Transgenic mosquito works to control dengue-carrying mosquitos

July 7, 2015, Oxitec
A TEM micrograph showing Dengue virus virions (the cluster of dark dots near the center). Image: CDC

Releases of the genetically engineered Oxitec mosquito, commonly known as 'Friendly Aedes aegypti', reduced the dengue mosquito population in an area of Juazeiro, Brazil by 95%, well below the modelled threshold for epidemic disease transmission.

The journal PLOS Neglected Tropical Diseases published today the results of a trial of Oxitec's mosquitoes. The results showed that in Juazeiro city, northeast Brazil, the Oxitec mosquito successfully controlled the Aedes aegypti mosquito that spreads fever, chikungunya and zika virus, by reducing the target population by more than 90%. Popularly known in Brazil as "Friendly Aedes aegypti", the Oxitec mosquito decreased the population of the so low that it would not support epidemic disease transmission according to mathematical models.

"The fact that the number of Aedes aegypti adults were reduced by 95% in the treatment area confirms that the Oxitec mosquito does what it is supposed to and that is to get rid of mosquitoes," said Dr Andrew McKemey, Head of Field Operations at Oxitec.

"According to published mathematical models reviewed and recommended by the World Health Organization (WHO) working group on dengue, it would also reduce the number of biting mosquitoes below the disease transmission threshold.

"The next step is to scale up to even larger studies and run mosquito control projects on an operational basis."

The study in the Itaberaba neighborhood of Juazeiro city in Bahia State, Brazil was led by University of Sao Paulo and Moscamed, a social company leading in environmentally friendly pest control. The treatment area included a population of approximately 1800 people.

How it works

This method of control is species-specific. The Oxitec male mosquitoes are released to mate with the pest females and their offspring die because of a self-limiting gene before they can reproduce and before they can become transmitters of disease. The also carry a colour marker for monitoring, and the insects and their genes do not persist in the environment.

Mosquito control in Brazil

"This invasive mosquito and the diseases it carries is a real challenge. Aedes aegypti is developing resistance to insecticides and even when we remove breeding sites, they continue to reproduce and transmit diseases because they live in areas that are difficult to treat. This is why we need new tools. We knew that the Oxitec mosquito was a promising tool, so we wanted to independently evaluate its effectiveness here in Brazil," said Professor Margareth Capurro of Sao Paulo University.

Brazil is leading the way in applying new approaches to fight the dengue mosquito. Following approval of the Oxitec mosquito by the national biosafety group CTNBio for release throughout the country, the city of Piracicaba has started the world's first municipal project of genetically engineered .

Explore further: Brazil to breed GM mosquitoes to combat dengue

More information: "Suppression of a Field Population of Aedes aegypti in Brazil by Sustained Release of Transgenic Male Mosquitoes." PLoS Negl Trop Dis 9(7): e0003864. DOI: 10.1371/journal.pntd.0003864

"Transmission thresholds for dengue in terms of Aedes aegypti pupae per person with discussion of their utility in source reduction efforts." Am J Trop Med Hyg January 2000 62:11-8

Related Stories

Brazil to breed GM mosquitoes to combat dengue

July 10, 2012
Brazil said Monday it will breed huge numbers of genetically modified mosquitoes to help stop the spread of dengue fever, an illness that has already struck nearly 500,000 people this year nationwide.

First domestic case of chikungunya in Brazil

September 17, 2014
Brazil's authorities on Tuesday reported the first domestically contracted cases of the mosquito-borne chikungunya virus, prompting the government to announce it was stepping up attempts to control the disease.

Virus-carrying mosquitoes are more widespread than ever, and spreading

June 30, 2015
Scientists behind the first global distribution maps of two species of dengue and chikungunya-carrying mosquitoes warn they are spreading to new areas where they could cause disease.

Recommended for you

Ambitious global virome project could mark end of pandemic era

February 23, 2018
Rather than wait for viruses like Ebola, SARS and Zika to become outbreaks that force the world to react, a new global initiative seeks to proactively identify, prepare for and stop viral threats before they become pandemics.

Forecasting antibiotic resistance with a 'weather map' of local data

February 23, 2018
The resistance that infectious microbes have to antibiotics makes it difficult for physicians to confidently select the right drug to treat an infection. And that resistance is dynamic: It changes from year to year and varies ...

Study reveals how kidney disease happens

February 22, 2018
Monash researchers have solved a mystery, revealing how certain immune cells work together to instigate autoimmune kidney disease.

Scientists gain new insight on how antibodies interact with widespread respiratory virus

February 22, 2018
Scientists have found and characterized the activity of four antibodies produced by the human immune system that target an important protein found in respiratory syncytial virus (RSV), according to new research published ...

Past encounters with the flu shape vaccine response

February 20, 2018
New research on why the influenza vaccine was only modestly effective in recent years shows that immune history with the flu influences a person's response to the vaccine.

Building better tiny kidneys to test drugs and help people avoid dialysis

February 16, 2018
A free online kidney atlas built by USC researchers empowers stem cell scientists everywhere to generate more human-like tiny kidneys for testing new drugs and creating renal replacement therapies.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.