Featured Research

from universities, journals, and other organizations

Novel control of Dengue fever

Date:
August 27, 2011
Source:
University of California - Davis
Summary:
The spread of Dengue fever in northern Australia may be controlled by a bacterium that infects mosquitoes that harbor the virus, researchers report.

The spread of Dengue fever in northern Australia may be controlled by a bacterium that infects mosquitoes that harbor the virus, Australian and U.S. researchers report Aug. 25 in two papers published in the journal Nature.

Related Articles


The result grew out of work more than 20 years ago by population biologist Michael Turelli, professor of evolution and ecology at UC Davis, and Ary Hoffmann, now at the University of Melbourne, Australia, who are among the coauthors of one of the new Nature papers.

Turelli and Nick Barton of the Institute of Science and Technology, Austria, also describe the mathematical basis of the dengue elimination project in a paper to be published in the journal American Naturalist in September.

Dengue fever is caused by four virus strains spread by the mosquito Aedes aegypti. The disease causes high fever and has been called "breakbone fever" because of the joint aches and muscle pains it causes. Dengue viruses can also cause a potentially fatal disease, dengue hemorrhagic fever, in people who have previously been infected with a different strain of the virus.

Dengue viruses are found throughout the tropics and subtropics and appear annually in northern Australia. The researchers released mosquitoes infected with the bacterial parasite Wolbachia, which suppresses the virus, and now report that the Wolbachia parasite spreads rapidly through the wild mosquito population.

"The results show we can completely transform local populations in a few months," Turelli said.

Wolbachia is transmitted by female mosquitoes to their offspring. A pair of infected mosquitoes produce slightly fewer eggs than an uninfected couple, but when an infected male mosquito mates with an uninfected female, she produces no eggs at all. That provides a big reproductive advantage to the spread of Wolbachia-infected mosquitoes, generation by generation.

"It's natural selection on steroids," Turelli said.

It turns out that Wolbachia also suppresses various other microbes living in the same mosquito -- including the dengue virus. As these virus-resistant mosquitoes spread through the wild population, dengue transmission should dry up.

Turelli and Hoffmann first described what turned out to be Wolbachia spreading among Drosophila flies in California's Central Valley in 1991, and Barton developed much of the relevant mathematics in the late 1970s while trying to understand the genetics of grasshoppers in the French Alps. That basic research by Turelli, Hoffman and Barton provides the biological and mathematical basis for the dengue control strategy.

"At the time, none of us expected that this original research might contribute to human health. This is very exciting, once-in-a-lifetime opportunity," Turelli said. "We never thought this would turn into an eradication project."

The mathematics is complicated because when Wolbachia is rare, its spread through an insect population is disadvantaged because infected couples lay fewer eggs than uninfected. However, once the frequency of the infection crosses a certain threshold, there is a strong advantage to its spread.

Originally, Turelli and other researchers lead by Scott O'Neill at the University of Queensland, funded by the Bill & Melinda Gates Foundation, tried to use Wolbachia to shorten the lifespan of Aedes so that the virus would not have the 12 days necessary to develop. However, that approach seems unlikely to work, based on the mathematics of the spread of that type of Wolbachia.

Instead, the team found that Wolbachia itself suppresses certain viruses. The Gates Foundation is providing further funding to support release of infected mosquitoes in Australia, Vietnam and Thailand.

Hoffmann is first author of the Nature paper on which Turelli is a coauthor, and O'Neill is the last (senior) author. Other authors are affiliated with the University of Queensland, Brisbane; Monash University, Melbourne; University of Melbourne; James Cook University, Cairns; and the Queensland Institute of Medical Research, Brisbane, Australia.

The research was supported grants from the Grand Challenges in Global Health Initiative of the Bill and Melinda Gates Foundation; The National Health and Medical Research Council, Australia; the Queensland Government; the U.S. National Institutes of Health; the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia; the U.S. National Science Foundation and fellowships from the Australian Research Council.


Story Source:

The above story is based on materials provided by University of California - Davis. Note: Materials may be edited for content and length.


Journal References:

  1. A. A. Hoffmann, B. L. Montgomery, J. Popovici, I. Iturbe-Ormaetxe, P. H. Johnson, F. Muzzi, M. Greenfield, M. Durkan, Y. S. Leong, Y. Dong, H. Cook, J. Axford, A. G. Callahan, N. Kenny, C. Omodei, E. A. McGraw, P. A. Ryan, S. A. Ritchie, M. Turelli, S. L. O’Neill. Successful establishment of Wolbachia in Aedes populations to suppress dengue transmission. Nature, 2011; 476 (7361): 454 DOI: 10.1038/nature10356
  2. T. Walker, P. H. Johnson, L. A. Moreira, I. Iturbe-Ormaetxe, F. D. Frentiu, C. J. McMeniman, Y. S. Leong, Y. Dong, J. Axford, P. Kriesner, A. L. Lloyd, S. A. Ritchie, S. L. O’Neill, A. A. Hoffmann. The wMel Wolbachia strain blocks dengue and invades caged Aedes aegypti populations. Nature, 2011; 476 (7361): 450 DOI: 10.1038/nature10355

Cite This Page:

University of California - Davis. "Novel control of Dengue fever." ScienceDaily. ScienceDaily, 27 August 2011. <www.sciencedaily.com/releases/2011/08/110824131544.htm>.
University of California - Davis. (2011, August 27). Novel control of Dengue fever. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2011/08/110824131544.htm
University of California - Davis. "Novel control of Dengue fever." ScienceDaily. www.sciencedaily.com/releases/2011/08/110824131544.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Cambodian Capital's Only Working Elephant to Retire in Jungle

Cambodian Capital's Only Working Elephant to Retire in Jungle

AFP (Nov. 25, 2014) Phnom Penh's only working elephant was blessed by a crowd of chanting Buddhist monks Tuesday as she prepared for a life of comfortable jungle retirement after three decades of giving rides to tourists. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Buzz60 (Nov. 24, 2014) A Swedish Adventure racing team travels to try and win a world title, but comes home with something way better: a stray dog that joined the team for much of the grueling 430-mile race. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins