Cell phones and backswimmers become weapons against malaria

If mosquitoes pick on you unfairly, you can blame your parents. Each of us has a unique chemical signature, partially determined by genetics, and some people produce more irresistible odors in their breath and sweat than others. Mosquitoes identify food sources and avoid predators by reading these chemical signatures, and researchers may have discovered an environmentally friendly insect repellant in the compounds given off by mosquito predators.

It wouldn't be so bad if mosquito bites caused nothing but a short-lived, if aggravating, itch, but they also transmit devastating diseases like malaria. Malaria damages red blood cells and deprives the brain and other organs of oxygen. Victims suffer from chills, intense fever and malaise. In more vulnerable populations, such as children and pregnant women, symptoms can progress to seizures, kidney and liver failure, coma and death. The National Institute of Allergy and Infectious Diseases reports that it directly causes the death of half of all children under the age of five throughout the world. Sub-Saharan Africa, in particular, has suffered under the social and economic burden caused by the disease. Malaria costs Africa an estimated $2 billion each year in lost income and medical bills, according to the World Health Organization.

Diagnosing malaria can be labor-intensive and require highly trained technicians to analyze blood smears. Microscopic analysis takes time, and can be considered a luxury in poverty stricken nations. This may soon change, as a mobile laboratory hits the market. Aydogan Ozcan of UCLA created a microscope attachment for cell phones. Cheap and small, the device can be used to examine blood and saliva samples in even remote areas of the world. Images can then be sent to a database or qualified technician to return a diagnosis. The device has won several awards and is currently being tested in Africa.

There is no effective, licensed vaccine against malaria. Preventative measures include the use of bed nets, insect repellants and eliminating sources of stagnant water, in which female mosquitoes lay their eggs. Soon you may be able to disguise your enticing chemical signature with kairomones and fool mosquitoes into thinking you want to eat them. Researchers at Rockefeller University and the University of Haifa in Israel have found that female mosquitoes avoid the kairomones produced by backswimmers, which prey on the blood-sucking insects, and cause them to lay fewer eggs in pools of water.

Researchers at the University of Arizona, meanwhile, have succeeded in creating malaria-proof mosquitoes. The insects typically act as a vector for malaria by carrying a parasite called Plasmodium. The parasitic cells infect a mosquito's salivary glands and wait to be injected into a new host, such as a human. After the insertion of a new piece of genetic code, the laboratory bred mosquitoes became resistant to Plasmodium. The researchers hope to someday release the genetically altered mosquitoes into the wild, where they can replace populations still susceptible to malaria. It remains to be seen whether the additional gene carries any other, perhaps harmful side effects.

The ideal habitat for a moquito is open, shady and wet. The insects prefer warm, humid environments and are unable to survive at temperatures below 50 degrees, but with global temperatures rising and deforestation continuing to spread, we can expect more mosquitoes and a growing risk from malaria epidemics. You may not be able to change your genetics, but you can at least make your scent less appealing to mosquitoes. To protect yourself without resorting to toxic insect repellants, you can disguise your scent with essential oils such as rosemary, mint or lemongrass. Avoid fruity fragrances, often found in soaps, detergents and perfumes, because these actually attract mosquitoes. Garlic, on the other hand, is a strong repellant. Your friends may not appreciate the odor either, but the chemicals in the plant oil will evaporate on your skin and combine with carbon dioxide to effectively mask your own chemical signature.