The study

Researchers interviewed more than 1,800 adults, 1,100 adolescents and 330 children at several fast food chains in New England. The interviews were done at McDonald's, Burger King, Subway, KFC, Dunkin' Donuts and Wendy's around dinnertime and lunchtime.

Study participants were asked to estimate their meal's calorie count. Researchers then collected the bill to later tally the correct amount of calories using nutrition info posted on the chain's website.

The results

At least 40% of the study participants reported eating at the restaurant where they were interviewed at least once a week. More than 20% of the adult participants noticed posted calorie information, but only 5% said they used that information when purchasing food.

The mean calorie count for adults' meals was 836 calories; teens purchased 756 calories and children ordered 733 calories. "At least two-thirds of all participants underestimated the calorie content of their meals, with about a quarter underestimating the calorie content by at least 500 calories," the study authors write.

Adults tended to underestimate their meals by about 175 calories, the same as children. Adolescents were more likely to underestimate by about 250 calories. Adults with a higher BMI were less likely to underestimate than their normal weight counterparts.

The restaurant most likely to confuse calorie-counters? Subway. Adult diners there underestimated their consumption by an average of 350 calories and teen diners underestimating by an average of 500 calories. Most of Subway's 6-inch sandwiches contain between 350 and 500 calories; consumers must double that if they order a foot-long sub and factor in extra calories for sides and/or drinks.

Limitations

More than half of the people researchers approached were unwilling to participate. Researchers also did not interview anyone going through the drive-thru. The people they did not talk to may have estimated their calorie counts differently than the study population.

The researchers also did not weigh each participant's food to determine its exact calorie amount, instead relying on generalizations from the restaurant's website.

The takeaway

The study authors are hopeful that listing calorie counts on menus in these establishments will encourage consumers to make healthier choices. But research on the effect of calorie displays has been mixed.

More important may be the sheer number of calories consumers are eating in a typical fast food meal. Depending on their age, children need between 1,200 and 2,000 calories per day. Eating more than 730 in one sitting (and remember, that's the mean - others ate up to 350 calories more than that) could lead to weight gain over time.

Experts recommend doing some research before you order out. View the restaurant's nutritional info online and decide what you'll eat ahead of time.

The study surveyed more than 22,000 Canadian children aged 12 to 17.  They were asked if anyone in their school, or anyone they knew personally had died by suicide and if they had seriously considered attempting suicide themselves in the past year. The researchers found that the risk of suicide was magnified even if the child did not know the deceased student personally.

Researchers found 12 to 13-year-old children were at greatest risk and were five times more likely to have suicidal thoughts than teens who had not been exposed to a death.  According to the study, 7.5% of these children attempted suicide after a fellow student did, compared to 1.7% of adolescents in this age group who did not have a schoolmate attempt suicide.

"The bottom line is that the suicide contagion theory may be real," says senior author Ian Colman, the Canada Research Chair in mental health epidemiology and assistant professor at the University of Ottawa.  "Being exposed to a suicide appears to be strongly associated with suicidal thinking and suicidal behavior and these effects may persist for a long time.

"This was remarkably common, at least in our study that is representative of the entire Canadian population. By the time these children were 16 or 17, one out of four were reporting that somebody in their school had died of suicide. That seems really high, but if you consider one child dies of suicide and they attend a school with 1,000 students, 1,000 students have been exposed to suicide."

Colman says suicide contagion, imitation or copycat suicides, has been around for a long time, but until now there wasn't strong evidence supporting the theory. Suicidal behavior is a global problem, he says. "It's the second leading cause of death among young people, and losing a loved one to suicide is incredibly distressing for the survivors."

In many cases, for years to come.

"We found that these effects weren't short-lived," Colman said. "The survey contacted the children every two years so we could follow up the reports of the school suicide to see if there was still an effect two years later. And in many cases, suicidal thinking and suicide attempts were still increased among those who had reported a suicide in their school two years previously."

Friends closest to the suicide victim were no more likely to have an increased risk of suicidal thoughts than other acquaintances, according to the study.

"We suggest schools should be thinking about doing interventions after a suicide schoolwide, involving everybody in the school, rather than just the friends or immediate classmates of the person who died," Colman said. "Schools should consider longer-term interventions or programs where they're going to revisit the intervention because we saw this longer-term effect."

Psychiatrist Dr. Karen Johnson says she doesn't believe the study should be considered "cut-and-dried information."

"As they mentioned, there are many other risk factors for teenagers, girls and boys, to attempt or consider suicide," says Johnson, associate chair of psychiatry at MedStar Washington Hospital Center.

"There was no indication as to what were the youngsters' state prior to their classmate's attempt," she noted. "Did these kids already have risk factors themselves prior to their classmate's attempt? Did they have a history of depression anxiety or substance abuse? Did they have a family history of suicide attempts or completions? Did they have a history of traumatic events in their life? It would have been good to know if the kids in the study met any of these criteria prior to the classmate attempt."

Colman says schools "may want to consider paying attention to the younger students, where these effects seem to be felt the strongest."  He says these children should not feel like they are alone and helpless.  "It's important to create a culture where students or children feel comfortable seeking help if they're struggling with their mental health. It's important for parents to talk to their kids about mental health. Be open, be supportive and make sure that your child knows that help is available."

A study in the journal Nature Climate Change suggests that heat deaths in Manhattan will increase over the rest of this century in connection with higher temperatures associated with global warming. In the 2020s, heat-related deaths could rise about 20% compared with the 1980s, according to the research.

"This paper helps to remind people that climate change is real, that it’s happening and we need to prepare and make ourselves as resilient as we can to climate change," said Patrick Kinney, the study's senior author and director of the Columbia Climate and Health Program at Columbia University's Mailman School of Public Health. "It’s a real problem that we face. It’s not insurmountable."

In the 2050s, the study projects, climate change could be associated with a rise of up to 49% in heat-related deaths. And by the 2080s, the average heat-related deaths could go up as much as 91%. For reference, the average number of heat-related deaths in the 1980s was 369.

Although rising temperatures mean fewer cold-related deaths, the magnitude of the heat-related deaths still results in an overall net loss of life when it comes to temperature-related mortality. Projections in this study comparing the two found a net increase in deaths of up to 6.2% in the 2020s, up to 15.4% in the 2050s and up to 31% in the 2080s.

Scientists paired projections of future temperatures, which are expected to rise because of climate change, and plugged them into a function relating this information to risk of death. To come up with that function, they analyzed data on daily temperatures and deaths in Manhattan in the 1980s.

These numbers all relate to a scenario in which greenhouse gases are high by the end of the century, with greenhouse gas emissions continuing to grow. The projected death tolls are slightly more modest in a scenario where social and environmental consciousness work to mitigate emissions, the study says, but even then, heat deaths would be expected to rise about 50% in 2080, as compared with 100 years earlier.

In the 2080s, the months of May and September are projected to have the largest percentage increases in temperature-related deaths.

Kinney's study does have some shortcomings. For example, it did not take into account the expected rise in population of Manhattan in the future, or the effects of hurricanes and other extreme weather events when calculating death tolls.

The study is similar to an analysis done in 2011 about Chicago, led by Francesca Dominici of Harvard School of Public Health. She and colleagues wrote in the journal Environmental Health Perspectives that between 2081 and 2100, Chicago could suffer up to 2,217 excess deaths per year that would be attributable to heat waves, although the lower estimate was 166 such deaths.

The consensus in the scientific community is that human activity - namely burning coal, oil and natural gas - has been the engine behind the rapidly rising carbon dioxide levels in the atmosphere.

Earlier this month, carbon dioxide levels reached a key milestone – 400 parts per million - at the Mauna Loa Observatory in Hawaii.

With warmer temperatures and melting icecaps, sea levels rise, making any individual storm more disastrous. The sea level near New York City was about 10 inches higher in 2012 than in 1900, which compounded the effects of Superstorm Sandy, said J. Marshall Shepherd, climate change expert and professor at the University of Georgia.

It's impossible to say that any given heat wave or severe storm is "caused by climate change," but changing climate patterns do raise the risk for these events.

Kinney likens this to drunk driving. A sober driver has a risk of getting into an accident to begin with, but after a couple of drinks, that risk goes up. Similarly, as humans pump more greenhouse gas into the atmosphere, the changes of extreme weather events go up.

"Greenhouse gases are kind of like the alcohol in the system of the climate," Kinney said.

New York is already planning strategies to combat heat-related illness from climate change, Kinney said. Planting trees and making "green" roofs, or simply painting black roofs white, can all help cool the city. When high temperatures are on the way, there could be better ways to get the word out to vulnerable populations.

"With careful planning we can protect most people from the effects shown in this paper," Kinney said.

Heatstroke: A deadly hazard of summer

Researchers in Spain followed more than 1,000 people for six and a half years, and found that participants who were on a Mediterranean diet and supplemented that diet with extra nuts or olive oil performed better on cognitive tests at the end of the study period than the control group, which followed a lower-fat diet. The study was published Monday in the Journal of Neurology, Neurosurgery and Psychiatry.

"We found that a Mediterranean diet with olive oil was able to reduce low-grade inflammation associated with a high risk of vascular disease and cognitive impairments," said Dr. Miguel Martinez-Gonzalez, the chairman of preventive medicine at the University of Navarra in Spain and a study author.

The Mediterranean diet is devoid of processed foods and bad fats, and high in whole grains, nuts, fruits and vegetables, legumes, fish and even red wine - all things that are high in antioxidant and anti-inflammatory compounds. These types of foods are known to help reduce vascular (circulatory) damage, inflammation and oxidative (free radical) damage in the brain.

But there are limitations to the study.

Dr. Dean Ornish, a well-known proponent of a very low-fat, largely plant-based diet says while the Mediterranean diet is good, it's unfair to compare it to a "low fat diet" in this particular study.

"It's erroneous to say (the Mediterranean diet in this study is) better than a low fat diet, when in fact they weren't following a low-fat diet," said Ornish. "If they said the Mediterranean diet improves cognition compared to standard American diet or standard Spanish diet, I would agree, but clearly, a 37% fat diet is not a low-fat diet."

Ornish, who recommends a diet that includes only 10% fat says in his studies, says he has seen similar effects - improved cognition, improved heart health and reduced depression.

"Good shouldn't be confused with optimal," when referring to the Mediterranean diet, he says.

Dr. Melina Jampolis, a physician-nutrition specialist, says the study findings are encouraging.

"The Mediterranean diet is high in antioxidants, it's anti-inflammatory, and it has a lot of vascular protective elements, so I don't think this is a stretch," said Jampolis. "In a high-risk vascular population, this could be beneficial, and it's worth evaluating further."

But she cautions that the Mediterranean diet should be stacked up against the typical American diet to get a true picture of how much it helps cognition.

While Dr. Martinez-Gonzalez agrees that the study isn't perfect, he says there is clear evidence that the Mediterranean diet is beneficial.

"The quantity of the difference between the groups was small from a clinical point of view, but it was statistically significant," he said. "The harmony, the combination of all of the micronutrients, when they are combined in traditional Mediterranean cuisine, is very important for the functioning of the central nervous system."

And he added that this is not only a healthy diet, it's a sustainable diet.

"The Mediterranean people enjoy this kind of diet every day," he said. "It is pleasant, it is healthy, it is sustainable, and it is not very expensive."

Researchers at NYU's Langone Medical Center have been following more than 200 kids for four decades. They found those who had ADHD in their early years were twice as likely to be obese at age 41.

"This study was started by Dr. Rachel Klein in 1970, and it involved a number of waves of evaluation, during which the results of having hyperactivity in childhood were assessed," said Dr. F. Xavier Castellanos, a professor of child and adolescent psychiatry at NYU and one of the study authors.

"We brought back individuals who were 41 years of age, and examined a number of measures, including brain imaging analyses.  But during those brain imaging analyses, we noted that men who had been hyperactive children had a greater difficulty sitting in the scanner - they were too large for the research scanner."

That's when the idea took shape to look at all of the subjects' height and weight.  Castellanos and his team instantly noticed the high levels of obesity – twice as high as those adults who never suffered from ADHD.

"This was not the first time this has been noted, so in that sense it is a confirmation," said Castellanos. "But other studies have not been able to be as definitive. Other studies have found a general tendency towards increased weight, but this is the first study that puts this in terms of clear clinical obesity."

However, there is no clear reason as to why ADHD may lead to obesity.

"The most reasonable explanation is that the characteristics of ADHD which involve being impulsive - having a difficult time selecting between (things) that maybe immediately gratifying but in the long run are not such a good idea - that that translates to the choices that are made at lunchtime and dinner and snacking," said Castellanos, though he said there was no direct evidence of that being the case, only speculation.

Other experts say while this correlation appears to be strong, more research needs to be done.

"The sample size was relatively small, and they only looked at white men," said CNN.com expert Dr. Jennifer Shu, a spokeswoman for the American Academy of Pediatrics. "That said, their conclusion summed it up nicely: people need to be aware that having childhood ADHD may put them at risk for later obesity."

Shu also suggested another possible explanation for the link - current treatments are largely centered around stimulant medications, which tend to reduce appetite. If the medication is stopped, appetite increases and patients may start gaining weight.

The bottom line, says Castellanos?

"It's very difficult across the board for people to lose weight and keep it off, so it's one of those things that is really best prevented," he said. "That's the major importance of alerting the public - we can look into the future and say, 'This is coming up, so it's better to not ignore this potential risk and wait for it to become a problem.'"

But it's not entirely the fault of the mosquitoes. Scientists are exploring how the malaria parasite itself may actually change a mosquito's behavior to make it more attracted to humans, as if controlling its mind so that the bug goes after us.

A new study in the journal PLOS One demonstrates, for the first time, that mosquitoes infected with malaria are more attracted to human odor than uninfected mosquitoes. This is only a proof of concept, however; more research needs to be done to confirm.

“What we've shown is malaria parasites can manipulate the mosquito's behavior to make it sense our body odor much more easily, and that means they’re much more likely to find us," said Dr. James Logan of the Department of Disease Control at the London School of Hygiene & Tropical Medicine, senior author of the study.

Methods

Researchers used 59 malaria-infected mosquitoes and 97 mosquitoes that were not infected. (Only female mosquitoes transmit the parasite.)

A male volunteer wore nylon socks for 20 hours to collect human odor on the material. Scientists then examined how mosquitoes responded to a human-smelling sock compared with a standard nylon sock without a human odor.

Results

Both groups of mosquitoes were generally uninterested in the sock without the human odor. But mosquitoes with malaria paid a lot more attention to the human-smelling sock, landing on it and probing it more than the non-infected mosquitoes.

This represents the first time female mosquitoes have exhibited a behavior change as a result of malaria in response to human odor, the study authors wrote.

Implications

Logan and colleagues have won a research grant to study this further over three years. In the next step, they will take body smell samples from 30 people, "mixing it all up so we’ve got an overall coverage of different types of human odor," he said. Scientists already know that individuals can differ in their attractiveness to mosquitoes.

Eventually, this may lead scientists to identify chemicals that can be used as lures for traps to target malaria-infected mosquitoes. Currently, the traps catch all kinds of mosquitoes, regardless of their malaria status. It would be more efficient, and better for monitoring purposes, to trap only those that have the parasite. This method might even be used to bring the population down.

There are some other intriguing examples in nature of how parasites control the minds of their hosts. A type of fungus, for example, can take over and eventually kill the ants it infects.

But these "zombie ants" don't have the tremendous human impact of malaria-carrying mosquitoes, which caused an estimated 660,000 deaths in 2010.

"The importance is that we showed in a biologically relevant system of a mosquito, a parasite and a blood host, that the parasite can manipulate the behavior of a mosquito," said lead study author Renate Smallegange, who now works at Wageningen Academic Publishers.

More: New discovery may be step toward ending malaria

Researchers at the Medical University of South Carolina explored covering key surfaces in hospital intensive care units in copper alloy, and found that this is an effective measure against the spread of some key types of bacterial infections. Their study is published in the journal Infection Control and Hospital Epidemiology.

Background

Up to $45 billion a year is spent on health care costs related to hospital-acquired infections, and an estimated 100,000 deaths occur annually because of them, the study authors wrote.

The antimicrobial properties of copper have been known for hundreds of years, said Michael Schmidt, the study's senior author - for at least 4,500 years. Ancient Indians realized that if water sits in a copper pot, this prevents illness, because the copper kills the bacteria. It's not used as often nowadays because molded plastics and stainless steel have taken over, being easy and in expensive.

How does it work? Copper is used to transmit electrons in walls for electricity. Similarly, bacteria will donate electrons to the copper metal, which places the organism in an electrical deficit. As a consequence, free radicals are generated inside the cell. The cell's proteins essentially get bleached, and its DNA get fractured. The electrical potential of the cell also gets collapsed.

"It's pretty hard to develop resistance from that multi-hit mechanism of action," Schmidt said.

How they did it

The study authors conducted the trial in the intensive care units of three different hospitals. Patients were randomly placed in copper or non-copper rooms. The study took place between July 2010 and June 2011.

Copper is an expensive material, so researchers carefully chose which parts of the ICU room should have the coating, based on the likelihood of a patient, staff member or visitor touching it. These included the rails that the patient uses to lift himself or herself out of bed, chair arms, the IV pole, the remote control and the tray that's used over the bed. On the whole, copper surfaces covered less than 10% of the room in the settings used in this study.

The researchers were most interested in the spread of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). They compared the rates of hospital-acquired infections from any cause, or colonization with one of these two types of bacteria in the patients. Colonization means the bacteria is present on the person - such as on the skin, respiratory tract or gastrointestinal tract - without signs or symptoms of infection, said lead study author Dr. Cassandra Salgado.

Results

Rooms with copper alloy surfaces were associated with lower infection and colonization for both of these types of bacteria than in normal ICU rooms. For hospital acquired infections, the rate was lowered from 0.081 to 0.034.

Implications

The challenge, of course, is investing the capital into buying new furniture and equipment for ICU rooms, Schmidt said. But he calculates that the cost of outfitting a room in this way would be recovered, in terms of money saved from preventing infections, after three months.

The researchers did not look at whether this intervention affects a patient's 30-day readmission rate, or whether it would work in a hospital room that's not part of an ICU.

Other researchers are looking at whether copper also stops carbapenem-resistant Enterobacteriaceae (CRE), a deadly, antibiotic-resistant strain of bacteria, Schmidt said.

"Bacteria have sex so quickly among their friends in their hospital environment, it may actually reduce the spread of CRE and other multi-drug resistant microbes, simply because the DNA is fractured," Schmidt said.

Some of the study authors reported financial connections to the Copper Development Industry, which is the market development, engineering and information services arm of the copper industry.

But this isn't the only research team that's looking into this question. A separate group at the University of California, Los Angeles, received a $2.5 million federal grant in 2012 to study the germ-fighting effectiveness of copper in hospitals. The cost effectiveness of that is still unclear, said Dr. Daniel Uslan, director of the antimicrobial stewardship program at UCLA's Geffen School of Medicine.

"I suspect the costs will be favorable, but more data is needed and I hope our study at UCLA will answer this important question," he said in an e-mail. "We also don't yet know which surfaces in a room are most critical. Can you get by with just coating one or two items, or do all the touch surfaces need to be copper coated? Obviously the costs will change dramatically depending on the number of surfaces coated."

The news follows a decades-long push to get Americans to reduce the amount of salt in their diet because of strong links between high sodium consumption and hypertension, a known risk factor for heart disease.

The IOM, at the request of the Centers for Disease Control and Prevention, reviewed recent studies published through 2012 that explored ties between salt consumption and direct health outcomes like cardiovascular disease and death. The organization describes itself as "an independent, nonprofit organization that works outside of government to provide unbiased and authoritative advice to decision makers and the public."

Researchers determined there wasn't enough evidence to say whether lowering salt consumption to levels between 1,500 and 2,300 mg per day could increase or decrease your risk of heart disease and mortality. But lowering sodium intake might adversely affect your health, the panel found.

"These new studies support previous findings that reducing sodium from very high intake levels to moderate levels improves health," said committee chair Brian Strom, the George S. Pepper professor of public health and preventive medicine at the University of Pennsylvania's Perelman School of Medicine. "But they also suggest that lowering sodium intake too much may actually increase a person's risk of some health problems."

Those problems, he said, could include heart attack or death.

The current Dietary Guidelines for Americans recommend that a sub-group of people - anyone older than  51, African Americans, and people with high blood pressure, diabetes or chronic kidney disease - limit their salt intake to 1,500 mg a day.

The IOM committee found no benefit, but possibly a risk of poor health outcomes with lower salt intake in people with these pre-existing conditions, but said that evidence is inconsistent and limited.

"While the current literature provides some evidence for adverse health effects of low sodium intake among individuals with diabetes, CKD (kidney disease), or pre-existing CVD (cardiovascular disease), the evidence on both the benefit and harm is not strong enough to indicate that these subgroups should be treated differently from the general U.S. population," the report said.

"Thus, the committee concluded that the evidence on direct health outcomes does not support recommendations to lower sodium intake within these subgroups to, or even below, 1,500 mg per day."

American adults eat on average 3,400 mg of salt a day, according to the IOM. Groups like the American Heart Association (AHA) support reducing that number. In 2011, the AHA called for a reduction in daily consumption, recommending all Americans eat no more than 1,500 mg a day.

The IOM report, the AHA said Tuesday, does not accurately assess salt impact on health. "While the American Heart Association commends the IOM for taking on the challenging topic of sodium consumption, we disagree with key conclusions," said the association's CEO, Nancy Brown. "The report is missing a critical component – a comprehensive review of well-established evidence which links too much sodium to high blood pressure and heart disease."

The Salt Institute says it welcomes the IOM study, calling it a major breakthrough in the salt debate.

"This whole thing has been blood pressure-driven and this study finally looks at overall health outcomes," said Morton Satin, vice president of science and research for the institute.

"The study makes it very, very clear that the level of 1,500 mg that has been recommended in the dietary guidelines is not warranted, despite this full-throated cry for these levels by some organizations ... We hope this is the opening of the much broader review of the available evidence and a devotion to ensuring that our guidelines reflect the science."

The IOM panel was not asked to make recommendations on what a healthy range should be. It says more research is needed to help shed light on how lower sodium levels affect health in all Americans.

On Monday, the Center For Science In The Public Interest published results of a new investigation on what they call the food industry's failed efforts to reduce sodium levels in pre-packaged and restaurant foods.  It called for phased-in limits in an effort to prevent heart disease.  The group tracked nearly 500 food products between 2005 and 2011.

"The strategy of relying on the food industry to voluntarily reduce sodium has proven to be a public health disaster," said  CSPI executive director Michael F. Jacobson.  "Inaction on the part of industry and the federal government is condemning too many Americans to entirely preventable heart attacks, strokes, and deaths each year."

"This suggests there is a subgroup of students who may place themselves, their passengers and others on the road at elevated risk for a crash-related injury or fatality by engaging in multiple risky MV (motor vehicle) behaviors," wrote the authors of the study, published Monday in the journal Pediatrics.

The study

Researchers analyzed data from the Centers for Disease Control and Prevention's 2011 national Youth Risk Behavior Survey, which asked high school students whether they had texted while driving in the 30 days previous. Nearly half of the 8,505 students aged 16 or older who answered that question reported doing so. The survey also queried participants on behaviors such as wearing a seat belt or riding in a car with a driver who had been drinking.

The results

Students who engaged in texting while driving (TWD) regularly were more likely to wear seatbelts irregularly; ride with a driver who had been drinking alcohol; and drive when they had also been drinking alcohol, according to the study.

"For example, students who engaged in TWD on 10 to 19 days, 20 to 29 days, or all 30 days were more likely than students who engaged in TWD on 1 to 2 days to ride with a driver who had been drinking alcohol and drive when drinking alcohol," study authors wrote.

Students who said they had texted while driving on all 30 days were more than 40% more likely to not always wear a seat belt as a passenger than students who said they had texted while driving on 1 to 2 days.

Separate research suggests that teenagers know such behaviors are unsafe, but "teenagers who engage in these behaviors may tend to view them as being less of a safety risk than teenagers who do not engage in them," according to the study.

The limitations

The findings have several limitations, the study noted. Survey questions did not distinguish between sending, receiving or reading texts, "which may be perceived as having different levels of risk."

In addition, the question regarding riding with a driver who has been drinking did not distinguish between parents or peer drivers: "Students may perceive they had no choice whether to ride with a parent who had been drinking alcohol."

Lastly, the data is self-reported, and the "extent of underreporting or over reporting of TWD on this survey cannot be determined."

The takeaway

Strategies to reduce texting while driving and other risky behaviors may include state laws and advances in technology, according to the study. However, "parental supervision of their teenage drivers may be the  most effective prevention strategy," the study said.

Researchers, however, now believe they have discovered a way to track the spread of drug-resistant malaria, and this discovery may help to finally eradicate the disease. Their study was recently published in the journal Nature Genetics.

“We’ve seen past cases of (malaria) drug resistance spread in a specific pattern,” said study author Nicholas White from Mahidol University in Bangkok, Thailand, and the University of Oxford in the UK. “It starts in Cambodia, spreads across Southeast Asia and crosses over to Africa, killing millions of children in the process.”

Resistance to artemisinins - the group of drugs doctors currently use to treat malaria - has been noticed in Cambodia in recent years, sparking concern that an untreatable type of malaria could spread worldwide.

But an international team of researchers says it has identified unique genetic fingerprints for artemisinin-resistant strains of the parasite. This, they say, may help detect and contain this hard-to-treat form of malaria before it spreads worldwide. They remain unsure, however, how soon humans might benefit.

Researchers looked at the genes of 825 malaria-causing parasites collected from 10 locations across Africa and Southeast Asia.

They found three previously undiscovered artemisinin-resistant strains of the parasite in western Cambodia. Each had a specific genetic makeup not seen in any other type of malaria-causing parasite.

This identification of genetic fingerprints specific to artemisinin-resistant malaria parasites is a significant step towards tracking and eventually stopping the spread of this type of malaria, said White.

In the future, the genetic fingerprints identified by the researchers could be used to create a blood test that may predict whether someone with malaria will respond to treatment with artemisinin, said WHO Global Malaria Program coordinator Dr. Pascal Ringwald. “Being able to test people in this way should quickly reveal which parts of the world the resistance has spread to,” said Ringwald.

Scientists can then push strategies, such as compulsory use of preventive medicines for travelers coming into these areas, to keep this type of malaria from moving beyond these areas, he added.

The WHO reports that global deaths from malaria have fallen by more than 25% since 2000, but around 3.3 billion people remain at risk of the disease – most of them children younger than 5.