Vital Sings: Virus Hunters

Premieres: April 6, 2020.

As run script Distribution Version

Sanjay Gupta: 00:25

They are known as zoonotic, these diseases that can jump from animals to humans. From bats for instance, or birds, with disease names like SARS or MERS. At a time when international travel has connected the world more than ever before, it takes a coordinated, global effort to prevent a widespread outbreak. This is Vital Signs, I’m Dr. Sanjay Gupta.

Sanjay Gupta: 00:45

Their titles might sound like something out of a flashy novel, virus hunter, disease detective but don’t let it fool you, these men and women are doing crucial work all over the globe. Here in the United States, the Centres for Disease Control and Prevention oversee 10 global disease detection centres worldwide. Their job, monitor viruses, help curb potential outbreaks of emerging infectious disease. In fact, they constantly monitor 30 to 40 public health threats every day.

Sanjay Gupta: 01:13

One of these centres is in South Africa. CNN’s David McKenzie met up with the team in the field for a closer look at the depths they go, literally, to do their job.

Sanjay Gupta: 01:30

It’s a slow and cumbersome descent, hindered by head to toe protective suits and respirators, but these are the only things standing between safety and exposure.

David McKenzie: 01:40

So we’re heading into the depths of the earth, in the Kurtworm Cave, and the aim is to find one of three bat species that could pose a viral threat.

Sanjay Gupta: 02:01 In this cave are thousands of bats, any number of which could contain deadly pathogens.

David McKenzie: 02:07

So what are we seeing here?

Wanda Markotter: 02:08

So this is Miniopteris Natulensis or the long fingered bat.

David McKenzie: 02:12

And these are insectites?

Wanda Markotter: 02:14

Yes, they are insectaforus bats, and they are in these huge amounts or large colonies in South Africa.

David McKenzie: 02:20

There are a lot of bats here.

Sanjay Gupta: 02:23

These are researchers with the University of Pretoria, and they are virus hunters. Their job, catch bats to catch diseases, before they transfer to humans.

Wanda Markotter: 02:34

So this is Miniopteris Nataulensis, and the reason they’re called the common is the long fingered bat is because these four arms are so long, and if you can stretch the wing.

David McKenzie: 02:47

Wow.

Wanda Markotter: 02:49

And this is a male.

David McKenzie: 02:51

Why could these bats pose a threat?

Wanda Markotter: 02:54

So this specific specie has been implicated in some of the rabies related viruses, ever Noro virus, and they’re in high population densities, and people that go into caves get into contact with them, but the other thing is also that they roost with a lot of other species that gets more into contact with humans. So they can also transfer pathogens to other species of bats.

Sanjay Gupta: 03:22

Something that might surprise you is where this work is taking place. This is not some remote cave, we are only miles away from the city of Johannesburg, a heavily populated urban area.

David McKenzie: 03:33

I mean this looks almost cute, but not this specific species, but bats in general, harbour zoonotic diseases.

Wanda Markotter: 03:44

They’re one of the species, and I think, unfortunately, they’ve been implicated quite a bit, and there’s different reasons for that. They’re 20% of all mammals, so they’re a huge group, it’s not just this bat, there’s 1,240 species almost worldwide. So they represent a big group of mammals, and that’s why we probably find a lot of viruses in them, but there’s not a lot of research of how many of those pathogens actually made people sick or made animals sick.

Wanda Markotter: 04:12

Even with Ebola, there’s not a direct link between the human outbreaks from the bats. We see some evidence in the bats, and we see human outbreaks, but we can’t say that bat caused the human outbreak. You know, so a lot is still unknown, yes.

Sanjay Gupta: 04:25

A lot’s still unknown, and a lot to keep track of.

Jordan Tappero: 04:34 If we look over here, you can see the global disease detection operation centre, and that shows where we are tracking infectious disease threats.

Sanjay Gupta: 04:44

That’s why having a central command centre is critical for this type of work. And you’ll find it at the Centres for Disease Control and Prevention headquarters in Atlanta Georgia. Dr. Jordan Tappero is the director of the global health protection centre here, at the CDC.

Jordan Tappero: 05:00

Only about 30% of countries even self report that they are able to prevent, detect, and respond to infectious disease outbreaks, and that’s through the international health regulations, and so we are working around the world to try and improve capacity so that we have partners everywhere to respond quickly.

Sanjay Gupta: 05:17

But within this organisation, how many threats if you will, are sort of being assessed, evaluated?

Jordan Tappero: 05:23

Yeah, one of the things that we have in our division is the global disease detection operation centre, GDD op centre. Let’s just use for example the 24 month period that we were activated for the Ebola response here in the emergency operation centre. During that time, we were tracking almost 300 infectious disease outbreaks of concern in 145 countries.

Jordan Tappero: 05:44

Many of them, because of that communication with our partners, ministries of health, WHO, animal health organisations, were able to be thwarted. Some of them have taken bigger response.

Sanjay Gupta: 05:56

That’s a huge number, I mean 300 potential disease outbreaks in 145 countries, just about every country on the globe. Do you have enough resources, and what does it take to really be able to stay on top of all that?

Jordan Tappero: 06:08

It’s a very good question. To start off, those 300 outbreaks that I just mentioned, in 145 countries, that’s just the ones that we’re critically monitoring. We have had over 1,700 outbreaks that we’ve participated in over the last six years alone. Those are more common outbreaks that we don’t raise to that threat where we’re really monitoring every day.

Sanjay Gupta: 06:31

That monitoring starts with teams on the ground, in caves like this one.

David McKenzie: 06:36 So they have to crawl through the narrow gaps into the different chambers, because in each chamber there could be a different type of bat, which could have different viruses.

Sanjay Gupta: 06:47

Each of these bats has the potential to carry Rabies, Marburg, perhaps even Ebola. Some of the planets deadliest and least understood viruses.

David McKenzie: 06:56

And then, do you ever get nervous doing this work?

Wanda Markotter: 07:00

The risk is low. I mean, it probably looks scary if you look at what we’re wearing, but the risk is really low, I mean these bats that we just caught were flying around, so they’re probably healthy, so we will probably look for antibodies that can just show that being exposed.

David McKenzie: 07:16

But why is it important to do this work for public health?

Wanda Markotter: 07:19

So, if you don’t know what’s in the animals, you won’t be able to identify human outbreak quickly. So, most of the time we only respond when there’s a lot of humans already dead, and then we don’t know where the virus came from or where the pathogen came from. So if we know what’s in the populations, we can actually tell people before hand to be careful. And if we know how it transmits, whether it’s through urine, or faeces, or a bite, then you can actually make public outbreak recommendations about it.

Wanda Markotter: 07:47

Otherwise, you just react when there’s already a lot of people dead, like we did in the Ebola outbreaks.

David McKenzie: 07:52

So if you just react, it’s often too late.

Wanda Markotter: 07:55

Yeah, and you respond too late. You know, because you only react when you see a lot of human deaths. Whereas if you can see what’s in the animal population, you know if it’s seasonal or when it occurs, you know when the risk is high. So for instance, if people build a house right outside this cave, you have an idea of what the risk to the human population will be, or to cavers that come in.

Sanjay Gupta: 08:19

Back on the surface, a makeshift lab is setup right outside the entrance to the cave. Samples are collected from the bats fur, mouth, and wings. Everything meticulously recorded, with the samples now from the bat cave, it’s time to move on to the next location.

Sanjay Gupta: 08:40

Next, David and the team are heading to a horse farm near Johannesburg, where tiny mosquitoes threaten the health of these large animals, and also serve as an early warning system for humans. Gail Foxcroft is a professional show jumper in South Africa, and her horses are more than just prize winning investments, they are part of the family.

Gail Foxcroft: 09:11

You’re asking so much of the horses. You’re asking them to do stuff for you. It’s not about force, it’s about, it really is a partnership. And you’re asking them to do really huge athletic endeavour, that you ask from them. The more they work with you, the easier it is, and the more likely you are to succeed.

Sanjay Gupta: 09:34

So when her champion horse, Lindenberg, became sick, it was devastating.

Gail Foxcroft: 09:39

He couldn’t put any weight on his front feet. So we were assessing his feet, thinking it was limonites, just an inflammatory disease. Then he started to get really shaky, and eventually he sort of sat down, he couldn’t control is back. Obviously it’s all neurological symptoms, and then he eventually laid down and we couldn’t get him up, he actually just could not stand up.

David McKenzie: 10:01

Were you trying to lift him up?

Gail Foxcroft: 10:03

Yeah we tried to do everything with him, and he couldn’t stand up, and then as I said, it got to where, he could still lift his head, but he couldn’t breathe properly, so he had to have a tracheotomy.

Sanjay Gupta: 10:15

The neurological symptoms became so bad, Gail made the painful decision to put Lindenberg down. But the symptoms didn’t quite line up with the original diagnosis, it was eventually determined that Lindenberg had Shuni Virus, one of the first cases here.

Gail Foxcroft: 10:32

I think that was the biggest thing that we needed to know. Another, yet another virus out there that we had to be careful of, and we had to vaccinate for.

Sanjay Gupta: 10:43

Like West Nile and Zika, Shuni Virus is transmitted by mosquitoes. So now, Gail invites researchers to her horse farm, to trap and test the insects.

Gail Foxcroft: 10:54

I know that at some stage last year, they found a huge number of the kulegs mosquito that carries the West Nile, but they didn’t find any of the virus in the mosquitoes. And we need to know, we need to know how to control it, what steps we take, and eventually, hopefully, how to combat the disease, because it’s something that has a huge mortality rate.

Sanjay Gupta: 11:17

It’s all part of the disease monitoring taking place here in South Africa, one of 10 global disease detection centres worldwide. The health of these horses is actually an early warning sign for what could be coming to humans.

David McKenzie: 11:30

Why is it important to have an early warning system?

Marietjie V: 11:35

It’s difficult in Africa, relative for example in the United States. When West Nile first emerged in the United States, they saw birds dying. So in Africa, the birds are genetically resistant many of the times, because these viruses have been around for many years. So, we can’t use them as an early warning system, but what we do is to then look for animals with the type of science that we know is associated with virus infections caused by these vika borne viruses. So for example, neurological symptoms, encephalitis symptoms, if we see paralysis, if we see fever outbreaks in lots of animals, and then for example abortion storms, that’s a way that we can then see what could potentially fever going around an abortion storm, or the viruses that we look at in this specific study that have neurological science.

Marietjie V: 12:29

In animals, it could be things like West Nile Virus, and then these African viruses that we’ve identified, such as Shuni Virus, Middlebuk Virus, and Reeses Braun Virus, for example, that also caused abortion in animals.

David McKenzie: 12:41

So why do you have to keep surveying the virus threats all the time?

Marietjie V: 12:45

So these viruses circulating in mosquitoes and we don’t know whether it occurs every year, or whether it’s associated with changes in temperatures or in rain fall and so on. So by actually doing continued surveillance from month to month, we can see what the seasonality of these viruses are, we can see when outbreaks happen, we have a early warning system to determine if there’s an increase in virus, and in the vectors that carries them, and we can potentially do something about it in prevent infections in humans and animals.

Sanjay Gupta: 13:16

For Gail it’s not just about protecting humans, but her horses too.

Gail Foxcroft: 13:21

You know you spend years and years bringing horses up to the top level, apart from the emotional impact that it has on you, it has all the other impacts. It’s financial, it’s also you know, you have a top competitor, starting his career, and the next thing, you’ve lost it, and it takes years and years, it takes a minimum of like six or seven years to get a horse to the top level.

David McKenzie: 13:40

It was obviously a great tragedy that you lost your prized horse, but do you see maybe some good coming out of this research for humans as well?

Gail Foxcroft: 13:49

Absolutely, I mean the fact that now, that medical research is here every month to take samples and things, we have to know how it’s spread, or what the concentration of mosquitoes is in a certain area at a certain time of the year to know which are the bad times, when you’ve got to use a lot more protection, all those kind of things. I mean it’s vital, and the fact that people can get the West Nile as well, it’s obviously a huge issue. So, it’s fantastic that they’re here, and we support it whole heartedly.

Sanjay Gupta: 14:23

So now that the team has samples from bats and mosquitoes, it’s time to visit the lab. Protective gear required again, because this place houses some of the most deadliest pathogens known to man. In 2014, West Africa saw an unprecedented outbreak of the Ebola virus. Cases were concentrated in Guinea, Sierra Leone, Liberia, but the disease was first discovered in Central Africa, in 1976. The recent outbreak was this race against the deadly virus, and laboratories all over the world were called to help.

Sanjay Gupta: 14:55

Imagine a workplace where some of the worlds deadliest pathogens are kept. That’s what these labs are working with, and it’s also where Dr. Sherif Zaki thrives, a disease detective in every sense of the phrase. From Anthrax to Ebola, and now Zika, he’s been solving the mysteries of pathogens for decades.

Sanjay Gupta: 15:20

At the CDC headquarters in Atlanta, Dr. Sherif Zaki’s lab is busy, under these microscopes are some virus you and I have likely never heard of, and would never want to.

Sanjay Gupta: 15:32

Given that you don’t know what exactly it is that you’re going to see under the microscope, how do you know how to protect yourself? How can you be 100% that what you’re dealing with isn’t something that could make you sick?

Sherif Zaki: 15:45

That’s a good question, so fortunately with pathology, we fix our tissues in a chemical that really kills all, most infections. So we feel comfortable dealing with it, but I think the problem, when you start worrying is when you’re taking those tissues, as a pathologist, at autopsy, or you’re collecting specimens, that’s when you have to worry about having the proper protection, but you know, your universal protections are pretty standard, as long as you’re practising  those, I don’t have any concerns about it.

Sanjay Gupta: 16:21

Over the last few years, Ebola was a big focus for Dr. Zaki and his team of pathologists. When you first started looking at Ebola, could you have predicted, based on anything you were seeing, how wide spread this outbreak would be?

Sherif Zaki: 16:36

We actually started looking at Ebola at least, myself, in the mid 90s, we went in Zaire, and didn’t know how much the virus spread. If you asked me 10 or 15 years ago, I would say no, this is not going to happen, so I would’ve been totally wrong, and the reasons are, they’re the poorest borders, 10 or 15 years, you wouldn’t have the same bus routes, etc, you used to. In fact, if you had Ebola, they put you in a hut, give you some food and water, and you either make it or not. So it didn’t travel much.

Sherif Zaki: 17:12

But nowadays with the global travels, people can be on an aeroplane before they become symptomatic. It’s not surprising that it would get to this magnitude, but that’s not hindsight, again, I would’ve been wrong, I would not have predicted that it would have happened.

Sanjay Gupta: 17:30

These new, emerging, infectious diseases typically don’t actually cause much disease in humans, we see them, they swap back and forth between animals and humans. Is there anything that you’re particularly keeping an eye on right now, something that’s new that you’re thinking, well, I got to keep an eye on that one?

Sherif Zaki: 17:46

It’s always the unknown, I mean you have to keep your options open in terms of something new. If anything we’ve learned that, expect the unexpected basically, and there are new diseases that come with new twists in terms of exposure, etc. So, I’m more worried about things that we don’t know about.

Sanjay Gupta: 18:08

Knowing about these viruses is certainly the first step. Before some of these pathogens reach Dr. Zaki’s lab, they come here.

JT Paweska: 18:17

So there’s only a few people who do have the privilege to actually open this door here, right. Okay. I hope it works.

Sanjay Gupta: 18:27

David McKenzie has been taking us on this journey with a team of South African virus hunters. The last stop is here, a level four bio lab in South Africa. The highest bio security level. And the only lab of its kind on the African continent.

JT Paweska: 18:46

You know, bio safety level four, we are working with the most dangerous pathogens known to science, and very often, the knowledge about how we are maintaining nature is very enigmatic, so there’s many questions about those viruses. But the major is that they are very dangerous pathogens, and often we don’t have much to offer to people who are actually infected with these viruses, there’s no vaccines, there’s no anti virals. That’s why operators in the DSL four, have to be well protected.

Sanjay Gupta: 19:20

Researchers have to train for a year before they can even step inside this lab.

David McKenzie: 19:25

And what is so crucial about the work that is being done here for public health?

JT Paweska: 19:31

What is crucial, this lab is mostly focusing on diagnostics, so we do provide the diagnostic services for these unusual pathogens, and this type of diagnostics can’t be done somewhere else. So you need this highly specialised and highly technical lab to process the specimens from Ebola infected patients, Maniel infected patients, or Lasa infected patients. So, for that you need these special facilities.

JT Paweska: 19:59

Obviously the diagnosis is extremely important in terms of patient management, but also if we diagnose, we know about the distribution and what’s happening with the viruses, and the outbreak, and we can actually help to implement some control measures. But also, you know, when we work on these viruses, we can also understand and actually develop as well the diagnostic reagents. So also diagnostic reagents are developed in these labs.

JT Paweska: 20:33

Also we test some components, some chemicals, or antivirals to eventually provide some kind of a treatment.

Sanjay Gupta: 20:42

From the field to the lab, you have to admire the bravery of these men and women. The unsung heroes working behind the scenes to keep us safe from emerging diseases. In a sterile environment, like a laboratory, wearing heavy hazmat suits and breathing through tubes, it can be easy to lose sight of the true impact here. Human lives often depend on this research, and the science. So if and when the next viral outbreak happens, no matter where it is, we can be ready for it. For Vital Signs, I’m Dr. Sanjay Gupta.

Sanjay Gupta: 20:42 (silence).