人工植物暗藏杀灭传染媒介的药物

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A 'Flower' That Delivers Disease-Killing Treatments to Mosquitoes

The most common way of fighting diseases like malaria, dengue fever, and West Nile today is to try to wipe out the mosquitoes carrying them and treat those who have been infected. Now there's an alternative on the horizon that promises to be safer and cheaper by zapping the germs while sparing the mosquitoes. The technology is hidden in an artificial flower designed to attract mosquitoes and treat them with pathogen-killing drugs that allow the insects to live and continue to perform important functions such as pollinating flowers and serving as food for animals and other insects.

MIT Holding, Inc., a Savannah, Ga., pharmaceuticals distributor, says its PROVECTOR \"flower\" reduced the number of viruses that cause dengue and parasites that cause malaria in mosquitoes in lab settings.

Although company is still considering what type of flower the PROVECTOR will resemble, the product is designed to use visual, olfactory and chemical signals to entice mosquitoes to ingest antimalarial and antiviral treatments that inhibit the development of the pathogens. This is a vastly different approach to current methods of fighting insect-borne diseases that involve treating populations with expensive preventive medications (which can have serious side effects and may not work), the wholesale killing of the insects using toxic pesticides and / or treating the infected bite victims.

A major problem with current treatments for malaria—a long-lasting, potentially fatal blood disease that kills more than 2.7 million people a year, according to the World Health Organization—is that the parasites may become drug-resistant; in such cases, they are spread along with the disease. A group of researchers led by Pennsylvania State University biology professor Andrew Read recently published findings on the Proceedings of the National Academy of Sciences USA Web site that indicate \"the more drugs you use, the worse you make the situation in terms of the evolution of drug resistance.\"

Lest you worry about the faux flower's impact on humans and other living things: the flower portion of the PROVECTOR is covered by a membrane that protects people, bees and other animals that touch it but is thin enough to be penetrated by a mosquito's long, pointy proboscis. Tests have shown that the chemicals inside the PROVECTOR not only kill pathogens but also suppress the development of Plasmodium parasites that cause malaria if a mosquito encounters them after being treated. \"There appears to be a strong prophylactic action in the mosquito,\" says Dr. Thomas Kollars, MIT Holding's chief scientific advisor and director of the Biodefense and Infectious Disease Laboratory at Georgia Southern University's Jiann-Ping Hsu College of Public Health in Statesboro.

Kollars says PROVECTOR'S drug—which is still being developed—will function similar to doxycycline, an antibiotic that slows or kills parasites in the blood that cause malaria and is taken to prevent the disease before traveling to (and while in) areas where malaria has been reported.

The impetus for Kollars's work began about a decade ago when he was working as a disease outbreak investigator in Thailand. \"We were testing antimalarial drugs for the army and their effects on mosquitoes,\" he says. There are antimalarial drugs available to prevent people from contracting the disease and treatments for those who actually get it, but few people in the most vulnerable regions—such as parts of Africa and Asia—can afford the tab. \"We needed to find a treatment that was in the $5-to-$10 range,\" he says, adding that the goal is to offer the PROVECTOR for less than $5 a flower.

The PROVECTOR will be designed to last about a year before its artificial petals need to be replaced. The product's lifespan will depend upon the mosquito population in a particular area and the amount of chemicals that they ingest.

Another dangerous mosquito-borne disease that Kollars hopes to stop is dengue fever, a disease in tropical areas that can cause headache, rash, achy joints and, in some cases—mostly in very young children—can be fatal if the victim goes into shock. \"Our goal is also to develop the technology,\" Kollars says, \"and then transfer that knowledge to help developing countries so they can produce them.\"

MIT Holding says it will cost about $3.7 million to conduct the next round of product development and testing, which will include trying out PROVECTOR on mosquitoes in rural Georgia come spring and in the Florida Everglades next summer. \"We hope to have received some funding by next fall for overseas trials,\" Kollars adds. He says his team is testing four different prototypes of PROVECTOR to come up with the most effective mix of color and chemicals—not to mention, disposable petals that are biodegradable.

\"ROVECTOR alone isn't the answer,\" Kollars acknowledges, \"but it will interdict at a different stage than other treatments for malaria and other diseases. I've seen kids dying of malaria; it behooves those of us who can do something to do something.\"