Monthly Archives: May 2017

How Floods Can Endanger Our Health

Houston and other parts of southeast Texas are in the midst of historic flooding from Harvey, now a tropical storm, with heavy rain still expected to batter the region in the coming days. How does flooding put people’s health at risk?

The public health implications run deeper than the risk of injury and drowning during a flood, though these are a serious concern. [In Photos: Hurricane Harvey Takes Aim at Texas]

Indeed, the Centers for Disease Control and Prevention (CDC) notes a slew of risks related to floodwater and standing water, including wound infections and the spread of infectious diseases and chemicals in the water.

Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University School of Medicine in Tennessee, said that the biggest concerns during and after a flood are injuries, access to medical care and providing people with clean water to drink.

Safe water is more important than food, Schaffner told Live Science. “Lack of food for a period of time is not a crisis,” but lack of water can lead to serious dehydration in the very young and the very old, he said.

People’s health is at risk even after they’ve been evacuated from a flood zone to relief centers.

When people are congregated in relief centers for long periods of time, it’s not uncommon for illnesses to spread, Schaffner told Live Science. Respiratory viruses such as the common cold can spread through shelters, and though it’s still a bit early for flu season, Schaffner said he’d still keep an eye out for cases of influenza.

Less common in the United States, Schaffner noted, is the spread of gastrointestinal illnesses after a flood. For example, although norovirus is “very readily transmitted,” there was only one outbreak of this virus in a relief center after Hurricane Katrina. Norovirus causes symptoms such as vomiting and diarrhea.

It takes “very few of those [norovirus] viral particles to cause infection,” Schaffner said. The virus, which often spreads on cruise ships, can be transmitted through water and food, and can also spread from person to person, he said. “If it gets into a shelter, it’s likely to spread to everybody in the shelter.”

Fortunately, gastrointestinal diseases such as cholera have not played a major role in the U.S. after natural disasters, which is “a testimony to the fact that we live in an environment with good sanitation,” Schaffner said. If that good sanitation were to break down, however, you could see outbreaks of more troublesome illnesses.

And although cholera is not a concern, a type of bacteria related to cholera could pose a threat, Schaffner said. This bug, called Vibrio vulnificus, can live in the water in the Gulf of Mexico and can cause a nasty infection if it gets into an open wound, he said. Wounds exposed to seawater after a coastal flooding disaster should be washed with soap and water as soon as possible, according to the CDC.

Another public health threat from hurricanes and flooding is moving people away from their usual sources of medical care.

People with diabetes or seizures may have left their medications at home, for example, Schaffner said. And events such as giving birth or having a heart attack can be more difficult to manage, because people are removed from their medical care resources, he said.

Even after the floodwaters recede, threats to health will remain, Schaffner said.

Standing water in puddles, small receptacles and gutters can provide “an ideal breeding ground for mosquitoes,” Schaffner said. And when you get mosquitos, you have to worry about mosquito-borne illnesses, includingWest Nile virus and Zika virus. Fortunately, Houston and Harris County — another area affected by the storm — have excellent mosquito control under normal circumstances, Schaffner added.

Once things get back to normal, “I would think that they would start monitoring [mosquito] populations and using their mosquito abatement techniques,” he said.

Another concern after a flood is mold, but Schaffner noted that in the vast majority of cases, mold is an annoyance and a nuisance rather than a source of illness. “Mold-related illness is really quite rare,” he said.

FDA Moves Forward on Ecstasy Material Testing for PTSD

The active ingredient in the drug ecstasy passed an important hurdle on the path to becoming a prescription drug for treating post-traumatic stress disorder.

The ingredient, MDMA, was granted “Breakthrough Therapy Designation” status by the U.S. Food and Drug Administration (FDA), according to a statement released Aug. 26 by the Multidisciplinary Association for Psychedelic Studies (MAPS), a nonprofit organization that advocates for medical research on psychedelic substances.

The Breakthrough Therapy Designation term means that the FDA will “expedite the development and review” of the drug. The designation is given to those drugs that are intended to treat a serious or life-threatening disease or condition; such drugs also present preliminary clinical evidence indicating that the drug may demonstrate substantial improvement over existing therapies, according to the FDA.

“By granting Breakthrough Therapy Designation, the FDA has agreed that this treatment may have a meaningful advantage and greater compliance over available medications for PTSD,” according to the MAPS statement.

MAPS has funded clinical trials looking into the use of MDMA along with psychotherapy as a treatment for PTSD. With the new designation from the FDA, the association will move forward with Phase 3 clinical trials and plans to conduct the trials in 2018. Phase 3 clinical trials are conducted after earlier trials have established that a new treatment works and is safe. Phase 3 trials are done in larger groups of people than earlier trials, and serve to confirm how well the treatment works and compare the new treatment to existing treatments, according to the National Institutes of Health.

The Phase 3 clinical trials will focus on “MDMA-assisted psychotherapy,” MAPS said. The treatment involves three daylong sessions, during which a participant is given either MDMA or a placebo in conjunction with psychotherapy over a 12-week period. In addition to the daylong sessions, the subjects will also participate in 12 90-minute therapy sessions, according to MAPS.

AI Can Predict Alzheimer’s Disease Two Years Ahead

An artificial-intelligence-driven algorithm can recognize the early signs of dementia in brain scans, and may accurately predict who will developAlzheimer’s disease up to two years in advance, a new study finds.

The algorithm — which accurately predicted probable Alzheimer’s disease 84 percent of the time — could be particularly useful in selecting patients for clinical trials for drugs intended to delay disease onset, said lead study author Sulantha Sanjeewa, a computer scientist at McGill University in Canada.

“If you can tell from a group of of individuals who is the one that will develop the disease, one can better test new medications that could be capable of preventing the disease,” said co-lead study author Dr. Pedro Rosa-Neto, an associate professor of neurology, neurosurgery and psychiatry, also at McGill University. [6 Big Mysteries of Alzheimer’s Disease]

The technology is still in its early stages, but the findings suggest that AI analysis of brain scans could offer better results than relying on humans alone, Rosa-Neto told Live Science.

The findings are detailed in a new study, which was published online in July in the journal Neurobiology of Aging.

Developing drugs that slow the onset of Alzheimer’s disease requires that the drugs be tested in clinical trials that run between 18 and 24 months, Rosa-Neto said. But if people who are selected for the trial never develop Alzheimer’s during that time, it’s impossible to say whether a drug was effective, he said.

“You want to include people who will be progressing from mild cognitive impairment to dementia in the time of the clinical trial,” Rosa-Neto said. Alzheimer’s disease is the most common form of dementia, according to the Alzheimer’s Association.

But selecting the best patients for these trials is a challenge, because it is difficult to predict who will develop the condition, Rosa-Neto said. Scientists know that the buildup of a protein called amyloid, which accumulates in various regions of the brain, can lead to cognitive impairment. But piecing together the complex patterns of where and how much of the protein builds up, and then using that information to predict when a person will develop Alzheimer’s disease is difficult to do by reading PET scans alone. (These scans are imaging tests that use a radioactive dye to identify certain diseases in the body.)

The presence of amyloid in the brain, however, doesn’t necessarily mean that a person will develop Alzheimer’s within a certain time; for some, it may take five to 10 years for the symptoms of dementia to appear, Rosa-Neto said. Others may never develop the disease, he said. But once a person has developed dementia, it is very difficult to return the brain to normal cognitive function, Rosa-Neto added.

The artificial intelligence program that Rosa-Neto’s team developed could help doctors identify the best participants for Alzheimer’s drug clinical trials by predicting who is likely to develop the disease within a two-year window.

Creating an effective AI algorithm involves three main steps: writing the software, training it and then testing it to see how well it works, the researchers said.

As they were writing the software, the software engineers gave the algorithm some hints to help it analyze the PET images, Rosa-Neto said. The engineers designed it to take into consideration a common problem that pops up when studying people with mild cognitive impairment: In any given population, only a small fraction of a people will develop dementia.

The programmers also designed the algorithm to consider that the buildup of amyloid protein can occur at different rates, in different concentrations and at different locations in the brain, according to the study. [10 Things You Didn’t Know About the Brain]

During the training portion of the study, the scientists used the algorithm to analyze the presence of amyloid in PET scans from nearly 200 patients who had mild cognitive impairment. The algorithm was then shown images from up to 24 months before the patients had developed the disease.

Once the program learned from this information, it was shown an entirely new set of amyloid PET brain scans from more than 270 individuals who had mild cognitive impairments. Of them, 43 were diagnosed with probable Alzheimer’s disease after the 24-month follow-up. However, the algorithm was shown only the images taken before the disease had fully developed. Using what it had learned, the AI algorithm predicted with 84 percent accuracy which individuals would develop the disease, according to the study.

In the study, the authorsnoted that no system that predicts Alzheimer’s disease based on images alone can be 100 percent accurate. In about 10 percent of diagnoses of “probable Alzheimer’s diseases,” for example, people actually have a different form of cognitive impairment.

The researchers also noted the group of people included in the study described themselves as having some loss of memory and may not represent the general public. The authors added that it would be highly desirable to replicate the findings in a general population.

Based on this study, the team also created a pilot version of a real-time prediction tool that will analyze individuals’ PET brain scans and spit out probabilities of when the individuals may develop dementia within a 24-month period. The tool is available to the public online.

How Fast Do You Go? The Answer You Can Predict The Risk Of Your Heart Disease Death

A simple question — how fast do you walk? — may help researchers determine who has a higher risk of death from heart disease, a new study from the United Kingdom suggests.

The study found that middle-age adults who said they typically walk at a slow pace were about twice as likely to die from heart disease during the study period, compared with those who said they walk at a brisk pace. The findings held even after the researchers accounted for factors that could affect the results, such as people’s exercise habits, their diets, and whether they smoked or drank alcohol.

The study suggests that “a simple, self-reported measure of slow walking pace” would help doctors determine people’s risk of death from heart disease, the researchers wrote in the Aug. 21 issue of the European Heart Journal. [Top 10 Amazing Facts About Your Heart]

For the study, the researchers analyzed information from more than 420,000 middle-age adults in the United Kingdom, who were followed for about six years. None of the participants had heart disease at the time they entered the study. Participants were asked to rate their usualwalking pace as “slow,” “steady/average” or “brisk.” The subjects also underwent an exercise test in a laboratory to determine their fitness levels.

During the study, nearly 8,600 of the participants died, and of these, about 1,650 died from heart disease.

People who said they were slow walkers were between 1.8 and 2.4 times more likely to die of heart disease during the six-year study period, compared with those who said they were brisk walkers. The risk was highest for those with a low body mass index (BMI), which could mean the individuals were malnourished or had high levels of muscle tissue loss with age (a condition known as sarcopenia), the researchers said.

The study also found that people’s self-reported walking pace was strongly linked with their levels of physical fitness on the exercise test. In other words, a low fitness level among slow walkers could explain their higher risk of death from heart disease, the researchers said.

“Self-reported walking pace could be used to identify individuals who have low physical fitness” levels and, consequently, higher risk of death from heart disease, study co-author Tom Yates, of the University of Leicester in the United Kingdom, said in a statement. These individuals might benefit from interventions to improve their physical fitness, he said. However, more research is needed to examine the extent to which people’s walking pace could be used to improve current predictors for risk of death by heart disease, the researches said.

The study also looked at whether walking pace was linked with people’s risk of death from cancer, but it did not find a consistent link.