Dengue fever and its more serious form, dengue hemorrhagic fever, are caused by dengue viruses. Dengue viruses are transmitted when a female mosquito (primarily Aedes aegypti) bites an infected human and then moves on to bite an uninfected human. The disease is most prevalent in equatorial regions of the developing world where mosquito and human populations are dense. Approximately 100 million cases occur every year. There is no vaccine available yet to prevent this disease. More information can be found about dengue on the CDC Dengue Fever web site.
A project initiated in 2005 as part of the Grand Challenges in Global Health program sought to apply genetic techniques to control the transmission of dengue viruses. Approaches for both reducing mosquito population densities and eliminating the ability of the mosquito to spread the virus were based on transgenic mosquito technologies. Strains of mosquitoes incapable of transmitting a specific serotype, dengue viruses 2, were developed. Also, a team of researchers with expertise in mosquito genetics, virology, computer modeling and ethical/cultural/social considerations was able to take a population suppression approach from the laboratory to large cage trials in a country endemic for dengue. Scientific efforts on the project concluded in 2013 and this web site provides a brief summary of the accomplishments and publications.
The adult female mosquito is responsible for transmitting dengue viruses among humans. The male mosquito is incapable of taking a blood meal and therefore of transmitting disease.