Healthier Mosquitoes, Healthier Kids: A New Weapon in the War on Malaria

The AP reports:

"Researchers have developed a malaria-resistant mosquito, a step that might one day help block the spread of an illness that has claimed millions of lives around the world."

Malaria is a scourge that kills nearly 3 million people worldwide every year, the vast majority of them in Africa and overwhelmingly children.  My wife got the falciparum strain while we were in Namibia and it nearly killed her. 

A team of researchers lead by Assistant Professor Jason Rasgon at Johns Hopkins University's Malaria Research Institute hopes to develop a transgenic mosquito that will resist malaria infection, would be less likely to transmit disease and more likely to out compete those that are carriers. 

"Working with the mouse form of malaria - not the human type - Rasgon's team was able to genetically engineer mosquitoes that were resistant to malaria.

Malaria infection does exact a toll on mosquitoes and in laboratory work they found that the resistant insects were able to out compete nonresistant mosquitoes.

Starting with the same number of resistant and nonresistant mosquitoes, they found that after nine generations the resistant type made up 70 percent of the population - raising the possibility of replacing regular mosquitoes with resistant ones that don't spread disease.

However, Rasgon stressed that in the lab work the insects were infected with a higher amount of the parasite than occurs in nature, and a larger proportion of the mosquitoes were infected.

"This was proof of principle," Rasgon said in a telephone interview. "The next step would be to work in a system more epidemiologically relevant" but still in the lab.

"We're not anywhere near a field release," he said. Now they need to turn their attention to working with human malaria and trying to engineer a mosquito resistant to that."

You can read more here, courtesy of Glenn Reynolds, and also here.

There may yet be unanticipated consequences of releasing a transgenic mosquito into the environment, as is often the case with aggressive, invasive species, but this would appear to be a situation where the benefits for human health should far outweigh the risk of intentionally introducing a super mosquito.

Comments

[GreenmanTim]

Good comment, BioTunes. I found it interesting that this story, which was all over the wires from Instapundit to NPR, attracted all that attention but really offered very little beyond a status update of lab tests that are a very long way from being, as the spokeperson for the project admitted, "epidemiologically relevant." I also could not find the abstract in the Proceedings of the National Academy of Sciences, as Professor Rasgon is apparently not the lead author.

[Biotunes]

I am very skeptical that this would work. Governments have blown a ton of money on the technique of irradiating pest insects (for ex. Medfly), making them sterile, and releasing them in the wild in the hopes that sterile males would mate with wild females and thus prevent them from reproducing. "Preliminary evidence" indicated that the technique was working on a small scale. Because the cost of raising the flies and irradiating them was high, labs started working on a technique called "genetic sexing," in which female larvae could be identified with a marker earlier in development and killed, so that only males would be raised and released. The only problem was that an entomologist who actually went into the field to watch their mating behavior discovered that the reason the technique was working somewhat was because irradiated females were mating with wild males, and depleting their sperm. The bloated bureaucracy responsible for the genetic sexing project was not interested to hear his information.

In my experience, the reductionists who try these projects know nothing about the animal's natural history, particularly behavior in the wild (although I haven't bothered to look up these authors to find out in this case), which can make a huge difference. A genotype "winning" in a laboratory cage says nothing about its potential success in the field. Zero. So apart from raising questions of releasing "new" species into the wild, one just has to be cynical about efforts such as these. The impacts of the recent and continuing decline of support for scientists who study whole organisms rather than chunks of their DNA is going to be more and more obvious as the reductionists try in vain to solve "real world" problems.