Tag Archive for: respiratory syncytial virus

illustration of lungs with coronavirus inside

Study compares outcomes of SARS-CoV-2 versus other respiratory viruses

illustration of lungs with coronavirus inside

Until now, little was known about the incidence and virus-specific patient outcome of SARS-CoV-2 compared to common seasonal respiratory viruses in children — including respiratory syncytial virus (RSV), human parainfluenza (hPIV), human metapneumovirus (hMPV), respiratory adenovirus and human rhinovirus (hHRV) and respiratory enterovirus (rENT).

Common respiratory viral infections were associated with a higher proportion of inpatient admissions but were similar in intensive care unit (ICU) admissions and death rates in hospitalized pediatric patients when compared to SARS-CoV-2, according to Children’s National Hospital researchers that led a study published in Infection Control & Hospital Epidemiology.

Until now, little was known about the incidence and virus-specific patient outcome of SARS-CoV-2 compared to common seasonal respiratory viruses in children — including respiratory syncytial virus (RSV), human parainfluenza (hPIV), human metapneumovirus (hMPV), respiratory adenovirus and human rhinovirus (hHRV) and respiratory enterovirus (rENT).

The researchers also noted that there was an overall substantial decrease in seasonal respiratory viral infections, especially the severe forms that require hospitalization. They believe that this correlation might be associated with the adoption of COVID-19 public health mitigation efforts, which played a major role in the reduction of these viruses that often circulate in fall and winter. The retrospective cross-sectional cohort study analyzed over 55,000 patient admissions between Match 15 and December 31, 2020. The findings shed light on the incidences of eight common seasonal respiratory viral infections before and during the COVID-19 pandemic. It also compared patient outcomes associated with COVID-19 and these other viral infections among pediatric patients at Children’s National.

Xiaoyan Song, Ph.D., M.Sc., chief infection control officer at Children’s National, spoke to us about the study.

Q: Why is this important work?

A: This is the first study to date that has described and compared hospitalization rates, ICU admission rates and death associated with COVID-19, RSV, seasonal influenza, rhinovirus, enterovirus and other common respiratory viral infections in children in one study. Previously, studies have compared one or two viruses at a time. This study compared 8 viruses, including the most detected ones – COVID-19, RSV, seasonal flu, rhinovirus and enterovirus.

Q: How will this work benefit patients?

A: This study will inform patients, families and the public that preventative measures like masking, hand hygiene, avoiding crowds and avoiding people who are ill are good practices that work to protect children from getting COVID-19 but also from getting infected with RSV, influenza and other viruses. Any of these respiratory viruses could harm a patient to a point where the child may have to be hospitalized or receive ICU care.

You can read the full study published in Infection Control & Hospital Epidemiology.

smiling baby sleeping

Link between early lower respiratory tract infections and obstructive sleep apnea

smiling baby sleeping

For the first time, researchers at Children’s National Hospital have identified the association between early LRTI and the development of OSA in children.

Several birth cohorts have defined the pivotal role of early lower respiratory tract infections (LRTI) in the inception of pediatric respiratory conditions. However, the association between early LRTI and the development of obstructive sleep apnea (OSA) in children had not previously been made.

Now, for the first time, researchers at Children’s National Hospital have identified the association between early LRTI and the development of OSA in children, according to a study published in the journal SLEEP.

“These results suggest that respiratory syncytial virus LRTI may contribute to the pathophysiology of OSA in children,” said Gustavo Nino, M.D., director of sleep medicine at Children’s National.

The study also demonstrated that children with a history of severe respiratory syncytial virus (RSV) bronchiolitis during early infancy had more than double the odds of developing OSA during the first five years of life independently of other risk factors.

“The results suggest that RSV LRTI may contribute to the pathophysiology of OSA in children, raising concern for the possibility that primary prevention strategies can hinder the initial establishment of OSA following early viral LRTIs,” said Dr. Nino. “Primary prevention of OSA in children would have a dramatic effect in reducing the increasing incidence of this condition and in preventing its detrimental effects on childhood health and beyond.”

The novel findings also raise the possibility that anticipatory strategies and interventions can be developed to identify and prevent the initial establishment of OSA following viral respiratory infections during early infancy. This could provide a dramatic effect in reducing the increasing incidence of this condition and its multiple detrimental effects on childhood health and beyond.

“Our study offers a new paradigm for investigating mechanisms implicated in the early pathogenesis of OSA in the pediatric population,” said Dr. Nino.

Marishka Brown, Ph.D., director of the National Center on Sleep Disorders Research at the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health (NIH), agreed.

“The findings from this study suggest that viral lower respiratory tract infections could predispose to the development of sleep-disordered breathing in later childhood,” Brown said. “More research to determine how these infections affect airway function could lead to a better understanding of how sleep apnea develops in pediatric patients.”

This study includes funding support from the NIH, including the NHLBI.

The Pulmonary Division at Children’s National has been ranked as one of the top ten programs in the nation by U.S. News & World Report.

RSV infected infant cells

$2.13M grant accelerates treatments for kids with Down syndrome experiencing respiratory viruses

RSV infected infant cells

Children’s National Hospital received a combined $2.13 million award from the National Institutes of Health’s (NIH) National Heart, Lung and Blood Institute to better understand the mechanisms of severe viral respiratory infections in patients with Down syndrome and to develop new diagnostic tools and innovative precision medicine approaches for this vulnerable population.

“We have a unique opportunity to discover novel targets that can treat severe viral respiratory infections, including SARS-CoV-2,” said Gustavo Nino, M.D., M.S.H.S., D’A.B.S.M., principal investigator in the Center for Genetic Medicine at Children’s National. “Part of the award will help us accelerate the development of these novel approaches to prevent severe respiratory infections caused by SARS-CoV-2 and other viruses like respiratory syncytial virus infection (RSV) in children and adults with Down syndrome.”

Lower respiratory tract infections are a leading cause of hospitalization and death in children with Down syndrome. Those children have a nine times higher risk for hospitalization and mortality due to respiratory viruses that cause lower respiratory tract infections.

Chromosome 21, which is an extra chromosome copy found in patients with Down syndrome, encodes four of the six known interferon receptors, leading to hyperactivation of interferon response in Down syndrome. With the central role of interferons focused on antiviral defense, it remains puzzling how interferon hyperactivation contributes to severe viral lower respiratory tract infections in children with Down syndrome. This is an area that the researchers will explore to better manage and treat viral lower respiratory tract infections in these patients, with the support of NIH’s INCLUDE initiative. INCLUDE provides institutions with grants to help clinical research and therapeutics to understand and diminish risk factors that influence the overall health, longevity, and quality of life for people with Down syndrome related to respiratory viruses.

“While many of the other studies focus on intellectual and other disabilities, we are exploring a novel viral respiratory infectious disease mechanism and are doing so by working directly with patients and patient-derived samples,” said Jyoti Jaiswal, M.Sc., Ph.D., senior investigator in the Center for Genetic Medicine Research at Children’s National.

Children with Down syndrome have historically been excluded in research related to airway antiviral immunity, which is a focus of this human-based transformative study to improve the health and survival of patients with Down syndrome. There is a critical need for studies that define targetable molecular and cellular mechanisms to address dysregulated antiviral responses in this patient population.

“The clinical expertise at Children’s National in studying Down syndrome and the work of our team in caring for these patients with respiratory and sleep disorders positions us well to pursue this work,” said Jaiswal. “This is further supplemented by our initial studies that have identified a novel mechanism of impaired airway antiviral responses in these patients.”

Congresswoman Eleanor Holmes Norton (D-DC) also celebrated Children’s National and its NIH research funding benefitting people with Down syndrome.

“I am pleased to congratulate Dr. Nino and staff on being the recipients of the National Heart, Lung, & Blood Institute grant. You were chosen from a competitive group of applicants and should be proud of this notable achievement,” said Norton in a letter. “By receiving this grant, you have demonstrated outstanding promise in your field. It is my hope that this grant will enable you to better the local and global community.”

electronic cigarette dispenser with different flavors of nicotine

Extreme difficulty breathing and swallowing linked to teen’s vaping?

electronic cigarette dispenser with different flavors of nicotine

After a teen was transferred to Children’s National Hospital suffering from severe difficulty breathing and swallowing, a multidisciplinary team continued the detective work and surmises that vaping was to blame for her unusual symptoms.

A teenage girl with no hint of prior asthma or respiratory illness began to feel hoarseness in her throat and a feeling that she needed to clear her throat frequently. Within a few weeks, her hoarseness and throat-clearing worsened with early morning voice loss and feeling as if food were lodged in her throat. She started having trouble swallowing and began to avoid food all together.

Her pediatrician prescribed loratadine for suspected allergies to no avail. Days later, an urgent care center prescribed a three-day course of prednisone. For a few days, she felt a little better, but went back to feeling like she was breathing “through a straw.” After going to an emergency room with acute respiratory distress and severe difficulty swallowing, staff tried intravenous dexamethasone, ampicillin/sulbactam, and inhaled racemic epinephrine and arranged for transfer.

When she arrived at Children’s National Hospital, a multidisciplinary team continued the detective work with additional testing, imaging and bloodwork.

Examining her throat confirmed moderate swelling and a partially obstructed airway draped with thick chartreuse-colored mucus. The teen had no history of an autoimmune disorder, no international travel and no exposure to animals. She had no fever and had received all her scheduled immunizations.

“With epiglottitis – an inflammation of the flap found at the base of the tongue that prevents food from entering the trachea – our first concern is that an underlying infection is to blame,” says Michael Jason Bozzella, D.O., MS, a third-year infectious diseases fellow and lead author of the case report published Feb. 5, 2020, in Pediatrics. “We tested her specimens in a number of ways for a host of respiratory pathogens, including human rhino/enterovirus, respiratory syncytial virus, influenza, Epstein-Barr virus, Streptococcus and more. All negative. We also looked for more atypical infections with bacteria, like Arcanobacterium, Mycoplasma and Gonorrhea. Those were all negative as well,” Dr. Bozzella adds.

She slowly improved during a seven-day initial hospital stay, though soon returned for another six-day hospital stay after it again became excruciatingly painful for her to swallow.

Every throat culture and biopsy result showed no evidence of fungal, bacterial or viral infection, acid-fast bacilli or other malignancy. But in speaking with doctors, the teen had admitted to using candy-and fruit-flavored e-cigarettes three to five times with her friends over the two months preceding her symptoms. The last time she vaped was two weeks before her unusual symptoms began.

According to the Centers for Disease Control and Prevention, 2,668 people in the U.S. have been hospitalized for e-cigarette or vaping product use-associated lung injury, as of Jan. 14, 2020. The Children’s National case report’s authors say the increasing use of vaping products by teenagers highlights the potential for unknown health risks to continue to grow.

“This teenager’s use of e-cigarettes is the most plausible reason for this subacute epiglottitis diagnosis, a condition that can become life-threatening,” says Kathleen Ferrer, M.D., a hospitalist at Children’s National and the case report’s senior author. “This unusual case adds to a growing list of toxic effects attributable to vaping. While we normally investigate infectious triggers, like Streptococci, Staphylococci and Haemophilus, we and other health care providers should also consider e-cigarettes as we evaluate oro-respiratory complaints.”

In addition to Drs. Bozzella and Ferrer, Children’s National case report co-authors include Matthew Allen Magyar, M.D., a hospitalist; and Roberta L. DeBiasi, M.D., MS, chief of the Division of Pediatric Infectious Diseases.

Human Rhinovirus

Finding the root cause of bronchiolitis symptoms

Human Rhinovirus

A new study shows that steroids might work for rhinovirus but not for respiratory syncytial virus.

Every winter, doctors’ offices and hospital emergency rooms fill with children who have bronchiolitis, an inflammation of the small airways in the lung. It’s responsible for about 130,000 admissions each year. Sometimes these young patients have symptoms reminiscent of a bad cold with a fever, cough and runny nose. Other times, bronchiolitis causes breathing troubles so severe that these children end up in the intensive care unit.

“The reality is that we don’t have anything to treat these patients aside from supportive care, such as intravenous fluids or respiratory support,” says Robert J. Freishtat, M.D., M.P.H., chief of emergency medicine at Children’s National Health System. “That’s really unacceptable because some kids get very, very sick.”

Several years ago, Dr. Freishtat says a clinical trial tested using steroids as a potential treatment for bronchiolitis. The thinking was that these drugs might reduce the inflammation that’s a hallmark of this condition. However, he says, the results weren’t a slam-dunk for steroids: The drugs didn’t seem to improve outcomes any better than a placebo.

But the trial had a critical flaw, he explains. Rather than having one homogenous cause, bronchiolitis is an umbrella term for a set of symptoms that can be caused by a number of different viruses. The most common ones are respiratory syncytial virus (RSV) and rhinovirus, the latter itself being an assortment of more than 100 different but related viruses. By treating bronchiolitis as a single disease, Dr. Freishtat says researchers might be ignoring the subtleties of each virus that influence whether a particular medication is useful.

“By treating all bronchiolitis patients with a single agent, we could be comparing apples with oranges,” he says. “The treatment may be completely different depending on the underlying cause.”

To test this idea, Dr. Freishtat and colleagues examined nasal secretions from 32 infants who had been hospitalized with bronchiolitis from 2011 to 2014 at 17 medical centers across the country that participate in a consortium called the 35th Multicenter Airway Research Collaboration. In half of these patients, lab tests confirmed that their bronchiolitis was caused by RSV; in the other half, the cause was rhinovirus.

From these nasal secretions, the researchers extracted nucleic acids called microRNAs. These molecules regulate the effects of different genes through a variety of different mechanisms, usually resulting in the effects of target genes being silenced. A single microRNA typically targets multiple genes by affecting messenger RNA, a molecule that’s key for producing proteins.

Comparing results between patients with RSV or rhinovirus, the researchers found 386 microRNAs that differed in concentration. Using bioinformatic software, they traced these microRNAs to thousands of messenger RNAs, looking for any interesting clues to important mechanisms of illness that might vary between the two viruses.

Their findings eventually turned up important differences between the two viruses in the NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells) pathway, a protein cascade that’s intimately involved in the inflammatory response and is a target for many types of steroids. Rhinovirus appears to upregulate the expression of many members of this protein family, driving cells to make more of them, and downregulate inhibitors of this cascade. On the other hand, RSV didn’t seem to have much of an effect on this critical pathway.

To see if these effects translated into cells making more inflammatory molecules in this pathway, the researchers searched for various members of this protein cascade in the nasal secretions. They found an increase in two, known as RelA and NFkB2.

Based on these findings, published online Jan. 17, 2018, in Pediatric Research, steroids might work for rhinovirus but not for RSV, notes Dr. Freishtat the study’s senior author.

“We’re pretty close to saying that you’d need to conduct a clinical trial with respect to the virus, rather than the symptoms, to measure any effect from a given drug,” he says.

Future clinical trials might test the arsenal of currently available medicines to see if any has an effect on bronchiolitis caused by either of these two viruses. Further research into the mechanisms of each type of illness also might turn up new targets that researchers could develop new medicines to hit.

“Instead of determining the disease based on symptoms,” he says, “we can eventually treat the root cause.”

Study co-authors include Kohei Hasegawa, study lead author, and Carlos A. Camargo Jr., Massachusetts General Hospital; Marcos Pérez-Losada, The George Washington University School of Medicine and Health Sciences; Claire E. Hoptay, Samuel Epstein and Stephen J. Teach, M.D., M.P.H., Children’s National; Jonathan M. Mansbach, Boston Children’s Hospital; and Pedro A. Piedra, Baylor College of Medicine.