News / Health

Scientists Infect Mosquitoes to Stop Dengue

Field tests suggest promise for new disease control strategy

Professor Scott O'Neill inspects the first Wolbachia Aedes aegypti to be released in North Queensland.
Professor Scott O'Neill inspects the first Wolbachia Aedes aegypti to be released in North Queensland.


Art Chimes

Australian researchers report success in attacking the insects that carry the dengue virus, a rarely fatal disease that nonetheless takes a huge toll in sickness and economic loss in the tropical areas where it is endemic.

There's no vaccine or even a specific treatment for the virus.

The World Health Organization says there may be 50 million dengue infections each year and 40 percent of the world's population is at risk.

The dengue virus is carried by a mosquito called Aedes aegypti, which carries the disease from person to person. Researcher Scott Ritchie of James Cook University says anti-dengue efforts have focused mainly on mosquito control.

"And the only way to control it is through the use of pesticides and perhaps community education, and some of the mosquitoes are getting resistant to those pesticides, so we need something novel and different," Ritchie says.

That's what Ritchie and other scientists have been working on, and they report their results in two papers in the journal Nature.

The researchers describe how the Aedes aegypti mosquito can be infected with a bacteria called Wolbachia, which blocks the ability of the dengue virus to grow, so it can't be passed on to the next person the mosquito bites.

To simulate a real-world situation, they released Wolbachia-infected mosquitoes into an indoor test facility filled with uninfected mosquitoes. Within a few months, the anti-dengue infected insects completely dominated the mosquito population as the infected mosquitoes mated with the uninfected ones.

The researchers then moved from a simulated real-world test to an actual real-world test, releasing the infected mosquitoes in two isolated Australian towns.

Chief investigator Scott O'Neill of Monash University says that as the infected insects were released over period of weeks, they began to dominate the native, uninfected mosquitoes.

"And then most importantly, once the release has stopped, Wolbachia continued to increase until the experiments came to a conclusion at the end of the wet season. And about that time we can see that we have almost complete penetration of the Wolbachia infection into the mosquito population at these sites."

Another team member, Ary Hoffman of the University of Melbourne, says the researchers next need to release Wolbachia into an area where dengue is endemic, to see if it actually prevents the disease.

"And until we go through that exercise, we would have to be cautious," Hoffman says. "So I think it's early...You know, at the moment we're very hopeful. But before we get to the stage where we can say, hey, Wolbachia can control dengue, that's a different matter, that's a bit down the track."

In a commentary also published in Nature, Johns Hopkins scientist Jason Rasgon says the Australia research heralds what he calls "the beginning of a new era in the control of mosquito-borne diseases," and suggests a strategy that could also apply to malaria.

Rasgon also notes that effects on the ecosystem should be minimal because the mosquitoes were changed, not eliminated.  

You May Like

Video Obama: Action on Climate Change 'Economic, Security Imperative'

President spoke to reporters on sidelines of UN Climate Summit outside Paris, where leaders are working to agree on binding measures

IMF Bets on China’s Resolve to Reform

IMF announcement already raising questions about just how much Beijing is committed to such reforms

What Happened When I Landed in Antarctica

Refael Klein chronicles what it's like to visit one of the coldest, most desolate places on Earth

This forum has been closed.
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
With HIV, Can We Get to Zero?i
Carol Pearson
November 29, 2015 1:23 PM
The theme of this year's World AIDS Day is "Getting to Zero." The U.N. says new HIV infections have been reduced by 35 percent since 2000 and AIDS-related deaths are down by 42 percent since the peak in 2004. VOA's Carol Pearson takes a look at what it might take to actually have an AIDS-free generation.

Video With HIV, Can We Get to Zero?

The theme of this year's World AIDS Day is "Getting to Zero." The U.N. says new HIV infections have been reduced by 35 percent since 2000 and AIDS-related deaths are down by 42 percent since the peak in 2004. VOA's Carol Pearson takes a look at what it might take to actually have an AIDS-free generation.

Video Political Motives Seen Behind Cancelled Cambodian Water Festival

For the fourth time in the five years since more than 350 people were killed in a stampede at Cambodia’s annual water festival, authorities canceled the event this year. Officials blamed environmental reasons as the cause, but many see it as fallout from rising political tensions with a fresh wave of ruling party intimidation against the opposition. David Boyle and Kimlong Meng report from Phnom Penh.

Video African Circus Gives At-Risk Youth a 2nd Chance

Ethiopia hosted the first African Circus Arts Festival this past weekend with performers from seven different African countries. Most of the performers are youngsters coming form challenging backgrounds who say the circus gave them a second chance.

Video US Lawmakers Brace for End-of-Year Battles

U.S. lawmakers are returning to Washington for Congress’ final working weeks of the year. And, as VOA's Michael Bowman reports, a full slate of legislative business awaits them, from keeping the federal government open to resolving a battle with the White House over the admittance of Syrian refugees.

Video Taiwan Looks for Role in South China Sea Dispute

The Taiwanese government is one of several that claims territory in the hotly contested South China Sea, but Taipei has long been sidelined in the dispute, overshadowed by China. Now, as the Philippines challenges Beijing’s claims in an international court at The Hague, Taipei is looking to publicly assert its claims. VOA’s Bill Ide has more from Beijing.

Video After Terrorist Attacks, Support for Refugees Fades

The terrorists who killed and injured almost 500 people around Paris this month are mostly French or Belgian nationals. But at least two apparently took advantage of Europe’s migrant crisis to sneak into the region. The discovery has hardened views about legitimate refugees, including those fleeing the same extremist violence that hit the French capital. Lisa Bryant has this report for VOA from the Paris suburb of Cergy-Pontoise

Video Syrian Refugees in US Express Concern for Those Left Behind

Syrian immigrants in the United States are concerned about the negative tide of public opinion and the politicians who want to block a U.S. plan to accept 10,000 Syrian refugees. Zlatica Hoke reports many Americans are fighting to dispel suspicions linking refugees to terrorists.

Video Thais Send Security Concerns Down the River

As Thailand takes in the annual Loy Krathong festival, many ponder the country’s future and security. Steve Sandford reports from Chiang Mai.

Video Islamic State Unfazed by Losses in Iraq, Syria

Progress in the U.S.-led effort to beat Islamic State on its home turf in Iraq and Syria has led some to speculate the terror group may be growing desperate. But counterterror officials say that is not the case, and warn the recent spate of terror attacks is merely part of the group’s evolution. VOA National Security correspondent Jeff Seldin has more.

Video Belgium-Germany Border Remains Porous, Even As Manhunt For Paris Attacker Continues

One of the suspected gunmen in the Nov. 13 Paris attacks, Salah Abdeslam, evaded law enforcement, made his way to Belgium, and is now believed to have fled to Germany. VOA correspondent Ayesha Tanzeem makes the journey across the border from Belgium into Germany to see how porous the borders really are.

Video US, Cambodian Navies Pair Up in Gulf of Thailand

The U.S. Navy has deployed one of its newest and most advanced ships to Cambodia to conduct joint training drills in the Gulf of Thailand. Riding hull-to-hull with Cambodian ships, the seamen of the USS Fort Worth are executing joint-training drills that will help build relations in Southeast Asia. David Boyle reports for VOA from Preah Sihanouk province.

Video Uncertain Future for Syrian Refugee Resettlement in Illinois

For the trickle of Syrian refugees finding new homes in the Midwest city of Chicago, the call to end resettlement in many U.S. states is adding another dimension to their long journey fleeing war. Organizations working to help them integrate say the backlash since the Paris attacks is both harming and helping their efforts to provide refugees sanctuary. VOA's Kane Farabaugh reports.

VOA Blogs