A new era of epidemics

{***Pause/Music***}

{***Noah***}

Coming up on Harvard Chan: This Week in Health…A new era of epidemics.

{***Marcia Castro Soundbite***}

(What makes it a new era is that we know those epidemics are going to keep happening. We just don’t know when and we don’t know what’s gonna be the pathogen.)

In this week’s episode: Two experts on Zika virus explain what that outbreak can teach us about responding to future epidemics.

{***Noah***}

Hello and welcome to Harvard Chan: This Week in Health. It’s Wednesday, October 25, 2017.

I’m Noah Leavitt. Amie Montemurro is off this week.

In this week’s episode, we’ll be speaking with two leading experts on Zika virus—which grabbed international attention when it sickened a million people in dozens of countries more than two years ago.

As we’ve discussed in previous episodes: Zika has been linked to microcephaly in children born to infected mothers. That’s a condition where infants are born with abnormally small heads.

And while Zika is primarily mosquito-borne, research has shown that it can also be sexually transmitted.

Today, Zika there are no large outbreaks of the virus, but researchers say it’s still endemic—meaning that there is regular transmission in some areas—including Brazil—which saw tens of thousands of Zika infections and more than a thousand infants born with microcephaly.

I had the chance to speak with two researchers who have studied Zika extensively.

Marcia Castro is Associate Professor of Demography in the Department of Global Health and Population at the Harvard Chan School. She has extensively studied the lingering effects of Zika in Brazil—including how the virus has affected physical and mental health—as well as its effect on birth rates in the country.

And Celina Turchi Martelli is Professor of Epidemiology of Infectious Diseases and a researcher at FIOCRUZ in Brazil. As the Zika outbreak began, Turchi worked closely with other scientists to track what was happening. Her research helped played a critical role in confirming that Zika did indeed cause microcephaly.

Both Castro and Turchi will be part of a panel discussion on October 26 as part of Harvard Worldwide Week. The event, The New Era of Epidemics: Surveillance, Response, Impacts, and Challenges will discuss lessons learned from past infectious disease outbreaks, and ways to prepare for future public health crises.

I spoke to Castro and Turchi about what Zika can teach us about preparing for future epidemics—as well as what Brazil did well in its response to the outbreak.

Just a note that we spoke with Turchi via Skype from Brazil so sometimes she can be hard to hear—so you may hear me jump in occasionally to paraphrase.

Now here’s our conversation.

{***Castro and Turchi Interview***}

NOAH LEAVITT: It what ways is Zika kind of emblematic of this new era of epidemics? And do you think that we’re likely to see more infections like Zika where, as you kind of described it, there was this massive outbreak? The headlines may be gone, but it’s still an endemic infection.

MARCIA CASTRO: I think that what makes it a new era is that we know those epidemics are going to keep happening. We just don’t know when. And we don’t know what’s going to be the pathogen. But it’s pretty much a done deal that they’re going to happen.

And we have a world that is much more connected. We have cities that face major infrastructure problems. So, you take any disease transmitted by Aedes aegypti, right? I mean the mosquito is the king in those urban areas. There are plenty of spaces where breeding habitats are– you can find them everywhere. So, it makes the challenge of even controlling the vector a daunting task, honestly.

So, you have a connected world. You have people moving for different reasons. You have conditions that favor any kind of infectious disease, honestly. If it’s transmitted by vectors, because of conditions of cities, but because of high density, you know, if it’s contagious person-to-person, you also have an ideal scenario.

So, in terms of Zika per se, or honestly, other diseases transmitted by Aedes aegypti, we have other viruses also transmitted by the same vector. And we could easily have an outbreak of some of those. Dengue is one example, but there are others. I personally think we are going to have another outbreak of Zika. I mean, if you look at the historical pattern of dengue, that’s what you have. You have epidemic years. It comes down. Then you have other epidemic years.

And if you look just in Brazil, ’14 was you had lots of dengue. And then ’15 you had the beginning of Zika. And ’16 was Zika. And then you had chikungunya. It’s all the same vector. You don’t have epidemics of all three concurrently, which is quite interesting by itself, which that’s a different story. So most likely, Zika is going to come back. Where and how severe, we’ll see. But I think it’s very unlikely that we’re not going to have another outbreak of Zika.

 

{***Noah***}

And a quick interruption here because Turchi made a key point, but it was a bit hard to understand.

Turchi says that one of the main challenges about Zika is that the disease was considered by most researchers to be benign—that there were no serious health effects associated with it.

Going forward, Turchi says scientists can’t afford to assume that past assumptions about a disease’s impact will hold true in the future.

CELINA TURCHI: So, we had no previous knowledge of the association of Zika virus and birth defect. We had no previous knowledge of the Zika virus introductions in large urban centers, like it did in the Northeast of Brazil. So, it was the first large epidemic of congenital viral infections since the ’40s. Remember the rubella.

But in a sense, it was different because there was a striking spread of the virus in the American continent. I mean, imagine in one, two year’s time. I mean, a map that was considered to be a blank space of Zika all become very completely colored by the Zika virus infection, and interesting, multiple routes of infection.

Probably we don’t know how much sexual transmission plays a role in disseminating to other areas. But now, we have a vector-borne disease that’s sexually transmitted. It’s vertically transmitted with a very severe birth defect and making epidemics of birth defects. That’s seems something very out of our public health, let’s say, radar, or public health imaginations.

{***Noah***}

And just to jump in again—Castro and Turchi say there are several factors driving this new era of epidemics.

One major factor is climate change—because changes in temperature may allow disease carrying insects—such as the aedes aegypti mosquito—to live longer than they otherwise might, or to spread to areas where they previously wouldn’t be able to survive.

But another key factor driving this new era of epidemics says Castro is our increasingly inter-connected world.

MARCIA CASTRO: We are much more mobile and connected than we used to be. I think another one is the pattern of urban growth that basically, the urban growth is much faster than the infrastructure that is provided in the city. So, you have those, basically, those concentrations of very, very poor housing. So, it’s almost as you have those– I don’t like to use this word– but hot spots where everything is lacking.

And in the health conditions, don’t even resemble the average health conditions in an urban area, which is supposed to be much better in rural areas. So, the urban growth is an issue. And it’s not by chance that one of the sustainable development goals is completely dedicated to sustainable cities. And although if you look at the targets of that goal, although they don’t even use the word health, if each one of those is achieved, you’re going to get rid of a series of diseases, including those transmitted by Aedes aegypti, because they basically deal with this major need of cities to have infrastructure and to have local conditions that basically promote a healthier environment. And therefore, it’s going to impact on the health of the individuals.

And the other thing is the whole way that people are changing, for example, deforestation. So, you take Ebola, right? So, you have the population getting closer contact with areas where the animals were living very peacefully with the virus, not creating any problems. But as you reduce this distance between the forest where you know the viruses is there, especially for zoonoses and where people are living, then the contact becomes much more likely.

And then the chance that you have either a zoonose that we know already or a new one emerging that then creates what Zika created. You don’t know what to do. You don’t know what it is. And you don’t know how to fight against it. It’s very likely. So, it’s a combination of mainly the human action, right, so transforming the environment, creating conditions in cities that are very suitable for disease to spread, and just the way we move around.

CELINA TURCHI: We have a very connected society at the moment, like, say, internet, media, WhatsApp. And it has its advantages, like you have information faster. You can produce data, and data coverage, and so on. But on the contrary, these tools, or these facilities also produce a lot of noise and a lot of fake news. And the idea of causing panic, I think, in this new world is much greater. And it’s a lot of public health concern about it. And doing research in a situation like an epidemic is such a pressure from– for results for a response and for all this noise.

MARCIA CASTRO: I think this is a terrific point because we live in an era where science is not really fully respected. And we, as scientists, have a really hard time in showing people that evidence based on facts is actually what should be taken into account, and not statements not based on facts. So, if you take Zika, for example, there were crazy assumptions about how the virus was spreading, a larvae sighting, a vaccine. And then in the middle of all of this, there was the Olympics as well. So, there was so much nonsense going on. And that’s just one example.

And then, I mean, the examples are innumerous. Like it’s vaccines are going to make you unable to have kids. I mean, you name it. And those things only set back efforts in public health. I have no idea how we’re going to fix this. I think the school is here. They are trying to make a big effort. Now, we have a site just to share ideas and try to reach a much larger audience. But sometimes, I feel that trying to break that is even harder than the research we do.

NOAH LEAVITT: I think you both touch on this idea of not creating unnecessary panic. So, what are some ways to do that? But I guess it is difficult, as you touched on, Celina, when it’s happening in the moment and you’re trying to gather evidence. So, are there any strategies from a communications perspective to maybe reduce the panic when we do have an outbreak like Zika?

CELINA TURCHI: The timing of science, it’s very different from the timing of surveillance and public health decisions. And sometimes, to give a response, science to give a quick response, there was something very, let’s say, very difficult for scientists because we do have to write projects. We have to be very careful with the answers. Maybe the understanding put forward that science is not a panacea.

I mean, it does not clear everything. You have to build up evidence. Science is more complex. But we do have to have clear guides, what’s possible for prevention and control. And so, I think scientists should learn to design better proposals to give some answers or to say things clearly within this complexity of science.

We don’t know everything. We’re just building evidence. And that’s the best we can say to make sure that the people understand that we don’t have the final answer. And maybe we don’t even have an answer right now. But we are searching. And we’re trying to cope. And we’re trying to collaborate with public health the best way we can.

NOAH LEAVITT: And Celina, so you mean, you had talked about kind of the challenge of surveillance, almost like in real-time as things are kind of unfolding. So, I’d be interested to know. I mean, with regards to Zika in Brazil, were there things that went particularly well with the response? Were there challenges? And I guess, are there any lessons to be learned for future disease outbreaks?

CELINA TURCHI: Yes, I think that the first lesson is that no virus can be thought to be not to cause anything in the community if we don’t know. I mean, we must pay attention to every new virus in a naive population and how this population, what is going to be the effect in this population. I think that the first lesson that we– the second lesson is that I think that we learn to share data and to have more collaboration. I think that science, we live a very competitive ground for money and very competitive for, let’s say, for projects or for funding. And I think that in a way, academics teaches that we have to collaborate between institutions. And we have to share data and share what we know in order to speed the knowledge of the field.

NOAH LEAVITT: I mean, it seems like– I mean, I’ve seen you guys have this idea of surveilling all the diseases everywhere. I mean, it seems like this daunting task. So, on a really broad scale, what can larger health systems do country level, international level, organizations like the WHO? I mean, what are the steps of these large systems should be taking in order to make sure people on the ground, scientists, are better prepared when an epidemic strikes?

MARCIA CASTRO: Different countries have different levels of being ready. Or even they have a surveillance system in place. Some countries just don’t have a good one in place. So, I think what happened in Brazil is first, because it was a disease very similar to dengue in the beginning, it caught attention, because it was similar, but it wasn’t dengue.

And we really have to acknowledge the work that the people right there on the field seeing the first cases had in bringing the issue to attention. And then the ministry called an emergency. So, there was a big role played by those people right there seeing the patients. So, you know, if you have that concern and if you do have some level of surveillance system, you probably can pick up things in the beginning.

The issue is sometimes you have an outbreak starting in a country that– take Ebola, right? How many physicians were in Liberia in the beginning? How many nurses were there in the beginning? I mean, you didn’t even have the infrastructure to respond, needless to say, to do surveillance. So, in that regard, I think we were lucky that Zika hit Brazil.

It’s an odd thing to say. Brazil was committed, was not hiding cases. Some countries were doing this, OK, because they don’t want to impact tourism. Brazil had the courage. It came out. It’s an emergency. It’s happening. And honestly, regarding all the constraints and money, it did the best it could. It wasn’t perfect, but it was great. Right?

So, it depends where it starts. And if it hits a country that doesn’t have like a health system that is, at minimum, prepared to handle an emergency, be it whatever it is, and that it can have the resources, human and financial to attack the problem in the beginning, then it can be a disaster. So, I think the answer is not a simple answer because it really depends on the conditions that you find on the ground when the epidemic hit.

One thing that is important for health systems to pay attention is at their borders, their country. So, as we mentioned here before, it’s a very interconnected world. So, you take Brazil. It’s a country of continental size. And we have a huge problem developing now, which is malaria in Venezuela. It’s all in the southern part. It’s mainly falciparum. And it’s a matter of time when those cases are going to start popping up in the northern part of Brazil, because they are mainly miners. This is all gold mining.

And, you know, the border is very fluid. People just cross back and forth. And there are some people from Venezuela coming to Brazil because the conditions there are so horrible that they’re just fleeing. So, you have to pay attention of what’s happening beyond your borders and be ready to respond. Because in situations like this, you treat your own population and you treat the population across the border, because that’s the only way to prevent that you’re going to have a major introduction of a pathogen because of the conditions happening in the other country.

And historically, that’s pretty much what Brazil does in all countries that border the Amazon region, exactly in the context of malaria. But Venezuela is a special case because malaria is completely out of control in the southern portion of the country, which is exactly the area bordering Brazil.

NOAH LEAVITT: I mean, that kind of seems like, again, what we were talking about before, like the world being interconnected. I mean, it’s not this matter of if. It’s just a matter of when. Is the kind of safety net, I guess, making sure that primary care systems are strong, because then doctors on the front lines are able to see that as things evolve? I mean, is that kind of the safety net underlying all of this?

MARCIA CASTRO: That is one of the most fundamental things. And, again, it’s not by surprise that one of the targets of the SDG for health is universal care. And primary health care is the cornerstone of providing universal care. And, again, I mean Brazil did an amazing thing in terms of providing primary care, which is a special program called Family Health Strategy. And it covers areas that before, had absolutely no access to primary care. And you have teams that go in there and provide care to the population.

So, we have plenty of evidence that providing a special attention to primary care could reduce a lot of the preventable conditions in the population. And I think one problem is sometimes, you lose this primary care because of political issues. So, we cannot neglect to consider that countries can go through economic crisis or political crises that can compromise gains of decades from the past.

And, again, Brazil is going through a major crisis right now. And the government approved some legislation that is basically dramatically cutting funds for health, and education as well, but cutting for funds for health. And it’s probably going to shrink dramatically how primary care is provided. So, if Zika was going to start in Brazil this year, I’m not quite sure what the outcome would be because there is a very different perspective on the role of the universal care in Brazil and the role of primary health care.

{***Noah***}

That was my conversation with Marcia Castro and Celina Turchi.

If you are able to make it, their event will be held on Thursday, October 26 at the Joseph B. Martin Conference Center here in Boston.

If you can’t make it, we’ll have complete coverage on our website, hsph.harvard.edu.

That’s all for this week’s episode.

A reminder that you can always find us on iTunes, Stitcher, or Soundcloud.