Carlos Varas, a Miami-Dade County mosquito control inspector, uses a Golden Eagle blower to spray pesticide to kill mosquitos in the Wynwood neighborhood as the county fights to control the Zika virus outbreak on August 2 in Miami, Florida.

Carlos Varas, a Miami-Dade County mosquito control inspector, uses a Golden Eagle blower to spray pesticide to kill mosquitos in the Wynwood neighborhood as the county fights to control the Zika virus outbreak on August 2 in Miami, Florida.

Over the last two years, the Zika virus has infected more than one million people, most of them in Latin America. Carried by mosquitos, the virus can be transmitted by a pregnant woman to her fetus, leading to possible birth defects. Zika is now found in 30 U.S. states. On Monday, the CDC warned pregnant women and their partners not to travel to a Miami neighborhood where 14 cases have been diagnosed. The new Zika infections are considered “locally grown” and came even after aggressive mosquito control efforts. Diane and guests discuss the spread of Zika in a South Florida neighborhood, how officials are responding and what it means for the rest of the country.


  • Dr. Anthony Fauci Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health
  • Dr. Irina Burd Director, Integrated Research Center for Fetal Medicine, Johns Hopkins University Hospital; she’s an OBGYN practicing in Baltimore, MD and an expert in maternal-fetal medicine
  • Dr. Michael Osterholm Regents professor and director, Center for Infectious Disease Research and Policy, University of Minnesota; frequent consultant to the WHO, NIH, CDC and FDA; member of both the National Academy of Medicine and the Council on Foreign Relations
  • Lizette Alvarez Miami bureau chief, The New York Times
  • Phil Goodman Chair, Florida Keys Mosquito Control District Board


  • 10:06:53

    MS. DIANE REHMThanks for joining us. I'm Diane Rehm. On Monday, the CDC warned pregnant women not to travel to a South Florida neighborhood where 14 new cases of Zika virus have been diagnosed. The travel warning is the first ever issued for the continental U.S. for an infectious disease outbreak. Joining me to talk about the spread of homegrown Zika virus in South Florida and how officials are responding, Dr. Irina Burd of Johns Hopkins University Hospital.

  • 10:07:29

    MS. DIANE REHMJoining us by Skype from Bethesda, Maryland, Dr. Anthony Fauci of the National Institutes of Health and by phone from Miami, Florida, Lizette Alvarez of the New York times. I'm sure many of you have questions as I do so I welcome your contribution to the program. Give us a call, 800-433-8850. Send us an email to Follow us on Facebook or Twitter.

  • 10:08:04

    MS. DIANE REHMAnd thank you all for being with us.

  • 10:08:07

    MS. LIZETTE ALVAREZThank you, Diane.

  • 10:08:08

    DR. ANTHONY FAUCIThank you, Diane.

  • 10:08:09

    DR. IRINA BURDHappy to be here.

  • 10:08:10

    REHMDr. Fauci, do I understand correctly that last night a new case was diagnosed outside of this neighborhood where 14 prior cases have been diagnosed?

  • 10:08:29

    FAUCIThat is correct. There's a 15th case now in that area, but if you look at that map, it's outside of the little green box, which is the neighborhood, but it's within the one mile parameter. So it's still within the parameter of restriction.

  • 10:08:43

    REHMSo what do you make of this homegrown Zika mosquito and the idea that the U.S. has, for the first time, issued a warning about do not travel?

  • 10:09:02

    FAUCIWell, the local case, Diane, is something that we had expected and actually predicted. And the reason is that we now have over 1600 travel-related cases in the United States between 3 and 400 of them are in Florida. And we also have the mosquitoes that have been very efficiently transmitting this infection in South and Central America and Puerto Rico. We have them right here in our own country, particularly concentrated in the southeast part of the country along the gulf coast.

  • 10:09:33

    FAUCISo given those ingredients, it is not unexpected that you would see a case or two or three and in this case, a cluster within a particular area. So it is not unexpected. The CDC's and the state of Florida's decision, I believe, was a prudent decision to put a travel alert, a restriction of travel of pregnant women to that area. So I agree completely with that restriction. It is, as you mentioned, unprecedented because that major issue is to protect pregnant women.

  • 10:10:04

    REHMNow, on Monday, Dr. Tom Friedman of the CDC said this is truly a scary situation. One wonders whether the 14 or 15 people had, at all, traveled outside the U.S. or were they infected right there in Miami.

  • 10:10:33

    FAUCIThey did very careful epidemiological study of this, Diane, and they're quite convinced that there was no travel nor did these individuals have any direct contact with people who had been infected. So the idea that this is mosquito-borne is pretty clear and pretty firm.

  • 10:10:52

    REHMAnd how did the people who were found to have Zika, how were they diagnosed?

  • 10:11:02

    FAUCIWell, they're diagnosed either by having the classical symptoms of fever, rash, muscle and aches and pains in their joints and in their muscles and conjunctivitis and then they got tested. And then, when the CDC and the Florida authorities -- actually the Florida authorities did that. They went and they did what's called uro-surveillance. They tested the urine of people who lived around that area and they found six additional individuals who had no symptoms, but who clearly were infected.

  • 10:11:33

    FAUCISo it was a combination of clinical diagnosis and laboratory diagnosis.

  • 10:11:37

    REHMYou know, that's very interesting, isn't it? I mean, we these people willing voluntarily to submit urine samples or we're they asked to submit? How did that work?

  • 10:11:55

    FAUCIWell, they certainly were willing because you can't do anything to anyone without their informed consent. But when you do the kinds of epidemiological surveys, you go from house to house or building to building and you explain the reason why you want to do that and the people who were quite concerned were very cooperative.

  • 10:12:11

    REHMI'm glad to hear that. All right. Turning to you, Lizette Alvarez, describe that Miami neighborhood that has been affected. What's it like there?

  • 10:12:24

    ALVAREZIt's just north of downtown Miami. It's a very urban pocket of Miami. It is now kind of rapidly gentrifying neighborhood. It's an arch district. It's very popular among people who like to go to galleries. It's got trendy but kind of bohemian, funky restaurants and bars. It attracts a younger crowd. But around it, there's still a lot of low income, middle to low income housing, some of it quite, you know, shabby. Like, it's not -- they're old buildings. Some of them are, you know, could use a little bit of work. Let's put it that way.

  • 10:13:05

    ALVAREZOn the other hand, on the northern end of it, there are now new high rises and condos. So, you know, you're getting both kinds of populations, a younger population that wants to rent now in kind of this urban district and then a population that's been there for a long time, lower income, and in the middle of it is this kind of buzz about galleries and just -- it's a cool place to hang out now. There's murals everywhere. A lot of it's mural art.

  • 10:13:29

    REHMWell, now how are the residents of that area reacting both to the presence of Zika and perhaps the fear of their neighbors?

  • 10:13:46

    ALVAREZI have found that people in that area, I was there last night, and in Miami in general seem pretty unconcerned about this, unless they're pregnant or they're planning on becoming pregnant. I think, in that neighborhood, the people who know about it -- I interviewed several people last night who were still completely unaware that there was Zika in the neighborhood, which I was, you know, I couldn't believe because there's news trucks everywhere.

  • 10:14:11

    ALVAREZAnd so the people who are aware are now taking the precaution of using spray. They're trying to take care of their standing water. But for the most part, people don't seem very concerned because they know that most people are asymptomatic. This is something that clears your system pretty quickly. They just don't seem too worried about it.

  • 10:14:29

    REHMInteresting. And to you, Dr. Irina Burd, are those residents right in sort of shrugging this off?

  • 10:14:42

    BURDWell, this is a great point. So I deal with pregnant women and so that's a little bit of a different perspective.

  • 10:14:48

    REHMOf course.

  • 10:14:48

    BURDSo in majority, people are not concerned. However, the pregnant women who are either traveling or even living in the area of D.C., not affected areas, are concerned. And I'm very glad that CDC and the communities have started a long time ago to prepare for such an incident with materials that have been available, how to counsel patients and how to tell them what precautions need to be made for -- if they're seeking to become pregnant, if...

  • 10:15:22

    REHMAll right. But what about those who are not seeking to become pregnant? Are there other concerns?

  • 10:15:30

    BURDOf course. And what needs to be mentioned, for those that are not pregnant, there's a potential of developing a condition called Guillain Barre. It's a very rare condition, neurological condition that might be associated with Zika and seen in clusters associated. So that's for adult patients that are not particularly pregnant.

  • 10:15:52

    REHMDr. Fauci, what about the possibility of developing Guillain Barre Syndrome.

  • 10:15:59

    FAUCIWell, as was correctly said, it is certainly possible. We've seen it with other virus infections, including influenza. We've seen it following certain bacterial infections. It's an autoimmune reaction where the body reacts against the neurological tissue. It causes and ascending paralysis. It generally resolves itself, but in some cases, individuals have paralysis of their breathing muscles so that's an issue. But it's a very rare condition, that's what we need to understand.

  • 10:16:27

    REHMOkay. Okay. So these mosquitoes have now been found in Florida. What's to stop them from traveling to other states? We know that Zika exists in 30 states in the U.S., for example, Minnesota. Are we telling people not to go to Florida?

  • 10:16:51

    FAUCIWell, we're not telling them not to go to Florida. We're telling them pregnant women should not travel to that circumscribed area. But, Diane, we really need to make a point so that people don’t get confused. You said mosquitoes travel. We don't care about the mosquitoes traveling. There's mosquitoes all over. So an infected mosquito in Florida is not going to travel to Washington and infect someone. What happens is that the mosquitoes that can transmit are already on various parts of the United States along the east coast and even up where we are in the Washington.

  • 10:17:26

    FAUCIThe issue is they will bite someone who is a travel-related case and then bite someone who's never left the country and that's how you get local. So we're worrying about the people being the carriers, not the mosquitoes. They don’t travel.

  • 10:17:42

    REHMAll right. We'll take a short break here. Dr. Anthony Fauci of NIH, Lizette Alvarez of the New York Times and Dr. Irina Burd of Johns Hopkins. They're all with us. We'll continue our conversation after a short break.

  • 10:20:00

    REHMAnd welcome back. Joining us now from Key West, Florida, is Phil Goodman. He's board chairman of the Florida Keys Mosquito Control District Board. Phil Goodman, I know you're beginning to assist the folks in Miami with the outbreak there. Why is it so difficult to wipe out these mosquitoes that carry the Zika virus?

  • 10:20:30

    MR. PHIL GOODMANGood morning, Diane. the problem with the Aedes aegypti mosquito, which is the one that we're speaking about that carries Dengue fever and Zika and Chikungunya and others is that it's -- it likes to live around people, and it doesn't -- it stays people, close to houses, low to the ground and is very difficult to hit with conventional adulticide pesticides. Also, many of the -- and most of the pesticides, this mosquito has become resistant to over the years, going back to the days actually when DDT was used.

  • 10:21:09

    MR. PHIL GOODMANSo the conventional methods of controlling this mosquito are not as effective as we need to really have a high degree of confidence that we can control the mosquito and the Zika virus.

  • 10:21:22

    REHMBut now what happened when you were trying to control mosquitoes in the Keys? How come this is different, Phil Goodman?

  • 10:21:34

    GOODMANWell, it's not different. One of the things in the -- I mean, we use the same mosquito control techniques and the latest techniques that are available. However, for -- in the Florida Keys, we have a very large program and have had for many years and I think do a relatively good job of controlling mosquitoes. Miami-Dade, because the mosquito situation there is different, they have a lot of sea breezes and breezes from the Everglades very much so, they've never really had a major mosquito control department there to really look after this.

  • 10:22:12

    GOODMANThey have a few people that are assigned from the county. So what happened now that it's become very important for them to control this mosquito, and they are looking for contractors. They've also talked with the Florida Keys Mosquito Control District, and we've offered our assistance. We are on a standby right now to do some spraying for them, you know, if they are not able to get the contractors they need to do this at the needed times.

  • 10:22:42

    REHMAnd of course there is a question of money. Lizette Alvarez, the Congress left town without failing to approve new monies for control of Zika. Do you suppose that's going to change anytime soon?

  • 10:23:04

    ALVAREZI doubt they're going to come back during recess to do anything about this. I just don't think that most members of Congress feel the same level of urgency that the Florida delegation does.

  • 10:23:14

    REHMAnd how concerned is Governor Rick Scott?

  • 10:23:17

    ALVAREZHe is very concerned. He's actually been very proactive on this issue and started early on to prepare for the eventuality that this would happen in terms of kind of rattling cages for money, freeing up state money, you know, holding press conferences and information conferences, round tables. I think he's actually on this issue done a pretty good job of creating awareness and trying to get money, but federal money is needed.

  • 10:23:44

    REHMI gather that the GOP version of the money bill has some language that would deny Zika funds from being sent to Planned Parenthood. Is that correct?

  • 10:24:01

    ALVAREZThat's correct, yeah, in terms of contraception it would hinder the access to contraception, basically, by Planned Parenthood and I think other similar organizations. And so that seemed counterproductive at a time when we know that Zika is being sexually transmitted, as well. I mean, it just -- you know, on any level it probably wasn't a good idea, and Democrats weren't going to go for it, but it seemed particularly problematic because Zika is also sexually transmitted.

  • 10:24:29

    REHMSo Dr. Fauci, this must be frustrating for you.

  • 10:24:34

    FAUCITo say the least, Diane, it's extremely frustrating. We're dealing with a very important and emerging public health problem, and we do need the resources. The president asked for $1.9 billion in February, and here we are in August, and we still don't have the money that we need. We've reached the point now, we've taken money from other accounts to start doing what we're doing, and we've really reached the point now we're essentially run out of money. So they've got to act quickly. This is very frustrating.

  • 10:25:04

    REHMHow could this affect tourism, Phil Goodman, the fact that people are hearing news about this one neighborhood in Miami could in fact, perhaps, scare people away from Miami altogether.

  • 10:25:20

    GOODMANThat's correct, and, you know, I know that everyone's concerned of this because this is, you know, our economy is based on tourism. And so that's why we want to do everything we have in the Florida Keys to help Miami in this situation to try to, you know, get this situation resolved because no one wants the thoughts of this impacting our tourist industry.

  • 10:25:46

    REHMAll right, we've got a tweet up on the board from Lydia. She says I live in Boca Raton with my 15-month-old daughter. Please talk about what the risks of Zika might be for a child her age, and we might add to that, Dr. Burd, what precautions she could take.

  • 10:26:10

    BURDThat's great. So CDC first of all recommends using EPA-registered insect repellants, and they're safe for babies, and those that are DEET-containing are safe for babies that are two months and older. Of course precautions, standard precautions for babies should be wearing long sleeves, pants, and if you're applying sunscreen on a baby, applying the insect repellant on top of the sunscreen, of course not using the repellant under their long sleeves.

  • 10:26:41

    BURDSo those are standard precautions that are recommended, staying in air-conditioned houses, or if air condition is not available using window nets and screens. Those are options. Getting rid of water containers around the house, tires that are laying around and collecting some water sources I think is important so that to decrease the number of mosquitoes. And if air conditioning are not available on the windows, sleeping under a mosquito net at home is important.

  • 10:27:15

    REHMDr. Fauci, I must say I have been reluctant myself ever to use DEET. I would wonder about using DEET on a 15-month-old child.

  • 10:27:31

    FAUCIWell, I wouldn't wonder about it, and you shouldn't be reluctant to use it yourself.

  • 10:27:36

    REHMI am, and I will not use it.

  • 10:27:39

    FAUCIWell, I'm not going to change you, Diane.

  • 10:27:40


  • 10:27:40

    FAUCIBut the fact is that it is really safe, and I think there is this understandable reluctance of people to put any chemicals on them but particularly in the situation right now that we're talking about, it really is very prudent to use the insect repellant up to 30 percent DEET.

  • 10:27:58

    REHMDr. Burd?

  • 10:28:00

    BURDThere are also natural insect repellants that are EPA registered, and they contain of oil of lemon eucalyptus. But what is interesting that those EPA-registered insect repellants should not be used for children younger than three years of age.

  • 10:28:16

    REHMNow why is that? I mean, how do you explain that?

  • 10:28:21

    BURDIt may have to do with the chemicals and developments. We just don’t know some of the origins of disease and what it could lead long-term.

  • 10:28:30

    REHMOkay, I know you have to leave very shortly, Dr. Fauci. I want to take one call before you go.

  • 10:28:37


  • 10:28:37

    REHMIt's from Mary in Miami, Florida. You're on the air.

  • 10:28:42

    MARYHi, I was wondering, I have an eight-month-old at home, but I was wondering more about if -- if a woman contracts Zika and goes through it and has, you know, the symptoms, develops antibodies to it, what about -- how does that affect future pregnancies, or how could it?

  • 10:29:04

    REHMThat's an interesting question. Do we know, Dr. Burd?

  • 10:29:08

    BURDAt this time we do not know how it affects your future pregnancies. That's a -- that's a short answer. But we do have some information that potentially once a person contracts Zika, they may be immune to future infections. But more research is needed to elucidate that, and we need the funding.

  • 10:29:30

    REHMAnd Dr. Fauci, here's an email from Nia in Homestead, Florida. She says, could you provide information regarding possible risks for growing babies? Could a baby who still has a developing brain have developmental issues later? If there's no evidence available, what is the prediction? Is DEET safe for babies?

  • 10:30:02

    FAUCIWell as was just mentioned, DEET is safe for babies who are older than two months old. So you would go ahead and do that. There's no evidence to indicate that even though you have a baby following birth who has a brain that continues to develop that if that baby gets infected there's any deleterious effects. So far the evidence does not indicate that there is a danger to the baby. However, that is the reason why we're doing large cohort studies to follow children following birth and children who get infected in the very early years of their life because we want to definitively prove that it's safe rather than just surmise based on a small amount of data.

  • 10:30:43

    REHMWell, but you're just starting this study, isn't that correct?

  • 10:30:49

    FAUCIYes, but there's observations in Brazil and Colombia of children who have gotten infect, and there does not seem to be any deleterious effect on the child other than the same as an adult. You clear the virus within about a week to 10 days.

  • 10:31:03

    REHMHow long has Zika been around?

  • 10:31:07

    FAUCIWell, it was discovered in 1947 in the Zika Forest of Uganda, hence the name Zika. The first human cases were recorded in Nigeria in 1952. It kind of went under the radar screen, likely infecting people in Africa and Southeast Asia, and nothing really happened until finally there was an outbreak a few years ago in the islands of Yap. That was followed by another outbreak in French Polynesia, and it kind of worked its way across the Pacific until it landed in South America, in Brazil, and you had the perfect storm.

  • 10:31:41

    FAUCIYou had a lot of mosquitoes, and you had a population of people that were immunologically naïve. They had never been exposed to Zika before, so they were very vulnerable, they had the right environmental and mosquito conditions, and that's why we had the first outbreak that was recognized and understood by the general public was in South America, even though there were signs of it as it worked its way across the Pacific.

  • 10:32:07

    REHMSo we do not know the long-term effects, or do we, of having had Zika?

  • 10:32:15

    FAUCIWell, if you look at the people who have been infected a few years ago in the islands of Yap and in French Polynesia, it appears, Diane, that it is a relatively mild, somewhat inconsequential infection except for pregnant women. So we don't believe there's long-term effects at all.

  • 10:32:36

    REHMAll right, I know you have to leave us, Dr. Fauci. Thank you very, very much for joining us.

  • 10:32:43

    FAUCIThank you, thank you very much.

  • 10:32:44

    REHMAnd joining us now from Minneapolis is Dr. Michael Osterholm. Actually, that's Osterholm. He's regents professor and director at the Center for Infectious Disease Research and Policy at the University of Minnesota. Dr. Osterholm, I know you've been listening to our discussion. How do you react to what you've heard? How serious do you regard the outbreak in that Miami neighborhood?

  • 10:33:22

    DR. MICHAEL OSTERHOLMWell first of all, good morning, Diane, and thank you. I think that one has to look at this as kind of a journey, and we are just on the first leg of what I would call Zika in the United States journey. What you see happening right now in Miami I think is going to play out over the next several months in multiple locations. Do not be surprised if these case numbers continue to increase in other locations in Florida, a cluster here, a cluster there.

  • 10:33:48

    DR. MICHAEL OSTERHOLMAnd it'll happen wherever people are concentrated who have actually come back recently from the Americas, in other words that part of the Americas outside of the continental United States where infection is occurring. Think about this right now. Up to five percent of the entire population of Puerto Rico has become infected on a monthly basis.

  • 10:34:05


  • 10:34:07

    OSTERHOLMSo if these people come to the United States, and as Dr. Fauci pointed out, the real risk is people who are infected then being bitten by a mosquito that's not infect, but then that mosquito becomes infected and transmits. So we have the following combination of recently infected people from the Americas arriving in the United States and this mosquito, you're going to see more clusters.

  • 10:34:26

    REHMAll right.

  • 10:34:26

    OSTERHOLMSo I think that this will happen quite a bit over the next few months.

  • 10:34:31

    REHMAnd you're listening to the Diane Rehm Show. Dr. Osterholm, one of the things we've been talking about a great deal is the younger child, the infant and, indeed, the fetus. What about age at the other end of the scale? Are older people more likely to have more serious effects of Zika than younger?

  • 10:35:02

    OSTERHOLMWell actually, this is one of the few good-news pieces to this situation to date is we don't have any evidence of that happening. As Dr. Fauci pointed out, we also don't have evidence at this time that young children, meaning those under a year of age, up to two years of age, if infected after birth also have any serious outcome beyond that which we just normally expect to see anyone else.

  • 10:35:26

    OSTERHOLMSo I think that the real focus remains primarily on the unborn child and then those few people who still, it's a significant health program, who develop Guillain-Barre syndrome, which we talked about. So nothing unusual at this point for those in the older ages of life.

  • 10:35:42

    REHMAll right, and we have a question from Jacques on Facebook, who says when in the gestational period is the most dangerous for development of the fetus, Dr. Burd?

  • 10:35:59

    BURDAnd that's a great question. What we believe now, given some data, is that different parts of gestation may have different effects on the fetus. The most -- the most common compilation that we've heard on media is microcephaly, of course. That's something that's connected to the -- and that's an increase -- and it's a decrease in the brain size, potentially, from either dying or misdeveloped neurons, the main cells in the brain.

  • 10:36:31

    REHMAnd what about the skull itself?

  • 10:36:32

    BURDAnd the skull of course is misshapen and smaller. That's the word micro, small. And so that's the most common complication that we hear about. There are other complications that happen with Zika that we know now, and it may have to do with infection of Zika placenta and potentially leading to growth restriction, being -- the whole baby being smaller. And that may be a later finding of a later gestation infection.

  • 10:37:06

    GOODMANBut outside of microcephaly, the brain malformation and the skull malformation, there are of course other brain malformations and eye problems for the baby.

  • 10:37:16

    REHMDr. Irina Burd, director of Integrated Research Center for Fetal Medicine at the Johns Hopkins University Hospital. Short break here, more of your questions, comments when we come back. Stay with us.

  • 10:40:01

    REHMAnd welcome back. As we talk about Zika in a particular neighborhood in Miami, Florida. Lots of people, Phil Goodman, are wondering about exactly what is being sprayed in South Florida.

  • 10:40:22

    GOODMANThat's a good question, and you know there are a number of chemical tools available that we've been using. And all of the products that we're using are FDA or EPA approved. We all use them by their -- by the label instructions, so that, you know, they're all very not toxic to individuals when we're using this quantities. So, there's several different types of chemicals being used, both from an adulticide and also a larvicide treatment to try to kill the mosquito before it hatches into an adult.

  • 10:40:59

    GOODMANThose are the two main types of products and these have different degrees of effectiveness. Here again, though, the problem is getting this spray to where these mosquitoes are to kill them is the big problem.

  • 10:41:16

    REHMLet's talk about what was used in Brazil, Dr. Burd. A different kind of spray, I gather.

  • 10:41:25

    BURDWell, there are several media reports in February of 2016 that suggested that larvicide, called pyriproxyfen might be linked to microcephaly itself. These media reports appear to be based on the February 3rd publication authored by Argentine Physicians Organization, which claimed that the drinking water in Brazil was responsible for the country's increase in microcephaly cases. However, the medication that was used, this pyriproxyfen, is a WHO approved for control of disease carrying mosquitoes. So, and there is no other countries that found this is -- there is a connection.

  • 10:42:06

    REHMI see. Well, so, what does that mean? Is that the same spray, Phil Goodman, being used in Miami?

  • 10:42:16

    GOODMANRight now, we are working with -- we are experimenting with pyriproxyfen with some different techniques, but not actually using it now. You know, our malathion and several other similar related products are being used here, which have been used traditionally in mosquito control. As well as some of the bacteria that are used for larvicide treatments.

  • 10:42:39

    REHMBut I thought that malathion had big questions about it years ago, Phil.

  • 10:42:47

    GOODMANWell, you know, there's a lot of these, you know, if you read the material safety data sheets on them, there's a lot of information on there that will, you know, scare you. But, however, you know, we follow -- if you follow all of the guidelines for application, you know, these are deemed safe and used quite widely in mosquito control. You know, the problem was that back in the 40s and 50s, the mid 40s and 50s, DEET was used. And as a result of the, this -- you know, it really controlled and eliminated this mosquito from many countries.

  • 10:43:20


  • 10:43:20

    GOODMANAnd from many parts of the USA. But what it did was the derivatives of that product, which, you know, there are end groups on some of these other chemicals that have some similarities. So, this mosquito has developed a resistant to most of these types of chemicals.

  • 10:43:37

    REHMWhat about that, Dr. Osterholm? What's your reaction to the kinds of sprays that are being used? Could malathion, for example, itself, cause harm to the pregnant woman or to anyone for that matter?

  • 10:43:59

    OSTERHOLMYeah, I think actually, Diane, the discussion here is -- is an important one, but at the same time, I think we need to keep focused on what's going to make the biggest difference. And while these sprays surely can help in reducing the mosquito populations, and I do believe that all the ones that we just talked about are safe to use on populations, even with young children. The biggest challenge is that for many of these mosquitoes, they're resistant to malathion. They're resistant to some of the other chemicals we're using.

  • 10:44:26

    OSTERHOLMAnd just like antibiotic resistance with bacteria, today, we have a major problem with pesticide resistance. And we've not had new pesticides developed in decades that really have any impact. But I think the focus here needs to stay on what really is going to make the difference is eliminating the breeding sites. The water sources, finding all the garbage. We now live in a plastic garbage world where one bottle cap sitting in a ditch is more than enough, is a great breeding site for this mosquito. A mosquito that, by the way, doesn't fly more than just a few hundred yards from where it's hatched.

  • 10:44:54

    OSTERHOLMSo, if we can get in lot by lot, house by house, building by building, we can actually do a great deal to reduce the risk of this by just eliminating all those water sources and chemicals should only be seen as the backup, not as the primary.

  • 10:45:07

    REHMAll right, and let's take a caller in Chesapeake Beach, Maryland. Hi there, Matt. You're on the air.

  • 10:45:16

    MATTGood morning, Diane and company. My wife is 19 and a half weeks pregnant and we became pregnant about three or four weeks after returning from a trip in St. Lucia back in February. I'm wondering how long after Zika exposure, if one of us had, had Zika, regardless of whether or not symptoms were evident, how long is there a lingering risk of, you know, being problematic for a potential baby if you are trying to become or become pregnant? And I'm also wondering at what stage during pregnancy you would be able to see measurable evidence of possible microcephaly.

  • 10:45:51

    REHMDr. Burd.

  • 10:45:52

    BURDThat's, that's a great question. So, what we recommend, and it's per CDC guidelines, if you're coming from the area that's affected with Zika, you would need to get testing done between two and 12 weeks from travel. If your wife is pregnant right now, she would also, would need to see a high risk obstetrical physician and be followed for ultrasounds in order to document well developing of your baby. And making sure that the brain and skull are developing appropriately. And that is, of course, if the immunologic testing comes back positive.

  • 10:46:33

    REHMAll right. And then, a tweet from Meghan. Can moms with Zika breastfeed their babies?

  • 10:47:00

    BURDWonderful question. As far as we know, there's no passage of Zika through breastfeeding and we recommend to continue breastfeeding. Because that has tremendous amount of benefit to the baby.

  • 10:47:00

    REHMAll right, and to Tracy in Lorton, Virginia. You're on the air.

  • 10:47:05

    TRACYHi. Good morning. I'm, I'm wondering if you could contrast the malaria with the Zika virus. Why is it that travelers to places in the world that are -- where Malaria is still prevalent are not bringing back the virus and starting an epidemic here?

  • 10:47:22

    REHMDr. Osterholm.

  • 10:47:24

    OSTERHOLMYes, well, first of all, that is a good question and it's actually one that actually does happen. Malaria, which is caused by a parasite is brought back into the United States by individuals. And again, it's a very different kind of mosquito. The Anopheles mosquito, which is quite different than the Aedes mosquito. Where it breeds, where it lives, how it bites people, et cetera. And so we do have cases in this country, and from time to time, we actually see clusters of cases around airports where mosquitoes that were in the cargo holds get out.

  • 10:47:51

    OSTERHOLMThat actually had the malaria parasite. We see it, particularly after the Vietnam War, we had a problem in this country where returning veterans came back with Malaria and as a result, we saw it showing up in blood banks and so forth. So, that can happen. It's not nearly as dynamic or as frequent as we're seeing with Zika. Zika is in a class of its own, right now, in terms of both the mosquito transmission, the sexual transmission and so forth. So, this does happen, actually, with Malaria too, but rare.

  • 10:48:15

    REHMHere's an email from Janet, who says, in June, we travelled to Costa Rica and while we were there, our host told us her mother was at the doctor's getting a vaccination for Zika. Have your guests heard of such a vaccine? Dr Osterholm.

  • 10:48:38

    OSTERHOLMAt this point, there are no commercial vaccines available and only in very, very early study stages at this point. And so, I, for one, am one of those that believe it will be a number of years before we see a safe and effective Zika vaccine license. There's some real questions on safety around Zika vaccine that we have to answer. And so, it won't -- that is not going to be our solution. We're going to need to just deal with the mosquito. But she -- I don't believe was getting a vaccine at that time.

  • 10:49:05

    REHMPhil Goodman, lots of people are wondering about genetically altered or modified mosquitoes. What's going on there?

  • 10:49:17

    GOODMANWell, you know, right now, the genetic modified mosquito by Oxitec is still under study by the FDA in the US. And, you know, they gave an initial finding of no significant impact several months ago, and then we went through a two month public comment period, which, there were quite a few. The FDA is now going through all of those comments and in a week, expect them to make another release sometime, we don't know when, you know, about whether they will give a final finding of no significant impact or require additional studies on the (unintelligible) .

  • 10:49:55

    GOODMANBut, you know, we've looked at it quite extensively here in the Florida Keys, and -- but the public, you know, there are still a lot of questions in the public about this as well about safety.

  • 10:50:06

    REHMYou seem to be more optimistic than the FDA.

  • 10:50:13

    GOODMANWell, you know, we had the initial finding. We're just now waiting to see the FDA's not been very -- not a lot of comments on it. We're just waiting to hear back their final results. You know, it could be that they do approve it or they want additional information, you know, before they make a final finding of no significant impact.

  • 10:50:33

    REHMWhat do you think about that, Dr. Osterholm?

  • 10:50:37

    OSTERHOLMWell, I think that every tool that we can bring to the war on this is a helpful one, but again, remember, this mosquito doesn't fly more than three to 400 yards from where it's hatched. You would have to release these mosquitoes, literally, in a carpet like manner every three to 400 yards in order to really have an impact on the problem. So, if we're talking about large areas that would need to be covered, square miles and miles, that's going to be a challenge with these mosquitoes.

  • 10:51:03

    OSTERHOLMAnd so, again, if we transmission ongoing in a small, localized area that we just can't seem to squelch, then these mosquitoes may play a role. But in general, it's not a high utility tool that's going to wipe this out across large areas.

  • 10:51:18

    REHMHere's an email from Ruth in Pennsylvania. She asks, is it true that the virus clears non-pregnant females in a short time but can take months to clear males and can be sexually transmitted? Dr. Burd.

  • 10:51:39

    BURDThat is right. What we know is that virus could stay longer in semen. And so, at Johns Hopkins, we recommend for those women or men who travel to the area of Zika, especially affected areas, they should wait for pregnancy. And then, they have Zika disease, after the infection, they should wait for eight weeks for women. And up to six months for men, because virus, once the infection happens, could stay in semen for up to six months.

  • 10:52:13

    REHMSo, you're telling men who have travelled to that area...

  • 10:52:17

    BURDAnd have disease. Right.

  • 10:52:18

    REHM...and have been infected to desist from sexual activity.

  • 10:52:22

    BURDThat's right.

  • 10:52:22

    REHMFor six months.

  • 10:52:24

    BURDOr protect themselves. That's right.

  • 10:52:26

    REHMOr protect themselves.

  • 10:52:28

    BURDRight. And definitely, we recommend for those that, you know, for those that are travelling in the area and don't have symptoms, to protect themselves from being bitten by mosquitoes. And that's the important part. Because some people don't have symptoms, so we know that this disease...

  • 10:52:49

    REHMThey can be bitten, but they have no symptoms whatsoever.

  • 10:52:51

    BURD...they could have an infection, and they may not have the symptoms, so they may not know.

  • 10:52:57

    REHMThis mosquito is very, very screwy. I don't like it. And you're listening to The Diane Rehm Show. Now, let's go to Sylvia in Westin, Maine. You're on the air.

  • 10:53:17

    SYLVIAHi. I can't believe that the Health Department is not advocating using baby oil as a bug repellant. I am highly allergic and I live up in a very buggy place and I even have to carry an EpiPen. But, baby oil just slathered all over your body will repel any insect.

  • 10:53:38

    REHMDr. Osterholm, do you agree with that?

  • 10:53:42

    OSTERHOLMI have never -- I haven't seen any data that supports that baby oil itself is an effective deterrent to mosquitoes or ticks. You know, we have many anecdotal reports of lots of different products and chemicals, which, when actually subjected to a very objective review, don't protect as some think. So, I would, at this point, be very cautious about making any recommendations about baby oil or baby lotion.

  • 10:54:08

    REHMOn the other hand, if it works for her, maybe it works, Dr. Burd.

  • 10:54:12

    BURDWell, CDC currently recommends that only certain EPA registered insect repellants could be used and those have to have active ingredients, such as DEET, picaridin, IR3535. Or, it could be oil of lemon eucalyptus or paramenthane diol. For the last two that are used, those cannot be used for babies that are less than three years of age.

  • 10:54:34

    REHMVery helpful. Thank you. And let's go to Pensacola, Florida. Michael, you're on the air.

  • 10:54:42

    MICHAELGood morning.

  • 10:54:42


  • 10:54:44

    MICHAELI was just curious, since they're spraying insecticide, what effect it's going to have on the next level of predators. Dragonflies, bats and swallows.

  • 10:54:53

    REHMPhil Goodman.

  • 10:54:55

    GOODMANYeah, so most of these pesticides, they do also kill small insects. And, you know, similar in size to a mosquito, maybe a little bit larger. Particularly if you're spraying by truck and maybe in the evening, if there's a concentration around a streetlight of animals -- I mean, of mosquitoes and other insects. When the truck goes by and you have the most concentrated area, you will get some collateral damage of other insects, including honeybees. But there's precautions you take in the community to try to minimize that.

  • 10:55:30

    REHMAny comment, Dr. Osterholm?

  • 10:55:33

    OSTERHOLMYeah, well, again, let's come back to this mosquito. And Diane, you said it a second ago. This is a -- is not a good mosquito. Aedes Aegypti actually is the Norway rat of mosquitoes. It loves to live in close contact with people. So it's in these kind of water vessels that we don't even think about. A plugged E spout, for example, that may have water in it. Bird baths, just plastic or garbage that's been thrown away. And in numerous studies they've been showing that the highest concentration of these mosquitoes in households actually is often in the closets.

  • 10:56:03

    OSTERHOLMWhere they hide in the darkness and come out during the day to feed. So oftentimes, spraying from airplanes or trucks have little impact at all. It looks good politically, because it makes you feel like you're doing something. It is really either spraying inside the homes or it is basically getting rid of these bodies of water that we need to concentrate on.

  • 10:56:22

    REHMAnd finally, to you Lizette Alvarez, how are people reacting to the spraying within the neighborhoods?

  • 10:56:33

    ALVAREZThat's something that does take place in Miami routinely. I don't know routinely, but people are accustomed to that happening here. Because we have mosquitoes all the time, and so spraying is something that happens here with frequency. So, I mean, I think people are fine with it. I don't think anybody has been bothered at all with the idea of spraying here. They're very comfortable with that. I think they would like to get rid of mosquitoes.

  • 10:56:58

    REHMOf course. All right, we'll leave it there. Lizette Alvarez is Miami Bureau Chief for the New York Times. Dr. Michael Osterholm is at the University of Minnesota. Phil Goodman is Board Chair of the Florida Keys Mosquito Control District. And Dr. Irina Burd is at Johns Hopkins University. I want to thank you all for joining us and giving us this information. And thanks all for listening. I'm Diane Rehm.

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