It sounds like the plot from a classic Halloween movie in which a community fighting to stop a deadly mosquito-borne virus is forced to take drastic measures.
Bats, genetically engineered organisms, and toxic chemicals are used but in the end, the community pays a high price. Not to mention, and typical of Halloween movies, the last scene shows a lone mosquito flying away, leading the audience to wonder if there will be a sequel.
Unfortunately, this story is real. Since July, people in Miami, Florida, have been fighting an outbreak of the Zika virus which has led to more than 50 infections.
The Zika virus is a mosquito-borne virus believed to cause severe birth defects. Called a "global health emergency" by the World Health Organization (WHO), the virus has had a large impact on Central and South America.
The most effective way to prevent Zika from spreading is to attack the mosquitoes that carry the virus. This is commonly done through insecticides which have been used in Miami and other parts of south Florida over the past few months, but this method has come under fire due to potential harm to the environment and/or side effects to those exposed.
In light of this, alternate methods of attacking the mosquitoes have been proposed, including using bats, a natural enemy of mosquitoes, and even genetically modified mosquitoes, engineered to produce offspring that can't survive.
Aerial Spray Pesticide
Naled, a mosquito insecticide, has been used in certain areas of Miami in an attempt to reduce the mosquito population and slow the spread of the Zika virus. A neurotoxin, Naled kills mosquitoes by interfering with their nervous systems.
Naled is sprayed from the air in small quantities and according to the Centers for Disease Control and Prevention, should not cause health problems for people or pets. It can, however, cause irritation for those sensitive to chemicals or those exposed to large amounts.
Local residents and environmentalists have expressed concerned over long-term exposure to chemical insecticides such as Naled and encourage city officials to investigate other ways to fight the spread of the Zika virus.
Genetically Modified Organisms (GMOs)
The Florida Keys (specifically Key Haven), home to more than 45 species of mosquito, are the proposed testing ground for introducing genetically modified mosquitoes. These mosquitoes, called OX513A, were developed by the British company Oxitec.
Primarily male, the OX513A mosquitoes have been modified to include a self-limiting gene that produces a protein, killing the mosquito. The mosquitoes live long enough to reproduce and pass along the self-limiting gene resulting in up to 97% of the offspring being unable to survive. The small percentage that do survive to adulthood are weak and only live a few days.
Previous trials have taken place in Brazil and Panama and have shown to reduce the mosquito population by almost 90%, although the genetically modified mosquitoes have not been shown to be harmful, many in the proposed testing area are against the idea. They do not want to be used as "guinea pigs" and fear that there are too many unknowns. Conversely, others believe that Zika is a major threat and that the risks associated with testing the genetically modified mosquitoes are worthwhile.
Assuming approval by the Food and Drug Administration, the Mosquito Control Board in Key Haven will have final say in whether the trial takes place; a referendum has been set for November to allow the community to vote. Although the vote is non-binding, 3 of the 5 commissioners have stated that they will adhere to the wishes of the voters.
If the trial does take place, it would be the first of its kind in the United States and could open the door for future tests using other GMOs.
Mosquito Eating Bats
With environmentalists protesting the use of insecticides, Miami's city commissioner, Kristin Rosen Gonzalez devised an alternate solution: using bats to help control the mosquito population. Bats can eat up to 3000 mosquitoes a day and are more environmentally friendly. The plan would be to place bat houses and bat-friendly habitats throughout the city to encourage bats to take up residence.
The American Mosquito Control Association has shown that bats alone have not been proven to significantly reduce mosquito population so they will not replace insecticides, but they can certainly help.
With the possibility of bats on the horizon, truth really may be stranger than the movies...
Kelly Servick. ScienceMag.org. Brazil will release billions of lab-grown mosquitoes to combat infectious disease. Will it work?
http://www.sciencemag.org/news/2016/10/brazil-will-release-billions-lab-grown-mosquitoes-combat-infectious-disease-will-it. Published October 13, 2016. Accessed October 20, 2016.
Catherine Thorbecke. ABC News. Bats Proposed as Latest Weapon to Fight Zika Virus in Miami.
http://abcnews.go.com/Health/bats-proposed-latest-weapon-fight-zika-virus-miami/story?id=42905072. Published October 19, 2016. Accessed October 20, 2016.
Gillian Mohney. Zika in Miami: What to Know About the Aerial Spray Pesticide Under Protest.
http://abcnews.go.com/Health/zika-miami-pesticide-protested/story?id=41944291. Published September 8, 2016. Accessed October 20, 2016.
Gillian Mohney. Fighting Zika in the US: The Battle Over GMO Mosquitoes.
http://abcnews.go.com/Health/fighting-zika-us-battle-gmo-mosquitoes/story?id=40408239. Published July 9, 2016. Accessed October 20, 2016.