Entries in Malaria (9)


Harvard Researchers Use Cell Phones for Tracking Malaria

iStockphoto/Thinkstock(BOSTON) -- There’s a new weapon in the war against malaria -- the cell phone.

Harvard researchers found they could track the spread of malaria in Kenya using phone calls and text messages from 15 million mobile phones.

“Before mobile phones, we had proxies for human travel, like road networks, census data and small-scale GPS studies,” said study author Caroline Buckee, an assistant professor of epidemiology at the Harvard School of Public Health. “But now that mobile phones have spread throughout the world, we can start using these massive amounts of data to quantify human movements on a larger scale and couple this data with knowledge of infection risk.”

Buckee and colleagues used mobile phone records from June 2008 and June 2009 to track the timing and origin of calls and texts among 15 million Kenyan mobile phone subscribers. They then compared the volume of subscribers in a particular region to that region’s known malaria prevalence.  By studying networks of human and parasite movement, the team could then determine primary sources of malaria and who was most likely to become infected.

The results, published Thursday in the journal Science, suggest that malaria transmission within Kenya is dominated by travel from Lake Victoria on the country’s western edge to the more central capital city of Nairobi.  And human carriers of the malaria parasite, who may not show symptoms, far outpace the flying limits of mosquitoes in endemic regions.

“How travelers acquire malaria elsewhere and bring it home has been mostly surmised from expert knowledge and judgment,” said Dr. William Schaffner, professor and chairman of the department of preventive medicine at Vanderbilt University. “Here we’ve used this unrelated cell phone technology.”

With 89 percent of the estimated 1 million annual malaria deaths occurring in Africa, the Harvard findings may help researchers better understand how human travel patterns can spread disease and potentially lead to improved public health efforts to curb the mosquito-borne infection.

“I think it is so neat and extraordinarily imaginative,” said Schaffner. “It has me bouncing up and down in my chair with excitement.”

Buckee anticipates that mobile technology could change approaches to malaria control. Long-employed anti-malaria strategies, such as the use of insecticides, bed nets, medications and mosquito-habitat removal, could be augmented by warning texts sent to travelers en route to and from malaria hot spots.

“I suspect that some people will get antsy about big brother following you,” Schaffner said, alluding to the privacy concerns that accompany mobile technology. “I’m more excited about the possibilities to prevent serious disease.”

Buckee said efforts to eradicate malaria in sub-Saharan countries, including Kenya, has been challenged by tight budgets.

“They can’t screen and treat everyone,” she said. “[Mobile phones] could be really powerful tools for targeting resources with very practical applications.”

Copyright 2012 ABC News Radio


Malaria Deaths Twice as High as Previously Reported

Stockbyte/Thinkstock(SEATTLE) -- Malaria kills 1.2 million people each year, more than twice as many deaths as previously thought, according to new research published in The Lancet.

However, according to the Institute of Health Metrics and Evaluation, which conducted the new research, efforts to combat the disease, both through drug treatments and prevention, have resulted in a decline in malaria-related deaths.

"This runs counter to most assumptions about the disease," said Dr. Stephen Lim, associate professor of global health at the Institute.  "The good news, though, is that even though the overall number of deaths is higher, the trend is sharply downward."

Researchers also found that while many believe most malaria deaths occur in children under age 5, in fact, 42 percent of all malaria deaths occur in older children and adults.

Authors from the Institute collected data on malaria deaths over two decades, from 1980 to 2010.  They found that 1.2 million people died of the disease in 2010: twice as many deaths as reported by the World Malaria Report released last year.  The World Health Organization estimated that about 650,000 people worldwide died of the disease in 2010.

Researchers said the higher death tally is likely due to the fact that more reliable data became available.

Based on the new numbers, malaria deaths have fallen by 32 percent since 2004, dropping from 1.8 million deaths worldwide to 1.2 million in 2010.

"That's a massive decrease, and it appears to be the result of the huge scale-up in spending to fight malaria, especially by the Global Fund to Fight AIDS, Tuberculosis and Malaria," Lim said.

Malaria is caused by a parasite passed to humans through mosquito bites.  The parasites then travel through the bloodstream to the liver and infect red blood cells, according to the National Institutes of Health.

The parasites multiply within the body, and then symptoms, including chills, fever, vomiting and coma, occur 10 days to four weeks after the mosquito bite occurs.  If left untreated, complications can include kidney failure, liver failure, meningitis and, ultimately, death.

Copyright 2012 ABC News Radio


Researchers Trace Origins of Malaria

MALARIA MOSQUITO HEAD, Getty Images(IRVINE, Calif.) -- Researchers at the University of California, Irvine think they know how malaria jumped continents may years ago.

The study, which will be published in the Proceedings of the National Academy of Sciences, traced the origins of the mosquito-borne disease back to the 16th century.

Researchers in Irvine say they relied on DNA as a molecular clock appearing to answer how malaria got from Africa to South America and then the rest of the Americas. The team of researchers say the disease, which kills over a million people a year, came aboard Spanish and Portuguese slave ships in the 16th century.

Copyright 2011 ABC News Radio


WHO Study Shows Malaria Deaths Decreased Globally

Stockbyte/Thinkstock(GENEVA) -- Malaria deaths have decreased worldwide says a new report issued by the World Health Organization (WHO).

According to the World Malaria Report 2011, mortality rates from malaria have fallen by 25 percent since 2000. The fall can be attributed to campaigns including promoting the use of bed nets and the distribution of malaria drugs.

"We are making significant progress in battling a major public health problem. Coverage of at-risk populations with malaria prevention and control measures increased again in 2010, and resulted in a further decline in estimated malaria cases and deaths," said Dr Margaret Chan, WHO Director-General.

African countries accounted for 81 percent of 216 million cases of malaria recorded in 2010 and 86 percent of cases affected children under 5 years of age.

Despite these gains in the malaria fight, the WHO says projected funding shows a significant decrease which could affect the strides already made in the global fight against the disease.

"We need a fully-resourced Global Fund, new donors, and endemic countries to join forces and address the vast challenges that lie ahead. Millions of bed nets will need replacement in the coming years, and the goal of universal access to diagnostic testing and effective treatment must be realized," said Dr Robert Newman, Director of WHO's Global Malaria Programme.

Copyright 2011 ABC News Radio


Mosquito Numbers Decline in Certain African Areas

Stockbyte/Thinkstock(TANZANIA) -- Malaria-affected mosquito populations are declining in certain areas across Africa, according to recent figures, though researchers are unsure as to why.

The Malaria Journal reports that researchers are unsure if the decline means the pesky insects have been eradicated for good, or if they will come back in a stronger force.

The BBC reports that malaria cases dropping in Tanzania, Eritrea, Rwanda, Kenya and Zambia, according to data.

Anti-mosquito bed nets are lessening the spread of the disease in some sub-Saharan countries.

Researchers also cite that mosquito traps installed over the course of 10 years have caught insects by the thousands in Tanzania, and the numbers have drastically been reduced over the years.

Scientists captured over 5,000 mosquitoes in 2004, and could only trap 14 in 2009.

Copyright 2011 ABC News Radio


Genetically-Engineered Spermless Mosquitoes Offer Malaria Hope

Stockbyte/Thinkstock(LONDON) -- Where mosquito netting and bug spray fail, European scientists are turning to a unique solution to stem the tide of malaria infection worldwide: they're breeding boy bugs that shoot blanks.

In a study released Monday in the Proceedings of the National Academy of Sciences, researchers in Italy and the U.K. showed they were able to genetically modify male Anopheles mosquitoes so that they wouldn't produce sperm. The bugs would still produce seminal fluid, so mating rituals would go on per usual, but the fruit of coupling would be sterile eggs that don't hatch.

"If mosquitoes [don't] produce any progeny...the number of mosquitoes in the wild will be reduced, eventually reducing the chances of malaria transmission," says study co-author Dr. Flaminia Catteruccia of the Imperial College in London.

Though there are thousands of mosquito species, only a handful of them can transmit malaria, Catteruccia says, so targeting these species has the potential to reduce the spread of disease and is less likely to negatively impact the local ecosystem.

The fact that the Anopheles species of mosquito tends to be monogamous only enhances the effect, as those females who mate with sterile males tended to not seek out other, potentially virile mates.

Sterility may even prove a reproductive boon for spermless males, authors note, because making sperm is energy-consuming, thus the modified males may appear to be stronger mates.

More than 225 million people worldwide suffer from malaria. Each year, nearly 800,000 people will die from the disease -- many of whom are children living in Africa.

"Given the constant spread of the disease, alternative approaches to the use of insecticides are urgently needed," the study's authors wrote.

Monday's research is just the most recent example of a number of mosquito-modifying techniques tested in the past few years in hopes of limiting the mosquito population or the bugs' disease-transmission capabilities.

Other mosquito-limiting tactics have included modifying males to be unable to fly (and who have offspring who also cannot fly) and injecting mosquitos with a special fungus that is thought to reduce the bug's ability to pass malaria to humans, even when the bugs themselves become infected.

The hope with these various methods is that disease rates can be lowered without negatively impacting the surrounding ecosystems, which often include several species of insects and animals that rely on mosquitoes for food.

Copyright 2011 ABC News Radio


Stinky Feet, Scented Deodorants Attract Mosquitoes

Jupiterimages/Thinkstock(MOUNT LAUREL, N.J.) -- From perfume, to the color of your shirt, right down to the smelliness of your feet, mosquitoes seem to find any reason to sink themselves into human skin.

Scientists say that stinky feet and socks can be added to the list of factors that attract mosquitoes to feed off human blood. One African scientist is now using that bit of research to help fight malaria in Tanzania by creating traps that give off chemically replicated smelly foot odors, hoping to lure the bloodsuckers that carry the disease to their hosts.

"Scientists have known for a long time that mosquitoes smell people; that they do not see us, but instead they smell us," wrote Dr. Fredros Okumu in an email from Tanzania where he heads the research project at the Ifakara Health Institute. "It is the things that we produce in our breath, sweat of skin that [mosquitoes] use as a signal to find us. So if you are wearing socks, these skin-derived chemicals remain on the sock fabric and can still be detected by mosquitoes even after you have removed your socks."

Okumu's project received a $775,000 grant Wednesday from the Bill and Melinda Gates Foundation and Grand Challenges Canada to fund the traps and help further development.

But unclean feet and dirty socks aren't the only things that entice a mosquito to go in for the kill. Experts say that Limburger cheese has also been found to be attractive to certain mosquito populations. Ned Walker, a professor in the Department of Microbiology and Molecular Genetics at Michigan State University, studies mosquitoes extensively. Walker said that everything from body build to the type of perfume you wear can be the difference between deterring and attracting the pests.

However, determining why some people leave a picnic covered in bites while others escape without a battle wound is still up for debate.

Joe Conlon, technical adviser at the American Mosquito Control Association, said genetics as well as fair skin may also play a role in appealing to mosquitoes, although scientists remain unsure whether the bites are simply more noticeable on people with fair skin.

And while fair skin might be more attractive to the insects, lighter colors of clothing turn them off.

Conlon said that the only surefire way of preventing mosquitoes from biting is to wear a repellant, to watch what clothes you wear and to get rid of standing water that collects in places like at the bases of flower pots and in the bottom of air conditioning drip pans.

He also cautioned against using any substitutes to DEET repellants like vitamin B, saying that double blind tests have proven these remedies not to work effectively.

Copyright 2011 ABC News Radio


Bug Buster? New Chemical Compound Could Ward Off Deadly Mosquitoes

Stockbyte/Thinkstock(NASHVILLE, Tenn.) -- Somewhere in the world, every 45 seconds, malaria claims the life of one child. The large majority of those are deaths are in Africa. And they are preventable.

"The most dangerous animal on the planet is the Anopheles gambiae,'' the mosquito that carries malaria, said Dr. Lawrence Zwiebel, a researcher at Vanderbilt University who has been working for the past six years to find a way to repel the deadly insects.

Zwiebel's team has taken a novel approach. Rather than looking for ways to eradicate the insects or disrupt the ecosystem, they sought to change the habits of the ancient pests, their feasting habits, to be precise, by making humans less appetizing to the nasty predators.

Last month, Zwiebel's team announced that they may have hit the jackpot. They identified what's called a behaviorally disruptive olfactory compound that they believe could be thousands of times more effective than the most commonly used insect repellent on the market, DEET.

The compound, which the Vanderbilt scientists have named VUAA1, works by activating all 76 of the insect's odor receptors at once, over-stimulating and confusing the bugs, said Patrick L. Jones, a postdoctoral research fellow working on Zwiebel's team.

If not humans, they would target birds and other mammals not treated with the repellent as their prey. "Mosquitoes are fairly promiscuous," he said.

What's more, Jones said, the compound seems to work on other bugs. "This a potential new repellent that could repel virtually every insect," disease-carrying as well as merely nuisance species.

"No one has ever seen a molecule like this with this type of activity," said Zwiebel. "We're trying to understand why it is able to do what it does."

Researchers hope their findings will lead to repellents that will deter crop-eating pests, which feast on and destroy the world's food sources, as well as flies attracted to human sweat.

The researchers, whose work, in partnership with John Carlson at Yale University, as well as laboratories in Gambia, Kenya and the Netherlands, is funded by the Bill & Melinda Gates Foundation and the National Institutes of Health, caution that while they are optimistic about their findings, there is a long road ahead before their work begins to save lives -- or make your backyard barbecue more comfortable.

It will take at least five years and millions of research and development dollars before a product based on the new compound is approved for sale and becomes available commercially. But when it does, they say, some of the profits from the product will be channeled to offset the costs of supplying the repellent to countries that cannot afford it.

Copyright 2011 ABC News Radio


How Climate Change May Make Killer Diseases Worse

Stockbyte/Thinkstock(NEW YORK) -- Malaria already kills a million people a year and now, researchers fear, climate change could make the problem even worse.

Working with the Kenya Meteorological Department, Madeleine Thomson, a senior research scientist for the International Research Institute for Climate and Society, has found that temperatures have increased significantly since the 1980s in the Kenyan Highlands.

Thomson, who has been working in Africa for the past 25 years, has looked at the possibility of increased risk of malaria from a rise in global temperatures for the past 10.

"Malaria is an appalling disease, particularly for those that don't have immunity, such as foreigners, young children and pregnant women and also the people who live in the highlands who normally don't get malaria," Thomson said.

"When I visited Tigre, a mountainous region in Ethiopia, I met people with malaria in the highlands and they were trying to understand what was going on," Thompson said. "We know that the rises in temperature that have been recorded at this site can significantly increase malaria. And it's the combination of climate change, drug resistant malaria and poor health conditions that can completely devastate an area."

Around the world, climate change is impacting human health -- from recent floods in India, Nepal and Bangladesh that have caused widespread waterborne disease that the U.N. attributes to global warming, to malaria-infected mosquitoes migrating to increasingly high elevations in the mountains of Africa.

"Climate change will touch the pillars of our health, food, water and shelter," Dr. Maria Neira, director of public health and environment for the World Health Organization, told ABC News. "In Asia, there are more people at risk of dengue fever due to global warming. In Mount Kenya, mosquitoes are being found at higher and higher elevations."

Others agree with her that the malaria could become an even bigger problem as the climate changes.

"As temperatures have been increasing, the mosquitoes that are transmitting the disease have better conditions to breed, reproduce, and transmit the disease," Neira said. "Vector-borne diseases are expanding their reach and death tolls."

As warming likely causes seawater level to rises, underground freshwater aquifers likely will get contaminated. Drought likely will continue to impact fresh water supplies for millions of people around the world, and more people will be forced to move.

Since 2008, Los Angeles, which gets a portion of its drinking water from the Colorado River, has faced long-term drought because of global warming. The river suffers from low volume and rising water temperatures. The shrinking river has raised health concerns for the 30 million people in seven states who depend on it for their water supply.

For humans to survive, they need fresh water. According to the U.N. high commissioner for refugees, Antonio Guterres, climate change could become the biggest driver of human displacement.

"Displacement causes conflict, creates a lot of health stress on the people who are displaced and the people taking in the refugees," Solomon said. "It can encourage the spread of disease from one part of the world to another. As people move, they can carry diseases with them."

Copyright 2011 ABC News Radio

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