Serum Procalcitonin Measurement and Viral Testing to Guide Antibiotic Use for Respiratory Infections in Hospitalized Adults: A Randomized Controlled Trial.

BACKGROUND: Viral lower respiratory tract illness (LRTI) frequently causes adult hospitalization and is linked to antibiotic overuse. European studies suggest that the serum procalcitonin (PCT) level may be used to guide antibiotic therapy. We conducted a trial assessing the feasibility of using PCT algorithms with viral testing to guide antibiotic use in a US hospital. METHODS: Three hundred patients hospitalized with nonpneumonic LRTI during October 2013-April 2014 were randomly assigned at a ratio of 1:1 to receive standard care or PCT-guided care and viral PCR testing. The primary outcome was antibiotic exposure, and safety was assessed at 1 and 3 months. RESULTS: Among the 151 patients in the intervention group, viruses were identified in 42% (63), and 83% (126) had PCT values of <0.25 µg/mL. There were no significant differences in antibiotic use or adverse events between intervention patients and those in the nonintervention group. Subgroup analyses revealed fewer subjects with positive results of viral testing and low PCT values who were discharged receiving antibiotics (20% vs 45%; P = .002) and shorter antibiotic durations among algorithm-adherent intervention patients versus nonintervention patients (2.0 vs 4.0 days; P = .004). Compared with historical controls (from 2008-2011), antibiotic duration in nonintervention patients decreased by 2 days (6.0 vs 4.0 days; P < .001), suggesting a study effect. CONCLUSIONS: Although antibiotic use was similar in the 2 arms, subgroup analyses of intervention patients suggest that physicians responded to viral and biomarker data. These data can inform the design of future US studies. CLINICAL TRIALS REGISTRATION: NCT01907659.

Lack of sensitivity of rapid antigen tests for the diagnosis of respiratory syncytial virus infection in adults.

The diagnosis of respiratory syncytial virus (RSV) infection in older individuals and adults with cardiopulmonary diseases using available rapid antigen detection tests may be difficult due to the low virus shedding in this population. These tests have been extensively evaluated in hospitalized infants, but there is only limited data on their usefulness in adult populations. We evaluated the performance of three different rapid antigen detection tests: Becton Dickinson Directigen RSV (BD), Bartels RSV Direct Fluorescent Antibody Test (DFA) and the VIDAS RSV assay (VIDAS) in nasopharyngeal specimens from 60 older persons with RSV infection documented by cell culture, serology or reverse transcription polymerase chain reaction (RT-PCR). The three rapid antigen assays tested on all 60 samples performed poorly. DFA detected 14 (23%), VIDAS detected 12 (20%) and BD detected only 6 (10%) of the RSV infected persons. Rapid antigen detection tests for the diagnosis of RSV respiratory illness in adults are of limited value.