Rapid diagnosis of pneumococcal pneumonia among HIV-infected adults with urine antigen detection.

Abstract

OBJECTIVES:

Streptococcus pneumoniae is the leading cause of bacterial pneumonia and associated bacteremia during HIV infection. Rapid diagnostic assays may limit inappropriate therapy.

METHODS:

Clinical signs and symptoms and sera and urine were collected prospectively from 70 adults with pneumococcal pneumonia, including 47 with HIV co-infection. Pneumococcal C-polysaccharide antigen was detected in urine using the Binax immunochromatographic test (ICT). A systematic review of 24 published studies was conducted.

RESULTS:

Clinical symptoms, signs, and laboratory parameters except leukocytosis, were similar in HIV-infected and HIV-seronegative pneumonia. The performance of the urine antigen ICT was independent of HIV-status (sensitivity 81%, specificity 98%, positive (PPV) and negative predictive values (NPV) 98%, and 82%, respectively). The sensitivity of sputum Gram's stain was 58% (34/59) with sputum unable to be provided by 16%. The CRP response was identical in HIV-infected (mean+/-SD) 133+/-88 vs. seronegative 135+/-104 mg/L (p=0.9). In the systematic review, the ICT performance revealed 74% sensitivity (95% CI 72-77%) and 94% specificity (95% CI 93-95%). Urine antigen testing increases etiologic diagnosis by 23% (range: 10-59%) when testing adults with community acquired pneumonia of unknown etiology.

CONCLUSIONS:

Urinary antigen detection provides a credible rapid diagnostic test for pneumococcal pneumonia regardless of HIV-status. CRP response to acute infection is similar in HIV co-infection and increases diagnostic certainty.

• Authors: David R Boulware, Charles L Daley, Cynthia Merrifield, Philip C Hopewell, Edward N Janoff
• Journal: The Journal of infection (J Infect) Vol. 55 Issue 4 Pg. 300-9 (Oct 2007) ISSN: 1532-2742 [Electronic] England
• PMID: 17692384 (Publication Type: Clinical Trial, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Review, Systematic Review)

Chemical References

• Antigens, Bacterial
• Polysaccharides, Bacterial
• polysaccharide C-substance (Streptococcus)
• C-Reactive Protein

Topics

• Adult
• Antigens, Bacterial (urine)
• C-Reactive Protein (analysis)
• Female
• HIV Infections (complications)
• Humans
• Male
• Middle Aged
• Pneumonia, Pneumococcal (diagnosis, etiology, urine)
• Polysaccharides, Bacterial (urine)
• Predictive Value of Tests
• Prospective Studies
• Urinalysis