Image: Wikimedia Commons/Centers for Disease Control and Prevention
Scientists may have developed a new tool for combating malaria, according to a recent study in the Proceedings of the National Academy of Sciences.
After more than 20 years of genetic experimentation, researchers have discovered how to breed malaria-resistant mosquitoes that are unable to infect humans with their bites.
"We see a complete deletion of the infectious version of the malaria parasite," said Anthony James, a microbiology and molecular genetics professor at the University of California, Irvine, and the lead author of the report. This can help to "significantly reduce human sickness and death," he added.
With the help of fellow researchers from the Pasteur Institute in Paris, James and his colleagues were able to alter the DNA of Anopheles stephensi mosquitoes, which are major transmitters of the most deadly strain of malaria -- Plasmodium falciparum.
By microinjecting a specially engineered gene into the mosquitoes' eggs, the scientists produced insects that were unable to transmit the disease when they reached adulthood.
More importantly, the gene that James' team created was dominant. In other words, introducing it into a wild population of mosquitoes would achieve the same result as placing a group of brown-eyed humans into a blue-eyed population: gradually, fewer children would be born with the recessive, blue-eyed gene.
This means that releasing the mosquitoes in strategic locations could dramatically reduce the spread of malaria, James said.
A disease poised to spread
According to the World Health Organization, more than 650,000 people died from malaria in 2010, most of whom were African children. Some researchers believe this number could climb even higher due to climate change, which is expected to increase rainfall in many regions. More puddles and swampland would provide additional breeding grounds for mosquitoes -- translating into more cases of malaria (ClimateWire, Nov. 21, 2011).
People who have never been exposed to the disease also run the highest risk of infection, so mosquitoes may spread malaria to countless new victims as they follow the rains into fresh territories, say experts.
To make James' malaria-fighting research a reality, millions of mosquitoes would need to be bred in a lab and released into the wild at key intervals.
"We have to figure out how these things are going to scale up," explained James, who says the process of caring for tropical mosquitoes can be very labor-intensive. "This is not something that people are going to be doing in their garage."
Aside from malaria, he believes, the research could ultimately be tailored to prevent other mosquito-borne diseases, such as the West Nile virus and dengue fever.
"I'm pretty enthusiastic that in five years, we'll have tools we'll be able to use," although the ethical, social and legal aspects will likely slow progress, he said.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500
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10 Comments
Add CommentKoi fish eat up these in China, so why don't we Americans use them in our ponds and streams?
Reply | Report Abuse | Link to thisWow! What a great idea. Introduction of a non-native species always seems to work out great. Lets recall past examples: cane toads and foxes in Australia, Zebra mussels in the great lakes, and nutrias in the south eastern U.S. All of which only damaged the ecosystems they were introduced to. Adding a non-native species has historically had detrimental and unpredictable effects on biodiversity and the environment. Always a BAD idea.
Reply | Report Abuse | Link to this(I'm not a scientist, so this is all speculation)
Reply | Report Abuse | Link to thisPersonally, I'd rather we come up with a way to exterminate the entire mosquito species... Say, an engineered disease. I'm sure we will sooner or later get to the point where we can make an airborne mosquito-exclusive disease that inserts time bombs into their DNA which continue to tick down in any future mosquito generations, eventually killing the mosquitoes after 5 years or so of the release date, by multiple methods (synthesizing a number of poisons, altering blood PH, breaking down their blood, stopping production of vital enzymes, I'm sure there are plenty of ways that could be thought of, and the more that were implemented the less likely any mosquito would be to happen to somehow be immune to all of them).
I assume, of course, that there is some way for an airborne mosquito disease to spread across the globe rapidly. I think mosquitoes can sneak onboard ships or planes? If not the disease could just be released on different continents simultaneously anyways.
Also, the odds of it mutating and infecting another species would hopefully be slim due to it only having 5 years before it would cease to exist, unless the folks making it weren't specific enough with the targeting criteria so it targeted more than one species from the beginning, of course... That's probably the only dangerous part (for us).
The problem with eliminating mosquitoes completely is that we really don't know the effect it would have on the ecosystems. Deleting the parasite changes far less.
Reply | Report Abuse | Link to thisI wonder what diseases the modified mosquitoes would spread instead of malaria... There are always consequences when we try to mess with nature. We need to understand the consequences before we act.
Reply | Report Abuse | Link to thisPrecisely!
Reply | Report Abuse | Link to thisTrafalagar: "Personally, I'd rather we come up with a way to exterminate the entire mosquito species."
Reply | Report Abuse | Link to thisI hope that is a joke. species of mosquitoes, especially the larva in the water are a major source of prey for many species...including dragonfly nymphs, water spiders, etc....then a major supply of food as adults for bats, birds, predatory wasps, etc.
The non-malarial breeding may be ok but there can be SO MANY consequences of messing with ecosystems.
well I see your point.But don't forget these genetically modified mosquitoes are not by natural means too.Just simply recall issues about genetically modified plants.First,we are not pretty sure about the safety of the food-whether it is gonna modify our genes in the long term.Secondly,the GM plants are more resistant to pests,bad weather....they are gaining an advantage over others.So will it be a better option to apply these GM mosquitoes?
Reply | Report Abuse | Link to thisThis might be the most important thing that scientists have done in the third millenium so far. Malaria is a good candidate for being the worst thing in the world. This could kill it. When people here make comments about how they don't give a f**k about millions of lives because, waa, they don't feel good about GM or non-native species, it makes me clench my fists in anger. But despite their moral depravity, I would not wish malaria on their own children. That's just too cruel.
Reply | Report Abuse | Link to thisKay, most likely you ingest genetically modified food everyday without even knowing it. Unless you eat completely organic or grow your own food that is. It is true that genetically modified plants (i.e. alfalfa crops) have gained an advantage which has caused problems for farmers. But the point of this research IS so the GE mosquitoes have an advantage so that they can wipe out the malaria carrying mosquitoes. Malaria kills half a million people a year, most of which are children under the age of 5. If these mosquito can prevent this then introduction into wild populations might be worth thinking about.
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