U scholars find malaria-resistant gene

Mosquitoes with the disease-related gene could be eliminated through screening.

Elena Rozwadowski

Every year the warm, damp summer days bring the return of what many call the Minnesota state bird, the mosquito. While the pesky insect can ruin a picnic or a fishing trip, Minnesota mosquitoes do not carry the diseases they do on other continents, infecting and killing millions each year.

Soon, however, those disease-carrying mosquitoes could be eliminated with the help of University scientists’ discovery of a new malaria-resistant gene found in some of the insects.

Research co-author Ken Vernick said the mosquito research began because the insects can be a target for prevention.

“Malaria is a disease that requires the involvement of three organisms: the malaria parasite, the human host and the mosquito host,” Vernick said.

The disease, he said, can be passed from one person to another through a mosquito.

“If you interrupt the life cycle of the parasite in either host, you block the transmission,” he said.

The new research is one of the efforts in the United States to combat malaria. In June 2005, for example, President George W. Bush introduced a plan to help treat and prevent malaria in Africa, increasing malaria treatment and prevention funds by more than $1.2 billion over the next five years.

“The toll of malaria is even more tragic because the disease itself is highly treatable and preventable,” Bush said when he introduced the plan. “Large-scale action can defeat this disease in whole regions.”

Vernick’s research suggests that some mosquitoes have an immune system that resists the parasite. Those that are not resistant might have a defective system.

“Most (mosquitoes) are resistant,” Vernick said. “What that means, then, is that the susceptible ones are basically the mutants.”

Malaria kills an estimated 700,000 to 2.7 million people each year, 75 percent of those being African children. While the disease usually exists in countries with more tropical climates, there were 1,337 reported cases in the United States in 2002, according to the Centers for Disease Control and Prevention.

Eventually the findings could be used to eliminate mutant mosquitoes from the gene pool, although this could be logistically very difficult.

“Anything in malaria is complicated,” Vernick said. “If you get scared away by logistical difficulty, it’s not a disease you can work on.”

One option, he said, could be the use of a fungus that does not infect humans but that can make insects sick. If the malaria-susceptible mosquitoes are also affected by the fungus, they could be killed off or at least be made sick enough to stop laying eggs.

Dr. Jasjit Ahluwalia from the School of Public Health said these initiatives are important, especially when it comes to educating the poverty-stricken populations that are most affected by diseases like malaria.

“Malaria is a deadly killer and it’s very preventable,” Ahluwalia said. “There’s no reason it has to be that way.”

Vernick’s research is not connected with Bush’s plan, but he said the new information could be a key to fighting the disease.

“In the future we’ll be able to detect which (mosquitoes) are susceptible, for example, with a DNA test,” Vernick said. “It makes the target much smaller.”