The largest component, 714 people, of the social network studied by Fowler and Christakis, on Dec. 8, 2009. Infected individuals are colored red, friends of infected individuals are colored yellow. (Credit: Image courtesy of University of California – San Diego)
GoogleNews.com, UCSanDiego, September 20, 2010 — Your friends are probably more popular than you are. And this “friendship paradox” may help predict the spread of infectious disease.
Nicholas Christakis, professor of medicine, medical sociology and sociology at Harvard University, and James Fowler, professor of medical genetics and political science at the University of California, San Diego, used the paradox to study the 2009 flu epidemic among 744 students. The findings, the researchers say, point to a novel method for early detection of contagious outbreaks.
Analyzing a social network and monitoring the health of its central members is an ideal way to predict an outbreak. But such detailed information simply doesn’t exist for most social groups, and producing it is time-consuming and expensive.
The “friendship paradox,” first described in 1991, potentially offers an easy way around this. Simply put, the paradox states that, statistically, the friends of any given individual are likely more popular than the individual herself. Take a random group of people, ask each of them to name one friend, and on average the named friends will rank higher in the social web than the ones who named them.
If this is hard to fathom, imagine a large cocktail party with a host holding court in the center while, at the fringes, a few loners lean against the walls staring at their drinks. Randomly ask the party-goers to each name a friend, and the results will undoubtedly weigh heavily in the direction of the well-connected host. Few people will name a recluse.
And just as they come across gossip, trends and good ideas sooner, the people at the center of a social network are exposed to diseases earlier than those at the margins.
As the 2009 influenza season approached, Christakis and Fowler decided to put these basic features of a social network to work, contacting 319 Harvard undergraduates who in turn named a total of 425 friends. Monitoring the two groups both through self-reporting and data from Harvard University Health Services, the researchers found that, on average, the friends group manifested the flu roughly two weeks prior to the random group using one method of detection, and a full 46 days prior to the epidemic peak using another method.
“We think this may have significant implications for public health,” said Christakis. “Public health officials often track epidemics by following random samples of people or monitoring people after they get sick. But that approach only provides a snapshot of what’s currently happening. By simply asking members of the random group to name friends, and then tracking and comparing both groups, we can predict epidemics before they strike the population at large. This would allow an earlier, more vigorous, and more effective response.”
“If you want a crystal ball for finding out which parts of the country are going to get the flu first, then this may be the most effective method we have now,” said Fowler. “Currently used methods are based on statistics that lag the real world — or, at best, are contemporaneous with it. We show a way you can get ahead of an epidemic of flu, or potentially anything else that spreads in networks.”
Indeed, the authors note that the same method could be used very widely — to anticipate epidemics of behaviors like drug use or even the diffusion of ideas or fashions.
John Glasser, a mathematical epidemiologist at the Centers for Disease Control in Atlanta, GA, who was not involved in this research, said: “Christakis’ and Fowler’s provocative study should cause infectious disease epidemiologists and public health practitioners alike to consider the social contexts within which pathogens are transmitted. This study may be unique in demonstrating that social position affects one’s risk of acquiring disease. Consequently, epidemiologists and social scientists are modeling networks to evaluate novel disease surveillance and infection control strategies.”
The study, published by PLoS ONE, was funded by Harvard University.
Fowler and Christakis are coauthors of “Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives.
Source: University of California – San DiegoJournal Reference:
- Nicholas A. Christakis, James H. Fowler. Social Network Sensors for Early Detection of Contagious Outbreaks. PLoS ONE, 5(9): e12948 DOI: 10.1371/journal.pone.0012948
A mouse earns a water reward for choosing the odor of samples of feces infected with avian flu over a feces sample from ducks that were not infected. (Credit: Maryanne Opiekun, Ph.D., Monell Chemical Senses Center)
American Chemical Society, September 2010 — Blood hounds, cadaver dogs, and other canines who serve humanity may soon have a new partner ― disease detector dogs ― thanks to an unusual experiment in which scientists trained mice to identify feces of ducks infected with bird influenza. Migrating ducks, geese, and other birds can carry and spread flu viruses over wide geographic areas, where the viruses may possibly spread to other species.
Reported in Boston at the 240th National Meeting of the American Chemical Society (ACS), the proof-of-concept study may pave the way for development of biosensors-on-four-feet that warn of infection with influenza and other diseases.
“Based on our results, we believe dogs, as well as mice, could be trained to identify a variety of diseases and health conditions,” said U.S. Department of Agriculture scientist Bruce A. Kimball, Ph.D., who presented the study results. The study was among nearly 8,000 scientific reports scheduled for presentation at the ACS meeting, one of the largest scientific gatherings of 2010.
“In fact, we envision two broad, real-world applications of our findings,” Kimball added. “First, we anticipate use of trained disease-detector dogs to screen feces, soil, or other environmental samples to provide us with an early warning about the emergence and spread of flu viruses. Second, we can identify the specific odor molecules that mice are sensing and develop laboratory instruments and in-the-field detectors to detect them.”
Kimball cited the likelihood that a suite of chemicals, rather than a single compound, are responsible for producing the difference in fecal odor between healthy and infected ducks. His team is investigating the use of instruments in detecting these so-called volatile, or gaseous, metabolites in animal feces. Once accomplished, they can use statistical techniques to sift through the data to determine the pattern of volatiles that indicate the presence of infection.
Kimball and colleagues from the Monell Chemical Senses Center trained inbred mice to navigate a maze and zero in on infected duck feces. The mice got a reward of water every time they correctly identified the infected sample and no reward when they zeroed in on feces from healthy ducks. Eventually, the mice became experts at identifying feces from infected ducks.
ScienceDaily (Sep. 20, 2010) — The seasonal flu vaccine is associated with a 19% reduction in the rate of first heart attack and early vaccination in the fall further increases the benefits, found a study published in CMAJ (Canadian Medical Association Journal).
As heart attacks increase significantly in winter when pneumonia and flu are prevalent, it has been suggested there may be a link between respiratory infections and heart attacks.
The study, by researchers from the United Kingdom, looked at 78 706 patients aged 40 years or older from 379 family practices in England and Wales. Of the total, 16 012 had had a heart attack and 8472 of these patients had been vaccinated. The researchers found that influenza vaccination within the past year was associated with a significantly reduced rate of heart attack. However, pneumococcal vaccination showed no additional benefit.
Early vaccination for influenza (between September and mid-November) was associated with a higher (21%) reduction in the rate of heart attacks compared with late vaccination which was associated with a 12% reduction.
“Our findings reinforce current recommendations for annual influenza vaccination of target groups, with a potential added benefit for prevention of acute myocardial infarction in those without established cardiovascular disease,” writes Dr. Niroshan Siriwardena, University of Lincoln, United Kingdom with coauthors Stella Gwini and Carol Coupland. “This benefit may lead to an increase in suboptimal rates of vaccination, particularly among younger patients.”
Because people with risk factors for heart attacks were more likely to be vaccinated than those with no risk factors, the researchers adjusted for possible bias in the sample.
They conclude that if additional research shows a similar effect, it could lead to changes in the recommended indications for and timing of vaccinations.
The flu vaccine can also be administered as a nasal spray instead of the usual injection method. It is an alternative for healthy, non-pregnant people age 5 to 49 who want to be protected from the flu virus. Unlike the regular vaccine, it is a live virus. Therefore, it is best if the person receiving it does not have close contact with people who have a weakened immune system.
Al.com/MobilePress-Register, by Mike Kittrell — The Mobile County Health Department offered adults 18 and older $8 seasonal flu shots during a walk-up and drive-through clinic at Hank Aaron Stadium Tuesday, Sept. 14, 2010, in Mobile, Ala. Children older than 6 months and younger than 18 can get the shot for free, officials said. The 2010-2011 seasonal flu vaccine injection includes the 2009 H1N1 virus strain along with two others that researchers predict will be most prevalent in the upcoming flu season. Health Department registered nurse Tifany Pike prepares a flu shot during the clinic.
ScienceDaily, September 2010 — A self-administered patch containing tiny microneedles may effectively deliver influenza virus-like particles through the skin and protect against potentially pandemic flu viruses such as H5N1.
Researchers from the U.S. and abroad report their findings in the September 2010 issue of the journal Clinical Vaccine and Immunology.
In the United States, seasonal flu epidemics often result in over 200,000 hospitalizations and 36,000 deaths each year. New pandemic flu strains continue to emerge, such as the 2009 H1N1 virus that resulted in the first pandemic influenza outbreak in the 21st century. Conventional vaccination programs require a painful injection administered by medical personnel and can take months to develop, emphasizing the need for vaccines that can be rapidly produced at low cost and distributed within weeks.
Influenza virus-like particles (VLPs) are potentially promising vaccine candidates as they are non-infectious and have been shown to induce long-lasting immunity against pandemic influenza viruses. An abundance of dermal dendritic cells, important members of the skins’ immune system, make the skin an appealing route for vaccine delivery.
In the study researchers vaccinated mice with microneedle patches containing influenza H5 VLPs derived from the H5N1 virus and found the resulting protective immunity to be equal to or higher than that induced from intramuscular inoculation. Significantly, human skin cells also responded to the influenza VLP vaccine delivered by the microneedle patch.
“Microneedle vaccination in the skin with H5 VLPs represents a promising approach for a self-administered vaccine against viruses with pandemic potential,” say the researchers.
Source: American Society for Microbiology
- J.-M. Song, Y.-C. Kim, A. S. Lipatov, M. Pearton, C. T. Davis, D.-G. Yoo, K.-M. Park, L.-M. Chen, F.-S. Quan, J. C. Birchall, R. O. Donis, M. R. Prausnitz, R. W. Compans, S.-M. Kang. Microneedle Delivery of H5N1 Influenza Virus-Like Particles to the Skin Induces Long-Lasting B- and T-Cell Responses in Mice. Clinical and Vaccine Immunology, 2010; 17 (9): 1381 DOI: 10.1128/CVI.00100-10
ScienceDaily (Sep. 17, 2010) — Flu vaccine will soon be available at local pharmacies and doctor’s offices, and government officials are urging everyone over 6 months of age to receive it. This year’s vaccine protects against H1N1 and two other strains of seasonal flu.
The recommendation represents a break from past years, when the government focused on vaccinating people in certain “high-risk” groups and those in contact with people at high risk.
“The message is simple now,” said David Weber, MD, MPH, professor of medicine, pediatrics and epidemiology at the University of North Carolina at Chapel Hill. “If you’re more than 6 months of age, get the vaccine.”
“In an average year, there are more than 200,000 hospitalizations and more than 35,000 deaths from flu. Many of those would be preventable by simply getting the flu shot,” said Weber. “Flu shots are far and away the best way for preventing flu.”
The Advisory Committee on Immunization Practices, a Centers for Disease Control and Prevention (CDC) advisory panel that set the recommendation for universal vaccination cited last year’s H1N1 outbreak — which affected many young, healthy people not traditionally considered to be at high risk for complications from flu — as part of the reason for the change. In addition, the list of conditions that put a person at high risk has grown so much over the years that many people are unaware of their high-risk status. Universal vaccination is expected to better protect individuals and the population as a whole.
People should receive the vaccine every year as soon as it becomes available, said Weber. “It’s important every year. This year it may be more important because anybody who didn’t get H1N1 last year is susceptible to it, and since that was the first year H1N1 was around, many people, if not most people, are susceptible.”
The vaccine is reformulated each year to provide protection against the virus strains that present the greatest public health threat for that year. People who contracted H1N1 last year may have a lower chance of contracting it again this year, but they should still receive the vaccine for protection against seasonal flu.
Adults need only one dose of the vaccine. Children 6 months to 8 years old may need two doses, depending on which vaccines they received last year.
The vaccine will be available at doctor’s offices and at many pharmacies as both a nasal spray and as a shot. The shot is recommended for people younger than 2 or older than 49, and people with a suppressed immune system. The nasal spray is appropriate for most other healthy people.
ScienceDaily, September 2010 — A recent study by researchers at the University of Utah determined that the 2009 pandemic influenza A (H1N1) caused a higher rate of neurological complications in children than the seasonal flu. The most common complications observed were seizures and encephalopathy. Full details of the study, the most extensive evaluation of neurological complications following H1N1 flu in children, are published in the September issue of Annals of Neurology, a journal of the American Neurological Association.
The H1N1 virus (swine flu) was identified in Mexico and the U.S. in April 2009 and quickly spread worldwide, prompting the World Health Organization (WHO) to declare the novel influenza A virus a pandemic. According to estimates from the Centers for Disease Control and Prevention (CDC), 43 million to 89 million Americans were infected with H1N1 between April 2009 and April 10, 2010, with approximately 14 million to 28 million of those cases in children 17 years of age and younger. On August 10, 2010 the WHO International Health Regulations Emergency Committee officially declared an end to the 2009 H1N1 pandemic.
In their retrospective study, Josh Bonkowsky, M.D., Ph.D., and colleagues examined neurological complications in children with H1N1 compared to the seasonal flu. Children (younger than 19 years of age) who were hospitalized with H1N1 and neurological complications between April 1 and November 30, 2009 were included in the study. In the comparison group, the research team used records of children hospitalized with seasonal flu and neurological complications from July 1, 2004-June 30, 2008. Neurological complications observed included seizures, febrile seizures, status epilepticus, encephalopathy, encephalitis, myositis, myalgia, aphasia, ataxia, neuropathy, Gullain-Barre syndrome, or other focal neurological complaints.
Researchers identified 303 children who were hospitalized with 2009 H1N1 of which 18 experienced neurological complications. Eight-three percent of these pediatric patients had an underlying medical condition — primarily neurological issues (66%). The research team found the most common neurologic symptoms in this group were seizures (67%) and encephalopathy (50%). More than half of those children who experienced seizures presented in a life-threatening state known as status epilepticus, where continuous seizure activity occurs for more than 5 to 30 minutes1.
The comparison group included 234 children who were hospitalized for seasonal flu with 16 patients experiencing neurological issues. In the seasonal flu cohort only 25% patients had underlying medical conditions. The researchers also noted that none of the patients with seasonal flu and neurological complications had encephalopathy, aphasia, or focal neurological deficits.
Compared to seasonal influenza, patients with H1N1 were more likely to have abnormal electroencephalogram (EEG) findings. “We found that more pediatric H1N1 patients had neurological deficits and required ongoing treatment with anti-epileptic medications upon discharge from the hospital,” commented Dr. Bonkowsky.
Additionally, researchers found the use of steroids or intravenous immunoglobulin was not beneficial in the treatment of encephalopathy. “The absence of proven treatments for influenza-related neurological complications underlines the importance of vaccination,” said Dr. Bonkowsky. For protection against the flu, the CDC recommends yearly flu vaccination and the U.S. 2010-2011 seasonal influenza vaccine will protect against an H3N2 virus, influenza B, and the 2009 H1N1 virus.
- Jeffrey J. Ekstrand, Amy Herbener, Julia Rawlings, Beth Turney, Krow Ampofo, E. Kent Korgenski, Joshua L. Bonkowsky. Heightened Neurologic Complications in Children with Pandemic H1N1 Influenza. Annals of Neurology, September 20, 2010 DOI: 10.1002/ana.22184
ScienceDaily, September 2010 — Coughing and wheezing patients could someday benefit from quicker, more accurate diagnosis and treatment for respiratory infections such as flu, through a simple blood test, according to scientists.
Dr. Aimee Zaas, presenting her work at the Society for General Microbiology’s autumn meeting in Nottingham describes how simply looking at an individuals blood ‘signature’ can be used to quickly diagnose and treat ill patients and could even predict the onset of a pandemic.
The team, from the Duke Institute for Genome Sciences & Policy and Duke University Medical Center in the US, looked at the blood of otherwise healthy individuals who had been exposed to rhinovirus, respiratory syncytial virus or influenza. The team found each viral infection stimulated the body to produce a very specific set of immune molecules that could be detected in the blood. Recording the distinct blood signatures for each virus in a database and matching them against blood samples from other ill patients pinpointed the cause of disease with more than 95% accuracy.
Respiratory infections, including colds and flu are a common reason for seeking medical help. As Dr. Zaas highlighted, “Current methods for accurate diagnosis are time and labour intensive and are not always accurate. This means GPs are sometimes overcautious and may prescribe antibiotics unnecessarily, for viral infections. During a pandemic, this has real consequences as there is an increased risk of spreading infection.”
Dr. Zaas explained how her test works completely differently to current diagnostic tests as it analyses each individual’s immune response to infection, rather than the actual micro-organism responsible. “We effectively look at the imprint in the blood that the virus makes, which is as individual as a signature,” she said. “Not only is this much more accurate than traditional testing, it also works much faster as it can be done through a simple blood test.”
This work was sponsored by the US Defense Department Advanced Research Projects Agency and is part of a large team effort. If developed further, the findings could be used in emergency departments and primary care clinics to diagnose respiratory viral illness. “This could allow patients quicker access to antiviral drugs, but could also give an accurate warning of an upcoming pandemic,” explained Dr. Zaas.
Source: Society for General Microbiology
RealAge.com, September 20, 2010 — Some research suggests that the flu shot wears off more quickly in older people. But here’s something you can do to counter that: Go for a walk.
In a study of older adults who weren’t regularly active, those who started exercising three times a week had more antibodies from the shot — and they kept those antibodies for longer than normal.
A Shot at Health
Up to 25 percent of older adults don’t get adequate protection from the flu, even though they receive a flu vaccine. That’s because the immune systems of older adults don’t respond as well to flu vaccines. No one really knows why, but dietary factors, underlying illness, immune system aging, prior vaccinations, and exposure to other flu viruses may all play a part in this decreased response.
Up Your Shot
But in the recent study, people nearing their seventh decade engaged in either flexibility training twice a week or stamina-building exercise — including cycling, elliptical training, stair climbing, and brisk walking — three times a week. Four months into training, everyone received a flu shot. Six months later, blood tests showed that those in the stamina-building group had continued immunity against the flu, while those in the flexibility exercise group did not. Researchers suspect cardiovascular exercise enhances antibody production or somehow interferes with antibody removal from the body
And to boost your immune system…………..
Your immune system is responsible for helping fight off everything from the common cold to cancer. A tall order!
Here are four foods to give your immune system a boost.
Sweet, Creamy, Steamy, Crunchy . . .
Oranges, yogurt, tea, and pumpkin seeds are the order of the day when it comes to giving your immune system a treat, according to RealAge experts Michael Roizen, MD, and Mehmet Oz, MD, authors of the best-selling (and now newly expanded and updated) YOU: The Owner’s Manual. Here’s how these four superfoods help:
- Oranges are chock-full of vitamin C, an antioxidant vitamin that helps your immune system fend off disease-causing invaders. Other good C options: bell peppers, strawberries, cantaloupe, and broccoli. Or take 400 milligrams of vitamin C three times daily..)
- Yogurt (unpasteurized) contains Lactobacillus acidophilus — a healthy bacterium that helps thwart fungus-related infections. Or take a 20-milligram acidophilus supplement twice daily.
- Tea is full of flavonoids, powerful vitamin-like substances that reduce immune-system aging. You’ll also find them in oats, onions, broccoli, tomatoes, apples, and berries.
- Pumpkin seeds are great year round, because they contain zinc — a nutrient that’s been shown to help reduce the average length of the common cold..)
Drs. Oz and Roizen Speak Out: Top 10 Benefits of Walking
By Mehmet C. Oz, MD, and Michael F. Roizen, MD.
RealAge.com, September 20, 2010
What’s not to love about the single best thing you can do for your health? The simple act of putting one foot in front of the other makes you healthier, gives you more energy, and makes you younger. Plus, doing it lets you talk with friends, think through problems, and see what’s new in the neighborhood. And if you happen to have some new walking gear, walking lets you show it off.
That’s just the beginning. Check out a few other great things walking does for you:
1. Fends off the #1 killer: Regular walkers have fewer heart attacks and strokes, have lower blood pressure, and have higher levels of healthy HDL cholesterol than couch sitters do. In one study of women, a regular walking program did just as much in the heart-protection department as more vigorous exercise did.
2. Changes your RealAge — pronto: As little as 90 days after starting a regular walking program, its age-reducing effects can be measured..
3. Dims your chances of diabetes: Thirty minutes of walking a day makes your muscles more sensitive to insulin. That allows glucose to do its duty inside your cells rather than pile up in your bloodstream (that’s what happens when you have diabetes) and cause other havoc.
4. Helps you kick the habit: Taking a daily 30-minute walk is one of the keys to the success of our YOU Can Quit plan. Even just a 5-minute walk cuts down on cigarette cravings — it engages your brain’s emotion centers, unleashing mood-enhancing hormones that decrease cravings and take your mind off that cigarette. And establishing a walking habit proves to you that you have the discipline to stick with your stop-smoking plan.
5. Slims you down: Burn more calories than you eat, and — voila! You’re wearing one-size-smaller clothes Plus, walking can help and nix the stress and anxiety that often lead to overeating.
6. Keeps you sharp: Physical activity nourishes brain tissue and stimulates its production of neurons, synapses, and blood vessels. Some studies have found that walking can counter faltering memories in people over age 50.
7. Reduces stress: Anyone who has come back from a walk in a different frame of mind than they went out with can attest to this. Studies back up that walking benefits your mood — and may even ward off depression and anxiety.
8. Revs up your energy: Not only can a walk perk you up when you need it, but also it helps improve the quality of your sleep, so you’re more energetic all day long.
9. Boosts your immune system: Walking regularly can lower your risk of arthritis, macular degeneration, and even cancer by an astonishing 50% compared with people who don’t exercise.
10. Keeps you going: Walking has the highest compliance rate of any exercise.
For more fitness information go to the above website