The Aedes aegypti mosquito is responsible for transmitting dengue, Zika, Chikungunya and yellow fever, diseases that plague tropical countries like Colombia and that were declared by the World Health Organization (WHO) as one of the top ten health risks of the planet.
Dengue cases, in particular, have multiplied by 30 since 1960, according to the WHO, and in Colombia the average number of reported cases of this disease each year is almost 86,000, according to the Ministry of Health. For this reason, the control of this vector mosquito has been the subject of research in recent years.
And now a study confirms the greatest alternative discovered so far to control outbreaks of these diseases based on a novel methodology that Colombia was part of in its pilot plans.
The most recent issue of The New England Journal of Medicine (NEJM) published the results of a multi-year investigation that finally managed to prove how the introduction of a bacterium led to a 77 percent reduction in the incidence of dengue and 86 percent percent of hospitalizations for this cause in Yogyakarta, Indonesia.
(Also read: Why do medical unions ask to postpone the reopening?)
The method that the scientists were able to test consists of infecting Aedes aegypti mosquitoes with a bacterium called wolbachia, which prevents the transmission of diseases such as dengue, Zika, chikungunya and yellow fever to humans.
The randomized controlled trial in which the wolbachia mosquitoes were released was conducted by Monash University’s World Mosquito Program in conjunction with Gadjah Mada University in Indonesia, using funds from the Tahija Foundation, donor for the study.
What the study sought to confirm was whether the introduction of wolbachia (wMel) into the local population of Aedes aegypti mosquitoes, through the release of mosquitoes infected with wolbachia, would reduce the incidence of virologically confirmed dengue among residents of Yogyakarta, Indonesia, with ages between 3 and 45 years.
“More than three years after mosquito releases ended, wolbachia continues at high levels among the local mosquito population. Since the trial, the wolbachia method has been implemented throughout the city of Yogyakarta and other releases have started in neighboring districts, covering a population of 2.5 million people, ”the authors note.
(See: They discover key piece in the puzzle called anxiety)
Colombia was part of the pilot projects of this study, which since 2015 covered areas where millions of people live in the cities of Niterói (Brazil), Medellín, Bello, Itaguí, Cali (Colombia) and La Paz (Mexico). “The number of dengue cases was reduced in all of them. In Colombia, no new outbreaks of dengue have been reported since the mosquitoes with wolbachia were released ”, states the statement that highlights the results of the study.
According to the researchers, these results have significant implications for the 40 percent of the world’s population that is at risk of contracting dengue and, in this regard, the WHO Advisory Group on Vector Control recognized “the value for wolbachia public health against dengue ”.
“This study proves that we are facing a revolutionary methodology that can dramatically reduce the incidence of dengue and other diseases in the American continent. We are optimistic that in the coming years we will be able to dramatically reduce dengue in the region, ”said Janina Khayali, regional director for the American continent of the World Mosquito Program (WMP).
(We recommend: the US approves an Alzheimer’s drug after two decades)
For his part, the Director of the World Mosquito Program, Professor Scott O’Neill, said: “This is the result we have been waiting for. We have evidence that our wolbachia method is safe, sustainable, and that it dramatically reduces the incidence of dengue. We have great confidence in the positive impact that this method will have worldwide, when it is offered to communities at risk of contracting these diseases transmitted by mosquitoes ”.
Regarding Colombia, the study is important because dengue, Zika, chikungunya and yellow fever are endemic diseases. Precisely for this reason, in 2015 local authorities invited the World Mosquito Program to begin to carry out pilot releases of wolbachia in Colombia.
There are currently four project sites in Colombia, in Medellín, Bello, Itagüí and Cali and to date, the releases have covered 2.76 million people living in 131 square kilometers in Medellín and Cali. “No new dengue outbreaks have been reported since these releases were carried out,” the researchers conclude.