Showing posts with label CAP. Show all posts
Showing posts with label CAP. Show all posts

Sunday, February 15, 2026

Community Acquired Pneumonia - and How To Avoid it

 


Disclaimer:  Like all posts on this blog this is intended for educational and commentary purposes and is not medical advice in any form.  All medical decisions need to be made in collaboration with your personal physician who knows your history.  For reasons stated below - vaccination information and recommendations are also less clear than they have ever been due largely to political influences that can also affect physicians.

 

This a strategic post about pneumonia.  By strategic I mean I hope to clarify what it is and how to prevent it.  This is not about diagnosing and treating it.  Most people reading this blog either don’t need to know that or know a lot more than me about it. Instead, I hope to address three things – misinformation about it, barriers in the modern healthcare system to acute care, and how to prevent it.

My focus will be on community acquired pneumonia (CAP).  It is a term I am very familiar with dating back 40 years to med school and my medical internship. As an intern I carried around my copy of Sanford’s antimicrobial therapy and the relevant section of Phantom Notes which was basically an outline of the leading Internal Medicine text at the time.  Thirty percent of the people I admitted to the hospital had some kind of pulmonary problem.  Depending on who you read chronic obstructive pulmonary disease (COPD) is as high as the third leading cause of death worldwide.  Exacerbations of COPD were very common reasons for hospital and ICU admission. 

CAP by definition is acquired in the community and not in a hospital setting.  It can be cause by a range of microorganisms and host factors.  It can also develop in people with no known risk factors. Conventional wisdom used to be that the lung was sterile territory but now we know that it contains a low biomass microbiome consisting of bacterial, viral, and fungal elements that are there via microaspiration of mouth contents.  Local physiological changes can occur to change the microbiome, or pathogens can be inhaled that establish primary infections (1).   Certain lung diseases like COPD and asthma can also lead to selective proliferation of elements of the microbiome. 

The ability of the lung to repair itself after injury or infection is controversial. Some research suggested that the lung was permanently changed by infection.  One example would be the association of asthma with previous rhinovirus infection. More recent work suggests there is room for optimism if the regenerative capacity of the lung can be activated (2).  

My motivation for this post was a clinical trial I read in the New England Journal of Medicine.  It was about treating CAP in East Africa.  The research question was whether adding glucocorticoids to antibiotic treatment as usual would improve outcomes.  That study quotes the mortality of CAP as 25-30%. The study was conducted in Kenya.  2,180 study patients were randomized to standard care versus glucocorticoids.  All patients were admitted to a hospital and CAP was defined as “the presence of at least two of the following signs and symptoms for less than 14 days: cough, fever, dyspnea, hemoptysis, chest pain, or crackles on chest examination.”  Imaging was not a criterion for study entrance because it was not available in many settings.  They were started on the protocol within 48 hours of admission. Glucocorticoids were provided for free as one of five glucocorticoids in bioequivalent doses for a total of 10 days (including after discharge) in addition to standard care (6 mg of dexamethasone, 160 mg of hydrocortisone, 30 mg of methylprednisolone, 50 mg of prednisolone, or 50 mg of prednisone).  Standard care was antibiotic therapy per World Health Organization (WHO) guidelines (beta lactam and macrolide antibiotics). Exclusion criteria are available in the paper.

30-day mortality was the primary endpoint in an intent-to-treat analysis.  To get to the treatment population a total of 46,224 patients were screened.  Of the 2,180 patients mortality was 530 (24.3%) at 30 days.  246 of 1089 (22.6%) were in the glucocorticoid group and 284 of 1091 (26.0%) in the glucocorticoid group.  That translates to a hazard ratio of 0.84.  The authors explain the limitations (comorbid illnesses – HIV, hypertension) and advantages (large N, lower media age) of their study.  That seems like a slight reduction in mortality for the intervention, but the authors point out that several other studies had better results up to a 50% reduction in mortality with glucocorticoids and it is a low tech readily available intervention.

In looking at the side effects of glucocorticoids   Pulmonary tuberculosis and hyperglycemia were the most common adverse effects in the glucocorticoid treated group.  Pulmonary tuberculosis and acute kidney injury were the most common adverse effects in the standard care group. 

The striking part of this study for me are the mortality figures. Although the researchers emphasized throughout their study that this was a pragmatic trial in a healthcare system with fewer resources – the estimated mortality for community acquired pneumonia in the United States is 6% at 30 days for hospitalized patients but that increases to 34% at 30 days for patients who do not initially improve initially (4).  There are treatment guidelines for primary care physicians about who can or cannot be treated on an ambulatory basis.  Age is a risk factor for increased incidence of pneumonia with the rate increasing from 248 (all adults) to 634 (ages 65 to 79) to 16,430 per 100,000 after the age of 80 (5).  Pre-existing COPD increases the risk of hospitalization 9-fold.

There are characteristic patterns of pneumonia by pathogen based on the immune response.  Bacterial infections elicit an infiltration of neutrophils into the alveolar space in a pattern of lobar or bronchopneumonia that results in an exudate of dead cells and phagocytes in the alveolar space.  Viral infections cause an interstitial pattern of inflammation with lymphocytic cell infiltrates.  Identification of the pathogen is largely done on a clinical basis due to difficulty identifying the pathogens.  Indirect methods can be used like determining acute and convalescent phase antibodies to specific viruses. Both types of infection compromise normal physiology and can lead to hypoxia and in the case of bacteria secondary infections - like meningitis.      

Recent sporadic and annual viral pandemics have created a confluence of factors at the hospital that are best avoided.  The first is the use of broad-spectrum antibiotics.  Since a significant portion of people admitted with viral pneumonia develop hospital acquired secondary bacterial infections – antibiotics are given prophylactically to prevent that complication.  Increasing exposure to increasingly potent antibiotics leads to multiple drug-resistant bacteria.  The best pathway is to avoid getting the respiratory infection in the first place. 

The absolute best way to avoid is vaccinations.  Vaccinations are currently available for influenza, COVID-19 (Sars-CoV-2), respiratory syncytial virus (RSV), and Streptococcus pneumoniae (pneumococcal pneumonia and meningitis).  They have all been tested and offer relative protection (rather than absolute) against serious illness, hospitalization, and death, especially for adults 65+ years of age.  Vaccinations have become a mixed bag of accessibility.  On the one hand you can get them from pharmacies and that is a recent development.  On the other hand we have an elected government that has appointed a well known antivaccination promoter as the head of Health and Human Services – Robert F. Kennedy, Jr.  So far there have been restrictions on the COVID vaccination to people who are 65+ or have an underlying health condition.  Since the administration is apparently making health decision based on politics and ideology many states and professional organizations are publishing their own guidelines.  As an example here is a list of respiratory virus vaccination guidelines from the American Academy of Family Practice (AAFP).  The CDC still has pneumococcal vaccination recommendations for children less than the age of 5 and adults over the age of 50.

The University of Minnesota Center for Infectious Disease Research and Policy (CIDRAP) program has a good brief on the vaccine controversy and chaos introduced by the Trump administration and the lack of scientific origins at this link.

Apart from vaccinations risk factor modification should be considered.  If you were born and raised in American culture – it is important to realize that you have been socialized to expect to get sick in the wintertime.  I did not realize that until I was getting sick 2-3 times a year on the inpatient unit where I worked.  They were viral illnesses that took 2-3 weeks to recover from.  The building was made in an era where preservation of heat was the primary design goal.  There was minimal circulation of clean air or filtration.  My suggestions to improve the air quality were ignored.  The mini-epidemics were made worse by admitting people who were ill with respiratory viruses and not using any precautions to prevent the spread of those viruses.  The new personal time off (PTO) policies that make no distinction between vacation and sick days also lead to increased exposure to sick employees who would rather work sick than use PTO days for sick time.  Since the COVID pandemic even outpatient clinics ask questions every time they see you to minimize staff exposure to respiratory viruses.

Masks work.  They must be N95 masks and fit correctly but there is no doubt that they work.  These days it is common to see political arguments and in the extreme ridicule heaped on people who use them. Large scale uncontrolled studies are often cited as evidence that they are a weak intervention.  These studies are almost all self report with no measures of actual adherence to masking.  The best studies are done in a lab that look at filtering virus sized particles and there is no doubt they are equal to that test.  

Risk factor modification is probably important.  Cardiopulmonary diseases are significant risk factors for pneumonia – so maintaining the best possible treatment for those conditions is important.  Weight control and activity level are also important.  There is at least one study showing that 65+ year olds who maintain high activity levels have better immunity than those who do not.  The specific dose of exercise for that effect is unknown currently. 

Expert advice on vaccine allergies is an important point.  I have personal history of an anaphylactic reaction to anti-rabies duck embryo vaccine in 1975.  For the next 30 years I did not get a single vaccine against influenza because it was egg based.  I had innumerable episodes of viral illness that was probably influenza and decided to see an immunologist to see if I could be desensitized to eggs so I could get the flu vaccine.  When he confirmed that I could eat eggs without a problem he said that I would probably not have any problems with the vaccine.  He was correct and I have not missed an annual dose since.

Look for respiratory infection season onset and peaks.  They are typically available through your state public health department and the CDC. When I notice it – I change my routine to shop at nonpeak hours and wear a mask in stores.  In addition to protection from the airborne transmission route hand washing is also important.  Shopping carts, door handles, and other high traffic areas are unavoidable areas for direct contact transmission. That may include being in a public bathroom any time somebody flushes a toilet.  Keep in mind that there are number of circulating common cold viruses that include 4 coronaviruses that can make you very ill.

What about barriers to care in the current healthcare non-system in the US?  There are many since businesses have taken over health care in the past 40 years.  Healthcare is rationed by both businesses and governments with only a very grudging nod to quality. The most obvious example is avoidance of the emergency department if you need it.  Anyone with previous experience knows about waits in emergency departments and delays in care.  People avoid paramedics and ambulances out of fear they will be billed for that service.  If you expect that you are ill beyond a typical cold and have additional warning signs like shortness of breath – seek help immediately.  I have given that advice to many people and it is included in the final paragraph of this AMA information sheet.   Keep in mind that pneumococcal infection can also cause meningitis which is even a more significant emergency and those symptoms can include a severe headache and neck stiffness.  Maintain a low threshold for checking these symptoms out with your primary care physician’s office during working hours and their call line after hours. But if that is not available or able to give you an answer call 911 and get a paramedic there in person to advise you and advocate for you getting timely care.  Even in our fragmented healthcare system you do not have to go it alone.  

Finally – you must realize that the infectious disease space has been infiltrated by many people who do not belong there.  They have mixed agendas involving politics and health and wellness profits.  In some cases, they are just promoting themselves.  This varies from a kernel of truth rhetoric (eg. “most people who get this virus do not die”) to outright lies (eg. “this vaccine has never been adequately tested”).  There are many points in between such as “He died of pneumonia not COVID”.  In outrageous cases they have attacked and threatened public health officials.  It is important to recognize who these people are and why they must be ignored to preserve your interest and that is your personal health. 

I attached a list of the main respiratory pathogen vaccinations as a supplementary below. The indications are taken directly from the FDA approved package insert that is in turn based on clinical trials for efficacy and safety. There are significant differences between the FDA approved indications and eligibility as determined by various organizations. There are also links to those graphics in the appended material. Note that for the COVID vaccinations especially the eligibility can vary based on age, susceptibility status, and what has been referred to as mutual decision making. In my opinion this is basically slow walking vaccine denial in as eligibility. Essentially all medical decisions are based on informed consent as mutual decision making. I did not get a single influenza vaccine for 30 years because of mutual decision making that was based on inadequate information. I asked an Internist about what he would recommend in the cased of COVID-19 vaccinations and he said: “Definitely recommend for over 65. Recommend for patients with multiple comorbidities. Recommend for healthy young adults if they were healthcare workers, teachers or in an occupation with lots of exposure to the public.” Why are the eligibility criteria not that simple?  As far as I can tell the answer is politics.

That is my overall strategy to avoid pneumonia.  It is most important as you age into categories where your risk doubles (65+ yrs old) and increases 25-fold (80+ yrs old).  I use these strategies myself and have found them to be very effective.  And remember the overall strategy is to avoid the physical virus or bacteria if at all possible and failing that make sure your immune system is activated by a vaccination to attack it if you are infected.

 

George Dawson, MD, DFAPA

 

References:

1: Li, R., Li, J. & Zhou, X. Lung microbiome: new insights into the pathogenesis of respiratory diseases. Sig Transduct Target Ther 9, 19 (2024). https://doi.org/10.1038/s41392-023-01722-y 

2:  Ainsworth C. Lung, heal thyself. Nature. 2026 Jan 29;649:S9 – S11.

3:  Lucinde RK, Gathuri H, Mwaniki P, et al. A Pragmatic Trial of Glucocorticoids for Community-Acquired Pneumonia. N Engl J Med. 2025 Dec 4;393(22):2187-2197. doi: 10.1056/NEJMoa2507100. Epub 2025 Oct 29. PMID: 41159889; PMCID: PMC12659994.

4:  Peyrani P, Arnold FW, Bordon J, et al. Incidence and mortality of adults hospitalized with community-acquired pneumonia according to clinical course. Chest. 2020;157(1):34-41.    

5:  Jain S, Self WH, Wunderink RG, et al.; CDC EPIC Study Team. Community-acquired pneumonia requiring hospitalization among U.S. adults. N Engl J Med. 2015;373(5):415-427.


Graphic:

Pages from my trusty copy of Phantom Notes that I used on wards as a medical student.  I went back to check to see if community acquired pneumonia was a thing back then and it was not.  If you can read it they do discuss where it was acquired under Classification (D3).   According to PubMed that term was used just twice in 1981 - but became progressively more popular in the 1990s.


Note also that we have an expanded list of viral pathogens compared with 1981.

Phantom Notes Medicine 79-80 edition copyright Joe D. Glickman, Jr, MD All Rights Reserved.  


A Shocking Anecdote about Pneumococcus:

When I was an intern on neurology (1983) I was called down to the emergency department to assess a 70 year old woman for "agitation".   That was all they could tell me aside from the fact that her labs and exam were normal.  She was unresponsive, groaning softly and rolling from side to side on the bed.  I proceeded with my examination and found that she had a stiff neck and pus draining out of her left ear.  I called my two senior neurology residents and they came sprinting to the ED.  A quick gram stain of the pus showed gram positive cocci and we gave her 1 gram of IV chloramphenicol, did a lumbar puncture and transferred her to the Neurology ICU.  She subsequently developed ARDS and required transfer to the medical ICU for ventilatory support.  She was discharged a month later and was completely deaf as a result of pneumococcal meningitis.


Vaccines for Respiratory Tract Infections: Indications versus Eligibility:

 

Vaccine

Indication (From Package Insert)

Eligibility (From CDC)

Influenza

FLUARIX is a vaccine indicated for active immunization for the prevention

of disease caused by influenza A subtype viruses and type B virus contained

in the vaccine. FLUARIX is approved for use in persons aged 6 months and older. (1)

 - Fluzone High-Dose is a vaccine indicated for active immunization for the prevention of disease caused by influenza A subtype viruses and type B virus contained in the vaccine. (1) Fluzone High-Dose is approved for use in persons 65 years of age and older. (1)

Annual all adults

CDC Guidance

COVID

Moderna - SPIKEVAX is a vaccine indicated for active immunization to prevent coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

SPIKEVAX is approved for use in individuals who are:

• 65 years of age and older, or

• 6 months through 64 years of age with at least one underlying condition that puts them at risk of severe outcomes from COVID-19

 

Pfizer - COMIRNATY is a vaccine indicated for active immunization to prevent

coronavirus disease 2019 (COVID-19) caused by severe acute respiratory

syndrome coronavirus 2 (SARS-CoV-2). (1)

COMIRNATY is approved for use in individuals who are:

 65 years of age and older, or

 5 years through 64 years of age with at least one underlying condition

that puts them at high risk for severe outcomes from COVID-19. (1)

Adults should discuss with their health care provider to see if this vaccine is right for them.

CDC Guidance

RSV

-Active immunization of pregnant individuals at 32 through 36 weeks gestational age for the prevention of lower respiratory tract disease (LRTD) and severe LRTD caused by respiratory syncytial virus (RSV) in infants from birth through 6 months of age. (1.1)

- Active immunization for the prevention of LRTD caused by RSV in individuals 60 years of age and older. (1.2)

-Active immunization for the prevention of LRTD caused by RSV in individuals 18 through 59 years of age who are at increased risk for LRTD caused by RSV

Adults 75+

Adults 50-74 at increased risk

CDC guidance

Pneumococcus

Pneumococcal Conjugate Vaccines (PCV)

 

PCV15 (Vaxneuvance): Protects against 15 types of pneumococcal bacteria.  is indicated for active immunization for the prevention of invasive disease caused by Streptococcus pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F, and 33F in individuals 6 weeks of age and older.

 

PCV20 (Prevnar 20): Protects against 20 types of bacteria; it has largely replaced the older PCV13 (Prevnar 13). Prevnar 20 is a vaccine indicated for

• active immunization for the prevention of invasive disease caused by Streptococcus pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F in individuals 6 weeks of age and older. (1)

• active immunization for the prevention of otitis media caused by S. pneumoniae serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F in individuals 6 weeks through 5 years of age. (1)

• active immunization for the prevention of pneumonia caused by S. pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F in individuals 18 years of age and older. (1)

The indication for the prevention of pneumonia caused by S.pneumoniae serotypes 8, 10A, 11A, 12F, 15B, 22F, and 33F in individuals 18 years of age and older is approved under accelerated approval based on immune responses as measured by opsonophagocytic activity (OPA) assay.

 

PCV21 (Capvaxive): A newer vaccine approved in 2024 for adults, protecting against 21 types, including several strains not covered by other vaccines. CAPVAXIVE™ is a vaccine indicated for:

• active immunization for the prevention of invasive disease caused by Streptococcus pneumoniae serotypes 3, 6A, 7F, 8, 9N, 10A,

11A, 12F, 15A, 15B, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B in individuals 18 years of age and older. (1)

• active immunization for the prevention of pneumonia caused by S. pneumoniae serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A,15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B in individuals 18 years of age and older. (1)

The indication for the prevention of pneumonia caused by S. pneumoniae serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B is approved under accelerated approval based on immune responses as measured

by opsonophagocytic activity (OPA).Continued approval for this indication may be contingent upon verification and description of clinical

benefit in a confirmatory trial. (1)

Pneumococcal Polysaccharide Vaccine (PPSV)

PPSV23 (Pneumovax 23)

PNEUMOVAX 23 is a vaccine indicated for active immunization for the prevention of pneumococcal disease caused by the 23 serotypes contained in the vaccine (1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F,14, 15B, 17F, 18C, 19F, 19A, 20, 22F, 23F, and 33F). (1.1)

PNEUMOVAX 23 is approved for use in persons 50 years of age or older

and persons aged ≥2 years who are at increased risk for pneumococcal disease. (1.1, 14.1)

Adults aged 50 or older according to CDC

 

 *High risk for severe outcomes:  For the comprehensive list of underlying medical conditions that place a person at risk for severe outcomes from COVID-19 see this CDC document: https://www.cdc.gov/covid/hcp/clinical-care/underlying-conditions.html

 FDA Vaccine, Blood, and Biologics Web Page:  https://www.fda.gov/vaccines-blood-biologics

 FDA Vaccines Licensed for Use in the United States:  https://www.fda.gov/vaccines-blood-biologics/vaccines/vaccines-licensed-use-united-states

CDC Vaccine Schedule with graphic:  https://www.cdc.gov/vaccines/imz-schedules/adult-easyread.html

COVID recommendation:  “Adults should talk to their health care provider to decide if this vaccine is right for them”.

 AAFP Adult Vaccination Schedule with graphic:  https://www.aafp.org/dam/AAFP/documents/patient_care/immunizations/2025%20adult%20Schedule_NOV.pdf

COVID recommendation:  “1 – 2 or more (age >65) does of the updated 2025-2026 vaccine”.

 Minnesota Department of Health Adult Vaccination Schedule with graphic: https://www.health.state.mn.us/people/immunize/resprecs.pdf

COVID recommendation:  “All adults especially 65+ (2 doses)”.