Role of Respiratory Virus Panels in Antimicrobial Stewardship in Immunocompromised Patients

Background: Respiratory virus (RV) panels have emerged as a novel method for detecting influenza and pathogens known to cause influenza-like-illness which may have clinical relevance in immunocompromised patients. The purpose of this study was to describe turnaround time (TAT) and antimicrobial stewardship interventions associated with in-house RV testing compared to send-out testing in an immunocompromised population.

Methods: This was an IRB-approved, pretest-posttest quasiexperiment at an 802-bed hospital in Detroit MI. Inpatients ≥18 years of age with solid organ and bone marrow transplant, or those with immunocompromising conditions in the intensive care unit (ICU) were included. Collection periods were RV season 1 (RVS1), Oct. 2014—Mar. 2015 (send-out testing), and RV season 2 (RVS2), Oct. 2015—Apr. 2016 (in-house testing). TAT was measured from specimen collection to result; time to intervention (TTI) was measured from specimen collection to change in drug therapy. RVS1 and RVS2 were compared using bivariate tests.

Results: 131 patients were included, 56 RVS1, 75 RVS2. 61.1% of patients were clinically diagnosed with pneumonia, 27.5% of which was microbiologically confirmed. The in-house panel reduced TAT and TTI, and had more positive testing (Table 1). Most common pathogens were influenza (8 in RVS1, 5 in RVS2), coronavirus (0 and 11), and rhinovirus (1 and 7). Differences were not observed between groups for frequency or type of intervention or outcome.

Conclusion: Diagnostic yield and TTI were improved by in-house RV testing, but this did not impact length of stay (LOS), duration of therapy (DOT), or frequency of drug-related interventions. The majority of interventions were discontinuation of oseltamivir, with minimal impact on antibacterial use.

Outcome	RVS1 (n=56)	RVS2 (n=75)	P
Positive test, n (%)	11 (19.6)	32 (42.7)	< 0.01
TAT, median hrs (IQR)	47 (11—61)	6 (3.5—11)	< 0.001
TTI, median hrs (IQR)	52 (38—69)	14( 9—30)	< 0.001
DOT, median days (IQR)	4 (2—7)	4 (2—7)	0.958
LOS, median days (IQR)	8 (4—14)	6 (3—13.5)	0.491
Intervention, n (%)	20 (35.7)	23 (30.6)	0.543
Start antiviral	3 (5.4)	7 (9.3)	0.515
Discontinue oseltamivir	14 (25.0)	13 (17.3)	0.283
Discontinue antibiotic	2 (3.6)	4 (5.3)	0.633
Adjust immunosuppression	1 (1.8)	2 (2.7)	0.739