Clinical and financial benefits of rapid detection of respiratory viruses:an outcomes study

To assess the expected benefits of rapid reporting of respiratory viruses, we compared patients whose samples were processed using standard techniques such as enzyme immunoassays, shell vial assays, and culture tube assays (y ear 1) to patients whose samples were processed with the same standard tech niques in addition to immunofluorescent testing (FA) directly on cytocentri fuged samples (year 2). The cytospin FA screened for influenza A and B viru ses, respiratory syncytial virus (RSV), parainfluenza viruses 1 to 3, and a denovirus (DAKO Diagnostics Ltd.). The specificity of the cytospin FA for a ll viruses was 100%. The sensitivities fur influenza A virus and RSV were 9 0 and 98%, respectively, but the sensitivities for influenza B virus and ad enovirus were unacceptable (14.3 and 0%, respectively). However, since the former viruses account for >85% of our isolates from clinical specimens, th e cytospin FA is an excellent screening test since the positive result was available within hours. The mean turnaround time for all positive viruses w as 4.5 days in year 1 and 0.9 day in year 2 (P = 0.001). This rapid reporti ng resulted in physicians having access to information sooner, enabling mor e appropriate treatment, The mean length of stay in the hospital for inpati ents with respiratory viral isolates was 10.6 days for year 1 versus 5.3 da ys for year 2. Mean variable costs for these patients was $7,893 in year 1 and $2,177 in year 2. After subtracting reagent costs and technological tim e, the savings in variable costs was $144,332/year. Summarizing, the cytosp in FA markedly decreased turnaround time and was associated with decreased mortality, length of stay, and costs and with better antibiotic stewardship .