A group of researchers has discovered that by injecting the bacteria 'Wolchabia' in the mosquitoes Aedes aegypti, which transmit the dengue fever, can block the transmission of virus of dengue and thus control the spread of this disease.

"The main finding that was seen when injecting this bacterium was its ability to reduce the transmission of dengue," explains the study's lead author and dean of the Faculty of Science at Monash University, Professor Scott O'Neill, who assures that "it has been seen that the dengue virus is almost completely eliminated in the body of the mosquito".

During the study, conducted at the University of Monash (Australia), and published in the journal 'Nature', O'Neill's group injected the bacteria into more than 2,500 embryos of mosquitoes capable of spreading dengue fever. After the birth of these insects, they were treated with blood mixed with the dengue virus, and none contracted the virus. In this way they have discovered that "the bacterium 'wolbachia' does not spread through the environment, it is transmitted from mothers to children through eggs," explains the expert.

"When a male mosquito copulates with an infected female, all the eggs die, which gives an indirect benefit to the wolbachia females because when they mate with the infected males, the eggs grow normally because all their eggs have 'wolbachia' becoming something more and more common with each generation, "says the scientist.

According to O'Neill, "there are two theories to explain why the 'wolbachia' is able to block the absorption of dengue, firstly, this bacterium stimulates the mosquito's immune system and protects it from viruses such as dengue and, secondly, Instead, it competes with the dengue of food inside the mosquito, making it difficult to spread the virus. "

Release infected mosquitoes

Currently, there is no specific vaccine or treatment for dengue, and the only way to prevent it is to control mosquito populations by eliminating breeding sites and using insecticides

More than 50 million people in more than 100 countries get sick and 20,000 die each year from dengue fever. Currently, there is no vaccine or specific treatment for the disease, and the only form of prevention is to control mosquito populations by eliminating breeding sites and using insecticides.

O'Neill's team disposed of about 299,000 infected mosquitoes in more than 370 sites in northeastern Australia, and the bacteria spread among the wild mosquito population successfully, including infecting their young within three months.

The team hopes that the release of these mosquitoes will be approved in those places where the dengue problem is endemic, such as Vietnam, Thailand, Indonesia and Brazil, in order to check whether the transmission rates of dengue in people are reduced.

"It is an alternative strategy for the control of dengue that can be low cost, sustainable and appropriate to carry out in large cities in developing countries," says O'Neill.

However, he adds that "when this strategy passes, it could become less effective, as with insecticides." It is not known how long it could take to occur, but if an effective control is carried out in 20 or 30 years, be a very important step to control dengue ", concludes the researcher.


Dengue and Chikungunya in Our Backyard: Preventing Aedes Mosquito-Borne Diseases (November 2019).