Is Pneumonia Still “The Old Man’s Friend”?

"Pneumonia may well be called the friend of the aged. Taken off by it an acute, short, not often painful illness, the old man escapes those 'cold gradations of decay' so distressing to himself and to his friends."

Sir William Osler, Canadian physician, Father of Modern Medicine and a founder of  Johns Hopkins Hospital and School of Medicine

“To care for those who once cared for us is one of the highest honors.”

Tia Walker, American author

From time immemorial, pneumonia has been a major cause of death, especially for older adults. In the early 20^th century (the pre-antibiotic era), Sir William Osler referred to pneumonia as the “old man’s friend” and also called it “the Captain of the Men of Death,” a phrase originally coined by 17^th century writer John Bunyan in refence to tuberculosis, the most lethal cause of pneumonia.  

In 1919, Osler ironically died of the “old man’s friend” at age 70, a time when the life expectancy was only 54.7 years. (This represented a significant rebound from the 1918 influenza pandemic low of 39.1 years.) As of 2023, life expectancy in the U.S. is 78.4 years (pre-COVID-19 pandemic life expectancy was 78.8 years), and about 17.7% of the U.S. population is considered elderly (age 65 or older). Pneumonia steadfastly continues to be a major cause of death in this age group.

In this week’s Germ Gems post, I briefly review the topic of pneumonia and revisit Osler’s view—a view from the pre-antibiotic era—that this infection often offers the elderly and infirm a swift and relatively peaceful death compared to the slow, drawn-out suffering from many other chronic and incurable conditions.

What is it and how is it classified? Pneumonia is an infection of one or both (double pneumonia) lungs. Dozens of pathogens from all four major groups of microbes (bacteria, viruses, fungi, and parasites) are known to cause pneumonia. It is therefore not surprising that a number of my earlier posts covered pneumonia caused by bacteria—including Mycobacterium tuberculosis, the planet’s most lethal infectious agent of humans—and viruses. (See, e.g., “Pneumonia: What Every Adult Needs to Know,” Germ Gems,  December 20, 2023; “Surge in Cases of Walking Pneumonia,” Germs Gems, November 6, 2024;“Legionnaire’s Disease: An Unusual Return to Philadelphia,” Germ Gems, October 4, 2023; “Leading Infectious Disease Killer in the World: TB Regains Its Title,” Germ Gems, April 10, 2024; see also, a myriad of posts on SARS-CoV-2 (COVID-19), influenza viruses (causes of often lethal seasonal flu and bird flu), and on respiratory syncytial virus).

Over 30 distinct pathogens are implicated in human pneumonia. (TM, Ramirez, JA., “Community-Acquired Pneumonia,”The New England Journal of Medicine, August, 2023). The most common bacterial pathogens include Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, and various Enterobacteriaceae. The disease can range in severity from mild to life-threatening or fatal.

While physicians are well aware of the pathogens that “commonly” cause pneumonia, for many cases (between 30% and 60% of cases of community-acquired pneumonia) the causative pathogen is never identified. This indicates a need for improved diagnostic techniques and suggests there are still unrecognized pathogens that cause pneumonia.

Clinicians use a number of schemes to classify pneumonia. As different types of pathogens are known to predominate in certain settings, the most common classification clinicians use is driven by where the pneumonia is acquired.  The three classifications clinicians use are: community-acquired pneumonia (CAP) where the pathogens Streptococcus pneumoniaeand respiratory viruses are known to predominate; hospital-acquired pneumonia (HAP) where gram-negative bacilli and Staphylococcus aureus are known to predominate; and nursing home-acquired pneumonia (NHAP) where Streptococcus pneumoniae and gram-negative bacilli predominate. Additionally, in each of these three settings the mortality rate of pneumonia is profoundly different. For example, CAP has the lowest mortality rate and NHAP the highest.

A number of factors determine the mortality, including not only the patient’s age but underlying medical conditions and how promptly treatment is instituted. The 30 day mortality for patients with CAP who are hospitalized is 2.8% for adults younger than 60 years-of-age, and 26.8% for adults older than 60. (Most CAP patients, however, are treated as outpatients.) For HAP, the mortality is estimated to be between 33% and 50%. And for NHAP, the mortality ranges from approximately 13% to 41%.

Treatment of pneumonia. Bacterial pneumonia should be treated promptly with an antibiotic. The choice of which antibiotic to use is a judgement call by your physician or healthcare provider. Often a broad spectrum agent is given initially. When results of laboratory tests are known, changing to a more narrow spectrum drug is appropriate to help prevent the emergence of multiply antibiotic-resistant bacteria.

While bacterial pneumonia usually receives the most attention, viral pneumonia caused by SARS-CoV-2, influenza virus and respiratory syncytial virus can also be life-threatening. In the case of SARS-CoV-2 and influenza virus, antiviral drugs should be given as soon as the diagnosis is considered. And for all three of these viral infections, vaccines are highly recommended to prevent pneumonia.

Can pneumonia still be an “old man’s friend”? When Sir William Osler and his colleagues practiced medicine, there was nothing they could really do to treat pneumonia. There were no antibiotics or antiviral drugs. They lacked access to supportive care for their pneumonia patients that is now routinely available such as intensive care units and respirators. Nonetheless, they “cared” for their elderly patients as nature took its course.

Early in my career as an infectious diseases specialist, I became interested in infections in elderly adults. In fact, I became an internationally recognized physician investigator in the field of geriatric infectious diseases due, in no small part, to the fact that I was one of the only academic physicians in the field. I was fortunate, however, to have an older mentor, Dr. Robert Breitenbucher, a bona fide geriatrician who knew how to care for older patients.

With his guidance, I learned that for some patients with NHAP, in particular, Sir William Osler was still right—pneumonia could be an old man’s “friend.” These patients didn’t need yet another antibiotic or another procedure. They needed comfort. It was time to let nature take its course.  As Osler said,“The practice of medicine is an art, not a trade; a calling, not a business: a calling in which your heart will be exercised equally with your head.”