979. Procalcitonin as a diagnostic tool to distinguish bacterial pneumonia in patients with pulmonary infiltrates
Session: Poster Abstract Session: Clinical Studies of Bacterial Infection
Saturday, October 22, 2011
Room: Poster Hall B1
Background: Bacterial infections, when left untreated, may result in serious health complications, even death. However, physicians’ fears for these outcomes frequently lead to the treatment of viral illnesses and non infectious inflammatory processes with broad spectrum antibiotics. This strategy is ineffective and contributes to increased antibiotic resistance, treatment-related toxicity and significantly higher health costs.  For these reasons, finding a reliable and readily available marker of bacterial infection is of great importance.  Procalcitonin (PCT) has been said to be a helpful marker distinguishing viral from bacterial infections. We hypothesized that the use of PCT upon admission of patients with pulmonary infiltrates would help to differentiate bacterial pneumonia

Methods: This was a prospective cohort observational study of adult patients hospitalized with the presence of a new pulmonary infiltrate. Cases were identified for study <48 hr after hospital admission by daily reviewing the records of new admissions. Patients were excluded if they were treated for pneumonia in the last 30 days, transferred from another facility or had a length of stay >48 hr. Serum procalcitonin levels were measured using discarded blood samples obtained within 48 hr of admission. The final diagnosis of infection was determined a posteriori by adjudicating process method.

Results: Of 107 patients, 93 were included in the final analysis; reasons for exclusion were lack of pulmonary infiltrates on admission, length of stay >48 hr, underlying chronic infection and transfer from another facility. The disease prevalence was 36%, the AUC of PCT for detection of bacterial infection was 0.83 (CI 0.74- 0.90; p < 0.0001). Using 0.55 ug/L as a cut-off, PCT showed 78.8% sensitivity for predicting bacterial infection, 78.3% specificity, positive predictive value of 66.7 % and negative predictive value of 87.0%.

Conclusion: Serum procalcitonin >0.55 ug/ maybe a useful diagnostic test in evaluating patients admitted with new pulmonary infiltrates.

Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

Ingrid Roig, MD1,2, Adriana M. Rueda, MD3,4, Mahwish Mushtaq, M.D3,4, Charles Stager, PhD3,5, Charlie Lan, D.O3 and Daniel Musher, MD, FIDSA3,4, (1)Baylor College of Medicine, Pearland, TX, (2)Internal Medicine Department, Michael E. DeBakey VA Medical Center, Houston, TX, (3)Michael E. DeBakey VA Medical Center, Houston, TX, (4)Baylor College of Medicine, Houston, TX, (5)Baylor College of Medicine , Houston, TX


I. Roig, None

A. M. Rueda, None

M. Mushtaq, None

C. Stager, None

C. Lan, None

D. Musher, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.