Luke Trinity and Scott Merrill are part of a team of University of Vermont researchers using video games and computational models to understand human behavior. (Sally McCay/University of Vermont)
Luke Trinity and Scott Merrill are part of a team of University of Vermont researchers using video games and computational models to understand human behavior. (Sally McCay/University of Vermont)

Video games aren't just for fun — they can also be used to fight disease, new research shows.

Scientists combined video games and computer models to show that the spread of a deadly pig disease can be slowed if farmers avoid risky behaviors. The authors say insights from the video games could be used to encourage people to follow rules, in the swine industry and beyond.

Since its emergence 40 years ago, porcine epidemic diarrhea virus (PEDV) has swept through pig farms in Europe, Asia and North America. When PEDV erupted in the U.S. in 2013, it wiped out 7 million pigs. "A thimbleful of this virus could infect every single pig in the United States," said Scott Merrill, a professor in the Department of Plant and Soil Science at the University of Vermont who was second author on the study.

PEDV is especially harmful to young pigs.

"More than 90 percent of [infected] piglets would die," said lead author Gabriela Bucini, a postdoctoral researcher.

Merrill added, "We've seen and had discussions where people decided that they're not going to work in the industry anymore because of PEDV, because it was just really hard to see this many animals get sick and die."

While PEDV remains a threat to U.S. pig populations, its incidence has dropped since 2013. The researchers attributed the decline to a change in how farmers and other members of the production pipeline implemented safety protocols, such as disinfecting vehicles, clothing and footwear that could transmit infection between farms.

It's clear that those protocols play an important part in preventing the spread of swine diseases, but until now there hasn't been a way to measure just how important.

Virtual pig farms

Bucini and her team used video games to tackle this problem.

In one game, players assume the role of pig farmers and try to complete tasks while preventing their pigs from being infected with a contagious virus. As they complete the tasks, players are reminded of the risk of infection and are given the option to obey or ignore safety protocols like disinfecting clothing when entering and exiting buildings. Complying with safety protocols decreases the odds of infection, but uses up valuable time.

The games provided insight into how people behave in the real world, which the researchers incorporated into a model of PEDV transmission to track how the disease would spread — and learn how best to contain it. One of the key variables was the number of farmers who avoided risk by following the recommended safety protocols.

"We did find that by nudging or shifting the population of producers toward more risk-averse positions, the disease was more under control," Bucini said.

Images from biosecurity video games show two risk scenarios. Players were more likely to comply with biosecurity practices when risk was presented graphically, right, rather than numerically, left. (UVM Social Ecological and Simulation Lab)

Even a small change could have a big effect.

The model showed that nudging just 10 percent of risk-tolerant farmers away from risky behaviors decreased the number of PEDV cases by 19 percent. However, in order to substantially slow the spread of the disease, more than 40 percent of risk-tolerant farmers needed to change their ways. 

Steve Dritz, a swine specialist and professor in Kansas State University's College of Veterinary Medicine who was not involved in the study, expressed hope that the model could be used to prevent the spread of future livestock disease outbreaks.

"It's a wonderful tool for when ... you're trying to figure out, 'What are the factors that I can control to keep incursions of disease out that I've never seen before?'" he said.

From pigs to people

The implications of the findings extend beyond pig farming to any situation where people need to follow rules to avoid negative consequences. Using their video games, the researchers found that changing how they presented the consequences of rule-breaking influenced the likelihood that people would follow the rules — even if the consequences themselves didn't change.

For example, conveying the risk of infection with a colorful dial rather than with percentages caused a dramatic jump in the number of game players choosing to take the time to disinfect their clothing when entering and exiting farm buildings, from 30 to 82 percent.

Merrill explained the significance of this finding using a basic hygiene practice: "If you're getting 30 percent of the people washing their hands versus 82 percent of the people washing their hands, that can be a huge difference in how quickly and how far any sort of disease spreads."

The research was published in Frontiers in Veterinary Science