Removing the novel coronavirus from the water cycle

Science Daily/University of California - Riverside

Scientists know that coronaviruses, including the SARS-CoV-19 virus responsible for the COVID-19 pandemic, can remain infectious for days -- or even longer -- in sewage and drinking water.

Two researchers, Haizhou Liu, an associate professor of chemical and environmental engineering at the University of California, Riverside; and Professor Vincenzo Naddeo, director of the Sanitary Environmental Engineering Division at the University of Salerno, have called for more testing to determine whether water treatment methods are effective in killing SARS-CoV-19 and coronaviruses in general.

The virus can be transported in microscopic water droplets, or aerosols, which enter the air through evaporation or spray, the researchers wrote in an editorial for Environmental Science: Water Research & Technology, a leading environmental journal of the Royal Society of Chemistry in the United Kingdom.

"The ongoing COVID-19 pandemic highlights the urgent need for a careful evaluation of the fate and control of this contagious virus in the environment," Liu said. "Environmental engineers like us are well positioned to apply our expertise to address these needs with international collaborations to protect public health."

During a 2003 SARS outbreak in Hong Kong, a sewage leak caused a cluster of cases through aerosolization. Though no known cases of COVID-19 have been caused by sewage leaks, the novel coronavirus is closely related to the one that causes SARS, and infection via this route could be possible.

The novel coronavirus could also colonize biofilms that line drinking water systems, making showerheads a possible source of aerosolized transmission. This transmission pathway is thought to be a major source of exposure to the bacteria that causes Legionnaire's disease, for example.

Fortunately, most water treatment routines are thought to kill or remove coronaviruses effectively in both drinking and wastewater. Oxidation with hypochlorous acid or peracetic acid, and inactivation by ultraviolet irradiation, as well as chlorine, are thought to kill coronaviruses. In wastewater treatment plants that use membrane bioreactors, the synergistic effects of beneficial microorganisms and the physical separation of suspended solids filter out viruses concentrated in the sewage sludge.

Liu and Naddeo caution, however, that most of these methods have not been studied for effectiveness specifically on SARS-CoV-19 and other coronaviruses, and they have called for additional research.

They also suggest upgrading existing water and wastewater treatment infrastructure in outbreak hot spots, which possibly receive coronavirus from places such as hospitals, community clinics, and nursing homes. For example, energy-efficient, light-emitting, diode-based, ultraviolet point-of-use systems could disinfect water before it enters the public treatment system.

Potable water-reuse systems, which purify wastewater back into tap water, also need thorough investigation for coronavirus removal, and possibly new regulatory standards for disinfection, the researchers wrote.

The extent to which viruses can colonize biofilms is also not yet known. Biofilms are thin, slimy bacterial growths that line the pipes of many aging drinking water systems. Better monitoring of coronaviruses in biofilms might be necessary to prevent outbreaks.

The surge in household use of bactericides, virucides and disinfectants will probably cause an increase of antibiotic-resistant bacteria in the environment. Treated wastewater discharged into natural waterways demands careful monitoring through the entire water cycle. Liu and Naddeo call on chemists, environmental engineers, microbiologists, and public health specialists to develop multidisciplinary and practical solutions for safe drinking water and healthy aquatic environments.

Lastly, developing countries and some regions within highly developed nations, such as rural and impoverished communities, which lack the basic infrastructure to remove other common contaminants might not be able to remove SARS-CoV-19 either. These places might experience frequent COVID-19 outbreaks that spread easily through globalized trade and travel. Liu and Naddeo suggest governments of developed countries must support and finance water and sanitation systems wherever they are needed.

"It is now clear to all that globalization also introduces new health risks. Where water and sanitation systems are not adequate, the risk of finding novel viruses is very high," Naddeo said. "In a responsible and ideal scenario, the governments of developed countries must support and finance water and sanitation systems in developing countries, in order to also protect the citizens of their own countries."

https://www.sciencedaily.com/releases/2020/04/200403132347.htm

Study shows how diligent we have to be to keep surfaces germ-free

Only half of surfaces in animal hospital disinfected

March 25, 2020

Science Daily/Ohio State University

During the COVID-19 pandemic, every frequently touched surface outside our home seems as dangerous as a hot pot right out of the oven. We won't get burned if we touch it, but we might get infected with a potentially dangerous virus.

A recent study suggests that even organized efforts to clean surfaces can fall short, a reminder for us all that keeping our surroundings clean may require some additional work.

For 5 ½ weeks, researchers tagged surfaces of a small-animal veterinary practice daily with a fluorescent dye visible only under black light. They checked tagged surfaces 24 hours later to see if the marks were showing. Surfaces were considered cleaned if the dye was completely removed.

Results showed that overall, only half of all surfaces were adequately cleaned during the study period. Human-touch surfaces -- such as medical instruments, dog run handles, and computer mice and keyboards -- were cleaned less frequently than areas touched primarily by animals. The results were similar to studies from other veterinary clinics.

The researchers recommended creating checklists of surfaces that need to be regularly cleaned and educating all staff on the importance of proper cleaning to protect animal and human health.

"The concept of infectious diseases is around us all the time, but now it's more important than ever to take steps to protect ourselves," said senior study author Jason Stull, assistant professor of veterinary preventive medicine at The Ohio State University.

"A recent study concluded the coronavirus causing COVID-19 has the ability to survive on certain types of surfaces for hours to a few days. At veterinary practices, other businesses and certainly human hospitals, surface cleaning and disinfection is extremely important. People come in and may contaminate an area and that area potentially can serve as a source of infection for other people."

The study is published in the February issue of the Journal of Small Animal Practice.

Stull specializes in veterinary infection control, including prevention of diseases that animals can share with each other or pass to humans -- such as Salmonella, E. coli and parasites.

For the current work, Stull and colleagues assessed almost 5,000 surfaces over the course of the study. On average, 50 percent of surfaces were cleaned, with broad variations by type of surface and hospital location. The human-touch surfaces were the least likely to be cleaned.

The study assessed everyday cleaning practices in a place where people spend lots of time with different animals and different people. It's not too much of a stretch to apply some lessons to what we're experiencing now with COVID-19, Stull said.

"Plenty of industries and groups outside of human health care have ramped up their efforts to clean and disinfect common-touch surfaces. The take-home messages from our study can have important parallels for others, such as other veterinary clinics, but also groups such as grocery stores.

"Our study also highlights that, despite our best efforts, 100 percent cleaning and disinfection is unlikely to occur. This is important to remember, as regardless of where you visit, it's also best to assume surfaces may be contaminated -- and before you come back into your home, you should follow the recommendations to clean your hands and clean items you've handled."

At home, Stull said, it makes sense to concentrate on cleaning common-touch surfaces like doorknobs and countertops.

"For the average person, it's thinking about your list of things in your own home and ensuring that in some way that you're actually hitting those pieces with reasonable effort," he said.

On a normal day, people who have touched commonly shared surfaces should wash their hands before eating or scratching their noses. But will we remain diligent about this level of personal cleanliness -- and community health -- once the worst of the coronavirus threat is behind us?

"People have a tendency to swing from extremes," Stull said. "Changing the innate behaviors of people is always difficult, and we've struggled in human and veterinary health care to change these everyday practices.

"The hard part is continuing these efforts. When we get to the end of this, and at some point that will happen, you will likely see people revert back to their norm. What we need is a culture shift, so people recognize that infection control through hand-washing and thorough cleaning of shared surfaces is a critically important thing we can all do all the time, and it has measurable impact."

Armando Hoet of Ohio State's College of Veterinary Medicine and Gregory Langdon of the College of Public Health also worked on the study.

https://www.sciencedaily.com/releases/2020/03/200325120849.htm

Anxious about COVID-19? Stress can have lasting impacts on sperm and future offspring

Study identifies biological mechanism by which stress alters sperm and impacts brain development in next generation

March 23, 2020

Science Daily/University of Maryland School of Medicine

Prolonged fear and anxiety brought on by major stressors, like the coronavirus pandemic, can not only take a toll on a person's mental health, but may also have a lasting impact on a man's sperm composition that could affect his future offspring. That is the finding of a provocative new study published in the journal Nature Communications by researchers at the University of Maryland School of Medicine.

The research outlines a biological mechanism for how a father's experience with stress can influence fetal brain development in the womb. The effects of paternal stress can be transferred to offspring through changes in the extracellular vesicles that then interact with maturing sperm. Extracellular vesicles are small membrane-bound particles that transport proteins, lipids, and nucleic acids between cells. They are produced in large amounts in the reproductive tract and play an integral role in sperm maturation.

"There are so many reasons that reducing stress is beneficial especially now when our stress levels are chronically elevated and will remain so for the next few months," said study corresponding author Tracy Bale, PhD, Professor of Pharmacology and Director of the Center for Epigenetic Research in Child Health & Brain Development at the University of Maryland School of Medicine. "Properly managing stress can not only improve mental health and other stress-related ailments, but it can also help reduce the potential lasting impact on the reproductive system that could impact future generations."

She and her colleagues did not specifically study those who were under stress due to the coronavirus pandemic.

To examine a novel biological role for extracellular vesicles in transferring dad's stress to sperm, the researchers examined extracellular vesicles from mice following treatment with the stress hormone corticosterone. After treatment, the extracellular vesicles showed dramatic changes in their overall size as well as their protein and small RNA content.

When sperm were incubated with these previously "stressed" extracellular vesicles prior to fertilizing an egg, the resulting mouse pups showed significant changes in patterns of early brain development, and as adults these mice were also significantly different than controls for how they responded to stress themselves.

To see if similar differences occurred in human sperm, the researchers recruited students from the University of Pennsylvania to donate sperm each month for six months, and complete questionnaires about their perceived stress state in the preceding month. They found that students who had experienced elevated stress in months prior showed significant changes in the small RNA content of their sperm, while those who had no change in stress levels experienced little or no change. These data confirm a very similar pattern found in the mouse study.

"Our study shows that the baby's brain develops differently if the father experienced a chronic period of stress before conception, but we still do not know the implications of these differences," said Dr. Bale. "Could this prolonged higher level of stress raise the risk for mental health issues in future offspring, or could experiencing stress and managing it well help to promote stress resilience? We don't really know at this point, but our data highlight why further studies are necessary."

The research team did find that stress-induced changes in the male reproductive system take place at least a month after the stress is attenuated and life has resumed its normal patterns. "It appears the body's adaptation to stress is to return to a new baseline," Dr. Bale said, "a post-stress physiological state -- termed allostasis."

This research was funded by the National Institute of Mental Health and included co-authors from the Institute for Genome Sciences at the University of Maryland School of Medicine and the Department of Pharmaceutical Science at the University of Maryland School of Pharmacy, as well as the University of Pennsylvania.

"This research represents a critical step in understanding important mechanisms that underlie the field of intergenerational epigenetics," said UMSOM Dean E. Albert Reece, MD, PhD, MBA, who is also the Executive Vice President for Medical Affairs, University of Maryland, and the John Z. and Akiko K. Bowers Distinguished Professor. "Such knowledge is crucial to identify early interventions to improve reproduction and early childhood development down the road."

While the study did not test stress management interventions to determine what effects they might have on attenuating the changes in sperm composition, Dr. Bale, who goes for regular runs to reduce the stress of the current COVID-19 pandemic, contends that any lifestyle habits that are good for the brain are likely good for the reproductive system.

"It is important to realize that social distancing does not have to mean social isolation, especially with modern technologies available to many of us," said Joshua Gordon, Director of the National Institute of Mental Health in his web message about coping with coronavirus. "Connecting with our friends and loved ones, whether by high tech means or through simple phone calls, can help us maintain ties during stressful days ahead and will give us strength to weather this difficult passage."

The Centers for Disease Control and Prevention has tips on "stress and coping" page on their COVID-19 site that recommends the following to "support yourself":

• Take breaks from watching, reading, or listening to news stories, including social media. Hearing about the pandemic repeatedly can be upsetting.

• Take care of your body. Take deep breaths, stretch, or meditate. Try to eat healthy, well-balanced meals, exercise regularly, get plenty of sleep, and avoid alcohol and drugs.

• Make time to unwind. Try to do some other activities you enjoy.

• Connect with others. Talk with people you trust about your concerns and how you are feeling.

https://www.sciencedaily.com/releases/2020/03/200323132410.htm

ACE inhibitors and angiotensin receptor blockers may increase the risk of severe COVID-19

March 23, 2020

Science Daily/Louisiana State University Health Sciences Center

James Diaz, MD, MHA, MPH & TM, Dr PH, Professor and Head of Environmental Health Sciences at LSU Health New Orleans School of Public Health, has proposed a possible explanation for the severe lung complications being seen in some people diagnosed with COVID-19. The manuscript was published by Oxford University Press online in the Journal of Travel Medicine.

The SARS beta coronaviruses, SARS-CoV, which caused the SARS (Severe Acute Respiratory Syndrome) outbreak in 2003 and the new SARS-CoV-2, which causes COVID-19, bind to angiotensin converting enzyme 2 (ACE2) receptors in the lower respiratory tracts of infected patients to gain entry into the lungs. Viral pneumonia and potentially fatal respiratory failure may result in susceptible persons after 10-14 days.

"Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are highly recommended medications for patients with cardiovascular diseases including heart attacks, high blood pressure, diabetes and chronic kidney disease to name a few," notes Dr. Diaz. "Many of those who develop these diseases are older adults. They are prescribed these medications and take them every day."

Research in experimental models has shown an increase in the number of ACE2 receptors in the cardiopulmonary circulation after intravenous infusions of ACE inhibitors.

"Since patients treated with ACEIs and ARBS will have increased numbers of ACE2 receptors in their lungs for coronavirus S proteins to bind to, they may be at increased risk of severe disease outcomes due to SARS-CoV-2infections," explains Diaz.

Diaz writes, this hypothesis is supported by a recent descriptive analysis of 1,099 patients with laboratory-confirmed COVID-19 infections treated in China during the reporting period, December 11, 2019, to January 29, 2020. This study reported more severe disease outcomes in patients with hypertension, coronary artery disease, diabetes and chronic renal disease. All patients with the diagnoses noted met the recommended indications for treatment with ACEIs or ARBs. Diaz says that two mechanisms may protect children from COVID-19 infections -- cross-protective antibodies from multiple upper respiratory tract infections caused by the common cold-causing alpha coronaviruses, and fewer ACE2 receptors in their lower respiratory tracts to attract the binding S proteins of the beta coronaviruses.

He recommends future case-control studies in patients with COVID-19 infections to further confirm chronic therapy with ACEIs or ARBs may raise the risk for severe outcomes.

In the meantime he cautions, "Patients treated with ACEIs and ARBs for cardiovascular diseases should not stop taking their medicine, but should avoid crowds, mass events, ocean cruises, prolonged air travel, and all persons with respiratory illnesses during the current COVID-19 outbreak in order to reduce their risks of infection."

https://www.sciencedaily.com/releases/2020/03/200323101354.htm

How to manage cancer care during COVID-19 pandemic

March 18, 2020

Science Daily/National Comprehensive Cancer Network

Experts from the Seattle Cancer Care Alliance (SCCA) -- a Member Institution of the National Comprehensive Cancer Network® (NCCN®) -- are sharing insights and advice on how to continue providing optimal cancer care during the novel coronavirus (COVID-19) pandemic. SCCA includes the Fred Hutchinson Cancer Research Center and the University of Washington, which are located in the epicenter of the COVID-19 outbreak in the United States.

"Responding quickly and confidently to the COVID-19 crisis is the health care challenge of our generation," said co-lead author F. Marc Stewart, MD, Medical Director, SCCA. "Our overarching goal is to keep our cancer patients and staff safe while continuing to provide compassionate, high-quality care under circumstances we've never had to face before. We are working around the clock to develop new guidelines and policies to address situations that we couldn't have imagined several weeks ago. When the pandemic ends, we will all be proud of what we did for our patients and each other in this critical moment for humanity."

"The COVID-19 pandemic is impacting every facet of our global and domestic societies and health care systems in unprecedented fashion," said Robert W. Carlson, MD, Chief Executive Officer, NCCN. "People with cancer appear to be at increased risk of COVID-19, and their outcomes are worse than individuals without cancer. The NCCN Member Institutions are rapidly gaining experience in preventing and managing COVID-19. As is the nature of the NCCN Member Institutions, they are sharing their experience in organizing and managing institutional and care systems responses and best practices in this rapidly evolving global effort."

The article stresses the importance of keeping channels of communication open between administrators and staff, patients, caregivers, and the general public. The authors recommend forming an Incident Command Structure (as illustrated below) to provide early coordination of institution-wide efforts and to rapidly respond to changing information. They highlight the need to remain flexible and ready for unexpected challenges.

Some of the anticipated challenges include:

• Staff shortages due to potential exposure and/or school closings

• Limitations of resources such as hospital beds, mechanical ventilation, and other equipment

• Impact on treatment from travel bans, including reduced access to international donors for allogeneic stem cell transplantation

The authors recommend mitigating some of these concerns through proactive measures that include:

• Providing patient information via handouts, signs, web-based communication, and a dedicated phone line for questions and triage

• Rescheduling "well" visits and elective surgeries, and deferring second opinion consultations (where care is already appropriately established)

• Increasing hours of general hospital operations to reduce the unnecessary use of emergency department resources

• Reinforcing a strict "stay at home when ill" policy and insuring staff have access to testing

• Restricting travel and enabling work-from-home wherever possible

• Prioritizing the use of soap and water over hand gel

• Limiting the number of team members who enter patients' rooms

• Considering lower thresholds for blood transfusions

• Moving some procedures from inpatient to outpatient

• Adopting a no visitor policy with rare exceptions such as end-of-life circumstances

• Having upfront, proactive palliative and end-of-life conversations with cancer patients who may become infected with COVID-19

The article also addresses the importance of self-care within and beyond the medical community. The authors call for the prioritization of measures to protect health and frontline staff and assure a safe work environment in order to prevent provider burnout. Those measures include compensation policies, reassignments to administrative roles for immunocompromised staff, and the creation of a back-up labor pool.

NCCN is also gathering documents and links from the leading cancer centers that comprise the nonprofit alliance, and sharing them all online at NCCN.org/covid-19. These include print outs for patient information, screening tools, visitation policies, and other essential forms. Hospitals worldwide are free to use or adapt these resources immediately. The site will be continuously updated as new resources become available.

Article link at NCCN.org/covid-19.

https://www.sciencedaily.com/releases/2020/03/200318143632.htm

Median incubation period for COVID-19

March 17, 2020

Science Daily/University of Massachusetts Amherst

A new study calculates that the median incubation period for COVID-19 is just over 5 days and that 97.5% of people who develop symptoms will do so within 11.5 days of infection.

A University of Massachusetts Amherst biostatistician who directs the UMass-based Flu Forecasting Center of Excellence was invited by the White House Coronavirus Task Force to participate Wednesday morning in a coronavirus modeling webinar.

The four-hour, virtual gathering will include 20 of the world's leading infectious disease and pandemic forecasting modelers, from researchers at Harvard, Johns Hopkins and the Centers for Disease Control and Prevention (CDC) in the U.S. to those based at institutions in England, Hong Kong, South Africa and the Netherlands.

According to the White House Coronavirus Task Force coordinator Dr. Charles Vitek, "This webinar is designed to highlight for the Task Force what modeling can tell us regarding the potential effects of mitigation measures on the coronavirus outbreak. The unprecedented speed and impact of the nCoV-19 epidemic requires the best-informed public health decision-making we can produce."

Nicholas Reich, associate professor in the School of Public Health and Health Sciences, heads a flu forecasting collaborative that has produced some of the world's most accurate models in recent years. He and postdoctoral researcher Thomas McAndrew have been conducting weekly surveys of more than 20 infectious disease modeling researchers to assess their collective expert opinion on the trajectory of the COVID-19 outbreak in the U.S. The researchers and modeling experts design, build and interpret models to explain and understand infectious disease dynamics and the associated policy implications in human populations.

Reich is co-author of a new study in the Annals of Internal Medicine that calculates that the median incubation period for COVID-19 is just over five days and that 97.5 percent of people who develop symptoms will do so within 11.5 days of infection. The incubation period refers to the time between exposure to the virus and the appearance of the first symptoms.

The study's lead author is UMass Amherst biostatistics doctoral alumnus Stephen Lauer, a former member of the Reich Lab and current postdoctoral researcher at the Johns Hopkins Bloomberg School of Public Health.

The researchers examined 181 confirmed cases with identifiable exposure and symptom onset windows to estimate the incubation period of COVID-19. They conclude that "the current period of active monitoring recommended by the U.S. Centers for Disease Control and Prevention [14 days] is well supported by the evidence."

https://www.sciencedaily.com/releases/2020/03/200317175438.htm

COVID-19 infections in U.S. may be much higher, new estimates show

But even moderate interventions can help reduce spread, according to study

March 9, 2020

Science Daily/Cedars-Sinai Medical Center

By March 1, 2020, between 1,043 and 9,484 people in the U.S. may have already been infected by the COVID-19 coronavirus, far more than the number that had been publicly reported, according to a new Cedars-Sinai study.

"This suggests that the opportunity window to contain the epidemic of COVID-19 in its early stage is closing," the researchers stated in their paper, which is posted online on a forum where physicians and researchers share information.

The range of possible patients is significantly higher than the number of confirmed and presumptive U.S. cases reported by the federal Centers for Disease Control and Prevention, which stood at 164 as of March 7. Some news media on March 8 were reporting more than 500 total cases. [Editor's note: as of its March 9 update, the CDC put the total number of COVID-19 cases in the U.S. at 423, including both confirmed and presumptive positive cases.]

Cedars-Sinai investigators, who led the study, said they chose "very conservative" methods to estimate the number of coronavirus cases. "This makes our current estimation likely to be an underestimation of the true number of infected individuals in the U.S.," they wrote.

Shlomo Melmed, MB, ChB, executive vice president of Academic Affairs and dean of the medical faculty at Cedars-Sinai, added: "Cedars-Sinai is committed to the global efforts to combat COVID-19 and we believe that early dissemination of this study and the free sharing of the code that underlies the model will help in those efforts."

To arrive at infection estimates for their new study, the researchers modeled only COVID-19 coronavirus cases "imported" directly to the U.S. from the area of Wuhan, China, before Jan. 23, when the Chinese government locked down the city, and they assumed the lockdown stopped all outbound traffic. Potential cases arriving in the U.S. from other parts of China, or other heavily affected countries such as South Korea, Italy or Iran, were not included in the estimate.

The scale of the COVID-19 epidemic in the U.S. was calculated based on: air traffic data between Wuhan and the U.S., totals of confirmed cases publicly released by the CDC and transmission dynamics as estimated from previous research. The study took into account the identification and quarantine of individual domestic cases in the U.S. Among other considerations, the research team assumed the imported cases were no longer spreading infection.

Based on all these assumptions and methods, the investigators estimated the total number of people in the U.S. infected with coronavirus as of March 1 to be between 1,043 and 9,484. The first figure assumed current preventive procedures -- such as quarantines and screening international travelers at airports -- had reduced as much as 25% of the transmissibility in unidentified cases. The second figure assumed no intervention procedures had been undertaken to reduce the transmissibility.

The disparity between the lowest and highest estimates has important implications for controlling the COVID-19 epidemic, said Dermot P. McGovern, MD, PhD, professor of Medicine and Biomedical Sciences at Cedars-Sinai and senior author of the new study.

"Our model suggests that even moderately effective population interventions to reduce transmission can have a profound impact on the scale of the epidemic," McGovern explained. "This finding supports the role of public health interventions in controlling this disease."

But slowing transmission is not an easy task, given that most COVID-19 cases appear to be mild or even asymptomatic, the researchers noted, which can make it difficult to identify infected individuals who may be spreading the virus.

Despite these obstacles, McGovern said, it may still be possible to mitigate the COVID-19 outbreak through steps already suggested by public health experts.These include promoting social distancing and personal hygiene and restricting large-scale gatherings for occasions such as sporting events.

Additionally, performing mass screening for infected individuals, while expensive and logistically challenging, also would potentially help to control the epidemic, said McGovern, who also is director of Translational Research in the Inflammatory Bowel and Immunobiology Research Institute at Cedars-Sinai.

Dalin Li, PhD, the new study's first author and co-corresponding author with McGovern, said the research team is releasing the just-completed study data online before the full study has been accepted in a journal due to the urgency of the COVID-19 outbreak.

"We are making the results public before peer review as it will be important for timely and informed public health decision-making. We are also making the model available to the research community so that others can build upon it." said Li, a research scientist in the Inflammatory Bowel and Immunobiology Research Institute.

The other co-authors of the study were Jonathan Braun, MD, PhD, professor of Medicine, and research operations associate Gregory Botwin from the Inflammatory Bowel and Immunobiology Research Institute at Cedars-Sinai; and Jun Lv, Weihua Cao and Liming Li, all from Peking University Health Science Center in Beijing.

Funding: Research reported in this publication was supported by the National Institutes of Health, the Helmsley Charitable Trust and the F. Widjaja Foundation.

https://www.sciencedaily.com/releases/2020/03/200309110456.htm

To predict an epidemic, evolution can't be ignored

March 2, 2020

Science Daily/College of Engineering, Carnegie Mellon University

Whether it's coronavirus or misinformation, scientists can use mathematical models to predict how something will spread across populations. But what happens if a pathogen mutates, or information becomes modified, changing the speed at which it spreads? Researchers now show for the first time how important these considerations are.

When scientists try to predict the spread of something across populations -- anything from a coronavirus to misinformation -- they use complex mathematical models to do so. Typically, they'll study the first few steps in which the subject spreads, and use that rate to project how far and wide the spread will go.

But what happens if a pathogen mutates, or information becomes modified, changing the speed at which it spreads? In a new study appearing in this week's issue of Proceedings of the National Academy of Sciences (PNAS), a team of Carnegie Mellon University researchers show for the first time how important these considerations are.

"These evolutionary changes have a huge impact," says CyLab faculty member Osman Yagan, an associate research professor in Electrical and Computer Engineering (ECE) and corresponding author of the study. "If you don't consider the potential changes over time, you will be wrong in predicting the number of people that will get sick or the number of people who are exposed to a piece of information."

Most people are familiar with epidemics of disease, but information itself -- nowadays traveling at lightning speeds over social media -- can experience its own kind of epidemic and "go viral." Whether a piece of information goes viral or not can depend on how the original message is tweaked.

"Some pieces of misinformation are intentional, but some may develop organically when many people sequentially make small changes like a game of 'telephone,'" says Yagan. "A seemingly boring piece of information can evolve into a viral Tweet, and we need to be able to predict how these things spread."

In their study, the researchers developed a mathematical theory that takes these evolutionary changes into consideration. They then tested their theory against thousands of computer-simulated epidemics in real-world networks, such as Twitter for the spread of information or a hospital for the spread of disease.

In the context of spreading of infectious disease, the team ran thousands of simulations using data from two real-world networks: a contact network among students, teachers, and staff at a US high school, and a contact network among staff and patients in a hospital in Lyon, France.

These simulations served as a test bed: the theory that matches what is observed in the simulations would prove to be the more accurate one.

"We showed that our theory works over real-world networks," says the study's first author, Rashad Eletreby, who was a Carnegie Mellon Ph.D. student when he wrote the paper. "Traditional models that don't consider evolutionary adaptations fail at predicting the probability of the emergence of an epidemic."

While the study isn't a silver bullet for predicting the spread of today's coronavirus or the spread of fake news in today's volatile political environment with 100% accuracy -- one would need real-time data tracking the evolution of the pathogen or information to do that -- the authors say it's a big step.

"We're one step closer to reality," says Eletreby.

https://www.sciencedaily.com/releases/2020/03/200302153551.htm

COVID-19 vaccine development

February 26, 2020

Science Daily/Hong Kong University of Science and Technology

Scientists have recently identified a set of potential vaccine targets for SARS-CoV-2 coronavirus, to guide experimental efforts towards vaccine development against novel pneumonia (COVID-19).

A team of scientists at the Hong Kong University of Science and Technology (HKUST) has recently made an important discovery in identifying a set of potential vaccine targets for the SARS-CoV-2 coronavirus, providing crucial leads for guiding experimental efforts towards the vaccine development against the novel pneumonia (COVID-19) caused by the virus.

Like SARS-CoV, which caused the SARS (Severe Acute Respiratory Syndrome) outbreak in 2003, SARS-CoV-2 belongs to the same Betacoronavirus genus. By considering the genetic similarity between SARS-CoV-2 and SARS-CoV, the team leveraged experimentally-determined immunological data to identify a set of SARS-CoV- derived B cell and T cell epitopes that exactly match to SARS-CoV-2. Epitopes are biomarkers recognized by the immune system to trigger actions against the virus. As no mutation has been observed in the identified epitopes among the available SARS-CoV-2 genetic sequences, immune targeting of these epitopes may potentially offer protection against the novel pneumonia COVID-19.

The team, led by data scientists Prof. Matthew McKay and Dr. Ahmed Abdul Quadeer, expected that their work can assist in guiding experimental research towards the development of effective vaccines against SARS- CoV-2.

Prof. McKay highlighted that "Despite similarities between SARS-CoV and SARS-CoV-2, there is genetic variation between the two, and it is not obvious if epitopes that elicit an immune response against SARS-CoV will likely be effective against SARS-CoV-2. We found that only roughly 20% of the SARS-CoV epitopes map identically to SARS-CoV-2, and believe these are promising candidates."

"For the identified T cell epitopes, we also performed a population coverage analysis and determined a set of epitopes that is estimated to provide broad coverage globally as well as in China" said Dr. Quadeer. The estimated population coverage represents the percentage of individuals within the selected population that are likely to elicit an immune response to at least one epitope from the identified set.

Prof. McKay is a Professor in the Departments of Electronic & Computer Engineering and Chemical & Biological Engineering; Dr. Quadeer is a post-doctoral fellow in the Department of Electronic & Computer Engineering. Their findings were recently published in the scientific journal Viruses this month.

"Our objective was to try to assist with the initial phase of vaccine development, by providing recommendations of specific epitopes that may potentially be considered for incorporation in vaccine designs" Prof. McKay added. "More generally, our work is part of a global effort seeking to capitalize on data for COVID-19, made available and rapidly shared by the scientific community, to understand this new virus and come up with effective interventions."

The beginning of 2020 has seen the emergence of SARS-CoV-2 outbreak in mainland China, which has quickly spread to over 30 countries around the world, infecting over 80,000 people and causing over 2,600 deaths as of late February 2020.

https://www.sciencedaily.com/releases/2020/02/200226091227.htm

Effectiveness of travel bans -- readily used during infectious disease outbreaks -- mostly unknown

February 13, 2020

Science Daily/University of Washington

While travel bans are frequently used to stop the spread of an emerging infectious disease, a new study of published research found that the effectiveness of travel bans is mostly unknown.

Because of the quick and deadly outbreak in late December of a novel coronavirus in Wuhan, China, now known as COVID-19 -- infecting tens of thousands and killing hundreds within weeks, while spreading to at least 24 other countries -- many governments, including the United States, have banned or significantly restricted travel to and from China.

And while travel bans are frequently used to stop the spread of an emerging infectious disease, a new University of Washington and Johns Hopkins University study of published research found that the effectiveness of travel bans is mostly unknown.

However, said lead author Nicole Errett, a lecturer in the UW Department of Environmental & Occupational Health Sciences in the School of Public Health, that's largely due to the fact that very little research into the effectiveness of travel bans exists.

"Some of the evidence suggests that a travel ban may delay the arrival of an infectious disease in a country by days or weeks. However, there is very little evidence to suggest that a travel ban eliminates the risk of the disease crossing borders in the long term," said Errett, co-director of the ColLABorative on Extreme Event Resilience, a research lab focused on addressing real-world issues relevant to community resilience.

The researchers combed through thousands of published articles in an effort to identify those that directly addressed travel bans used to reduce the geographic impact of the Ebola virus, SARS (Severe Acute Respiratory Syndrome), MERS (Middle East Respiratory Syndrome) and the Zika virus. They did not include studies of influenza viruses, for which travel bans have already been shown to be ineffective in the long term.

In the end, the researchers were able to identify just six studies that fit their criteria. Those six were based on models or simulations, not data from actual bans after they were implemented, to assess the effectiveness of travel bans in controlling outbreaks. Consequently, to improve research in this area, the study authors recommend that research questions, partnerships and study protocols be established ahead of the next outbreak so empirical data can be collected and assessed quickly.

"Travel bans are one of several legal options that governments have drawn on to mitigate a pandemic," said co-author Lainie Rutkow, a professor of health policy and management at Johns Hopkins Bloomberg School of Public Health. "As coronavirus spreads, our study raises the importance of understanding the effectiveness of legal and policy responses intended to protect and promote the public's health."

"When assessing the need for, and validity of, a travel ban, given the limited evidence, it's important to ask if it is the least restrictive measure that still protects the public's health, and even if it is, we should be asking that question repeatedly, and often," said co-author Lauren Sauer, an assistant professor of emergency medicine at Johns Hopkins University's School of Medicine and director of operations with the university's Office of Critical Event Preparedness and Response.

Consequently, the authors write, additional research is "urgently needed" to inform policy decisions, especially in light of the tremendous social, economic and political impacts of their implementation.

https://www.sciencedaily.com/releases/2020/02/200213175923.htm