The next generation of insect repellents could be in the pipeline with research from the U.S. suggesting seven possibilities.
Researchers from a government mosquito and fly research unit in Florida say they have identified seven likely candidates for the next mosquito repellents and some of them promise to provide longer protection.
Repellents currently available which are effective often contain DEET (N,N-diethyl-meta-toluamide), which was also originally developed for military use in 1946.
DEET has a good safety record, but some people are concerned about its use with children and pregnant women and the Environmental Protection Agency (EPA) says that DEET has been implicated in seizures among children, but there is not enough information to confirm it as the cause of the incidents.
According to the EPA one-third of the U.S. population uses products containing DEET every year to repel biting insects such as ticks and mosquitoes.
Ticks and mosquitoes, which are becoming an increasing problem in many parts of the world, can cause and spread a range of diseases - among them encephalitis, Lyme disease, Rocky Mountain spotted fever, malaria, Dengue Fever, yellow fever, Rift Valley fever, Ross River Fever, St. Louis encephalitis, West Nile virus, Japanese encephalitis, La Crosse encephalitis, Chikungunya and Eastern equine encephalitis and Western equine encephalitis.
The researchers say though DEET repellents offer broad-based protection from a variety of insects, mosquitoes continue to spread diseases such as malaria and some mosquitoes can bite through an application of DEET.