Closer to the prevention of dengue fever

19 07 2012

The programme for the eradication of dengue (Eliminate Dengue Project), developing a new approach to reduce the impact of this disease in the world, begins to bear fruit. The research team managed to enter the bacterium Wolbachia in wild populations of the transmitter the dengue mosquito to reduce their ability to spread the virus to people.

El equipo de investigación consiguió introducir la bacteria Wolbachia en poblaciones salvajes del mosquito que transmite el dengue. Imagen:Eliminate Dengue Program

The research team managed to enter the Wolbachia bacteria in wild populations of the mosquito that transmits dengue. Image:Eliminate Dengue Program

Two new studies reveal the success of the trials of biological control with wild populations of Aedes aegypti, the mosquito which transmits the virus of the dengue. The work, published in Nature, they represent a new approach to reduce their infection in the world.

The scientific team managed to enter the Wolbachia, a bacterium that reduces the sensitivity of the mosquito of dengue virus, in wild populations of the insect. "It's the first release of mosquitoes infected with the bacteria" Wolbachia "in the nature to replace an existing population of insects", explain the authors, who claim that if these results are repeatable, "there is the possibility of drastic reductions in the incidence of dengue virus".

These results are the work of the programme for the eradication of dengue (Eliminate Dengue Project), directed by Scott O'Neill, of Monash University (Australia), in which Australia research institutes collaborate, Viet Nam, Thailand, USA and Brazil.

Current methods of control, based on the use of insecticides, they fail to stop this global health problem. However, "the methods that use the" Wolbachia they are easy to use and could be the key to a sustainable new approach to control dengue, that should adapt to the great cities of the developed world, in which conventional control measures have proved effective and little expensive. "The method should also be compatible with the vaccines when starting to use", says O'Neill.

The World Health Organization (WHO) estimated that 2.500 millions of people live in areas of transmission of dengue and recorded more than 50 million cases per year.

So far, experiments for years demonstrated that it could introduce the Wolbachia in the mosquito in the laboratory, However, the articles published this week describe also the successful introduction of the same strain of Wolbachia in wild populations of Australia mosquito.

Effectiveness in five weeks

In January of this year, the researchers freed-carrying mosquitoes of the Wolbachia Yorkeys Knob and Gordonvale, two areas on the outskirts of Cairns, in Queensland (Australia). In three months, the Wolbachia It had completely invaded the local mosquito populations.

"The field test implies release mosquitoes with" Wolbachia every week for more than two months. Five weeks after releasing mosquitoes, We calculated that the 100% Yorkeys Knob mosquitoes and the 90% of the Gordonvale wore the Wolbachia. "It was a great day", drew O'Neill.

The authors provide for further testing when time becomes more humid, in order to analyse if the Wolbachia It extends to areas less controlled than the first test was performed. After the success, you are trying to get legal approval for testing in Thailand, Viet Nam, Brazil and Indonesia that directly determine the efficacy of the method in reducing the incidence of dengue in human populations.

Bibliographic references:

T. Walker, P. H. Johnson, L. A. Moreira, I. Iturbe-Ormaetxe, (F). (D). Frentiu, (C). J. McMeniman, Y. S. LEONG,AAND. Dong, J. Axford, P. Kriesner, A. L. Lloyd, S. A. Ritchie, S. L. O'Neill and. A. Hoffmann. "The" wMel Wolbachia "blocks and dengue strain invades caged Aedes aegypti populations". Nature, 25 in August of 2011. DOI:10.1038/nature10355.

A. A. Hoffmann, (B). L. Montgomery, J. Popovici, I. Iturbe-Ormaetxe, P. H. Johnson, (F). Muzzi, M. Greenfield, M. Durkan, Y. S. LEONG, AND. Pong, H. CookA J. Axford, A. M. Callahan, NL Kenny, (C). Omodei, E. A. McGraw, P. A. RyanS S. A. Ritchie, M. Turelli y S. L. O’Neill. “Successful establishment of Wolbachia in Aedes populations to suppress dengue transmission”. Nature, 25 in August of 2011. DOI:10.1038/nature10356. [en línea] Madrid(ESP):, 19 in July of 2012 [REF. 24 in August of 2011] Available on Internet: