Over the last several months, the Zika virus has become a regular part of media coverage. It seems that everyone you talk to has an opinion, a fear or a question that is not being answered. In this episode, we try to answer some of those questions. We also dig a little deeper to look at how Zika has brought together so many areas in the field of public health.
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Clare: Zika sort of came on fast a furious this winter and I think partly because it has served to highlight so many facets of public health, the individual behavioral issues about how people protect themselves from vector-borne diseases the environmental issues around access to water, sanitation, safe housing. And then the policy issues where you’ve had these very dramatic governmental responses to Zika, that have actually ended up having a really complicated impact on the health of populations. So all the factors that make certain populations more vulnerable to getting a vector-borne disease, Zika has kind of just really put all of these many levels and different competing issues on to the table. All focused on this one really dramatic health outcome that affects the most vulnerable population possible, infant children.
Jessica: Thank you for listening to Public Health Behind the Scenes. This is an update on the Zika virus. In this episode, we talk to experts from medicine and public health, and hear first-hand accounts of individuals who have been on the front lines of the epidemic.
Naya: We also explore the social and behavioral aspects of Zika, such as birth control and how the media has driven the story so far. We started out trying to answer the question of “Why are talking about Zika?” Of course, there was no single answer. In the beginning of the podcast, you heard from Clare Barrington. Clare is an associate professor in the Department of Health Behavior at the Gillings School. We will hear from her again momentarily. For now, let’s start at the beginning.
Helen: So this isn’t a new virus, this is a virus that’s been known to science for some 70 years, but it’s up until very recently been quite obscure and so most of what we know about Zika virus has been learned very recently.
Jessica: Helen Lazear is an assistant professor in the microbiology and immunology department at the school of medicine here at UNC. She has been working with Zika for a couple of years.
Helen: Even though we haven’t studied Zika virus very long, other viruses that are related to Zika virus, so that’s viruses like dengue virus, west nile virus, yellow fever virus. These are viruses that have been studied quite extensively, so we can make some pretty educated guesses about how Zika virus will behave based on it’s relatives. But ultimately, there is a lot we need to learn about this virus specifically.
Naya: Those education guesses are pretty important, especially considering that we can use data on the West Nile virus and its introduction to the United States in 1999. That’s because the vector-control measures we used back then are related to the same approach we would take with Zika.
Jessica: And it’s even more important that two other viruses–Chikungunya and Dengue–are spread by the same mosquito that carries Zika.
Helen: Aedes Egyptia are found throughout the southern United States and there’s other species of Aedes mosquitoes found further north as well.
Naya: In other words, the same mosquito that has always been here has carried viruses responsible for epidemics in other parts of the world.
Jessica: Well, what’s so different about this particular outbreak?
Helen: Before the current outbreak in Latin America and the Caribbean, we had no reason to think that Zika virus is something that would cause birth defects. The other viruses that are related to Zika virus have never previously been associated with birth defects, so this was really an unexpected association.
Elizabeth: What I believe that we know is that Zika virus can be passed from mom to her developing fetus. We know that the Zika virus has been detected in the amniotic fluid after an infection, after a maternal infection. And that one consequence on the fetus that has been infected with Zika is microcephaly and brain damage.
Jessica: Elizabeth Stringer is an MFM (maternal fetal medicine) doctor here at UNC. MFM is a specialty in obstetrics and gynecology that focuses on, among other things, infections in pregnancy. Using an ultrasound, MFM doctors can make fetal diagnoses on how, say, an infection can affect the mother and her developing child.
Elizabeth: Microcephaly can usually be detected in the 3rd trimester. So we think after 24-28 weeks, however there may be other signs of fetal infection with the fetal brain that may be able to be diagnosed as early as 20 weeks.
Naya: On April 13, scientists at the CDC issued a major announcement.
Audio from this CBS Evening News report, “And we’ll begin tonight with breaking news, late today the CDC confirmed what had been suspected. That Zika virus does in fact cause sever birth defects …”
Jessica: Many of the concerns or fears raised over pregnancy since the outbreak began have dominated the news cycle. And with that, facts have been hard to come by. We do know that the CDC recommends for women who are pregnant or planning to become pregnant to avoid places where Zika is circulating.
Naya: But what else? What if you had Zika at some point in your life?
Elizabeth: We know that after someone becomes infected that the virus or the viremia can be detected in their blood for about a week. And that is likely the most high risk time for a mom to pass it to her baby.
Jessica: And if you are pregnant and have traveled to one of these areas, this shouldn’t deter an expecting mom from ever getting tested.
Elizabeth: I hear a lot of people say, “why screen for Zika infection if a woman has gone to an endemic area, because there is nothing we can do if the fetus is infected. And that’s correct. We don’t have any treatments yet, but an important thing to remember is that a negative test or a negative ultrasound or negative amniocentesis is also incredibly important information for a pregnant woman to have.. Because there’s so much anxiety out there surrounding Zika and, we need to try to allay the fears of pregnant women.
Courtney: A lot of the work thus far with the Zika has really been focused on vaccination and kind of surveillance of the population and there hasn’t been, I’d say a strong response from the research community in terms of advocating for better sanitation and sewage, but particularly sanitation within the regions that are impacted.
Naya: Courtney Woods, a researcher and instructor in the school’s environmental sciences and engineering department, worked in Brazilian fishing communities severely impacted by chronic environmental hazards, mainly to get a sense of what people’s perceptions were to risks of pollutants.
Courtney: So while this was a concern that was kind of explicitly expressed in communities I was working with, for trying to understand exposures to air pollution, this issue also impacts the kind of ability for vector-borne diseases to be spread.
Naya: At the time, Sao Paolo was experiencing one of the worse droughts in years and—due to the lack of continuous piped water service—residents were hording large amounts of water in their homes.
Courtney: And so this was, I think my first, kind of the light bulb switched on and made me realize that there was this connection with lack of regular water service, particular behavior by the public or by the residents to count for that, and this kind of increase in rates of vector-borne disease.
Jessica: This storage became a perfect breeding ground for mosquitoes, particularly Aedes Egypti.
Naya: That’s right. In addition to carrying these vector-borne diseases, Aedes Egypti likes to be in the home.
Courtney: One entomologist kind of liken this mosquito to a house cat, to a pet, because they are often bred in the home as a result of residents storing water and they hide in dark places and they often maybe, he said 50 percent of the population of this particular mosquito often never leave the home.
Jessica: This is important to note because efforts to control these mosquitoes with outdoor fumigants is not as effective for this particular mosquito.
Naya: This is compounded with another public health issue: solid waste pickup. In northeast Brazil, up to 30 percent of residents don’t have regular solid waste service.
Courtney: So this means that you know litter and trash, old tires, lots of things that could be containers or areas where standing water could be held are close to homes and again those serve as perfect breeding grounds for mosquitoes.
Jessica: Are there any other lessons to learn about sanitation? Remember the West Nile outbreak of 1999? We go back to Helen to ask how we reacted then and where we stand now.
Helen: Since the those initial, waves of West Nile Virus infection happened, a lot of that vector control capacity and funding has not been sustained. And what we’ve seen time and time again is when there is an outbreak of vector-borne disease there’s a surge of interest and funding and we step up vector control efforts, but it’s really hard to sustain those efforts in between outbreaks. Which is when you start to see these sorts of breakthrough epidemics occur.
Naya: Which is exactly what happened in South America where the Aedes Egypti mosquitoes were largely eradicated. However, as government funding dried up, the mosquitoes eventually returned with Dengue, Chikungunya and Zika. And now, the control efforts have become even harder for a larger, diverse urbanized and rural population.
Clare: I think a lot of the discourse and discussion that’s come up with Zika, goes way beyond a vector-borne disease carried by a mosquito. The most dramatic effect is seen in infants and so that has created a really heightened sensitivity and these dramatic images of severely affected babies. That when you contrast it to the way governments and the public health world have reacted and responded to dengue fever or the Chickungunya virus that was/ is continuing to affect the same region. The response has been dramatically different.
Jessica: Remember Clare from the beginning of our podcast? Part of her work is based in mixed-method research to examine social network and structural influences.
Clare: And again, what’s concerning is that some of those reactions actually potentially have negative impacts for the health of women and for the health populations by creating an even more repressive environment around sexual and reproductive health.
Naya: In countries like Brazil, longstanding cultural norms and practices are not shaped by public health science. For example, there are laws that restrict a woman’s ability to practice safe sex through birth control pills. Also, abortion is illegal in Brazil.
Rita: We are discussing now abortion problems, because abortion is not permitted in Brazil.
Naya: It’s illegal.
Rita: It’s illegal in Brazil.
Naya: But now they are saying it might be okay.
Rita: No, they are discussing if it is legal or not, no it is a long discussion about permission or not of abortion, some parts of public health are completely in favor as a public health question because many of women die because they make illegal abortions and it’s not permitted in public health system.
Naya: Rita Franco Ragu is a visiting scholar at UNC. In Brazil, she serves as associate professor of medicine at the Federal University of Bahia. In addition to working as an epidemiologist for 12 years, Rita was a director of a municipal health department. Her expertise rests in sanitation and how it relates to the health of populations.
Rita: We don’t have a lot of education of the people, it’s another difficulty for control, all of the epidemic that we have.So we have lack of sanitation, we have lack in terms of education, and we don’t have a lot of money to give the services, and we don’t know many things about Zika and this disease that is new for us we need some help, I know for researchers. So we have good center for research, but we don’t have a lot of researchers, and we don’t have money to pay a lot of researchers, that’s one problem
Jessica: And there’s something else. The Olympics are around the corner and the fears of traveling to Brazil are part of regular media coverage.
ABC news clip, “The latest on that dangerous Zika virus is spreading out of Florida where the Governor has declared a State of Emergency in four counties, and ground zero for the outbreak, Brazil, is struggling to contain it with prominent voices now calling for this summer’s Rio Olympics to be canceled …”
Naya: Since this outbreak began, Brazil has taken vigilant measures to manage the breeding grounds of mosquitoes. How vigilant you may ask? Here’s Courtney.
Courtney: They’ve enlisted the military as a part of their public health regime. And I think the last numbers that I read are something like 200,000 troops have been going door to door essentially.
Jessica: That’s right. Troops have been deployed to go door-to-door to ensure residents don’t have these standing-water breeding grounds in or around their homes.
Naya: In addition to inspecting, troops pass out fliers and communicate the symptoms of Zika and how it differs from Dengue.
Courtney: They’ve also gone into abandoned homes, so not just homes where residents are, but if they notice that there’s a home that is abandoned they’re essentially kicking in doors. I mean the article I read they said they’ve declared a war on Zika, so they’re really using military tactics to fight it.
Jessica: What else might there be? Is there a silver lining to all of this? In public health, there are opportunities where backgrounds cross paths, where experts from differing backgrounds come together to solve a public health problem. Clare explains this intersection.
Clare: What I find sort of exciting and invigorating about the conversations that have been happening at least here at UNC is that it has brought out these dialogues that are crossing disciplines and crossing perspectives and bringing lots of different types of knowledge and science and facts to the table. and I think we’ve had a really productive series of conversations where we are able to identify these multiple different pieces and figure out how can we all help chip away at them. That’s an exciting, at least for someone like me who works at that intersection of public health and social science and biomedicine. That’s been a very invigorating conversation to be a part of.
Elizabeth: I think in two to five years we’re going to understand a lot more about Zika virus. And I think this is incredibly important for the scientific community especially, because this isn’t going to be the last virus that we see. There are many flaviviruses out there dengue, chikungunya that have shown to cause these severe fetal affects. but we have to better understand how we can prevent these infections and understand how they are transmitted and consequences. So I think in two to five years we’re going to have a much better understanding and this is putting light on flavivirus which are endemic in South America and Central America. And that’s a really important thing.
Jessica: This episode was produced by Branson Moore, Naya Villarreal, (me) Jessica Southwell, and Natalie Smith. For more information on Zika virus, please visit www.cdc.gov/zika.
Naya: If you like what you heard, tell a friend and subscribe to us on iTunes. Thanks!