Bacteremic and Nonbacteremic Pneumococcal Pneumonia A Prospective Study

Abstract

We prospectively identified cases of pneumococcal pneumonia and used stringent criteria to stratify them into bacteremic and nonbacteremic cases. Although patients were distributed among racial groups in proportion to all patients seen at this medical center, the proportion of African-Americans with bacteremic disease was significantly increased. All patients had at least 1 underlying condition predisposing to pneumococcal infection, and most had several. Although the mean number of predisposing factors was greater among bacteremic patients than nonbacteremic patients, only alcohol ingestion was significantly more common. Nearly one-third of patients had substantial anemia (hemoglobin < or = 10 g/dL) on admission, which may have predisposed to infection. In the case of other laboratory abnormalities, such as albumin, creatinine, and bilirubin, it was difficult to determine which abnormality might have predisposed to pneumococcal infection and which might have resulted from it. The radiologic appearance was varied. Airspace consolidation and air bronchogram on chest X-ray were highly associated with bacteremic disease, as was the presence of pleural effusion. Although the Pneumonia Patient Outcomes Research Team (PORT) risk score was a predictor of mortality, it did not help to predict the presence of bacteremia in an individual case. Most patients who died in the first week in hospital were bacteremic, and a high PORT risk score with bacteremia reliably predicted a high likelihood of a fatal outcome. Eleven patients had extrapulmonary disease with meningitis, empyema, and septic arthritis predominating; all of these patients were bacteremic. The antibiotic susceptibility of our strains correlated well with those that have been reported in the United States during the years of this study. The use of numerous antibiotics of different classes in many patients, especially those who were the most ill, precluded analysis of outcome based on antibiotic therapy. Only 17 patients had been vaccinated. Since nearly all patients had conditions for which pneumococcal vaccine is recommended and more than one-third had been hospitalized in the preceding 6 months, the low rate of vaccination can be regarded as a missed opportunity to administer a potentially beneficial vaccine.

Invasive pneumococcal disease in adult hematopoietic stem cell transplant recipients: a decade of prospective population-based surveillance

“…This is also similar to the published literature where mortality for bacteremic pneumococcal pneumonia is 14-17%. 8,12,13 Antimicrobial resistance rates were significantly higher especially to TMP/SMX and this is likely due to the use of TMP/SMX prophylaxis. The routine strategy at our centers is to discontinue TMP/SMX prophylaxis at 1-year post transplant in the absence of GVHD.…”

“…7 Nonbacteremic pneumococcal pneumonia was defined as: (1) a clinical presentation including symptoms (cough, sputum and fever) and physical findings consistent with pneumonia; (2) an infiltrate on chest radiograph; (3) microscopic examination of a Gram-stained sputum showing X20 WBC per highpower field and a predominance of Gram-positive cocci in pairs or chains and a sputum culture that grows only S. pneumoniae and (4) no positive blood cultures for S. pneumoniae. 8 All patients with a pneumococcal infection were followed for 30 days from the onset of illness and the following variables were assessed: clinical symptoms, length of hospitalization, 7 day and 30 day mortality. Early or late IPD was defined as that occurring at o100 days or X100 days post transplant, respectively.…”

Absence of leukocytosis in bacteraemic pneumococcal pneumonia

“…Such a low count has been found to be strongly associated with a poor prognosis. [8][9][10] It is not known what proportion of patients with bacteraemic pneumococcal pneumonia present with a normal WBC count and thus might have a deferred or incorrect diagnosis and treatment.…”

Toll-Like Receptor 2 Plays a Role in the Early Inflammatory Response to Murine Pneumococcal Pneumonia but Does Not Contribute to Antibacterial Defense

“…S treptococcus pneumoniae is the leading causative pathogen in community-acquired pneumonia and a major cause of morbidity and mortality in humans (1)(2)(3). Pneumococci account for up to 36% of adult community-acquired pneumonia in the United States.…”

“…The first line of defense against invading bacteria is provided by the innate immune system, which recognizes pathogen-associated molecular patterns (PAMPs), 3 conserved microbial patterns shared by large groups of pathogens, but not found in higher eukaryotes (7)(8)(9). Over the last few years, it has become evident that both the recognition and the subsequent response to pathogens is mainly transferred by members of the Toll-like receptor (TLR) family (for review, see Refs.…”