Antigènuries pneumocoque ou Legionella et antibiothérapie à spectre restreint au cours des pneumonies aiguës communautaires

Evaluation of pneumococcal urinary antigen testing for respiratory tract infection investigations

OBJECTIVE

The pneumococcal urinary antigen test enables rapid bacteriological diagnosis in respiratory tract infections. The objective was to identify factors associated with a positive pneumococcal urinary antigen test result.

PATIENTS AND METHODS

This seven-year retrospective monocentric study was performed on consecutive patients presenting with respiratory tract infections reported as pneumococcal-positive. Epidemiological, biological, and radiological factors were analyzed, and severity scores were calculated.

RESULTS

A total of 223 patients were included. Significant associations were observed between positive test results and age over 65years (P=0.01), positive test results and immunosuppression factors (blood disease [25% Ag+ group vs. 4% Ag- group, P=0.001], immunosuppressive therapy [10% Ag+ group vs. 0% Ag- group, P=0.02]). Clinically, fever (64% Ag+ group vs. 42% Ag- group, P=0.01) and cough (46% Ag+ group vs. 19% Ag- group, P<0.01) were associated with a positive result, as were radiological alveolar opacities (67% Ag+ group vs. 44% Ag- group, P=0.01). High PSI score was associated with the Ag+ group (79% vs. 56% Ag- group, P=0.001).

CONCLUSION

Age, immunosuppressive factors, typical pneumococcal symptoms, and PSI scores were associated with a positive pneumococcal urinary antigen result.

Cost effectiveness of pneumococcal urinary antigen in Emergency Department: a pragmatic real-life study

Community-acquired pneumonia (CAP) is frequent and can be life-threatening. Streptococcus pneumoniae is the main bacteria involved, and is susceptible to penicillin A. Rapid microbiological diagnosis could then help reduce the antimicrobial spectrum. The pneumococcal urinary antigen (PUA) test is fast and easy to perform, but its impact on antimicrobial prescription and cost-effectiveness in emergency departments (ED) is not well known. We performed a pragmatic real life retrospective study in an adult ED to assess its usefulness: proportion of positive results, impact on antimicrobial prescriptions and cost-effectiveness. Over 3 years (from January 1st 2012 to December 31st 2014), 979 PUA tests were reutilized in our ED among 1224 patients who consulted for CAP; 51 (5.2%) were positive. Among them, 10 led to a modification of the antimicrobial treatment, but only 7 (14.3%) were in accordance with the results. The total cost of a PUA test is 27€. As only 7 PUA tests led to appropriate antimicrobial modification, we deemed that 972 had no impact, and the potential cost savings, if the test had not been used, would have been 26,244 € (972 × 27) during 3 years, that is 8748 € per year. Thus, it seems that the PUA test should not be generally used in the ED considering its low rate of positivity and the difficulties for physicians to adapt antibiotic treatment accordingly. This attitude change in utilization would lead to substantial cost savings.

Community-acquired pneumonia: impact of empirical antibiotic therapy without respiratory fluoroquinolones nor third-generation cephalosporins

Guidelines for inpatients with community-acquired pneumonia (CAP) propose to use respiratory fluoroquinolone (RFQ) and/or third-generation cephalosporins (Ceph-3). However, broad-spectrum antibiotic therapy is associated with the emergence of drug-resistant bacteria. We established a guideline in which RFQ and Ceph-3 were excluded as a first course. Our aim was to evaluate the impact of our therapeutic choices for CAP on the length of hospital stay (LOS) and patient outcome. This was a cohort study of patients with CAP from July 2005 to June 2014. We compared patients benefiting from our guideline established in 2008 to those receiving non-consensual antibiotics. Disease severity was evaluated through the Pneumonia Severity Index (PSI). The empirical treatment for PSI III to V was a combination therapy of amoxicillin-clavulanic acid (AMX-C) + roxithromycin (RX) or AMX + ofloxacin. Adherence to guidelines was defined by the prescription of one of these antibiotic agents. Requirement for intensive care or death defined unfavorable outcome. Among 1,370 patients, 847 were treated according to our guideline (61.8 %, group 1) and 523 without concordant therapy (38.2 %, group 2). The mean PSI was similar: 82 vs. 83, p > 0.5. The mean LOS was lower in group 1: 7.6 days vs. 9.1 days, p < 0.001. An unfavorable outcome was less frequent in group 1: 5.4 % vs. 9.9 %, p = 0.001. In logistic regression models, concordant therapy was associated with a favorable outcome: adjusted odds ratio (AOR) [95 % confidence interval (CI)] 1.85 [1.20-2.88], p = 0.005. CAP therapy without RFQ and Ceph-3 use was associated with a shorter LOS and fewer unfavorable outcomes.