2007年VOA标准英语-Researchers Develop Mosquitoes Resistant to Mal（在线收听）

By Paul Sisco
Washington
23 March 2007

U.S. scientists in the United States say they have moved a step closer toward success in the fight against malaria, by developing mosquitoes that are resistant to at least one form of the deadly illness.  More on this report from VOA's Paul Sisco, who says caution is always advisable when medical breakthroughs are in the news, and this story is no exception.

 
Malaria is spread by mosquitoes
Scientists at Johns Hopkins University in the United States say they have modified the genes of mosquitoes and developed a strain that appears to be resistant to malaria.

Johns Hopkins researcher Jason Rasgon, puts the problem in context. "Malaria infects over 300 million people per year.  Almost three million people die every year from that.  That's mostly children.  Malaria kills an African child about every 30 seconds, on average.  So these are very devastating … it's a very devastating disease."

 
John Rasgon
There are reasons to be cautious about the implications of Professor Rasgon's work.  His malaria-resistant mosquitoes were fed on malaria-infected mice.  The parasite that causes malaria in humans is different, so it is still uncertain whether or when the laboratory breakthrough can help protect people from the disease.

But experts are optimistic that genetic modification can be a potent weapon in fighting malaria.  Professor Rasgon's genetically modified mosquitoes seem much stronger than those that spread malaria, so there is hope that the non-resistant strain could eventually be wiped out. "If we keep going forward with this, these types of experiments will hopefully, ultimately, one day lead to the release of genetically modified mosquitoes that are unable to transmit the malaria parasite."

There are other important concerns, however, according to Professor Rasgon. "We need to deal with all the social, ethical, and legal issues associated with releasing a genetically modified mosquito into the environment.  These social issues are going to take a long time."

Research aimed at defeating malaria continues on a number of fronts, but for now, the Hopkins researchers are one step closer to the goal of developing mosquitoes that cannot transmit malaria to human victims.