Nav: Home

NIH researchers discover highly infectious vehicle for virus transmission among humans

August 08, 2018

Researchers have found that a group of viruses that cause severe stomach illness--including the one famous for widespread outbreaks on cruise ships-- get transmitted to humans through membrane-cloaked "virus clusters" that exacerbate the spread and severity of disease. Previously, it was believed that these viruses only spread through individual virus particles. The discovery of these clusters, the scientists say, marks a turning point in the understanding of how these viruses spread and why they are so infectious. This preliminary work could lead to the development of more effective antiviral agents than existing treatments that mainly target individual particles.

The researchers studied norovirus and rotavirus--hard-to-treat viruses that are the most common cause of stomach illness, or gastroenteritis, and that afflicts millions of people each year. The viruses cause symptoms ranging from diarrhea to abdominal pain and can sometimes result in death, particularly among young children and the elderly. Their highly contagious nature has led to serious outbreaks in crowded spaces throughout many communities; most notably in cruise ships, daycare centers, classrooms, and nursing homes. Fortunately, vaccines against rotavirus are now available and are routinely given to babies in the United States.

"This is a really exciting finding in the field of virology because it reveals a mode of virus spread that has not been observed among humans and animals," said study leader Nihal Altan-Bonnet, Ph.D., senior investigator and head of the Laboratory of Host-Pathogen Dynamics at the National Heart, Lung, and Blood Institute (NHLBI). "We hope that it will provide new clues to fighting a wide range of diseases involving many types of viruses, including those that cause gastrointestinal illnesses, heart inflammation, certain respiratory illnesses, and even the common cold."

The study was supported in part by the Intramural Research programs of the NHLBI and the National Institute of Allergy and Infectious Diseases (NIAID), both part of the National Institutes of Health. It is featured as the cover story of Cell Host & Microbe and is scheduled for online publication on August 8.

Until a few years ago, most scientists believed that viruses, particularly those responsible for stomach illnesses, could only behave as independent infectious agents. However, in 2015 Altan-Bonnet and her colleagues showed that polioviruses could transmit themselves in packets, or membrane-bound vesicles containing multiple virus particles. The scientists compared this new model of viral transmission to a Trojan horse: A group of membrane-bound viruses arrives at a host cell and deposits viruses in the cell while dodging detection by the immune system. The scientists did not know whether this system applied to animals and humans, or how effective these packets were in infecting host cells.

To find out, they focused on rotaviruses and noroviruses, which mainly get spread by accidentally ingesting tiny particles of an infected person's stool--through, for example, contaminated food or liquids. The researchers obtained fecal samples of humans and animals (pigs and mice) and found that the viruses are shed in the stool as virus clusters inside membrane-bound packets. In addition, they found that these virus-containing vesicles were significantly more infectious than the free, unbound viruses within the samples.

The researchers determined that the high level of infectiousness was likely due to the vesicles delivering many viruses at once to the target tissues; protecting their viral cargo from being destroyed by prolonged exposure to enzymes; and possibly by making their viral cargo invisible to the antibodies that are in the stool or gut of the host. More studies are needed, but the extreme potency of the virus packets, they said, has a clear consequence: it not only enhances the virus' ability to spread more aggressively; it also increases the severity of the disease it causes.

"Our findings indicate that vesicle-cloaked viruses are highly virulent units of fecal-oral transmission and highlight a need for antivirals targeting vesicles and virus clustering," Altan-Bonnet noted. Handwashing with soap and water helps prevent the spread of viruses.
-end-
NIH support also includes the following grant from the NIAID: RO1-AI091985.

Part of the National Institutes of Health, the National Heart, Lung, and Blood Institute (NHLBI) plans, conducts, and supports research related to the causes, prevention, diagnosis, and treatment of heart, blood vessel, lung, and blood diseases; and sleep disorders. The Institute also administers national health education campaigns on women and heart disease, healthy weight for children, and other topics. NHLBI press releases and other materials are available online at http://www.nhlbi.nih.gov.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

This press release describes a basic research finding. Basic research increases our understanding of human behavior and biology, which is foundational to advancing new and better ways to prevent, diagnose, and treat disease. Science is an unpredictable and incremental process-- each research advance builds on past discoveries, often in unexpected ways. Most clinical advances would not be possible without the knowledge of fundamental basic research.

NIH/National Heart, Lung and Blood Institute

Related Virus Articles:

A new biosensor for the COVID-19 virus
A team of researchers from Empa, ETH Zurich and Zurich University Hospital has succeeded in developing a novel sensor for detecting the new coronavirus.
How at risk are you of getting a virus on an airplane?
New 'CALM' model on passenger movement developed using Frontera supercomputer.
Virus multiplication in 3D
Vaccinia viruses serve as a vaccine against human smallpox and as the basis of new cancer therapies.
How the Zika virus can spread
The spread of infectious diseases such as Zika depends on many different factors.
Fighting the herpes virus
New insights into preventing herpes infections have been published in Nature Communications.
Strategies of a honey bee virus
Heidelberg, 23 October 2019 - The Israeli Acute Paralysis Virus is a pathogen that affects honey bees and has been linked to Colony Collapse Disorder, a key factor in decimating the bee population.
Tracking the HI virus
A European research team led by Prof. Christian Eggeling from the Friedrich Schiller University Jena, the Leibniz Institute of Photonic Technology (Leibniz IPHT), and the University of Oxford has now succeeded in using high-resolution imaging to make visible to the millisecond how the HI virus spreads between living cells and which molecules it requires for this purpose.
Prior Zika virus or dengue virus infection does not affect secondary infections in monkeys
Previous infection with either Zika virus or dengue virus has no apparent effect on the clinical course of subsequent infection with the other virus, according to a study published August 1 in the open-access journal PLOS Pathogens by David O'Connor of the University of Wisconsin-Madison, and colleagues.
Smartphone virus scanner is not what you think
The current leading method to assess the presence of viruses and other biological markers of disease is effective but large and expensive.
Early dengue virus infection could "defuse" zika virus
The Zika virus outbreak in Latin America has affected over 60 million people up to now.
More Virus News and Virus Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Speedy Beet
There are few musical moments more well-worn than the first four notes of Beethoven's Fifth Symphony. But in this short, we find out that Beethoven might have made a last-ditch effort to keep his music from ever feeling familiar, to keep pushing his listeners to a kind of psychological limit. Big thanks to our Brooklyn Philharmonic musicians: Deborah Buck and Suzy Perelman on violin, Arash Amini on cello, and Ah Ling Neu on viola. And check out The First Four Notes, Matthew Guerrieri's book on Beethoven's Fifth. Support Radiolab today at Radiolab.org/donate.