Episode #45 Changing Landscape of Community-Acquired Pneumonia with Dr. Thomas File

Dr. Albert Rizzo:
So welcome back to Lungcast, the monthly respiratory health podcast series from the American Lung Association and medical news site HCP Live. I’m your host, Dr. Albert Rizzo, Chief Medical Officer of the American Lung Association.

Before we introduce our guest today, just a reminder that Lungcast is available on all your favorite streaming platforms. You can subscribe on YouTube to get new and archived episodes, as well as interview segments and highlights. A link to the show page, as well as the American Lung Association and HCP Live homepages, can be found in each episode description.

For those of you who prefer a podcast, you can subscribe to Lungcast on Spotify, Apple Podcasts, and your favorite listening platforms. You can also register for more respiratory news and insights at both lung.org and hcplive.com.

Today’s guest is Dr. Thomas File, Distinguished Physician of the Infectious Disease Division and the Antimicrobial Stewardship Program at Summa Health in Akron, Ohio. He’s also Professor Emeritus of Medicine and Master Teacher of the Infectious Disease Section of Northeast Ohio Medical University. His research interests include randomized clinical trials for safety and efficacy of new antimicrobials, community-acquired pneumonia, and the impact of new diagnostics and antimicrobial stewardship on patient outcomes.

Dr. File has been very active in the Infectious Diseases Society of America (IDSA), serving as president and on multiple committees, including chair of the practice guidelines committee from 2005 to 2008, and as a board member from 2008 to 2011 and again from 2017 to 2022.

Thank you for joining me today, Dr. File.

Dr. Thomas File:
Well, hi Dr. Rizzo, it’s certainly a pleasure to be with you, and I thank you for inviting me to join this podcast.

Dr. Rizzo:
I believe the most recent guidelines on the diagnosis and treatment of community-acquired pneumonia were put out by the American Thoracic Society and the Infectious Diseases Society of America back in 2019. At that time, they updated several recommendations from the 2007 guidelines—almost 12 years earlier. I hope we can highlight some of those changes during our discussion today.

Since the guidelines were published in 2019, you were part of a multidisciplinary group that helped develop an updated clinical pathway finalized in September 2023. The first section was on criteria for defining severity of community-acquired pneumonia. Does the updated guideline use prediction tools similar to those in the past, such as the Pneumonia Severity Index (PSI) or CURB-65? Can you comment on their utility and when one may be better than the other?

Dr. File:
Yes, first let me explain that this updated clinical pathway was developed by IDSA with support from the CDC. The main purpose was to apply good antimicrobial stewardship principles to the 2019 ATS/IDSA guidelines. We also added daily management recommendations, not just initial evaluation, which makes this pathway a little unique.

Both the 2019 guidelines and this new pathway use decision-analysis tools for severity assessment to help determine site of care. The pathway specifically used CURB-65, which is based on confusion, urea, respiratory rate ≥30, blood pressure <90 systolic, and age ≥65. Each counts for one point, and generally a score of two or more suggests hospitalization.

The Pneumonia Severity Index (PSI) is more comprehensive—20 different variables—and while often more accurate, it’s less practical in clinical practice. That’s why CURB-65 tends to be used more routinely, though in clinical trials we still use PSI to stratify patients.

Dr. Rizzo:
That makes perfect sense. Another section of the update dealt with diagnostic tools. Can you address the diagnostic tools discussed in the update algorithm, and how the pandemic and increased availability of PCR testing have influenced this?

Dr. File:
Yes, one of the most significant advances has been the development of rapid molecular tests that identify pathogens within hours. This allows for pathogen-directed management, which we recommend using if institutions have access.

This was not included in the 2019 ATS/IDSA guideline since it predated the pandemic, but COVID-19 taught us the importance of recognizing viral pneumonia. We now know that 25–30% of hospitalized community-acquired pneumonia cases are viral alone. These panels detect not just SARS-CoV-2 and influenza, but also RSV, human metapneumovirus, adenovirus, and others.

If a viral pathogen is identified, with no bacterial coinfection and the patient is stable, we can stop antibacterial therapy. This represents a major shift from broad empiric antibiotics given to nearly everyone in the past.

Of course, there are considerations: these tests are very sensitive, so we need to interpret colonization versus true infection. But overall, they improve stewardship by allowing us to narrow therapy, reduce duration, and minimize adverse events like C. diff and resistance.

Dr. Rizzo:
So you’re clearly a strong supporter of PCR tools. I’d also like your opinion on procalcitonin. Several biomarkers exist, but procalcitonin has emerged as an important tool in stewardship. Can you comment on its use and timing?

Dr. File:
Yes, I’m a strong supporter of procalcitonin. It rises quickly within 4–6 hours of systemic bacterial infection and decreases rapidly when infection is controlled with antibiotics. That makes it useful for monitoring treatment response and deciding when to stop antibiotics.

If levels fall by more than 80% from peak, there’s good evidence therapy can be discontinued. However, it’s not perfect—false positives can occur with kidney injury or shock, and atypical bacteria like Mycoplasma may not raise levels. So it should be used as a supplement to clinical judgment, not as a standalone test.

In our institution, it’s helped reduce both length of stay and unnecessary antibiotic use.

Dr. Rizzo:
Great caveats. Let’s talk about the treatment algorithm. Can you walk us through the updated recommendations, especially around MRSA and Pseudomonas considerations?

Dr. File:
Sure. For empiric therapy, we target core pathogens like Streptococcus pneumoniae, Haemophilus, and atypicals, while also assessing MRSA and Pseudomonas risk factors.

For non-severe patients on the general ward, MRSA risk is based on a prior MRSA culture, while in ICU patients, prior hospitalization also counts. Similarly for Pseudomonas, general ward risks include advanced lung disease or a history of infection in the past year; ICU risks include recent hospitalization or parenteral antibiotics.

For most ward patients without MRSA/Pseudomonas risks, empiric therapy is a beta-lactam (commonly ceftriaxone) plus a macrolide, or a respiratory fluoroquinolone. We try to avoid fluoroquinolones when possible due to adverse effects.

If Pseudomonas risk is present, we use an anti-pseudomonal beta-lactam like piperacillin-tazobactam plus atypical coverage. For MRSA risk, vancomycin or linezolid is used, but if nasal MRSA PCR is negative, we stop coverage.

One big change from the 2007 guideline: macrolide monotherapy is no longer recommended due to high resistance rates. Instead, doxycycline or amoxicillin can be considered for healthier outpatients without risk factors.

Dr. Rizzo:
That’s very helpful. Let’s stay with stewardship for a moment. What are the key practices regarding duration of therapy?

Dr. File:
This is an area that’s changed significantly. Historically, two weeks of antibiotics was common. Now, evidence shows that if patients are clinically stable by day three, total therapy of three to five days is often sufficient.

The pathway also gives daily recommendations: de-escalate therapy once culture or PCR results are available, transition to oral agents when appropriate, and discharge when stable. This reduces unnecessary exposure and improves outcomes.

Dr. Rizzo:
Looking ahead, do you see changes coming with new antimicrobials or other therapies?

Dr. File:
Yes. New agents like lefamulin and omadacycline have been FDA-approved for community-acquired pneumonia and provide options for patients who can’t tolerate standard agents.

Beyond antibiotics, there’s growing interest in host-directed therapies. For example, recent data suggest glucocorticoids may benefit patients with severe pneumonia. There’s also research into targeting pathogen virulence factors.

Dr. Rizzo:
Let’s touch on prevention. With vaccines now available for pneumococcus, influenza, COVID-19, and RSV, what are the key recommendations?

Dr. File:
All these vaccines are important, especially for patients with lung disease. Unfortunately, vaccine hesitancy remains a challenge, but the strongest motivator is a provider’s recommendation.

Rather than list each vaccine schedule here, I advise clinicians and patients to refer directly to the CDC’s ACIP recommendations, which are regularly updated and easy to follow by age and risk group.

Dr. Rizzo:
You also recently wrote in The New England Journal of Medicine about areas of uncertainty. Can you briefly comment on the lung microbiome, PCR technology, and links between pneumonia and cardiovascular disease?

Dr. File:
Yes. First, the lung microbiome: we now know the lungs aren’t sterile, and disruption of the microbiome may influence health and disease. We need more research on its role in infections.

Second, PCR technology: we know it improves pathogen identification, but we need more data on its true clinical and cost impact.

Finally, pneumonia and cardiovascular disease: we now recognize pneumonia is associated with increased cardiovascular events, not just coincidental. We need to better understand mechanisms and potential interventions.

Dr. Rizzo:
That’s excellent. Any closing thoughts?

Dr. File:
Yes—pneumonia is not just an acute illness. It has both short- and long-term consequences. Understanding and addressing these will improve outcomes for our patients.

Dr. Rizzo:
Well, thank you again, Dr. File, for your time and expertise. To our listeners: if you want to hear more discussions on respiratory infections, check our archive, including episode 37 with Dr. Barbara Taylor on RSV vaccines and episode 17 with Dr. Shantonu Ghosh on influenza.

Be sure to subscribe to Lungcast on your preferred platform, and visit lung.org and hcplive.com for more resources. The American Lung Association also funds research in all aspects of lung disease—more information is available at lung.org/research.

Until next time, I’m Dr. Albert Rizzo, reminding you that if you can’t breathe, nothing else matters.