us today are the director of CDC Dr. Tom Frieden as well as Dr. Denise J. Jamieson, Dr. Paul Mead. And Dr. Julie Villanueva.  We are also joined by Dr. Luciana Borio and she’s with us from FDA, and now I’ll turn the call over to Dr. Frieden for opening remarks. 

TOM FRIEDEN: Good afternoon.  Today it’s been six weeks to the day from CDC’s first announcement and travel briefing about Zika.  In these past six weeks we’ve done a lot and we’ve learned a lot about this unprecedented situation.  In fact, we’re literally learning more about Zika every day.  In this briefing we have a lot of information to cover so please bear with us.  We’re going to outline new findings and developments.  For the American public, the bottom line hasn’t changed from the time of our initial announcement.  If you’re pregnant, avoid travel to a place where Zika is spreading.  If you’re in a place such as Puerto Rico where Zika is spreading, do everything you can to avoid mosquito bites and also avoid risk of sexual transmission of Zika. The most serious risk in this outbreak is to pregnant women and to the developing fetus. 

In these past 6 weeks there has been  two anticipated developments and one unanticipated development.  First, we anticipated that there would be continued rapid spread of the Zika virus in places where the mosquito species that spread it lives, including Puerto Rico and, in fact, that’s what we’ve seen.  Second, we anticipated that there would be many, possibly hundreds or even thousands of American travelers returning from Zika affected areas and this too is what we’re seeing.  We did not, however, anticipate that we would see this many sexually transmitted cases of Zika.  When sexual transmission in the current outbreak was first documented, we issued guidance indicating that men who live in or who have returned from a Zika affected area use a condom if they have sex with a woman who is pregnant.  Today’s report underscores the importance of that recommendation. 

As of today, 147 cases have been reported to CDC. Of these, 107 are travel related cases in 24 states and the District of Columbia.  The other 40 are mostly locally acquired infections in U.S.  Territories.  Puerto Rico is by far the most affected area.  It makes the numbers a little confusing but I would like to indicate that today after closure of the CDC number that I just mentioned for the whole country including Puerto Rico from this past week, Puerto Rico posted their latest information which indicates that they have so far 117 known diagnosed cases.  CDC’s response and that of other parts of the federal government as well as other countries is extensive.  Today’s briefing covers just a few aspects of this. 

One critical aspect is increasing access to diagnosis of infection with the virus.  There are fundamentally two different types of tests for Zika.  One tests for active infection.  Another tests for infection at least a week and up to several months after that infection.  The CDC laboratory has developed tests for both of these and is rolling them out to laboratories in the CDC laboratory response network or LRN over the next several weeks.  The tests for active infection can already be performed by more than 20 laboratories around the U.S. using CDC materials.  These labs cover most of the returning at risk travelers and returning travelers in other parts of the country can have their specimens sent to CDC.  We’ll hear more about testing shortly but first we’ll hear from Dr. Denise Jamieson about today’s MMWR article, Zika virus infection among U.S. pregnant travelers August 2015 to February 2016.  This is important information and even though the numbers are small, they are of considerable interest.  We understand that the occurrence of fetal malformation, fetal loss, miscarriage, or a child with a birth defect is something that can be devastating to a family.  That’s why we’re working so hard to understand more what’s happening and how it can be prevented.  Dr. Jamieson? 

DENISE JAMIESON: thank you, Dr. Frieden.  Good afternoon. After reports of microcephaly and other adverse pregnancy outcomes in women with Zika virus infection, CDC issued a travel alert on January 15th, 2016.  This advisory recommended that pregnant women consider postponing travel to areas with ongoing Zika virus transmission.  Shortly thereafter on January 19th, CDC released guidelines for U.S. health care providers who care for pregnant women who traveled to an affected area.  We updated those guidelines on February 5th to include women residing in those areas with local Zika virus transmission and expanded our recommendations to offer testing to asymptomatic women with possible Zika virus exposure.  As of February 17th, 2016, nine U.S. pregnant travelers with Zika virus infection had been reported to CDC.  Among these women, there were no Zika virus related hospitalizations or deaths.  Among the six women with Zika virus disease who experienced symptoms during the first trimester, two women experienced spontaneous pregnancy losses, two women chose to undergo elective pregnancy termination, one women delivered an infant with microcephaly, and one pregnancy is continuing without complications.  Two women with Zika virus disease were exposed during the second trimester of pregnancy.  One delivered an apparently healthy infant and the other pregnancy is continuing.  The one confirmed case of Zika virus disease in a woman who was exposed during the third trimester of pregnancy resulted in the delivery of a healthy infant.  All of the confirmed cases were among U.S. women who had traveled to areas with local Zika virus transmission, including American Samoa, Brazil, El Salvador, Guatemala, Haiti, Honduras, Mexico, Puerto Rico and Samoa.  To better understand the effects of Zika virus during pregnancy, CDC has established the U.S. pregnancy registry for Zika virus infection.  This registry will provide information about the effects of Zika virus on pregnant women and their children.  Information about the registry will soon be available on the CDC website. In addition, CDC maintains a 24/7 consultation service for health  officials and health care providers caring for pregnant women with possible Zika virus infection. To contact the service call 1-800-CDC-info or e-mail ZikaMCH Now Dr. Paul Mead will share the latest information about what we know about sexual transmission. 

DR. PAUL MEAD: Thank you, Dr. Jamieson.  Good afternoon. Today we released a report in the MMWR about transmission of Zika virus through sexual contact with travelers to areas of active transmission.  After we published CDC’s interim guidance to help prevent sexual transmission of Zika virus on February 5th, 2016, we and state health departments have received new reports of additional instances of possible sexual transmission of Zika virus. During February 6th through 22nd, 2016, roughly the two weeks after our recommendation, we received numerous reports of possible sexual transmission of Zika virus from multiple states. In conjunction with state and local health doctors, nurses, laboratory experts and disease control specialists, we are investigating each of these reports. These investigations take time, not only to interview the patients for detailed information, but also to obtain laboratory samples and test them for Zika.  The test that is most able to confirm the diagnosis of Zika requires actual growth of the virus in the laboratory, something which takes about a week.  At this point we’re reporting on the six most advanced investigations.  Two laboratory confirmed cases and four probable cases of Zika virus disease in women who had not traveled themselves and whose only known risk factor was sexual contact with a symptomatic male partner who had recently traveled to an area with ongoing Zika transmission.  All six confirmed or probable cases occurred in women, including some who were pregnant.  Median patient age was 22 years.  In all cases where the type of sexual contact was documented, the contact included vaginal intercourse without a condom and occurred when the male partner was symptomatic or shortly after symptoms resolved. 

Please note that we are not releasing details of pregnancy status, age, state of residence of these patients out of respect for patient privacy and confidentiality and we trust you in the media will also respect patient privacy.  While these investigations are being completed, CDC encourages state and local public health departments, clinicians and the public to be aware of and to follow our recommendations for preventing sexual transmission of Zika virus. This is particularly important for men who have pregnant partners or for pregnant women. 

These recommendations advise pregnant women who have partners who live in or who have traveled to Zika affected areas to discuss the male partner’s potential exposure and any history of Zika like illness with their health care provider. Providers should consult CDC’s guidelines for evaluation and testing of pregnant women which are available on CDC’s webpage.  Men who reside in or have traveled to an area of active Zika virus transmission and who have a pregnant sex partner should use a condom during sex the right way, every time, or consider not having sex during the partner’s pregnancy.  Using latex condoms the right way every time reduces the risk of sexual transmission of many infections and including those caused by other viruses.  Of note, all the women who were confirmed or likely to have transmitted Zika in our investigations – excuse me, all the men who were confirmed and likely to have transmitted Zika in our investigations so far have done so when they were ill or shortly after their illness resolved.  This does not mean that transmission later on is impossible.  It may be that we simply haven’t seen this yet because spread of Zika is relatively recent.  Studies to determine how long Zika remains in semen after illness are not completed and will likely take months to complete.  These investigations are preliminary.   CDC will update its guidance as more information becomes available. 

DR. FRIEDEN: Thank you Dr. Jamieson and Dr. Mead.  And now Dr. Julie Villanueva will provide information on the diagnostic test. 

DR. JULIE VILLANUEVA: The CDC Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay (Zika MAC-ELISA) can detect proteins called antibodies that the human body makes to fight a Zika virus infection.  These antibodies in this case, immunoglobulin M or IgM, appear in the blood in a person affected with Zika virus beginning as early as four days after the start of illness and can last for several weeks.  The Zika MAC-ELISA can help determine whether a person may have been recently infected with Zika virus.  This new test will be available in qualified U.S. public health laboratories through the LRN.  The CDC was able to make the test available quickly because we worked very closely with our colleagues at the Food and Drug Administration using a special expedited process to authorize its use called an emergency use authorization or EUA. An EUA is a tool that FDA can use to allow the use of certain medical products for emergencies based on scientific data.  The U.S. secretary of Health and Human Services has declared that circumstances exist to allow the emergency use of authorized diagnostic tests for Zika virus infections such as the CDC Zika MAC-ELISA.  We’re fortunate enough to have Dr. Borio from the FDA on the phone today to be available to answer any other questions you may have about the emergency use authorization process.  Dr. Frieden? 

DR. FRIEDEN: thank you very much.  And I want to particularly thank Secretary Burwell of HHS and FDA and our own lab team for having worked so hard to make this lab test available.  This is a test that has been developed over years in the CDC laboratory and over a question of just weeks we’ve been able to scale up production, with the support of the Secretary, Secretary Burwell and the FDA, get through regulatory approvals and we’re rolling this test out to laboratories throughout the United States.  It will take time before it’s widely available, and we’ve completed all of the quality assurance checks with all of the laboratories that are doing it but it’s an encouraging step forward.  Before we take questions I would like to just spend a moment summarizing what we know now, what we don’t know, and what we’re doing.  We know that Zika is spreading widely in parts of the world where the particular mosquito species is present and we know it’s associated with a potentially devastating fetal malformation, microcephaly.  We know while at least while men are symptomatic they can spread Zika to their sexual partners. We know that Zika and microcephaly are associated although we do not yet have definitive proof that Zika infection alone is the cause of microcephaly.  Although the evidence for this is getting stronger by the day.  We know that Guillain-Barré Syndrome is very likely triggered by Zika in a small proportion of infections as it is after a variety of other infections and we know that, unfortunately, the mosquitos that spread Zika are very hard to get rid of.

 The key is reducing the risk to pregnant women.  That means reducing travel of pregnant women to areas where Zika is spreading.  That means reducing the risk of sexual transmission of Zika.  And that means trying to reduce the mosquito population in areas where Zika is spreading and this last is the hardest.  Because the particular mosquito that spreads Zika has been referred to as the cockroach of mosquitos.  It lives indoors in dark places, hard to get rid of and efforts to do so have often been frustrated by the sheer numbers of the mosquito and the difficulty in getting rid of it.  There are also many things we wish we knew and are working hard to find out.  We don’t know for sure that Zika infection causes microcephaly and if it does whether there are co-factors that make it more likely to do so.  We don’t know whether there’s any phase of pregnancy in which infection is at lower or no risk for the fetus.  We don’t know if infants born without microcephaly will have any other health problems and unfortunately this is something we may not know for many years.  We don’t know if the prior findings that 80% of infections are asymptomatic will hold true in this outbreak.  CDC’s commitment to protecting Americans from health threats is absolute.  It’s why we’re here.  It’s what makes the thousands of doctors, lab experts, disease control experts and other scientists come to work every day.  In Atlanta and throughout the U.S. including in Puerto Rico and the other affected U.S.  Territories, more than 600 CDC staff are working to continue to learn more and do more to protect people.  CDC is one part of the U.S.  Government’s overall response to Zika.  Our friends at NIH are working hard on vaccines.  FDA is doing tremendous work to get approvals quickly for diagnostic tests and other urgent tools. The President has asked Congress for $1.9 billion in emergency funding to enable us to further prepare for and respond to the Zika virus outbreak both domestically and internationally.  Of this $828 million is intended for use by the CDC to allow us to do more, including increasing lab capacities throughout the country.  Establishing rapid response teams to limit potential clusters of cases in the U.S.  Expanding monitoring systems so we can track what’s happening including Guillain-Barré syndrome, birth defects in the U.S. and our territories.  Increasing research and the link between Zika, microcephaly and other health outcomes.  Providing targeted information for people who need it most including pregnant women and health care providers and most importantly figuring out ways to reduce the risk of Zika.  We’re continuing to inform people about Zika and to learn more about the links between Zika and health outcomes.  CDC has deployed 25 staff to assist in Puerto Rico in addition to the 50 staff who work there year round in our dengue branch.

 They are providing support including investigation and monitoring for other Zika cases, assessing local mosquito populations for their susceptibility or resistance to different insecticides, and helping with mosquito control efforts.  There is the potential for hundreds of thousands of Zika cases in Puerto Rico and potentially, tragically, effected pregnancies as well.  CDC is helping local teams in any way we can.  We’re also working closely with public health teams in Brazil, tracking the spread of Zika virus and studying the links between Zika and microcephaly and other adverse birth outcomes.  An HHS delegation just returned from Brazil and another team of CDC experts is working in close partnership with Brazil on research and evaluation. Team members in Colombia are working to develop a detailed study of pregnant women who have been infected by the Zika virus.  This will be a very  important way for us to learn more over time.  In addition, we’re continuing work to help prevent Zika infection in places with ongoing transmission.  Because there’s no vaccine to prevent Zika the best way to prevent it is to protect yourself and your family from mosquito bites and sexual transmission.  That’s particularly relevant in terms of mosquitos bites only in areas where Zika is spreading and in the U.S. that’s currently only Puerto Rico, American Samoa and U.S. Virgin Islands as far as information available to date.  This is a challenge for some people right now and for that reason CDC has worked with the CDC Foundation to develop Zika prevention kits or ZPKs.  The ZPKs inform women about the Zika virus, its risks and how to avoid infection.  The kits provide pregnant women with an initial supply of prevention tools. The kits are not intended to take them through the entire pregnancy.  Kits contain educational materials, mosquito repellents, condoms, a thermometer, tablets that can be put into standing water, that is water that can’t be eliminated and prevent mosquitos from multiplying.  Kits are being provided at no cost to women who need them in Puerto Rico, American Samoa, and US Virgin Islands. We’ll be rolling out the distribution of these kits over the next several weeks.  And they will help women in areas of local Zika transmission learn more and do more to protect themselves and their pregnancy. 

KATHY HARBEN: thank you very much, Dr.  Frieden and our other speakers.  Karen, we’re now ready for questions. 

OPERATOR: Thank you.  At this time we’ll start the question and answer session. If you want to ask a question please press star then 1. Our first question comes from STAT News. 

KAREN WEINTRAUB: I was wondering is there a line, a moment when we can say yes Zika does cause microcephaly or Guillain-Barré, something you’re looking for or waiting for to make that decision? 

TOM FRIEDEN: Well, let’s take them separately.  In both cases we have additional studies under way. In terms of Guillain-Barré we may be learning more in the coming days and weeks.  Microcephaly is more complicated because the question isn’t only is there an association, there’s clearly an association.  The question is also is it absolutely causal and are there any co-factors.  What point in the pregnancy is the highest risk period?  Whether obviously affected children have any health effects.  So there’s a lot more we still will be learning over the coming days, weeks and months, and some of it will simply take time.  For example, as women who are exposed more recently deliver infants, we may tragically find out that microcephaly is present in some of those infants. 

KAREN WEINTRAUB: and Guillain-Barré, is there something that specifically you need to know in order to declare that causal? 

TOM FRIEDEN: there are studies under way including one we did with Brazil and when the laboratory work from that comes back, we may have more definitive information.  But i would emphasize it’s really important to think of these two conditions differently.  Guillain-Barré is something that we see after many different infections, including West Nile virus which is related to Zika. So we would not be the least bit surprised if Guillain-Barré is definitely associated with Zika and given the time course of clusters of Guillain-Barré after peak Zika virus infection I think most epidemiologists who have looked at it would say it’s certainly related.  In the case of microcephaly it’s much more complicated.  This is an extraordinarily unusual occurrence. It has been more than 50 years since a pathogen causing microcephaly or other serious birth defects has been identified.  And, in fact, we’re not aware of any previous documentation of a mosquito borne cause of an infection that can cause a severe birth defect such as microcephaly.  So I think things do develop over time and part of science is uncovering information step by step and trying to be sure to not overstate what the data shows, but also as soon as we have information as we’re doing today to share that openly with the public. 


OPERATOR: Yes, sir. Our next question comes from Maggie Fox of NBC News.  ma’am, your line is open. 

MAGGIE FOX: thanks very much.  We’re very confused about some of the numbers here.  Can we go through some of the cases that we have already known about and reported on and what are new among the nine pregnancies that you’re reporting on?  For instance, I believe the one case the baby born with severe microcephaly must be referring to the case in Hawaii, and a couple of the miscarriages is this linked to Zika. 

DR. DENISE JAMIESON: In our report out today we’re not linking any of the cases to specific states.  We’re just reporting that there were nine pregnant travelers with Zika infection and then reporting on those cases by trimester.  So, I don’t think I can comment on the states where the pregnant women are from. 

MAGGIE FOX:  you can understand why we might be confused and where the numbers start to get conflated. For purpose of clarity can we say one case delivered is one we knew about and that the cases that were either aborted or miscarried has been described before? 

DR. DENISE JAMIESON:  Perhaps the confusion is this the first time we reported on U.S. pregnant travelers.  The prior cases that CDC reported on were in Brazil. 

MAGGIE FOX:   Thank you. 

OPERATOR: our next question comes from Mike Stobbe from the associated press.  Your line is open. 

MIKE STOBBE: Okay.  Thanks for taking the call.  I share Maggie’s confusion and desire for clarity but let me ask.  Of the nine pregnant women, were all U.S. citizens and then i also have a question about the tests.  Are you all saying that these this now is going to be available in commercial labs and what are the rates of false positives and false negatives for this test? 

TOM FRIEDEN: All right.  That was a few questions.  Let me first clarify the previous answer.  So, to Maggie Fox’s question.  A previous MMWR reported on two early infant deaths, infants who died in the first 24 hours of life with severe microcephaly and on two miscarriages.  That was a prior MMWR.  All four of those were in Brazil, in Brazilian women.  None of those four are reported in today’s set of nine.  CDC has not previously reported any of the nine; some may have been in news media in various places. The diagnostic tests are currently going to be made available through the Laboratory Response Network. We are in conversation with several commercial entities about providing a non-exclusive license agreement to them to develop the test and we are open to providing materials and information and technology transfer to other parts of the private-sector but our first priority is to make sure that public health departments throughout the United States have access to the test. I’ll ask Dr. Villanueva to say anything more about the distribution of the virus as well as false positives and false negatives. 

DR. JULIE VILLANUEVA: Thank you. So with any diagnostic assay there’s a risk of a false positive and a false negative.  When the FDA does post our instructions for use on their website you’ll be able to look at the performance characteristics of this test.  If you have a positive result with the Zika MAC-ELIZA test, it’s likely you were recently infected with Zika virus but there is a chance the test can give a false positive result that is incorrect.  This is because there are very — there are other very closely related flaviviruses such as dengue virus that can cause a positive result.  So those positive specimens will be sent to CDC or a laboratory designated by CDC for further confirmation. 

TOM FRIEDEN: Thank you. Next question. 

OPERATOR: Thank you. Our next question is coming from Betsy McKay of the Wall Street Journal. Your line is open. 

BETSY MCKAY: Thanks.  Just to clarify, I’m following up on Maggie and Mike, Dr.  Frieden I think what you were saying is this is the first time that CDC has reported on any pregnant travelers, right?  All of the nine include all cases that have been reported to CDC whether they were reported in the media elsewhere first. 

TOM FRIEDEN: correct. 

BETSY MCKAY:  Okay. Good. Thank you. Then I just wanted to ask a couple of questions or two about the pregnant, the cases. Could you maybe Dr. Jamieson describe for us where Zika was found in the cases, in the pregnancies of patients a and b. In other words was it an amniotic fluid or placenta or elsewhere, you said it was in products of conception, i think and then lastly is CDC looking into the possibility that previous infection with dengue might be a factor for these women who also had Zika and have had babies born with microcephaly?  Thanks. Sorry, lots of questions. 

DR. DENISE JAMIESON:  So, in the early spontaneous abortion or early fetal loss the product of conception were positive by PCR and immunohistochemistry.  In the infant case, the placenta was positive by PCR and immunohistochemistry. 

BETSY MCKAY:   But what is products of conception.  Can you describe what that means for us? 

DR. DENISE JAMIESON: Well early in gestation its sometimes hard to differentiate what the different products are.  In some cases the fetus hasn’t even begun developing.  So just in general the products from the conception were positive by PCR and immunohistochemistry.  But we’re not specifically stating which part of that early pregnancy loss was positive. 

TOM FRIEDEN: does that answer your question? 

TOM FRIEDEN:  Next question. 

OPERATOR: our next question comes from Sabrina Tavernise of the “New York Times.”  Your line is open. 

SABRINA TAVERNISE: Hi, everybody.  Thank you.  In plain English how would one render that product? 

TOM FRIEDEN:  Let’s just be clear here.  There are now a series of miscarriages among women who have been infected with Zika.  As we did report earlier in the patients from Brazil, our laboratory identified Zika in the placental tissues there.  So that’s suggestive that Zika may have caused the miscarriage but it’s important to note that I believe 10% to 20% of all pregnancies may end in a spontaneous miscarriage.  The fact that it’s present doesn’t necessarily mean it is what caused them.  However its presence in the placenta is certainly suggestive that it may have.   

SABRINA TAVERNISE:  Do we know why terminated? 

DR. DENISE JAMIESON:  We don’t have information about how that personal decision was made.  However, there were brain abnormalities noted on ultrasound and on MRI in the case of termination. 

OPERATOR:  thank you.  Our next question comes from Dan Childs of ABC news. 

DAN CHILDS: this addresses something we heard often about this virus that infection is only present in terms of symptoms in 20% of people, up to four out of five people affected may be asymptomatic.  Do you intend to study if asymptomatic men can pass the infection and likewise if asymptomatic women could still give birth to a child with microcephaly?  Considering this could account for so many infections out there.

TOM FRIEDEN: We wish we knew the answer to those questions and we’re studying that.  It’s quite difficult to study because you then have to test a large number of people without symptoms to identify the moment when infection may be present. So, yes, those are very important questions. Yes we’re investigating them. But no we don’t have answers as of today and it may take some time before we have answers. 

DAN CHILDS:  Just one quick follow-up. 

TOM FRIEDEN:  No one is more impatient than we are to get answers to these questions. 

DAN CHILDS:   How would such a study be conducted hypothetically? 

TOM FRIEDEN: For example, what we have done with chikungunya in Puerto Rico is to get blood from people who are donating blood and tested for the chikungunya virus and that’s how we determine that it spread extremely quickly in Puerto Rico. That within just eight or nine months about a quarter of the adult population have become infected with the chikungunya virus. And if you combine that with asking about symptoms that you can then know how much asymptomatic infection there is since you would have screened out those with symptoms or would have a record of it. For the issue of asymptomatic women having a potential risk of transfer to fetus, the studies we’re doing in Colombia have a good chance of identifying that since we have women whom of a definitive infection with Zika.  The problem is they are all asymptomatic.  Dr. Jamieson you want to say anything more? 

DR. DENISE JAMIESON: That’s right.  You have to enroll a cohort of pregnant women who were not symptomatic and follow them throughout their pregnancy and maybe test them every month to find those who are infected and may not have symptoms. 

TOM FRIEDEN:  The further complexity, just to give you a sense of the challenges that our teams are working with is that in the areas where Zika spread, dengue and chikungunya is also present and there’s a lot of cross reactivity even with the best tests in the world that may make it difficult to differentiate one infection from the other. These are very challenging studies to do and something that we continue to work hard on. 

OPERATOR: Thank you. 

OPERATOR:  Our next question comes from Brady Dennis of “the Washington post.”  Your line is open. 

BRADY DENNIS: Hi.  Thank you guys for holding the call today.  I’m sorry if i missed but i heard an earlier question asked about whether the nine pregnant women with Zika were all U.S.  Citizens or not and if there was an answer i missed it so I just wanted to ask again.  Also I’m curious if you can talk a little bit about given the worries of pregnant women in this situation what we know and don’t know about how early in pregnancy you might be able to detect brain abnormalities and other problems.  What are we learning about that?  Thank you. 

DR. DENISE JAMIESON: Regarding the nine pregnant women they were all U.S. travelers.  So I can’t comment on their citizenship but they were all women who reside in the U.S. and traveled to a place with ongoing Zika virus transmission. 

BRADY DENNIS: Its okay to say they are all U.S. residents, essentially. 

DR. DENISE JAMIESON: that’s true. 

BRADY DENNIS They all live here. Got it. 

DR. DENISE JAMIESON: In terms of how soon we can detect these abnormalities, in terms of microcephaly, microcephaly can be hard to detect on ultrasound early on so its possible to see abnormalities at 18-20 weeks of gestation — but it’s not very reliable for picking up these abnormalities early on.  The later in pregnancy, the easier it is to see the abnormalities of the skull and brain.  However, it’s not clear whether these abnormalities developed later on and that’s why you don’t see them at 18 to 20 weeks for example when many women receive a routine screening ultrasound or whether we’re just not very good at picking them up earlier on.  So there’s still a lot we don’t know about when Zika has an effect and when we can first detect these effects and we are studying these issues. 

BRADY DENNIS: I’m sorry.  That was Denise? 


BRADY DENNIS thanks so much. 

OPERATOR: Thank you.  Our next question comes from Amy Birnbaum of CBS News.  Your line is open. 

AMY BIRNBAUM: To clarify a couple of things.  You note brain abnormality were noted on the ultrasound and it was terminated.  The case report just as one.  That’s one question.  Then I also wanted to ask about sexual transmission.  You mentioned a few cases of sexual transmission for women who are pregnant.  Did you give a number?  And then finally i want to ask the FDA about progress on a test for the blood supply. Thank you very much. 

DR. DENISE JAMIESON: To the first question regarding terminations, we only reported the results for one of the terminations that, again, had the brain abnormalities on ultrasound and MRI.  No additional details about the other termination. 

TOM FRIEDEN: We’re about 45 minutes into this call and I believe FDA had to drop-off the call. 


TOM FRIEDEN: So I’ll refer you to their office for further questions. 

AMY BIRNBAUM Thank you.  And then if you can just clarify the sexual transmission and pregnancy. 

DR. PAUL MEAD:  I assume you’re referring to the number of cases.  Several of the patients were pregnant however we’re not releasing the details of those again out of respect for patient confidentiality. 

AMY BIRNBAUM okay.  Thank you. 

OPERATOR: thank you.  Our next question comes from Maryn McKenna of National Geographic. Your line is open. 

MARYN MCKENNA: This is another request for a little more clarity in the numbers, please.  so in the discussion of pregnancies you have nine lab confirmed pregnancies among travelers, you have ten additional reports of pregnancies you’re following up on and you also have — we have a separate set of cases of confirmed or probable sexual transmission.  Did those two sets of patients overlap?  In other words are some of those pregnancies that you are investigating cases of sexual transmission? 

DR. DENISE JAMIESON: No, because the first — the case series of pregnant women are just travelers.  Women who traveled and were exposed in those countries or areas with ongoing Zika virus transmission.  So they do not include pregnant women who may have been  exposed sexually.  They are not overlapping. 

MARYN MCKENNA:  That includes the time you’re following up because you said ten pregnant women not ten travelers. 

DR. DENISE JAMIESON: That’s correct. 

MARYN MCKENNA:  okay.  All right.  Thank you very much. 

OPERATOR:  Thank you.  Our next question comes from Robert Lowes, from MedScape Medical News.  Sir your line is open. 

ROBERT LOWES thanks for take my call. I see a news report that the Oregon health authority says Oregon has its first case of the Zika virus that was spread by sexual transmission.  Is this occasion part of what has been reported today or is this an additional case? 

DR. PAUL MEAD:  Yeah.  Again, this is Paul Mead.  I need to refer you to Oregon for that information.  I think our approach here is to respect the states that have asked us to keep that sort of information private for now.  Thank you. 

OPERATOR: Thank you. Our next question comes from Lynn Peterson. Your line is open. 

LYNN PETERSON thank you.  So given that the Brazilians apparently markedly undercounted microcephaly before 2015, how much does the current observed rate of cases exceed the expected number because I think there are cases of microcephaly without Zika and so given the birth rate and the known rates of microcephaly elsewhere, is the number really excessive?  And what about here in the U.S.  As well. 

DR. DENISE JAMIESON: The numbers here are small in the United States, so we do have good baseline data here for the rate of microcephaly. And microcephaly does occur for lots of different reasons.  But we did not expect to see these brain abnormalities in this small case series of U.S. pregnant travelers.  It is unexpected and greater than we would have expected. 

TOM FRIEDEN: Thank you.  We’ll take one more question. 

OPERATOR: Thank you.  Our next question comes from Dan Vergano of Buzzfeed news.  Your line southern plains. 

Dan Vergano thanks, folks.  I was wondering can you do a little more to put that in perspective.  If we report to people that you had nine pregnant travelers, and two miscarriages, two terminations with brain abnormalities, a case of microcephaly on delivery, that’s like five out of nine.  Should people take that as the rate of problems after a Zika infection in pregnancy if not tell us and put it in perspective. 

TOM FRIEDEN: No. We just don’t know.  It’s too soon to say.  We’re providing information as it becomes available and there is important information in this case series.  For example, if you look at the numbers of women known to have been infected in the first trimester of pregnancy, two had miscarriages and one had a child with microcephaly, and one has an ongoing pregnancy and two had voluntary termination of pregnancy.  So the first trimester we expect from rubella a parallel experience might be a period of higher risk but what proportion of all women infected develop, have their fetus develop a problem — that can only to be done with large scale studies such as those that we have teams on the ground doing today in both Brazil and Colombia. 

TOM FRIEDEN So Ii want to first thank everyone for participating in this briefing and i want to recap and mention a couple of the really key issues.  I want to close by come back to the bottom line.  For most people in the U.S. the bottom line is that pregnant women should postpone travel to Zika affected areas.  As we get more reports of confirmed sexual transmission of the Zika virus we strongly encourage pregnant women and their male partner who has traveled to or lives in an area where Zika is spreading to use protection with condoms if they have sex.  Third, pregnant women who themselves have traveled to an area where Zika has been spreading should and can now be tested for the virus between two and 12 weeks after return.  We continue to learn more about Zika every day.  And we’re developing new tools to help diagnose it.  There’s something that everyone can do.  Pregnant women can defer travel or if they live in a Zika affected area do their best to avoid mosquito bites.  Communities can reduce mosquito populations by mosquito control and investing in effective mosquito control strategies.  We at CDC and throughout HHS and the rest of the federal government are working 24/7 to scale up testing for Zika, track the virus, implement the best ways we have today to protect people and figure out better ways to kill mosquitos, and prevent Zika.  We are committed to telling people what we know, when we know it and as always when we learn more we’ll share it.  So Americans can decide best how to protect their own health.  Thank you very much. 

KATHY HARBEN: Thank you to all of our speakers and to Karen our operator.  This concludes our telebriefing.  A transcript of this call will be posted to the CDC newsroom as soon as possible.  If you need additional information or have other questions, please call the CDC press office at 404-639-3286, or e-mail us at  You can also find information in the two MMWR articles that were published today.  Thank you very much. 


Page last reviewed: February 26, 2016