News / Science & Technology

Study: Mosquitoes Can Smell Malaria

FILE - Scientists collected odor compounds in glass jars from malaria-infected mice. (Credit: Nick Sloff, De Moraes & Mescher Research Group)
FILE - Scientists collected odor compounds in glass jars from malaria-infected mice. (Credit: Nick Sloff, De Moraes & Mescher Research Group)

Malaria infection makes mice smell a bit better to mosquitoes, raising the odds that they’ll be bitten and spread the disease. That’s according to a new study in the Proceedings of the National Academy of Sciences.

The research could point the way to a Breathalyzer-style diagnostic test for malaria infection.

And it’s the latest example of how parasites manipulate the creatures they infect for their own nefarious aims.

Penn State University biologist Mark Mescher has seen it before. But not in people, in squash.

When squash plants are infected with cucumber mosaic virus, they produce chemicals that attract aphids. The aphids pick up the virus when they come to the plant for the advertised meal.

The virus even goes an extra step: It makes the plant less nutritious to the insects. After a few bites, Mescher said, the aphids “don’t like the plant very much. So, rather than staying there for the long term they move on and go to the next plant,” spreading the virus with them.

Mescher wondered if something similar was happening with malaria. A couple of studies in people and birds have suggested mosquitoes prefer the malaria-infected over the uninfected. But the studies did not explain why.

Eau de mouse

Mescher and his colleagues found that they could get the same tantalizing effect in malaria-infected mice. Given a choice, about 60 percent of the mosquitoes in their experiment were drawn to an infected mouse, while around 40 percent went for the uninfected.

The mice didn't even need to be there. The scientists collected the volatile chemicals wafting off infected and uninfected mice and let mosquitoes smell it. Eau de infected mouse had the about same attractive effect as an actual infected mouse.

The researcher found a handful of chemicals in the mouse-odor cocktail that were at higher levels in infected animals than healthy ones. A dab of those chemicals would make even a healthy mouse more appealing to mosquitoes.

“The malaria parasite is enhancing the odor cues the mosquito is already using to find their host,” Mescher said, which helps the parasite hitch a ride to the next victim.

Malaria breathalyzer

Knowing what the mosquitoes are smelling could help identify people who are carrying the malaria parasite but don’t know it.

“It would be nice to have biomarkers that you could use to identify infected individuals that are not actually sick with malaria, or have asymptomatic infections, but are still capable of transmitting the disease,” Mescher said.

It’s a long way off, he added, but, “If you can identify a chemical signature of infection, then you could imagine something like a Breathalyzer, or something along those lines, that would be quick and easy to get the sample and analyze right there in the field.”

“The question is whether it will go beyond solving the mouse malaria problem and get on to the people malaria problem,” joked Peter Hotez, dean of tropical medicine at Baylor College of Medicine.

Parasite manipulation

Hotez noted that malaria is not the only parasite that tweaks the animal it infects in order to improve the odds for its offspring.

A germ called Toxoplasma gondii needs to infect a cat as part of its life cycle. Mice infected with Toxoplasma conveniently lose their fear of cats.

“The way [the germ] propagates itself is by getting eaten and infecting the new animal,” Hotez explained. “It’s a very innovative story that’s emerging in the biology of the host-parasite relationship.”  

Innovative ... and a bit creepy.

You May Like

Multimedia VOA SPECIAL REPORT: US Army Turns Its Best Minds Toward Ebola

Scientists at America's premier biological research center race to find effective drugs, speedier tests and a safe vaccine amid the deadliest outbreak of Ebola in history More

Kurdish Poet Battles to Defend Language, Culture

Kawa Nemir's work is an example of what he sees as an irreversible cultural and political assertiveness among Kurds in Turkey More

Dissident Venezuelan General Resurfaces in New York

Antonio Rivero has resurfaced after nearly a year in hiding, appearing at United Nations in New York More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Filmmakers Produce Hand-Painted Documentary on Van Goghi
X
George Putic
January 29, 2015 9:43 PM
The troubled life of the famous 19th century Dutch painter Vincent van Gogh has been told through many books and films, but never in the way a group of filmmakers now intends to do. "Loving Vincent " will be the first ever feature-length film made of animated hand-painted images, done in the style of the late artist. VOA’s George Putic reports.
Video

Video Filmmakers Produce Hand-Painted Documentary on Van Gogh

The troubled life of the famous 19th century Dutch painter Vincent van Gogh has been told through many books and films, but never in the way a group of filmmakers now intends to do. "Loving Vincent " will be the first ever feature-length film made of animated hand-painted images, done in the style of the late artist. VOA’s George Putic reports.
Video

Video Rock-Consuming Organisms Alter Views of Life Processes

Scientists thought they knew much about how life works, until a discovery more than two decades ago challenged conventional beliefs. Scientists found that there are organisms that breathe rocks. And it is only recently that the scientific community is accepting that there are organisms that could get energy out of rocks. Correspondent Elizabeth Lee reports.
Video

Video Paris Attacks Highlight Global Weapons Black Market

As law enforcement officials piece together how the Paris and Belgian terror cells carried out their recent attacks, questions are being asked about how they obtained military grade assault weapons - which are illegal in the European Union. As VOA's Jeff Swicord reports, experts say there is a very active worldwide black market for these weapons, and criminals and terrorists are buying.
Video

Video Activists Accuse China of Targeting Religious Freedom

The U.S.-based Chinese religious rights group ChinaAid says 2014 was the worst year for religious freedom in China since the end of the Cultural Revolution. As Ye Fan reports, activists say Beijing has been tightening religious controls ever since Chinese leader Xi Jinping came to office. Hu Wei narrates.
Video

Video Super Bowl Ads Compete for Eyes on TV, Web

Super Bowl Sunday (Feb. 1) is about more than just the NFL's American football championship and big parties to watch the game. Viewers also tune in for the world famous commercials that send Facebook and Twitter abuzz. Daniela Schrier reports on the social media rewards for America’s priciest advertising.
Video

Video Theologians Cast Doubt on Morality of Drone Strikes

In 2006, stirred by photos of U.S. soldiers mistreating Iraqi prisoners, a group of American faith leaders and academics launched the National Religious Campaign Against Torture. It played an important role in getting Congress to investigate, and the president to ban, torture. VOA's Jerome Socolovsky reports.
Video

Video Freedom on Decline Worldwide, Report Says

The state of global freedom declined for the ninth consecutive year in 2014, according to global watchdog Freedom House's annual report released Wednesday. VOA's William Gallo has more.
Video

Video MRI Seems to Help Diagnose Prostate Cancer, Preliminary Study Shows

Just as with mammography used to detect breast cancer, there's a lot of controversy about tests used to diagnose prostate cancer. Fortunately, a new study shows doctors may now have a more reliable way to diagnose prostate cancer for high risk patients. More from VOA's Carol Pearson.
Video

Video Smartphones About to Make Leap, Carry Basic Senses

Long-distance communication contains mostly sounds and pictures - for now. But scientists in Britain say they are close to creating additions for our smartphones that will make it possible to send taste, smell and even a basic touch. VOA’s George Putic reports.
Video

Video Former Sudan 'Lost Boy' Becomes Chess Master in NYC

In the mid-1980’s, thousands of Sudanese boys escaped the country's civil war by walking for weeks, then months and finally for more than a year, up to 1,500 kilometers across three countries. The so-called Lost Boys of the Sudan had little time for games. But one of them later mastered the game of chess, and now teaches it to children in the New York area. VOA’s Bernard Shusman in New York has his story.
Video

Video NASA Monitors Earth’s Vital Signs From Space

The U.S. space agency, NASA, is wrapping up its busiest 12-month period in more than a decade, with three missions launched in 2014 and two this month, one in early January and the fifth scheduled for January 29. As VOA’s Rosanne Skirble reports, the instruments being lifted into orbit are focused on Earth’s vital life support systems and how they are responding to a warmer planet.
Video

Video Crowded Republican Presidential Field Off to Early Start for 2016

It seems early, but the 2016 U.S. presidential election campaign is already heating up. Though no one has officially announced a candidacy, several potential Republican contenders have been busy speaking to conservative groups about making a White House run next year. Many of the possible contenders are critical of the Obama administration’s foreign policy record. VOA national correspondent Jim Malone reports.

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More

All About America

AppleAndroid