T he number of people infected with dengue and one of the least related viruses in places where mosquitoes were infected with a bacterium called Wolbachia have been released and have established themselves, reported on Thursday.
The results, from Australia, Indonesia, and Brazil, are dramatic, with a 76% drop in dengue infections in Indonesia where the mosquitoes were released. In Brazil, treated neighborhoods in Rio de Janeiro. Infections with chikungunya, which are spread by the same mosquitoes, were 75% lower there – in a year when the disease was at epidemic levels elsewhere in the area.
The most extraordinary results come from North Queensland, Australia, where Wolbachia- were recently released in 2011. North Queensland, in the northeast of the country, had had regular dengue outbreaks. It has been reported that these infections have been reported in the past few years.
The few dengue cases have been recorded where the Wolbachia-infected mosquitoes have been released. Cameron Simmons, director of impact assessment with the World Mosquito Program, which is operating the project.
“What we're really seeing is the real world of public health that was predicted to happen when this technology was deployed,” Simmons told STAT. “It's Obviously Really Exciting.”
He and colleagues reported their findings Thursday at the annual meeting of the American Society of Tropical Medicine and Hygiene, taking place in National Harbor, Md.
Wolbachia is a ubiquitous bacterium that infects about 60% of insect species. It is a naturally occurring infection, which is largely responsible for the spread of dengue, chikungunya, Zika, yellow fever, and Mayaro viruses, which are responsible for an enormous burden of disease in Africa, South and Central America, and Asia.
The bacterium does not harm the mosquitoes, but it blocks the virus.
Mosquitoes that have been bred to be infected (19659003) Simmons said the one with one of the following: time cost is currently between $ 2 and $ 10 per person protected. But the World Mosquito Program, a nonprofit that is funded by the Wellcome Trust, the Bill and Melinda Gates Foundation, and other organizations, is the best way to save $ 1 per year.
That one -time cost might seem steep for some of the countries where these diseases are entrenched, but the benefits accrued by the costs spread over years. Still, Simmons said the goal is as low as possible. “We want it dirt is not a barrier to implementation decisions,” he said.
Aedes aegypti live close to people and typically do not travel far afield. Simmons said once Wolbachia-infected mosquitoes are established in a location, that could translate into a long-term protection against these viruses.
“Will viruses develop a workaround? … With evolution, anything's possible. But I think we are going to be able to buy from protection, “he said.
Dr. Chandy John, President of the American Society of Tropical Medicine and Hygiene, called the work exciting, coming at a time when dengue's reach is expanding. There is currently little more than enough to control the disease, beyond chemical insecticide.
There are several strains of dengue viruses in the world, but they do not have the same effect. Simmons said Wolbachia blocks all four strains.)
“The combination of advanced science and committed community engagement is impressive – and essential to its success,” John said.
Next year the World Mosquito Program hopes to be released in Yogyakarta, Indonesia, where 24 neighborhoods – home to 350,000 people – have been randomized, with half having Wolbachia-mosquito releases. That will provide gold-standard evidence, Simmons said.
Meanwhile, the program's work continues, with projects in 12 countries in Asia, the South Pacific, and Central and South America. The challenge going forward, Simmons said,
“The challenge for us is to go to where we are now to be able to do efficiently to big cities – Ho Chi Minh City, Bangkok, Jakarta, New Delhi, any of the big municipalities of Brazil. So that's where we hope to be, protecting 100 million people by 2023, “he said. “We're only going to do that if we get the technology right to produce cheap mosquitoes cheaply and deploy them superbly.”