From Ebola to West Nile to Zika, potentially epidemic viruses lurk everywhere.
For the past seven years, tracking, mapping and trying to thwart the next deadly virus outbreak has been the focus of Dr. Jonna Mazet, a UC Davis wildlife epidemiologist and veterinary science professor. She heads a global group, PREDICT, whose researchers and scientists have helped identify more than 800 viruses worldwide that have the potential to “spill over” from wildlife to humans. On Wednesday, she appears in a new PBS special, “Spillover – Ebola, Zika & Beyond,” that chronicles worldwide efforts to identify – and avert – the next killer virus.
Last week, we talked with Mazet by phone. Here’s an edited version of her comments on virus hunting, hot spots and other topics:
Q: You’ve been called a virus hunter. Is that an accurate description of your work?
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People like to come up with sexy names. A lot of the hard drudgery work of what we’re doing is not so sexy. … I don’t think of myself as a virus hunter, but someone trying to catalog all these viruses so we can predict and prevent these types of catastrophic events. We really want to understand all of the situational pieces: ecology, epidemiology and human/animal behaviors that can result in a spillover.
Q: Your group claims to have discovered 800 previously unknown viruses in the past five years. How alarming is that?
In the scientific community, it’s not particularly alarming. No one had ever looked for these viruses before. The question remains: Which viruses are candidates for the next big bad (outbreak)? We’re working hard to evaluate that risk, using virology (how viruses infect cells), epidemiology, ecology, the different animal hosts and how they interact with people. … Our primary targets now are bats, nonhuman primates and rodents. Those are the high-risk hosts.
Q: Deadly virus outbreaks are inherently scary. West Africa’s Ebola deaths were horrifying, and the recent wave of Brazilian babies born with malformed heads from Zika virus are especially heartbreaking. With the Olympics starting Friday in Rio, do you fear any new exposures or vulnerabilities?
We’ve had people go to Olympic Games before where Zika existed but we just didn’t know it. It’s been in Africa more than 50 years and has been slowly moving through the world. … In Brazil, it’s definitely a hot zone of infection at this particular time. The majority of people who become infected with Zika have only minor symptoms or none at all. We don’t yet know what is the probability of your baby having ill effects, like microcephaly. It’s not 100 percent, but if you are pregnant or planning to become pregnant in the near future, you probably wouldn’t want to be in a transmission hot spot, like Brazil. But any time you bring people together in a huge population confluence, there is risk of illness and disease, like norovirus on a cruise ship.
Q: There’s a human behavior side to combatting virus epidemics. In Bangladesh, researchers discovered that date palm harvesters were unwittingly helping spread Nipah virus. They hung syrup-collecting pots on palm trees at night, when fruit bats swooped in to drink the syrup and then urinated into the pots. How did that situation get turned around?
That scenario was the basis for the movie “Contagion.” … Rather than look at the zombie-apocalypse side of things, I like to look for the positive. We needed to find a solution that was acceptable to the community. People want to drink that palm syrup. It’s delicious. Communities have been drinking it for hundreds of years. There was a campaign to stop people from drinking palm syrup but it wasn’t effective. … The harvesters figured out a wonderful solution. They put a woven bamboo skirt right above the bucket, and it kept the bats out. It was very cheap, cleaner and less disgusting than a drink with bat saliva and urine in it, and had the added benefit of preventing contamination by the virus.
Q: You’ve also found that people’s jobs can affect virus spillover.
In Southeast Asia, there’s a developing market for bat guano. People are actually starting to farm bat guano (for fertilizer). They set up pergolas and shade structures with palm fronds that attract bats. It’s a developing industry because people need a good livelihood, and there’s a market for it. But in bat feces, there are lots of viruses and some can be infectious to people, like MERS and SARS. … We have a whole human behavior team that does assessment of what might be reasonable interventions. It could be disinfectant, proper hygiene, personal protective gear. We want to understand the (virus) risk and figure out how (farmers) can protect themselves and do their work safely, or help them choose other livelihoods that feed their families.
Q: How do we prevent virus outbreaks?
Our government is doing more than any government in the world. We’re making a huge investment ($175 million over 10 years for PREDICT’s work). We’re training people around the world to be safer. … They’re getting trained in laboratory techniques, safety techniques so they’re in a good place to detect and diagnose.
In West Africa’s early stages of Ebola, they weren’t equipped to detect the virus in the laboratory. They thought it was lassa fever, a similar virus (from infected rats). If they’d had laboratory capacity to identify what they were seeing, we could have seen a more rapid response and fewer deaths. There was an outbreak near Congo that was handled quickly. Using existing laboratories, our team helped with detection and diagnosis in just a few days. Travel restrictions were put in place and resulted in very few deaths and the halting of an epidemic. … It takes an informed surveillance system, a qualified laboratory network and an informed community to listen, understand and take effective action. That’s our goal in every community: to have a plan.
Q: Some experts say it’s not a matter of if, but when, another global virus outbreak will occur. Are there particular hot spots that worry you?
The entire world is vulnerable. … It’s proven to us every single year when influenza comes around. (Viruses occur) as people search for new occupations, as more (development) pushes into wildlands, as there’s more contact between people and wildlife, which are the natural hosts. We’re seeing increases in these spillover events and diseases. … They used to be super-rare but they are happening.
But I don’t find the world any scarier than it ever was. Getting in my car is probably the scariest thing I do. I find information empowering. Giving people information and empowering them to understand risks and make good choices. If you want to start a family this year, maybe you don’t go into a hyper-endemic (Zika) area. You can make choices to reduce your risk.
Spillover: Ebola, Zika & Beyond
A new PBS documentary on global viruses that jump from wildlife to humans airs at 10 p.m. Wednesday on KVIE, Channel 6. The hourlong show includes interviews with Dr. Jonna Mazet, a UC Davis wildlife epidemiologist and veterinary science professor, who oversees PREDICT, a group that tracks animal-to-human viruses in 30 countries, seeking to prevent them from becoming epidemics.