Clinical Diagnosis, Viral PCR, and Antibiotic Utilization in Community-Acquired Pneumonia

Novel and Rapid Diagnostics for Common Infections in the Critically Ill Patient

There are several novel platforms that enhance detection of pathogens that cause common infections in the intensive care unit. These platforms have a sample to answer time of a few hours, are often higher yield than culture, and have the potential to improve antibiotic stewardship.

Novel and Rapid Diagnostics for Common Infections in the Critically Ill Patient

There are several novel platforms that enhance detection of pathogens that cause common infections in the intensive care unit. These platforms have a sample to answer time of a few hours, are often higher yield than culture, and have the potential to improve antibiotic stewardship.

Nucleic Acid-based Testing for Noninfluenza Viral Pathogens in Adults with Suspected Community-acquired Pneumonia. An Official American Thoracic Society Clinical Practice Guideline

Background: This document provides evidence-based clinical practice guidelines on the diagnostic utility of nucleic acid–based testing of respiratory samples for viral pathogens other than influenza in adults with suspected community-acquired pneumonia (CAP).

Methods: A multidisciplinary panel developed a Population–Intervention–Comparison–Outcome question, conducted a pragmatic systematic review, and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations.

Results: The panel evaluated the literature to develop recommendations regarding whether routine diagnostics should include nucleic acid–based testing of respiratory samples for viral pathogens other than influenza in suspected CAP. The evidence addressing this topic was generally adjudicated to be of very low quality because of risk of bias and imprecision. Furthermore, there was little direct evidence supporting a role for routine nucleic acid–based testing of respiratory samples in improving critical outcomes such as overall survival or antibiotic use patterns. However, on the basis of direct and indirect evidence, recommendations were made for both outpatient and hospitalized patients with suspected CAP. Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was not addressed in the literature at the time of the evidence review.

Conclusions: The panel formulated and provided their rationale for recommendations on nucleic acid–based diagnostics for viral pathogens other than influenza for patients with suspected CAP.

Disease severity and clinical outcomes of community-acquired pneumonia caused by non-influenza respiratory viruses in adults: a multicentre prospective registry study from the CAP-China Network

Although broad knowledge of influenza viral pneumonia has been established, the significance of non-influenza respiratory viruses in community-acquired pneumonia (CAP) and their impact on clinical outcomes remains unclear, especially in the non-immunocompromised adult population.Hospitalised immunocompetent patients with CAP were prospectively recruited from 34 hospitals in mainland China. Respiratory viruses were detected by molecular methods. Comparisons were conducted between influenza and non-influenza viral infection groups.In total, 915 out of 2336 adult patients with viral infection were enrolled in the analysis, with influenza virus (28.4%) the most frequently detected virus, followed by respiratory syncytial virus (3.6%), adenovirus (3.3%), human coronavirus (3.0%), parainfluenza virus (2.2%), human rhinovirus (1.8%) and human metapneumovirus (1.5%). Non-influenza viral infections accounted for 27.4% of viral pneumonia. Consolidation was more frequently observed in patients with adenovirus infection. The occurrence of complications such as sepsis (40.1% versus 39.6%; p=0.890) and hypoxaemia (40.1% versus 37.2%; p=0.449) during hospitalisation in the influenza viral infection group did not differ from that of the non-influenza viral infection group. Compared with influenza virus infection, the multivariable adjusted odds ratios of CURB-65 (confusion, urea >7 mmol·L^-1, respiratory rate ≥30 breaths·min^-1, blood pressure <90 mmHg (systolic) or ≤60 mmHg (diastolic), age ≥65 years) ≥3, arterial oxygen tension/inspiratory oxygen fraction <200 mmHg, and occurrence of sepsis and hypoxaemia for non-influenza respiratory virus infection were 0.87 (95% CI 0.26-2.84), 0.72 (95% CI 0.26-1.98), 1.00 (95% CI 0.63-1.58) and 1.05 (95% CI 0.66-1.65), respectively. The hazard ratio of 90-day mortality was 0.51 (95% CI 0.13-1.91).The high incidence of complications in non-influenza viral pneumonia and similar impact of non-influenza respiratory viruses relative to influenza virus on disease severity and outcomes suggest more attention should be given to CAP caused by non-influenza respiratory viruses.

The rapid diagnosis of viral respiratory tract infections and its impact on antimicrobial stewardship programs

We aimed to describe the potential benefit of new rapid molecular respiratory tests (MRT) in decreasing inappropriate antibiotic use among the inpatients presenting with influenza-like illness (ILI). We included patients from inpatient and outpatient departments who had ILI and performed MRT between 1 January 2015 and 31 December 2016 in a 265-bed private hospital in Istanbul. At the end of 2015, we implemented antimicrobial stewardship including systematic use of MRT. Then, we compared our observations between the year 2015 and the year 2016. We designed the study according to the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) tool. A U.S. Food and Drug Administration (FDA)-cleared multiplexed polymerase chain reaction (PCR) system (BioFire FilmArray, Idaho Technology, Salt Lake City, UT) which detects 17 viruses and three bacteria was used for diagnosis. In total, 1317 patients were included; 630 (48%) were inpatients and 569 (43%) were older than 16 years of age. At least one virus was detected in 747 (57%) patients. Rhinovirus/enterovirus, influenza virus, and adenovirus were the most commonly detected. Among hospitalized patients, in children, a significant decrease in antibiotic use (44.5% in 2015 and 28.8% in 2016, p = 0.009) was observed, but in adults, the decrease was not statistically significant (72% in 2015 and 63% in 2016, p = 0.36). The duration of antibiotic use after the detection of virus was significantly decreased in both children and adults (p < 0.001 and p = 0.007, respectively). By using MRT, inappropriate antibiotic use and, also, duration of inappropriate antibiotic use after the detection of virus was significantly decreased. It is time to increase the awareness about the viral etiology in respiratory tract infections (RTIs) and implement MRT in clinical practice.

Multiplex Respiratory Virus Testing for Antimicrobial Stewardship: A Prospective Assessment of Antimicrobial Use and Clinical Outcomes Among Hospitalized Adults

Background

Respiratory tract infections are frequent causes of hospitalization and initiation of empirical antimicrobial therapy. Testing for a broad panel of respiratory viruses has been advocated as a useful tool for antibiotic stewardship. We conducted a prospective observational study to assess the impact of rapid viral test results on antimicrobial prescriptions and clinical outcomes among hospitalized adults.

Methods

Eight hundred patients admitted with respiratory symptoms were tested by a 12-virus respiratory panel (RVP) during 3 consecutive winters in Montreal, Canada. The primary outcome measure was change in antimicrobial prescriptions (ie, de-escalation of empirical antimicrobial therapy or commencement of new antimicrobial therapy) after RVP results were available. Clinical outcomes were also assessed.

Results

Influenza virus was identified in 53% of individuals in the study population, and other viruses were identified in 10%. Influenza virus positivity was associated with shorter duration of hospitalization and appropriate antiviral management. Antibiotic management was most significantly correlated with radiographic suspicion of pneumonia and less so with results of the RVP. Positivity for viruses other than influenza virus was not correlated with significantly different outcomes.

Conclusions

Physicians respond to results of testing for influenza virus when managing hospitalized adult patients but respond less to test results for other viruses. These data can inform the design of stewardship interventions and the selection of viral testing panels for hospitalized patients.

Antibiotic Discontinuation Rates Associated with Positive Respiratory Viral Panel and Low Procalcitonin Results in Proven or Suspected Respiratory Infections

INTRODUCTION

The differentiation of viral from bacterial pneumonia is important in determining whether antibiotics are appropriate for treatment of these infections. Advances in diagnostic technologies such as respiratory panels (RP) utilizing polymerase chain reactions to detect viruses and determination of procalcitonin (PCT) concentrations may aid in this differentiation. However, some studies have shown limited impact for this purpose and thus continuation of antibiotics despite results suggesting viral infection. Our objective was to characterize clinician-prescribing behavior at our institution once RP and/or PCT results were known and suggestive of a viral respiratory infection.

METHODS

This retrospective analysis was based upon records of hospitalized patients in whom proven or possible respiratory infections as indicated by RP testing, respiratory bacterial culture or International Statistical Classification of Diseases and Related Health Problems 9th revision codes for acute infectious respiratory illness was documented. Patients evaluated were required to have a RP or PCT within the first 72 h of presentation. Drug orders were evaluated for discontinuation of antibiotic therapy within 48 h of a procalcitonin of <0.25 μg/mL, a positive viral RP result, or both.

RESULTS

Of 4869 patients with PCT and/or RP results, 2031 were included. PCT and RP testing were obtained in 503 and 1823 patients, respectively, with 295 patients having both. Results of these tests suggested 789 patients were potential candidates for antibiotic avoidance. These included 219 with a PCT <0.25 μg/mL, 601 with a positive viral RP result, and 31 with both. Antibiotics were administered to 307 patients (39%) within the first 72 h. In these, antibiotics were discontinued within 48 h of laboratory results availability.

CONCLUSION

These results suggest that positive viral RP and low PCT results are infrequently associated with discontinuation of antibiotic therapy in proven or possible respiratory infections at our institution. Direct interventions with clinicians are likely needed to correct this behavior and decrease unnecessary antibiotic use.