Community-acquired pneumonia: Impact of immune status

Linda M. Mundy, Paul G. Auwaerter, David Oldach, Mary Laird Warner, Albert Burton, Estil Vance, Charlotte A. Gaydos, J. Mehsen Joseph, Ramana Gopalan, Richard D. Moore, Thomas C. Quinn, Patricia Charache, John G. Bartlett

Research output: Contribution to journalArticlepeer-review


This cross-sectional and prospective one year study evaluated adults admitted to an inner city hospital with community-acquired pneumonia. The study used extensive diagnostic methods to evaluate the etiologies of community-acquired pneumonia in hospitalized patients with differing immunologic status. Of 385 study patients, concurrent problems associated with immunosuppression were noted in 221 (57%) patients, 180 of whom were human immunodeficiency virus (HIV)-infected. The five most common causes of community-acquired pneumonia were: Streptococcus pneumoniae, Pneumocystis carinii, aspiration, Hemophilus influenzae, and gram-negative bacilli. Only 8.3% of patients had either Legionella, Chlamydia pneumoniae or Mycoplasma pneumoniae. Despite use of state-of-the-art diagnostic techniques, no diagnosis was made in 46 of 180 (25.6%) HIV-infected patients, 56 of 164 (34.1%) immunocompetent patients, and 20 of 41 (48.8%) non-HIV-infected immunosuppressed patients. The diagnostic yield of pre-antibiotic sputum culture for conventional bacteria was 99/155 (63.9%) compared to 52 of 169 patients (32.7%) with adequate post-antibiotic sputum culture (p < 0.0001). Although S. pneumonia continues to be the most commonly identified etiologic agent of commmunity-acquired pneumonia, it is surpassed by P. carinii in the HIV-infected patient population. The apparent decline in the frequency of S. pneumoniae in our series presumably reflects administration of antibiotics prior to procurement of sputum culture. The paucity of atypical agents in this study support the current American Thoracic Society guidelines for selective use of macrolide therapy in immunocompetent adults hospitalized with community-acquired pneumonia. The causes of community-acquired pneumonia in hospitalized adults in the 1990s reflects a changing patient population, in whom a majority may be immunosuppressed by HIV infection, transplantation, malignancy, or immunosuppressive drug regimens.

Original languageEnglish (US)
Pages (from-to)1309-1315
Number of pages7
JournalAmerican journal of respiratory and critical care medicine
Issue number4 I
StatePublished - Oct 1995
Externally publishedYes

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Critical Care and Intensive Care Medicine


Dive into the research topics of 'Community-acquired pneumonia: Impact of immune status'. Together they form a unique fingerprint.

Cite this