Community-Acquired Pneumonia

This issue of Seminars in Respiratory and Critical Care Medicine is devoted to the topic of community-acquired pneumonia (CAP). International experts from Europe and the United States have contributed to this issue with the goal of comparing European and U.S. points of view. For example, it is evident that Europe and the United States have differing recommendations for antibiotic treatment given the differences in epidemiology and microbiological resistance patterns.

Drs. Welte and Köhnlein open this issue with an article that explains the structure, organization, and results of the German CAPNETZ Network.

The manuscript from Dr. Mark Woodhead reviews the incidence of CAP and the treatments recommended by European guidelines. These guidelines do not recommend quinolones as a first-line treatment for outpatients.

The third article, by Dr. Richard Wunderink, discusses adjunctive therapies. Despite potent antibiotics CAP remains the most common cause of death from infection. For this reason interest has been redirected toward nonantibiotic therapeutic measures such as corticosteroids, drotecogin-α, tifacogin, statins, and others.

Treatment failure is a matter of great concern in the management of CAP and accounts for 10 to 15% of hospitalized CAP patients. Drs. Garcia-Vidal and Carratalà describe the different patterns of failure, their causes, and how to detect them, including the usefulness of biological markers.

The drug options for antibiotic treatment of CAP are increasingly limited given increased resistance and the side effects of some promising antibiotics withdrawn from the market. Dr. Rodríguez de Castro and colleagues review these problems as well as the novel molecules or classes of antibiotics potentially useful for CAP.

In the last decade several international and national societies have released guidelines for the management of CAP, including recommendations for initial antibiotic treatment, microbiological testing, decision to hospitalize and admit to the intensive care unit, and management of nonresponding patients. Recent studies show that implementation of guidelines for the management of CAP is followed by improvement in outcome, including mortality. Dr. Martínez and colleagues provide evidence of the beneficial effects of guideline implementation.

Dr. Niederman presents the U.S. view of CAP. He reviews the most recent American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines. The U.S. perspective differs from the European in placing a greater emphasis on the role of atypicals, a more defined role for quinolones as a first therapy, less reliance on oral therapy for hospitalized patients, and less regard for the value of certain β-lactam agents. Finally, methicillin-resistant Staphylococcus aureus (MRSA) in the community is a key difference when comparing CAP in the United States with that in Europe.

Streptococcus pneumoniae is the leading cause of CAP, and invasive pneumococcal disease (IPD) is the main expression of disease severity. There are several risk factors associated with IPD. Vaccinating adults and high-risk patients with the pneumococcal polysaccharide vaccine reduces the incidence of IPD but has limited benefit in the population at large. Drs. Lynch and Zhanel review in depth the epidemiology of IPD and the utility of pneumococcal vaccination. In addition, the same authors review the current perspectives on S. pneumoniae resistant to penicillin and other antibiotics.

The 2005 ATS/IDSA guidelines for hospital-acquired pneumonia defined specific criteria for a new category, so-called healthcare-associated pneumonia (HCAP). Various studies have shown, that, in comparison with CAP, patients with HCAP are significantly older, have a higher number of comorbidities, and show worse functional status and mortality. The microbial etiology of HCAP remains controversial because the microbial etiologies differ in comparisons of U.S. studies and European studies, probably indicating differences in the types of populations. Drs. Polverino and Torres review the issue of HCAP, suggesting additional risk factors to those described by ATS/IDSA guidelines and recommending reclassification of this “new” type of pneumonia.

In summary this issue of Seminars deals with the most controversial aspects of CAP. It is my hope that the information provided will be useful to the reader and will shed some additional light on the management of this frequently encountered respiratory infection.