In this multidisciplinary roundtable discussion, Albert Rizzo, MD, interviews Barbara Taylor, MD, MS, and Leonard R. Krilov, MD, about guidelines in the management of patients with RSV, including pediatrics VS adults and how to differentiate RSV, influenza, and COVID-19.
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TRANSCRIPTION:
Albert A. Rizzo, MD
I am Dr Albert Rizzo, Chief Medical Officer of the American Lung Association. Thank you for joining us today.
Respiratory syncytial virus or RSV is the leading cause of lower respiratory tract infections in both infants and young children. Now, 4 to 5 million children younger than four years of age acquire RSV infection and more than 125,000 are hospitalized annually in the United States because of this infection. Unfortunately, the impact of RSV infection is not limited to only young children. It’s responsible for about 177,000 hospitalizations and 14,000 deaths in those over 65 years of age in this country alone. Globally, it costs an estimated $5 billion and more significantly causes more than 100,000 deaths and over 3.5 million hospitalizations per year, mostly in infants in low-middle-income countries.
Now because of the wide range of individuals who are affected by RSV, we’ve been able to develop a panel today of experts who are going to tell us about the population basis for treating RSV and talk about the vaccines as well. But I want to let them introduce themselves. Dr Krilov?
Leonard R. Krilov, MD:
Good afternoon. My name is Lenny Krilov. I’m presently the Chair of the Department of Pediatrics at the NYU Grossman Long Island School of Medicine and NYU Langone Hospital. I’m also a pediatric infectious disease specialist by training and have been involved with RSV both clinically and research-wise most of my career.
Albert A. Rizzo, MD
Thank you. Dr Taylor?
Barbara Taylor, MD, MS:
Hi, good afternoon. Thank you so much for having me. My name is Barbara Taylor. I’m a professor of infectious diseases here at UT Health San Antonio in the Lozano Long School of Medicine, and I am an adult infectious diseases physician by training and have worked in the inpatient service and in the outpatient clinics and have worked on COVID and some HIV clinical trials.
Albert A. Rizzo, MD
Thank you. So before we get into the specifics of vaccination and treatment, we know we’re entering this fall season with both RSV, influenza, and COVID peaking, and we’ve had tridemics in the past, specifically last year in 2022, it really hit the health care systems simultaneously.
What we need to know is how do you feel physicians should understand the presentation of this RSV infection both in the pediatric population, we’ll go to Dr Krilov and then in the adult population with Dr Taylor.
Leonard R. Krilov, MD:
So in the pediatric population, the main severe burden of RSV disease is in infants and young children, the highest burden is in babies in their first six months of life or if they have underlying medical issues, specifically prematurity or chronic lung disease or severe congenital heart disease, as well as the number of neuromuscular and other conditions. And that’s where we see, you mentioned 125,000 hospitalizations per year, the bulk of the hospitalizations. And with that, it’s not just hospitalization, 10%+ wind up in intensive care units and needing additional types of ventilatory support, so a major illness for those babies.
Additionally, all children get the virus, and hospitalizations, as in any condition, are the tip of the iceberg. You can add a factor of at least tenfold for additional medically attended respiratory illness visits and emergency department visits. So you can appreciate it’s got a huge burden in children, and that’s the acute illness.
Furthermore, we do get reinfected with this virus throughout our lifetime, although it’s usually the first infection that’s the most severe until we get to the second childhood infection, when I’ll turn over to Dr Taylor when we see severe disease again. But the other factor with RSV is the association with subsequent wheezing episodes. So it’s not just the initial infection, how much RSV is causal in that versus a marker that these were children who have abnormal airways and we’re going to wheeze anyway. I think it’s multifactorial. But it adds to the burden of RSV disease as well. So I think that’s a pediatric snapshot that I would give you.
Albert A. Rizzo, MD
Very good. Dr. Taylor, what should the adult treating physicians be on the lookout for?
Barbara Taylor, MD, MS:
So in adults, fortunately, again, this is mostly a cold, RSV is incredibly common and I think we’ve learned a lot about how common RSV is in adults just in the last decade when we have had more testing that includes RSV in it. I would say when I started as an infectious diseases doctor we did not really recognize that there was a lot of RSV in adults, and it turns out there is. However, some folks, particularly those older than 60 and particularly amongst those people, people who are immunocompromised can really have severe disease. And so we worry about this, especially in our transplant population, people who are profoundly immunocompromised based on immunomodulatory therapy that they might be receiving for rheumatologic disorders. Some in people with advanced HIV and some in just very older patients who are immunocompromised due to age can really be a severe pneumonia that can progress to rapid hypoxia, and that can be a life-threatening condition.
Albert A. Rizzo, MD
With the three viruses I mentioned, influenza, COVID, and RSV, what are some of the tools that are being used to differentiate them at the time of diagnosis in the ER or the doctor’s office?
Leonard R. Krilov, MD:
Well, so theoretically in young children, the hallmark of RSV disease that might be a bit different than influenza and COVID is the diffuse small airway disease, so-called bronchiolitis with wheezing. Not to say there’s not some overlap, influenza can present that way somewhat, COVID typically less so. In fact. In many ways, COVID is milder in even young children. Most of our COVID admissions are more related to very young infants with fever who have some respiratory symptoms, but not the severe lower tract disease that we saw either in 2020 or that adults with risk factors may get.
So yes, there’s a somewhat distinct clinical presentation, but it also comes down to that now the progression and testing and the multiplex PCR panels that, as Dr. Taylor mentioned, has really opened the understanding of RSV in adults, but also in children provides the differential. And interestingly, 10 to 14% of children with positive PCR panels and more than one virus. So determining who the culprit is sometimes is an issue, but those would be the main clinical features, the diagnosis and then lab testing make it much easier.
Albert A. Rizzo, MD
Dr. Taylor, in the adults?
Barbara Taylor, MD, MS:
In adults, it’s the clinical presentation is largely the same, it’s an upper respiratory infection or then viral pneumonia. One of the things that we definitely benefit from the PCR-based or nucleic amplification tests that can allow us to test for multiple viruses, we definitely see multiple infections in adults as well. I’ve taken care of people with RSV and influenza or RSV and COVID and it does become a, which is the virus in question, and often it’s all of the above. There are also some rapid antigen tests that are available on the market, which take about 30 minutes. Those are less sensitive than the PCR test and I could be corrected on this, I think they actually perform better in children than in adults. So we don’t see the use of that as much in the adult population. We tend to rely on the multiplex PCRs.
Leonard R. Krilov, MD:
So you’re right, they do perform better in children probably because children have a larger viral load most of the time. So the less sensitive test is more apt to pick it up. But the antigen for a number of the home-based tests that people use, and right now those are mostly COVID or COVID and flu is coming, there is some development of home RSV tests. I’m not sure when or how useful they’ll be. But the other side of the coin is the PCR test being so much more sensitive. Sometimes it’s problematic because some of them, like rhinoviruses, can last for 60 days or more, and for RSV it’s been shown even two to four weeks, so you no longer know when it’s acute or what the significance is for the detection sometimes as well.