Mosquito bites are a nuisance to humans, but the diseases transmitted through them can have serious consequences.

Experts are brainstorming new ways to control insect populations — like genetic modification to prevent them from transmitting diseases.

Since the 1950s, the Centers for Disease Control and Prevention and other organizations have tried to eradicate diseases that transfer to humans through insects, like malaria. Genetically modifying mosquitos is one method experts are using to try to curb malaria and yellow fever, but the risks of releasing genetically engineered insects into the wild are largely unknown.

Researchers from the University of Minnesota created a risk analysis framework to show scientists and officials the potential effects of releasing genetically modified insects. The scientific journal Ecology and Evolution published the study in its October issue.

Experts are aware of some of the ecological effects genetically engineered insects may produce, said entomology doctoral candidate and study co-author Amy Morey. But the study offers an inclusive list of the potential short- and long-term effects.

“It’s all surrounding this idea that when you have a new technology, you want to know what’s going to happen,” she said.

The framework may help genetic engineers, government officials and scientists analyze any risks and make safer decisions, doctoral candidate and co-author Alexander Roth said.

Uncertain risks

Since the impact of genetically engineered insects on the environment is largely unknown, some are opposed to using them to control disease.

People for the Ethical Treatment of Animals college campaign coordinator Kenneth Montville said experts plan to release modified insects in environments with fragile ecosystems, which could harm the environment.

“Very rarely do these sort of risk assessments actually assess the risks of animals involved,” he said. “We’ve had anti-malaria agents for years and years; keeping mosquitos at bay is almost a non-issue.”

In 2010, the World Health Organization recorded about 219 million malaria cases worldwide, and about 660,000 people died that year of the disease.

Montville said there are better methods to avoid mosquito-transmitted diseases, like using citronella candles, growing basil plants around the home or eating a vitamin B-rich diet.

Despite the uncertain outcomes from releasing genetically engineered insects, Roth said some companies are moving forward with the technology.

In 2009, British biotechnology company Oxitec began field trials with genetically engineered mosquitos in the Cayman Islands. Oxitec made the mosquitos sterile to reduce the population.

Now, the company has started looking to conduct trials in the Florida Keys to reduce the viral disease Dengue fever.

“They’re still in the process of figuring out if the technology works and what the effects are,” Roth said.

A safer future

University researchers didn’t create the framework to decide which risks were better or more likely than others, doctoral candidate and co-author Joe Kaser said.

Instead, the framework shows multiple possible outcomes. It will be up to the policymakers and scientists reading it to decide whether the risk is worth the cost.

Ecology, evolution and behavior doctoral candidate and co-author Aaron David said that because scientists have released few genetically engineered insects, the research group looked at other methods of insect control like pesticide use to develop the framework.

The researchers predicted eight evolutionary and ecological outcomes of releasing genetically engineered mosquitoes into the wild. One prediction says genetically modified mosquitos could eventually evolve to lose the initial changes to their genes, Kaser said.

Another possibility is that humans wouldn’t develop immunity to malaria if mosquitos don’t infect people with the disease anymore, Kaser said, so humans would be more susceptible to a future malaria outbreak.

The study serves as a stepping point for future risk analysis, Morey said.

“It’s a very big field,” she said. “At the very beginning, you’re just trying to come up with what could possibly happen [and] where should we even begin to look.”