Mosquito
Mosquito-borne diseases are currently most prevalent in East Africa, Latin America,  Southeast Asia, and India; however, emergence of vector-borne diseases in Europe have recently been observed. A weighted risk analysis demonstrated associations to climate for 49% of infectious diseases in Europe including all transmission routes. One statistical model predicts by 2030, the climate of southern Great Britain will be climatically-suitable for malaria transmission "Plasmodium vivax" malaria for 2 months of the year. By 2080 it is predicted that the same will be true for southern Scotland.
Mosquito-borne disease
In many insect species, such as "Drosophila melanogaster", researchers found that a natural infection with the bacteria strain "Wolbachia" "pipientis" increases the fitness of the host by increasing resistance to RNA viral infections. Robert L. Glaser and Mark A. Meola investigated "Wolbachia"-induced resistance to West Nile virus (WNV) in "Drosophila melanogaster" (fruit flies). Two groups of fruit flies were naturally infected with "Wolbachia." Glaser and Meola then cured one group of fruit flies of "Wolbachia using" tetracycline. Both the infected group and the cured groups were then infected with WNV.  Flies infected with "Wolbachia" were found to have a changed phenotype that caused resistance to WNV. The phenotype was found to be caused by a “dominant, maternally transmitted, cytoplasmic factor”. The WNV-resistance phenotype was then reversed by curing the fruit flies of "Wolbachia." Since "Wolbachia" is also maternally transmitted, it was found that the WNV-resistant phenotype is directly related to the "Wolbachia" infection. West Nile virus is transmitted to humans and animals through the Southern house mosquito, "Culex quinquefasciatus." Glaser and Meola knew vector compatibility could be reduced through "Wolbachia" infection due to studies done with other species of mosquitoes, mainly, "Aedes aegypti". Their goal was to transfer WNV resistance to "Cx. quinquefasciatus" by inoculating the embryos of the mosquito with the same strain of "Wolbachia" that naturally occurred in the fruit flies. Upon infection, "Cx. quinquefasciatus" showed an increased resistance to WNV that was transferable to offspring. The ability to genetically modify mosquitoes in the lab and then have the infected mosquitoes transmit it to their offspring showed that it was possible to transmit the bacteria to wild populations to decrease human infections.