Coughing and sneezing not required for transmission
It is easier to spread the influenza virus (flu) than previously thought, according to a new University of Maryland-led study released today. People commonly believe that they can catch the flu by exposure to droplets from an infected person’s coughs or sneezes or by touching contaminated surfaces. But, new information about flu transmission reveals that we may pass the flu to others just by breathing.
The study “Infectious virus in exhaled breath of symptomatic seasonal influenza cases from a college community,” published in the Proceedings of the National Academy of Sciences, provides new evidence for the potential importance of airborne transmission because of the large quantities of infectious virus researchers found in the exhaled breath from people suffering from flu.
“We found that flu cases contaminated the air around them with infectious virus just by breathing, without coughing or sneezing,” explained Dr. Milton, M.D., MPH, professor of environmental health in the University of Maryland School of Public Health and lead researcher of this study. “People with flu generate infectious aerosols (tiny droplets that stay suspended in the air for a long time) even when they are not coughing, and especially during the first days of illness. So when someone is coming down with influenza, they should go home and not remain in the workplace and infect others.”
Researchers from the University of Maryland, San Jose State University, Missouri Western State University and University of California, Berkeley contributed to this study funded by the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health.
Dr. Milton and his research team captured and characterized influenza virus in exhaled breath from 142 confirmed cases of people with influenza during natural breathing, prompted speech, spontaneous coughing, and sneezing, and assessed the infectivity of naturally occurring influenza aerosols. The participants provided 218 nasopharyngeal swabs and 218 30-minute samples of exhaled breath, spontaneous coughing, and sneezing on the first, second, and third days after the onset of symptoms.
The analysis of the infectious virus recovered from these samples showed that a significant number of flu patients routinely shed infectious virus, not merely detectable RNA, into aerosol particles small enough to present a risk for airborne transmission.
Surprisingly, 11 (48%) of the 23 fine aerosol samples acquired in the absence of coughing had detectable viral RNA and 8 of these 11 contained infectious virus, suggesting that coughing was not necessary for infectious aerosol generation in the fine aerosol droplets. In addition, the few sneezes observed were not associated with greater viral RNA copy numbers in either coarse or fine aerosols, suggesting that sneezing does not make an important contribution to influenza virus shedding in aerosols.
“The study findings suggest that keeping surfaces clean, washing our hands all the time, and avoiding people who are coughing does not provide complete protection from getting the flu,” said Sheryl Ehrman, Don Beall Dean of the Charles W. Davidson College of Engineering at San José State University. “Staying home and out of public spaces could make a difference in the spread of the influenza virus.”
According to the authors, the findings could be used to improve mathematical models of the risk of airborne influenza transmission from people with symptomatic illness and to develop more effective public health interventions and to control and reduce the impact of influenza epidemics and pandemics. Improvements could be made to ventilation systems to reduce transmission risk in offices, school classrooms and subway cars, for example. Meanwhile, we can all heed the advice to stay home, if possible, when we are beginning to get sick to prevent even greater numbers of flu cases. And, get vaccinated — it is not perfect but does prevent a significant amount of severe illness.
The Aftermath of Michael Jackson’s Antigravity Lean
The infamous lean.
In Michael Jackson’s 1987 music video “Smooth Criminal,” the legendary performer leans forward 45 degrees from a straight-up position — and comes back. It’s a feat that seemingly defies both physics and physiology, and the move has become another element of MJ’s aura of mystery.
Some type of cinematic or mechanical trick must be responsible, since most people can manage only a 20-degree forward tilt before toppling headlong. Yet Jackson performed the move live on tours around the world for years.
In a study published this week in the Journal of Neurosurgery, three scientists examine the so-called Antigravity Lean, not from a physics but from a physiological perspective. The three neurosurgeons, all at the Postgraduate Institute of Medical Education and Research in Chandigarh, India, combine in the article their knowledge of Jackson with data on spine biomechanics.
It’s been known for years how Jackson defied gravity. His shoes had a slot that slid onto a bolt in the floor, allowing him to perform the dramatic lean.
Bending forward is limited by the erector spinae muscles, which act like cables to support forward bends up to 20 degrees, though some dancers can achieve 30 degrees, the paper says. When near the max of a bend, you can feel the strain on the Achilles’ heel as the ankles become the fulcrum for balance. People soon return to vertical or catch themselves from falling headlong.
Though Jackson’s 45-degree bend is not physically possible without trickery, the King of Pop still needed incredible core strength and leg muscles to pull it off, the authors write. Not just anyone can lock their shoes into the floor and become Michael Jackson, it seems.
“Several MJ fans, including the authors, have tried to copy this move and failed, often injuring themselves in their endeavors,” the researchers write.
Figure A shows the Antigravity Tilt (a 45-degree forward bend) and the normal limit that most people can bend forward. Jackson used shoes with a slot that slid onto a bolt in the floor. Figure B shows the shift when the body’s fulcrum is the hip and when it’s the Achilles’ tendon. (Illustration courtesy of Manjul Tripathi)
Tough Act to Follow
Jackson’s sleight of foot inspired generations of dancers who push the limits physically. This has resulted in spinal stresses not previously seen by neurosurgeons.
This is not to point the finger at Jackson. But it does suggest the reality that injuries can occur that might require implant spinal surgery, the article says, something potentially devastating to a dancer.
But it’s not all bad news — neurosurgeons have gained a lot of new information on how to treat spinal cord injuries in recent years, something that could be in part thanks to MJ’s envelope-pushing dance moves.
“The King of Pop has not only been an inspiration but a challenge to the medical fraternity,” Tripathi says.
Your Emergency Contact Does More Than You Think
You know when you’re filling out your medical paperwork and it asks for your emergency contact? Sure, the process might be annoying, but that emergency contact could actually be put to good use by researchers.
Since many of us use a family member, those contacts can help scientists create family trees. And they can also be used for genetics and disease research, according to a study released Thursday in Cell. Discovering what diseases are inheritable can be a laborious and expensive process — patients must be recruited and researchers must clearly determine patients’ phenotypes (physical traits that include eye color, height, and overall health and are often influenced by your genes).
To make that process easier researchers from three major New York medical centers generated family trees from millions of electronic medical records to create a database.This is the first time electronic health records have been used to trace ancestry and it’s the largest study of heritability using such records.
The More You Know
The researchers identified 7.4 million relatives with an algorithm that matched names, addresses and phone numbers from three medical centers. They found 500 inheritable phenotypes in the data just by looking at test results and observations in health records. The traits included diseases affecting skin, blood and mental health.
The data can help determine the heritability level of many common diseases. For example, researchers found that having an increase of HDL (good) cholesterol is 50 percent heritable, while LDL (bad) cholesterol is only 25 percent heritable. The study’s findings were consistent across the participating medical centers and published studies.
Previous heritability research primarily documented Caucasians of northern European descent, according to the study’s first author Fernanda Polubriaginof, but this research is much broader.
“This dataset will allow us for the first time to compute whether there are differences in other races and ethnicities,” said Polubriaginof in a news release.
Future studies could look at medical records for the hereditary contribution of any trait. Due to privacy issues, patient identifiers were removed for the data, which can only be used for research at the moment. Though, with patient consent, emergency contacts could be put to important use in the future.
Mosquito Bites Leave A Lasting Impression On Our Immune System
Mosquito bites are like a gross form of French kissing — the insects swap your blood with their saliva, and leave a trail of salivary secretions behind like mosquito cooties. Some of those compounds prevent clotting as the insects slurp up your blood. Now researchers find mosquito spit aggravates your immune system for days afterward. The findings could help scientists develop vaccines for mosquito-born diseases like Zika.
Rebecca Rico-Hesse, a virologist at Baylor College of Medicine in Houston, Texas, wanted to know how mosquitoes exploit our immune systems with their drool. So, she and her team exposed mice with human-like immune systems to live mosquitoes. Then, they sized up the mice’s immune response as it reacted to the mosquito spittle.
The bug’s saliva toyed with their immune systems in both bone marrow and skin cells with effects that lasted up to seven days after biting, the team reports today in PLoS: Neglected Tropical Diseases. The researchers say their discovery could explain how these tissues might act as virus incubators and help spread disease.
In 2012, Rico-Hesse was looking to untangle how Dengue virus causes Dengue hemorrhagic fever — an illness that affects 400 million people each year and can lead to death — when she came across a strange occurrence. Mice infected with the virus from mosquito bites fared far worse than mice that had received an injection of the virus but hadn’t been served as a mosquito meal. The result made Rico-Hesse take a step back.
It seems that mosquito bites caused the immune system to behave differently, and in ways that could potentially give infectious diseases a leg up.
To find out, Rico-Hesse and her team set starving Aedes aegypti mosquitoes on mice that had received a dose of human stem cells to make their immune systems look more like a human’s. Each mouse endured eight mosquito bites total. Then the team checked out different parts of the immune system — blood, bone marrow, spleen, and skin cells — six and 24 hours after biting, as well as seven days later. By then, the immune system should have returned to normal.
Instead, the team discovered immune cells that had disappeared from the skin at least six hours post-bite came back seven days later after maturing in bone marrow, something that shouldn’t have happened. If those cells harbored a virus, they could then pass it on to new mosquitoes, who could infect others.
The research is pointing out new ways in which mosquito bites affect our immune systems, and it goes beyond simple itching and scratching.
“Mosquito saliva has evolved to modify our immune system,” Rico-Hesse said. And as their new research shows, viruses and parasites could be hijacking that activity to get to the cells they reproduce in, like bone marrow cells, faster, according to her.
Essentially, viruses might be taking advantage of the immune system’s response to travel from their point of entry — the skin — to a place they can multiply in that’s away from attacks by the immune system.
“It’s mind-blowing,” Rico-Hesse said. “No one has ever seen this before.”
Ultimately, the work could lead to infection-blocking vaccines, said Duane Gubler, an international health expert who was not involved in the research.
That’s what Rico-Hesse hopes, too. “If we can make a vaccine that would protect us against the effects of the [mosquito] saliva, or blocking our immune reaction … then we could stop global vector-born diseases,” she said.
HUMAN PARASITES4 months ago
Tonights Episode: Strongyloids Hyper Infection with Curezones Sharkman
PARASITES3 months ago
Parasite-schizophrenia connection: One-fifth of schizophrenia cases may involve the parasite T. gondii
Videos4 months ago
My Lyme Disease Story | Health Journey
IN THE NEWS4 months ago
New Lyme disease tests could offer quicker, more accurate detection
Health4 months ago
Baby Fat Is Far More Than Cute
PODCAST4 months ago
Tonights Discussion: Morgellons
PARASITES4 months ago
When Parasites Were Edited Out Of The Medical Books, So Were The Cures
PARASITES4 months ago
Human Parasites Members Upcoming Video