A National Study of the Impact of Rapid Influenza Testing on Clinical Care in the Emergency Department

Principal Component Patterns of Pediatric Respiratory Viral Testing Across Health Care Settings

BACKGROUND AND OBJECTIVES

Factors prompting clinicians to request viral testing in children are unclear. We assessed patterns prompting clinicians to perform viral testing in children discharged from an emergency department (ED) or hospitalized with an acute respiratory infection (ARI).

METHODS

Using active ARI surveillance data collected from November 2017 through February 2020, children aged between 30 days and 17 years with fever or respiratory symptoms who had a research respiratory specimen tested were included. Children's presentation patterns from their initial evaluation at each health care setting were analyzed using principal components (PCs) analysis. PC-specific models using logistic regression with robust sandwich estimators were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) between PCs and provider-ordered viral testing. PCs were assigned respiratory virus/viruses names a priori based on the patterns represented.

RESULTS

In total, 4107 children were enrolled and tested, with 2616 (64%) discharged from the ED and 1491 (36%) hospitalized. In the ED, children with a coviral presentation pattern had a 1.44-fold (95% CI, 1.24-1.68) increased odds of receiving a provider-ordered viral test than children showing clinical symptoms less representative of coviral-like infection. Whereas children in the ED and hospitalized with rhinovirus-like symptoms had 71% (OR, 0.29; 95% CI, 0.24-0.34) and 39% (OR, 0.61; 95% CI, 0.49-0.76) decreased odds, respectively, of receiving a provider-ordered viral test during their medical encounter.

CONCLUSIONS

Viral tests are frequently ordered by clinicians, but presentation patterns vary by setting and influence the initiation of testing. Additional assessments of factors affecting provider decisions to use viral testing in pediatric ARI management are needed to maximize patient benefits of testing.

Practice patterns and perceptions of influenza testing amongst pediatric urgent care providers

INTRODUCTION

Despite a sensitivity of 50% to 70% the rapid influenza diagnostic test (RIDT) continues to play an important role in clinical decision-making due to its quick turn-around time, high specificity, relative simplicity of use, and low cost.

METHODS

A quantitative study using a web-based survey was distributed to 110 members of the Society of Pediatric Urgent Care aimed to assess RIDT use for diagnosis and management of influenza in outpatient pediatric patients.

RESULTS

Responses from 61 providers were received. Forty-two percent (95% CI 29.5-54.5%) of respondents report higher confidence in their diagnosis of influenza with the aid of a positive RIDT. 28% of respondents (95% CI 16.6-39.4%) report a higher likelihood of prescribing antiviral medications to low-risk patients if an RIDT is positive than without laboratory confirmation.

CONCLUSION

Most pediatric urgent care respondents reported higher confidence in their diagnosis and higher likelihood of prescribing antivirals with a positive RIDT rather than by clinical symptoms alone.

Provider views on rapid diagnostic tests and antibiotic prescribing for respiratory tract infections: A mixed methods study

BACKGROUND

Respiratory tract infections (RTIs) are often inappropriately treated with antibiotics. Rapid diagnostic tests (RDTs) have been developed with the aim of improving antibiotic prescribing but uptake remains low. The aim of this study was to examine provider knowledge, attitudes and behaviors regarding RDT use and their relationship to antibiotic prescribing decisions across multiple clinical departments in an urban safety-net hospital.

METHODS

We conducted a mixed methods sequential explanatory study. Providers with prescribing authority (attending physicians, nurse practitioners and physician assistants) who had at least 20 RTI encounters from January 1, 2016 to December 31, 2018. Eighty-five providers completed surveys and 16 participated in interviews. We conducted electronic surveys via RedCap from April to July 2019, followed by semi-structured individual interviews from October to December 2019, to ascertain knowledge, attitudes and behaviors related to RDT use and antibiotic prescribing.

RESULTS

Survey findings indicated that providers felt knowledgeable about antibiotic prescribing guidelines. They reported high familiarity with the rapid streptococcus and rapid influenza tests. Familiarity with comprehensive respiratory panel PCR (RPP-respiratory panel PCR) and procalcitonin differed by clinical department. Qualitative interviews identified four main themes: providers trust their clinical judgment more than rapid test results; patient-provider relationships play an important role in prescribing decisions; there is patient demand for antibiotics and providers employ different strategies to address the demand and providers do not believe RDTs are implemented with sufficient education or evidence for clinical practice.

CONCLUSION

Prescribers are knowledgeable about prescribing guidelines but often rely on clinical judgement to make final decisions. The utility of RDTs is specific to the type of RDT and the clinical department. Given the low familiarity and clinical utility of RPP and procalcitonin, providers may require additional education and these tests may need to be implemented differently based on clinical department.

The limited value of triage vital signs in predicting influenza infection in children aged 5 years and under in the emergency department: A single-center retrospective cross-sectional study

Diagnosing influenza in children aged 5 years and under can be challenging because of their difficulty in verbalizing symptoms. This study aimed to explore the value of the triage heart rate (HR), respiratory rate (RR), and temperature, either alone or when combined with individual symptoms and signs, in predicting influenza infection in this age group.This was a retrospective study covering 4 influenza seasons from 2017 to 2019 in an emergency department (ED) in Hong Kong. We recruited patients ≤5 years of age who had an reverse transcription polymerase chain reaction influenza test within 48 hours of ED presentation. The diagnostic performance of the triage HR, RR, and temperature was evaluated as dichotomized or categorized values with diagnostic odds ratios (DORs) calculated based on different age-appropriate thresholds. Linear discriminant analysis was performed to assess the combined discriminatory effect of age, HR, RR, and temperature as continuous variables.Of 322 patients (median age 26 months), 99 had influenza A and 13 had influenza B infection. For HR and RR dichotomized based on age-appropriate thresholds, the DORs ranged from 1.16 to 1.54 and 0.78 to 1.53, respectively. A triage temperature ≥39.0 °C had the highest DOR (3.32) among different degrees of elevation of temperature. The diagnostic criteria that were based on the presence of fever and cough and/or rhinitis symptoms had a higher DOR compared with the Centers for Disease Control and Prevention influenza-like illness criteria (4.42 vs 2.41). However, combining HR, RR, or temperature with such diagnostic criteria added very little to the diagnostic performance. The linear discriminant analysis model had a high specificity of 92.5%, but the sensitivity (18.3%) was too low for clinical use.Triage HR, RR, and temperature had limited value in the diagnosis of influenza in children ≤5 years of age in the ED. Fever and cough and/or rhinitis symptoms had a better diagnostic performance than the Centers for Disease Control and Prevention influenza-like illness criteria in predicting influenza in this age group.

Association of physician experience with a higher prescription rate of anti-influenza agents in low-risk patients

During the influenza season, most patients suspected of having influenza undergo rapid influenza diagnostic tests (RIDTs) in Japan despite their low sensitivity. However, the physician's actual rationale for prescribing antivirals, besides the results of RIDTs, remains poorly understood. Our study sought to identify the role of clinical information and physicians' experience in the initiation of anti-influenza agents. We retrospectively reviewed 380 patients who underwent RIDTs at the emergency department of our hospital from September 2018 to May 2019. Data regarding sex, age, etc., which could affect the decision of prescribing antivirals, were extracted from medical records. We performed logistic regression analysis to analyze the concurrent effect of potentially relevant clinical factors, results of RIDTs, and the physician's status on antiviral prescription. Multivariable analysis revealed that a positive RIDT had the largest effect on antiviral prescription, followed by physician status, high regional influenza activity, and patients' presentation within 12 h of symptom onset. Patient's age, comorbidities, and presentation after 48 h of symptom onset were not associated with antiviral treatment. Physicians with more years of experience were significantly more likely to prescribe antivirals for patients with low risk of complications. Our findings revealed the physicians' rationale for initiating antiviral treatment and the discrepancy with guideline indications of antivirals, which is the patient's age and comorbidities. Physicians, especially those with more than 3 years of experience, frequently prescribed antivirals for patients with low risk of complications; thus, educational interventions against this population could be useful to improve this situation.

Reducing Antibiotic Use in Ambulatory Care Through Influenza Vaccination

BACKGROUND

Improving appropriate antibiotic use is crucial for combating antibiotic resistance and unnecessary adverse drug reactions. Acute respiratory illness (ARI) commonly causes outpatient visits and accounts for ~41% of antibiotics used in the United States. We examined the influence of influenza vaccination on reducing antibiotic prescriptions among outpatients with ARI.

METHODS

We enrolled outpatients aged ≥6 months with ARI from 50-60 US clinics during 5 winters (2013-2018) and tested for influenza with RT-PCR; results were unavailable for clinical decision making and clinical influenza testing was infrequent. We collected antibiotic prescriptions and diagnosis codes for ARI syndromes. We calculated vaccine effectiveness (VE) by comparing vaccination odds among influenza-positive cases with test-negative controls. We estimated ARI visits and antibiotic prescriptions averted by influenza vaccination using estimates of VE, coverage, and prevalence of antibiotic prescriptions and influenza.

RESULTS

Among 37 487 ARI outpatients, 9659 (26%) were influenza positive. Overall, 36% of ARI and 26% of influenza-positive patients were prescribed antibiotics. The top 3 prevalent ARI syndromes included: viral upper respiratory tract infection (47%), pharyngitis (18%), and allergy or asthma (11%). Among patients testing positive for influenza, 77% did not receive an ICD-CM diagnostic code for influenza. Overall, VE against influenza-associated ARI was 35% (95% CI, 32-39%). Vaccination prevented 5.6% of all ARI syndromes, ranging from 2.8% (sinusitis) to 11% (clinical influenza). Influenza vaccination averted 1 in 25 (3.8%; 95% CI, 3.6-4.1%) antibiotic prescriptions among ARI outpatients during influenza seasons.

CONCLUSIONS

Vaccination and accurate influenza diagnosis may curb unnecessary antibiotic use and reduce the global threat of antibiotic resistance.

Association Between the Use of Antibiotics, Antivirals, and Hospitalizations Among Patients With Laboratory-confirmed Influenza

BACKGROUND

Clinicians may prescribe antibiotics to influenza patients at high risk for bacterial complications. We explored the association between antibiotics, antivirals, and hospitalization among people with influenza.

METHODS

A retrospective cohort study of patients with confirmed influenza with encounters during January 2011-January 2019 was conducted using data from the Veterans Affairs Informatics and Computing Infrastructure (VINCI). We compared inpatient hospitalizations (all-cause and respiratory) within 30 days of influenza diagnosis between 4 patient cohorts: (1) no treatment (n = 4228); (2) antibiotic only (n = 671); (3) antiviral only (n = 6492); and (4) antibiotic plus antiviral (n = 1415). We estimated relative risk for hospitalization using Poisson generalized linear model and robust standard errors.

RESULTS

Among 12 806 influenza cases, most were white men (mean age, 57-60 years). Those with antivirals only, antibiotic plus antiviral, and antibiotics only all had a statistically significant lower risk of all-cause and respiratory hospitalization compared to those without treatment. Comparing the antibiotic plus antiviral cohort to those who were prescribed an antiviral alone, there was a 47% lower risk for respiratory hospitalization (relative risk, 0.53 [95% confidence interval, .31-.94]), and no other statistical differences were detected.

CONCLUSIONS

Those prescribed an antiviral, antibiotic, or both had a lower risk of hospitalization within 30 days compared to those without therapy. Furthermore, intervention with both an antibiotic and antiviral had a lower risk of respiratory hospitalization within 30 days compared to those with an antiviral alone. Importantly, the absolute magnitude of decreased risk with antibiotic plus antiviral therapy is small and must be interpreted within the context of the overall risk of antibiotic usage.

Differences in antibiotic and antiviral use in people with confirmed influenza: a retrospective comparison of rapid influenza PCR and multiplex respiratory virus PCR tests

BACKGROUND

Influenza is a highly contagious respiratory virus with clinical impacts on patient morbidity, mortality and hospital bed management. The effect of rapid nucleic acid testing (RPCR) in comparison to standard multiplex PCR (MPCR) diagnosis in treatment decisions is unclear. This study aimed to determine whether RPCR influenza testing in comparison to standard MPCR testing was associated with differences in antibiotic and antiviral (oseltamivir) utilisation and hospital length of stay in emergency department and inpatient hospital settings.

METHODS

A retrospective cohort study of positive influenza RPCR and MPCR patients was performed utilising data from the 2017 influenza season. Medical records of correlating patient presentations were reviewed for data collection. An analysis of RPCR versus MPCR patient outcomes was performed examining test turnaround time, antibiotic initiation, oseltamivir initiation and hospital length of stay for both emergency department and inpatient hospital stay. Subgroup analysis was performed to assess oseltamivir use in high risk populations for influenza complications. Statistical significance was assessed using Mann-Whitney test for numerical data and Chi-squared test for categorical data. Odds ratio with 95% confidence intervals were calculated where appropriate.

RESULTS

Overall, 122 RPCR and 362 MPCR positive influenza patients were included in this study. Commencement of antibiotics was less frequent in the RPCR than MPCR cohorts (51% vs 67%; p < 0.01, OR 0.52; 95% CI 0.34-0.79). People at high risk of complications from influenza who were tested with the RPCR were more likely to be treated with oseltamivir compared to those tested with the MPCR (76% vs 63%; p = 0.03, OR 1.81; 95% CI 1.07-3.08). Hospital length of stay was not impacted when either test was used in the emergency department and inpatient settings.

CONCLUSIONS

These findings suggest utilisation of RPCR testing in influenza management can improve antibiotic stewardship through reduction in antibiotic use and improvement in oseltamivir initiation in those at higher risk of complications. Further research is required to determine other factors that may have influenced hospital length of stay and a cost-benefit analysis should be undertaken to determine the financial impact of the RPCR test.

Point-of-Care Testing for the Emergency Department Patient: Quantity and Quality of the Available Evidence

CONTEXT.—

Point-of-care test (POCT) instruments produce lab results with rapid turnaround times. Based on that fact, emergency department (ED) POCT requests are predicated on the belief that rapid test turnaround times lead to improved care, typically a decreased ED length of stay (LOS).

OBJECTIVE.—

To compile the available peer-reviewed data regarding use of POCT in the ED with an emphasis on ED-LOS.

DATA SOURCES.—

An English-language PubMed search using the following free text terms: ("EMERGENCY" AND "POINT OF CARE") NOT ULTRASOUND as well as "RAPID INFECTIOUS DISEASE TESTING." In addition, the PubMed "similar articles" functionality was used to identify related articles that were not identified on the initial search.

CONCLUSIONS.—

Seventy-four references were identified that studied POCT ED use to determine if they resulted in significant changes in ED processes, especially ED-LOS. They were divided into 3 groups: viral-influenza (n = 24), viral-respiratory not otherwise specified (n = 8), and nonviral (n = 42). The nonviral group was further divided into the following groups: chemistry, cardiac, bacterial/strep, C-reactive protein, D-dimer, drugs of abuse, lactate, and pregnancy. Across all groups there was a trend toward a significantly decreased ED-LOS; however, a number of studies showed no change, and a third group was not assessed for ED-LOS. For POCT to improve ED-LOS it has to be integrated into existing ED processes such that a rapid test result will allow the patient to have a shorter LOS, whether it is to discharge or admission.

Ultrasensitive and Highly Specific Lateral Flow Assays for Point-of-Care Diagnosis

Lateral flow assays (LFAs) are paper-based point-of-care (POC) diagnostic tools that are widely used because of their low cost, ease of use, and rapid format. Unfortunately, traditional commercial LFAs have significantly poorer sensitivities (μM) and specificities than standard laboratory tests (enzyme-linked immunosorbent assay, ELISA: pM-fM; polymerase chain reaction, PCR: aM), thus limiting their impact in disease control. In this Perspective, we review the evolving efforts to increase the sensitivity and specificity of LFAs. Recent work to improve the sensitivity through assay improvement includes optimization of the assay kinetics and signal amplification by either reader systems or additional reagents. Together, these efforts have produced LFAs with ELISA-level sensitivities (pM-fM). In addition, sample preamplification can be applied to both nucleic acids (direct amplification) and other analytes (indirect amplification) prior to LFA testing, which can lead to PCR-level (aM) sensitivity. However, these amplification strategies also increase the detection time and assay complexity, which inhibits the large-scale POC use of LFAs. Perspectives to achieve future rapid (<30 min), ultrasensitive (PCR-level), and "sample-to-answer" POC diagnostics are also provided. In the case of LFA specificity, recent research efforts have focused on high-affinity molecules and assay optimization to reduce nonspecific binding. Furthermore, novel highly specific molecules, such as CRISPR/Cas systems, can be integrated into diagnosis with LFAs to produce not only ultrasensitive but also highly specific POC diagnostics. In summary, with continuing improvements, LFAs may soon offer performance at the POC that is competitive with laboratory techniques while retaining a rapid format.

Impact of Rapid Influenza Molecular Testing on Management in Pediatric Acute Care Settings

OBJECTIVES

To measure the impact of rapid influenza real-time qualitative reverse transcriptase polymerase chain reaction (RT-PCR) on patient management in busy pediatric emergency department (ED) and urgent care clinic settings.

STUDY DESIGN

We developed a brief, elective survey that clinicians completed when an influenza RT-PCR order was placed in the ED or urgent care clinic between February 18, 2019, and March 13, 2019. We captured the clinical suspicion for influenza, intended management plans, and actual management plans once influenza RT-PCR results were available.

RESULTS

We evaluated 339 encounters, of which 164 (48.4%) had a positive influenza RT-PCR. Clinical suspicion for influenza was a nonsignificant predictor for influenza PT-PCR positivity (P = .126). After rapid influenza RT-PCR results were available, clinicians changed their original plans in 44.5% of influenza RT-PCR positive vs 92.6% of influenza RT-PCR negative cases (P < .0001). Change in plans for antiviral use was observed in 26% of influenza positive vs 77% of influenza negative cases (P < .0001). A total of 135 antiviral prescriptions were avoided in patients with negative influenza RT-PCR.

CONCLUSIONS

Implementation of a rapid and accurate influenza RT-PCR in the acute care setting is important to systematically diagnose influenza in children and improve outpatient management decisions, because clinical suspicion for influenza is inaccurate. A negative influenza RT-PCR decreases unnecessary antiviral use and has the potential for significant cost savings.

Collaborative Antimicrobial Stewardship in the Emergency Department

Given the large number of patients seen in the emergency department (ED) and concerns with antibiotic overprescribing, the ED is an important setting to target for antimicrobial stewardship (AS) initiatives. The ED is positioned between ambulatory and inpatient settings, making AS collaboration with clinicians and other health care providers in the hospital, long-term care facilities, and ambulatory settings critical to success. This article details ED-focused AS strategies on empiric antimicrobial selection, prompt administration, preventing ED return and readmissions, suggested collaborations between ED AS leadership and other key partners, and potential future strategies for expansion.

Clinical impact of rapid influenza PCR in the adult emergency department on patient management, ED length of stay, and nosocomial infection rate

BACKGROUND

Seasonal influenza causes significant morbidity and mortality and incurs large economic costs. Influenza like illness is a common presenting concern to Emergency Departments (ED), and optimizing the diagnosis of influenza in the ED has the potential to positively affect patient management and outcomes. Therapeutic guidelines have been established to identify which patients most likely will benefit from anti-viral therapy.

OBJECTIVES

We assessed the impact of rapid influenza PCR testing of ED patients on laboratory result generation and patient management across two influenza seasons.

METHODS

A pre-post study was performed following a multifaceted clinical redesign including the implementation of rapid influenza PCR at three diverse EDs comparing the 2016-2017 and 2017-2018 influenza seasons. Testing parameters including turn-around-time and diagnostic efficiency were measured along with rates of bed transfers, hospital-acquired (HA) influenza, and ED length of stay (LOS).

RESULTS

More testing of discharged patients was performed in the post-intervention period, but influenza rates were the same. Identification of influenza-positive patients was significantly faster, and there was faster and more appropriate prescription of anti-influenza medication. There were no differences in bed transfer rates or HA influenza, but ED LOS was reduced by 74 minutes following clinical redesign.

CONCLUSIONS

Multifaceted clinical redesign to optimize ED workflow incorporating rapid influenza PCR testing can be successfully deployed across different ED environments. Adoption of rapid influenza PCR can streamline testing and improve antiviral stewardship and ED workflow including reducing LOS. Further study is needed to determine if other outcomes including bed transfers and rates of HA influenza can be affected by improved testing practices.

COVID-19: An Emerging Threat to Antibiotic Stewardship in the Emergency Department

While current research efforts focus primarily on identifying patient level interventions that mitigate the direct impact of COVID-19, it is important to consider the collateral effects of COVID-19 on antimicrobial resistance. Early reports suggest high rates of antibiotic utilization in COVID-19 patients despite their lack of direct activity against viral pathogens. The ongoing pandemic is exacerbating known barriers to optimal antibiotic stewardship in the ED, representing an additional direct threat to patient safety and public health. There is an urgent need for research analyzing overall and COVID-19 specific antibiotic prescribing trends in the ED. Optimizing ED stewardship during COVID-19 will likely require a combination of traditional stewardship approaches (e.g. academic detailing, provider education, care pathways) and effective implementation of host response biomarkers and rapid COVID-19 diagnostics. Antibiotic stewardship interventions with demonstrated efficacy in mitigating the impact of COVID-19 on ED prescribing should be widely disseminated and inform the ongoing pandemic response.

Point-of-Care Testing in Microbiology: A Mechanism for Improving Patient Outcomes

BACKGROUND

Increasingly, demands for improved health and quality of life conflict with the realities of delivering healthcare in an environment of higher expenditures, adherence to test utilization, and patient-centered experience. Patient-centered care is commonly identified as a goal of healthcare delivery, and yet healthcare systems struggle with delivery of care to patients, often failing to identify the seriously ill and capitalize on the predictive qualities of diagnostic testing. Point-of-care (POC) testing provides access to rapid diagnosis and predictive value key to realizing patient outcomes. An evaluation of cost-effective models and the clinical impact of POC testing for clinical microbiology is needed.

CONTENT

Accurate and rapid diagnostics have the potential to affect healthcare decisions to a degree well out of proportion to their cost. Contemporary healthcare models increasingly view POC testing as a mechanism for efficient deployment of healthcare. POC testing can deliver rapid diagnosis in environments where testing results can be used to direct management during patient visits and in areas where centralized laboratory testing may limit access to care. Nucleic acid assays, designed for POC testing, can match, or exceed, the sensitivity of conventional laboratory-based testing, eliminating the need for confirmation testing. Here, the goals of POC testing for microbiology, applications, and technologies, as well as outcomes and value propositions, are discussed.

SUMMARY

The combination of rapid reporting, an increasing array of organisms capable of causing disease, actionable resulting, and improved patient outcomes is key in the evolution of POC testing in clinical microbiology.

Rapid diagnostic tests for infectious diseases in the emergency department

Background

Rapid diagnostic tests (RDTs) for infectious diseases, with a turnaround time of less than 2 hours, are promising tools that could improve patient care, antimicrobial stewardship and infection prevention in the emergency department (ED) setting. Numerous RDTs have been developed, although not necessarily for the ED environment. Their successful implementation in the ED relies on their performance and impact on patient management.

Objectives

The aim of this narrative review was to provide an overview of currently available RDTs for infectious diseases in the ED.

Sources

PubMed was searched through August 2019 for available studies on RDTs for infectious diseases. Inclusion criteria included: commercial tests approved by the US Food and Drug Administration (FDA) or Conformité Européenne (CE) in vitro diagnostic devices with data on clinical samples, ability to run on fully automated systems and result delivery within 2 hours.

Content

A nonexhaustive list of representative commercially available FDA- or CE-approved assays was categorized by clinical syndrome: pharyngitis and upper respiratory tract infection, lower respiratory tract infection, gastrointestinal infection, meningitis and encephalitis, fever in returning travellers and sexually transmitted infection, including HIV. The performance of tests was described on the basis of clinical validation studies. Further, their impact on clinical outcomes and anti-infective use was discussed with a focus on ED-based studies.

Implications

Clinicians should be familiar with the distinctive features of each RDT and individual performance characteristics for each target. Their integration into ED work flow should be preplanned considering local constraints of given settings. Additional clinical studies are needed to further evaluate their clinical effectiveness and cost-effectiveness.

Utility of Rapid Influenza Molecular Testing in an Outpatient Hemodialysis Unit: A Prospective Cohort Study

Background:

Early initiation of antiviral therapy for individuals at risk for severe influenza infection is important for improving patient outcomes. Current guidelines recommend empiric antiviral therapy for patients with end-stage kidney disease presenting with suspected influenza infection. Rapid molecular influenza assays may reduce diagnostic uncertainty and improve patient outcomes by providing faster diagnostics compared to traditional batched polymerase chain reaction (PCR) testing.

Objective:

To determine the utility of implementing a rapid influenza PCR assay compared to the standard of care in a hemodialysis unit.

Design:

This is a prospective cohort study.

Setting:

A hospital-based dialysis unit in a tertiary care hospital.

Patients:

Adult patients with end-stage kidney disease on intermittent hemodialysis.

Measurements:

Patient characteristics, influenza PCR swab results, antibiotic prescriptions, antiviral prescriptions, emergency room visits and hospitalizations.

Methods:

From November 1, 2017 to March 31, 2018, we assigned samples collected from a single center, hemodialysis unit to be processed using a rapid influenza PCR (cobas® Influenza A/B & respiratory syncytial virus assay) or the standard of care (in-house developed multiplex PCR). Samples were assigned to the rapid PCR if the patient received dialysis treatment in the morning dialysis shift, while the remainder were processed as per standard of care. Study outcomes included the time from collection to result of nasopharyngeal swab, prescription of influenza antiviral therapy, time to receiving prescription, and the need for emergency department visit or hospitalization within 2 weeks of presentation.

Results:

During the study period, 44 patients were assessed (14 with the rapid PCR and 30 with the standard of care assay). Compared to conventional testing, the time to result was shorter using rapid PCR compared to conventional testing (2.3 vs 22.6 hours, P < .0001). Individuals who were tested using the rapid PCR had a tendency to shorter time to receiving antiviral prescriptions (0.7 days vs 2.1 days, P = .11), and fewer emergency department visits (7.1% vs 30%, P = .13) but no difference in hospitalizations (14.3% vs 30%, P = .46) within 2 weeks of testing.

Limitations:

This is a single center non-randomized study with a relatively small sample size. Patients who were tested using the standard of care assay experienced a delay in the prescription of antiviral therapy which deviates from recommended clinical practice.

Conclusions:

Rapid influenza molecular testing in the hemodialysis unit was associated with a shorter time to a reportable result and with a tendency to reduced time to prescription of antiviral therapy. Rapid molecular testing should be compared with standard of care (empiric therapy) in terms of economic costs, adverse events, and influenza-related outcomes.

Evaluation of high-throughput digital lateral flow immunoassays for the detection of influenza A/B viruses from clinical swab samples

We evaluated the performance of new high-throughput digital lateral flow immunoassays (LFIAs) detecting influenza antigens and compared them with those of the widely used digital LFIA and the rapid nucleic acid amplification test (NAAT). We tested 199 clinical nasopharyngeal (nasal) swab samples using three LFIA tests (BD Veritor Plus, STANDARD F Influenza A/B FIA, and ichroma TRIAS) and the rapid NAAT (ID NOW Influenza A & B2). Agreements and clinical performances (sensitivity and specificity) were evaluated based on the results of reverse transcriptase-polymerase chain reaction (RT-PCR) and verification panel. The agreement of each test with RT-PCR was moderate to almost perfect. The sensitivity of ID NOW was significantly higher than that of LFIAs (P = .0005, .0044, and .0026 for influenza A and P = .0044, .0026, and .0044 for influenza B, respectively). The specificities were not significantly different between the four tests (P > .05). However, the reference panel suggests that ichroma TRIAS test is more sensitive than the other two LFIA tests. All three LFIA assays performed similarly with no false positives against influenza A. For influenza B, ichroma TRIAS had 2 of 166 false positives whereas there were no false positives for the other two LFIA tests. Influenza antigen digital LFIAs have advantages in terms of the workflow when simultaneous tests are required. Rapid NAAT has higher sensitivity, while new antigen LFIAs are efficient and high-throughput. It is recommended that users select appropriate methods and algorithms according to the number of specimens and laboratory conditions in each clinical laboratory.

Clinical Utility of Advanced Microbiology Testing Tools

Advanced microbiology technologies are rapidly changing our ability to diagnose infections, improve patient care, and enhance clinical workflow. These tools are increasing the breadth, depth, and speed of diagnostic data generated per patient, and testing is being moved closer to the patient through rapid diagnostic technologies, including point-of-care (POC) technologies.

Advanced microbiology technologies are rapidly changing our ability to diagnose infections, improve patient care, and enhance clinical workflow. These tools are increasing the breadth, depth, and speed of diagnostic data generated per patient, and testing is being moved closer to the patient through rapid diagnostic technologies, including point-of-care (POC) technologies. While select stakeholders have an appreciation of the value/importance of improvements in the microbial diagnostic field, there remains a disconnect between clinicians and some payers and hospital administrators in terms of understanding the potential clinical utility of these novel technologies. Therefore, a key challenge for the clinical microbiology community is to clearly articulate the value proposition of these technologies to encourage payers to cover and hospitals to adopt advanced microbiology tests. Specific guidance on how to define and demonstrate clinical utility would be valuable. Addressing this challenge will require alignment on this topic, not just by microbiologists but also by primary care and emergency room (ER) physicians, infectious disease specialists, pharmacists, hospital administrators, and government entities with an interest in public health. In this article, we discuss how to best conduct clinical studies to demonstrate and communicate clinical utility to payers and to set reasonable expectations for what diagnostic manufacturers should be required to demonstrate to support reimbursement from commercial payers and utilization by hospital systems.

Timing of respiratory virus molecular testing in emergency departments and its association with patient care outcomes: a retrospective observational study across six Australian hospitals

OBJECTIVE

A rapid molecular diagnostic test (RMDT) offers a fast and accurate detection of respiratory viruses, but its impact on the timeliness of care in the emergency department (ED) may depend on the timing of the test. The aim of the study was to determine if the timing of respiratory virus testing using a RMDT in the ED had an association with patient care outcomes.

DESIGN

Retrospective observational study.

SETTING

Linked ED and laboratory data from six EDs in New South Wales, Australia.

PARTICIPANTS

Adult patients presenting to EDs during the 2017 influenza season and tested for respiratory viruses using a RMDT. The timing of respiratory virus testing was defined as the time from a patient's ED arrival to time of sample receipt at the hospital laboratory.

OUTCOME MEASURES

ED length of stay (LOS), >4 hour ED LOS and having a pending RMDT result at ED disposition.

RESULTS

A total of 2168 patients were included. The median timing of respiratory virus testing was 224 min (IQR, 133-349). Every 30 min increase in the timing of respiratory virus testing was associated with a 24.0 min increase in the median ED LOS (95% CI, 21.8-26.1; p<0.001), a 51% increase in the likelihood of staying >4 hours in ED (OR, 1.51; 95% CI, 1.41 to 1.63; p<0.001) and a 4% increase in the likelihood of having a pending RMDT result at ED disposition (OR, 1.04; 95% CI, 1.02 to 1.05; p<0.001) after adjustment for confounders.

CONCLUSION

The timing of respiratory virus molecular testing in EDs was significantly associated with a range of outcome indicators. Results suggest the potential to maximise the benefits of RMDT by introducing an early diagnostic protocol such as triage-initiated testing.

CLIA-waived molecular influenza testing in the emergency department and outpatient settings

Respiratory tract infections are a common cause of visits to emergency departments and outpatient settings. Infections with influenza viruses A and B in particular, are responsible for significant morbidity and mortality in both pediatric and adult populations worldwide. A significant number of influenza diagnoses occur in the emergency departments with many being performed using rapid influenza diagnostic tests (RIDT) which have sensitivities as low as 30% depending on the specific RIDT and patient population. More recently, rapid molecular tests for the detection of influenza viruses A and B have become commercially available as point-of-care platforms. In the United States, several of these new tests are approved by the Food and Drug Administration as CLIA-waived tests. In this report, we review the data on the analytical and clinical performance of RIDTs and CLIA-waived molecular tests, present and discuss potential key challenges and opportunities for implementation of CLIA-waived molecular tests at or near point of care in the emergency departments and outpatient settings.

Influenza Antiviral Prescribing Practices and the Influence of Rapid Testing Among Primary Care Providers in the US, 2009-2016

Background

Early influenza antiviral treatment within 2 days of illness onset can reduce illness severity and duration. Reliance on low sensitivity rapid influenza diagnostic tests (RIDTs) to guide antiviral prescribing has been reported. We describe antiviral prescribing practices among primary care providers from a large surveillance network in the United States.

Methods

From 2009-2016, a network of 36 to 68 outpatient clinics per year collected respiratory specimens and clinical data for patients with influenza-like illness (ILI). Specimens were tested for influenza using polymerase chain reaction (PCR). We used multivariable logistic regression to assess factors influencing antiviral prescribing.

Results

Among 13 540 patients with ILI, 2766 (20%) were prescribed antivirals. In age groups recommended to receive empiric antiviral treatment for suspected influenza, 11% of children <2 years and 23% of adults ≥65 years received a prescription. Among 3681 patients with a positive PCR test for influenza, 40% tested negative by RIDT. In multivariable analysis, prescription receipt was strongly associated with a positive RIDT (adjusted odds ratio [aOR] 12, 95% CI 11-14) and symptom onset ≤2 days before visit (aOR 4.3, 95% CI 3.8-4.9). Antiviral prescribing was also more frequent among pediatric and private family practice clinics compared with community health centers (aOR 1.9, 95% CI 1.6-2.2, and 1.3, 95% CI 1.1-1.5, respectively).

Conclusion

Primary care providers were more likely to prescribe antivirals to patients with a positive RIDT, but antivirals were prescribed infrequently even to patients in high-risk age groups. Understanding patient and provider characteristics associated with antiviral prescribing is important for communicating treatment recommendations.

Implementation of point-of-care testing in a pediatric healthcare setting

Point-of-care testing (POCT) refers to testing performed outside the clinical laboratory near the patient or at the site of patient care. This could be in critical care settings like the intensive care unit (ICU) and emergency department (ED) or primary care settings like physician offices where testing is performed by nonlaboratory personnel. POCT circumvents several steps in central laboratory testing including specimen transportation and processing resulting in faster turnaround times. Provider access to rapid test results at the site of patient care allows for prompt medical decision making which can lead to improved patient outcomes, operational efficiencies, patient satisfaction, and even cost savings in some cases. In addition to providing results rapidly, POCT devices have small specimen volume requirements compared to central laboratory tests making POCT particularly attractive for pediatric healthcare settings. The availability of published reports on the impact of POCT implementation in pediatric care are helpful resources when evaluating the clinical necessity of POCT prior to implementation. Even though several studies have shown advantages to implementing POCT in different pediatric settings, it is important to note that limitations exist that might limit the utilization of certain POCTs in some pediatric populations. So, it is important that these limitations and the analytical performance of a test are considered while keeping the target patient population in mind. Since POCTs are performed by non-laboratory staff who are not trained laboratory personnel, one challenge with POCT is maintaining regulatory compliance and quality assurance. It is therefore important that regulatory and quality assurance programs be put in place prior to implementing POCT in the pediatric hospital. With advances in POCT technology, most POCT devices have the capability to interface to the laboratory information system (LIS) and electronic medical record (EMR). POCT device interfacing allows for improved compliance to regulatory and quality assurance standards. Maintaining a cost efficient POCT program is becoming increasingly important as hospitals and healthcare systems are undergoing consolidation and harmonization. This includes assessing the clinical and operational benefit of POCT before implementation and inventory management to ensure minimal reagent wastage. This review discusses these different considerations when implementing POCT with a focus on the pediatric healthcare setting.

Impact of Rapid Molecular Diagnostic Testing of Respiratory Viruses on Outcomes of Adults Hospitalized with Respiratory Illness: a Multicenter Quasi-experimental Study

A standard multiplex PCR offers comprehensive testing for respiratory viruses. However, it has traditionally been performed in a referral laboratory with a lengthy turnaround time, which can reduce patient flow through the hospital. We aimed to determine whether the introduction of a rapid PCR, but with limited targets (Cepheid Xpert Flu/RSV XC), was associated with improved outcomes for adults hospitalized with respiratory illness. A controlled quasi-experimental study was conducted across three hospitals in New South Wales, Australia. Intervention groups received standard multiplex PCR during the preimplementation, July to December 2016 (n = 953), and rapid PCR during the postimplementation, July to December 2017 (n = 1,209). Control groups (preimplementation, n = 937, and postimplementation, n = 1,102) were randomly selected from adults hospitalized with respiratory illness during the same periods. The outcomes were hospital length of stay (LOS) and microbiology test utilization (blood culture, urine culture, sputum culture, and respiratory bacterial and virus serologies). The introduction of rapid PCR was associated with a nonsignificant 8.9-h reduction in median LOS (95% confidence interval [CI], -21.5 h to 3.7 h; P = 0.17) for all patients and a significant 21.5-h reduction in median LOS (95% CI, -36.8 h to -6.2 h; P < 0.01) among patients with positive test results in an adjusted difference-in-differences analysis. For patients receiving test results before disposition, rapid PCR use was associated with a significant reduction in LOS, irrespective of test results. Compared with standard PCR testing, rapid PCR use was significantly associated with fewer blood culture (adjusted odds ratio [aOR], 0.67; 95% CI, 0.5 to 0.82; P < 0.001), sputum culture (aOR, 0.56; 95% CI, 0.47 to 0.68, P < 0.001), bacterial serology (aOR, 0.44; 95% CI, 0.35 to 0.55, P < 0.001) and viral serology (aOR, 0.42; 95% CI, 0.33 to 0.53, P < 0.001) tests, but not with fewer urine culture tests (aOR, 0.94; 95% CI, 0.78 to 1.12, P = 0.48). Rapid PCR testing of adults hospitalized with respiratory illnesses can deliver benefits to patients and reduce resource utilization. Future research should consider a formal economic analysis and assess its potential impacts on clinical decision making.

Impact of Rapid Molecular Detection of Respiratory Viruses on Clinical Outcomes and Patient Management

To determine if rapid molecular testing for respiratory viruses in patients with respiratory illnesses can provide advantages to patients and hospitals, rigorous investigations on the impacts of using these assays are required. Well-conducted studies are needed to inform decisions about implementation of new rapid assays to replace standard molecular testing or to initiate testing in laboratories that are currently not doing molecular tests for respiratory viruses due to the complex nature of standard panels. In this issue of the Journal of Clinical Microbiology, N. Wabe et al. (J Clin Microbiol 57:e01727-18, 2019, https://doi.org/10.1128/JCM.01727-18) report the results of their evaluation of the impact of using a rapid molecular test for influenza A/influenza B and RSV on outcomes for adults hospitalized with respiratory illness. The median time from admission to test result of the rapid test was 7.5 h compared to 40.3 h for the standard PCR assay. Compared to the use of the standard molecular assay, use of a rapid test significantly shortened time in the hospital and reduced the number of other microbiology tests performed. The authors concluded that rapid PCR testing of adults hospitalized with respiratory illnesses could provide benefits to both the patients and the hospital. Patients were able to leave the hospital earlier and a greater proportion of them had received their test results before discharge, which would allow appropriate treatment to be provided more quickly.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

The impact of rapid molecular diagnostic testing for respiratory viruses on outcomes for emergency department patients

OBJECTIVE

To determine whether rapid polymerase chain reaction (PCR) testing for influenza and respiratory syncytial viruses (RSV) in emergency departments (EDs) is associated with better patient and laboratory outcomes than standard multiplex PCR testing.

DESIGN, SETTING

A before-and-after study in four metropolitan EDs in New South Wales.

PARTICIPANTS

1491 consecutive patients tested by standard multiplex PCR during July-December 2016, and 2250 tested by rapid PCR during July-December 2017.

MAIN OUTCOME MEASURES

Hospital admissions; ED length of stay (LOS); test turnaround time; patient receiving test result before leaving the ED; ordering of other laboratory tests.

RESULTS

Compared with those tested by standard PCR, fewer patients tested by rapid PCR were admitted to hospital (73.3% v 77.7%; P < 0.001) and more received their test results before leaving the ED (67.4% v 1.3%; P < 0.001); the median test turnaround time was also shorter (2.4 h [IQR, 1.6-3.9 h] v 26.7 h [IQR, 21.2-37.8 h]). The proportion of patients admitted to hospital was also lower in the rapid PCR group for both children under 18 (50.6% v 66.6%; P < 0.001) and patients over 60 years of age (84.3% v 91.8%; P < 0.001). Significantly fewer blood culture, blood gas, sputum culture, and respiratory bacterial and viral serology tests were ordered for patients tested by rapid PCR. ED LOS was similar for the rapid (7.4 h; IQR, 5.0-12.9 h) and standard PCR groups (6.5 h; IQR, 4.2-11.9 h; P = 0.27).

CONCLUSION

Rapid PCR testing of ED patients for influenza virus and RSV was associated with better outcomes on a range of indicators, suggesting benefits for patients and the health care system. A formal cost-benefit analysis should be undertaken.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Clinical Impact of Rapid Point-of-Care PCR Influenza Testing in an Urgent Care Setting: a Single-Center Study

Seasonal influenza virus causes significant morbidity and mortality each year. Point-of-care (POC) testing using rapid influenza diagnostic tests (RIDTs), immunoassays that detect viral antigens, are often used for diagnosis by physician offices and urgent care centers. These tests are rapid but lack sensitivity, which is estimated to be 50 to 70%. Testing by PCR is highly sensitive and specific, but historically these assays have been performed in centralized clinical laboratories necessitating specimen transport and increasing the time to result. Recently, Clinical Laboratory Improvement Amendments (CLIA)-waived, POC PCR influenza assays have been developed with >95% sensitivity and specificity compared to centralized PCR assays. To determine the clinical impact of a POC PCR test for influenza, we compared antimicrobial prescribing patterns of one urgent care location using the Cobas LIAT Influenza A/B assay (LIAT assay; Roche Diagnostics, Indianapolis, IN) to other urgent care centers in our health system using traditional RIDT, with negative specimens being reflexed to PCR. Antiviral prescribing was lower in patients with a negative LIAT PCR result (2.3%) than in patients with a negative RIDT result (25.3%; P < 0.005). Antivirals were prescribed more often in patients that tested positive by LIAT PCR (82.4%) than in those testing positive by either RIDT or reflex PCR (69.9%; P < 0.05). Antibacterial prescriptions for patients testing negative by LIAT PCR were higher (44.5%) than for those testing negative by RIDT (37.7%), although the difference was not statistically significant. In conclusion, having results from a PCR POC test during the clinic visit improved antiviral prescribing practices compared to having rapid results from an RIDT.

Practical Guidance for Clinical Microbiology Laboratories: Viruses Causing Acute Respiratory Tract Infections

Respiratory viral infections are associated with a wide range of acute syndromes and infectious disease processes in children and adults worldwide. Many viruses are implicated in these infections, and these viruses are spread largely via respiratory means between humans but also occasionally from animals to humans. This article is an American Society for Microbiology (ASM)-sponsored Practical Guidance for Clinical Microbiology (PGCM) document identifying best practices for diagnosis and characterization of viruses that cause acute respiratory infections and replaces the most recent prior version of the ASM-sponsored Cumitech 21 document, Laboratory Diagnosis of Viral Respiratory Disease, published in 1986. The scope of the original document was quite broad, with an emphasis on clinical diagnosis of a wide variety of infectious agents and laboratory focus on antigen detection and viral culture. The new PGCM document is designed to be used by laboratorians in a wide variety of diagnostic and public health microbiology/virology laboratory settings worldwide. The article provides guidance to a rapidly changing field of diagnostics and outlines the epidemiology and clinical impact of acute respiratory viral infections, including preferred methods of specimen collection and current methods for diagnosis and characterization of viral pathogens causing acute respiratory tract infections. Compared to the case in 1986, molecular techniques are now the preferred diagnostic approaches for the detection of acute respiratory viruses, and they allow for automation, high-throughput workflows, and near-patient testing. These changes require quality assurance programs to prevent laboratory contamination as well as strong preanalytical screening approaches to utilize laboratory resources appropriately. Appropriate guidance from laboratorians to stakeholders will allow for appropriate specimen collection, as well as correct test ordering that will quickly identify highly transmissible emerging pathogens.

Antimicrobial Stewardship in the Emergency Department

The emergency department (ED) is the hub of the US health care system. Acute infectious diseases are frequently encountered in the ED setting, making this a critical setting for antimicrobial stewardship efforts. Systems level and behavioral stewardship interventions have demonstrated success in the ED setting but successful implementation depends on institutional support and the presence of a physician champion. Antimicrobial stewardship efforts in the ED should target high-impact areas: antibiotic prescribing for nonindicated respiratory tract conditions, such as bronchitis and sinusitis; overtreatment of asymptomatic bacteriuria; and using two antibiotics (double coverage) for uncomplicated cases of cellulitis or abscess.

Laboratory Diagnosis of Respiratory Tract Infections in Children - the State of the Art

In the pediatric population, respiratory infections are the most common cause of physician visits. Although many respiratory illnesses are self-limiting viral infections that resolve with time and supportive care, it can be critical to identify the causative pathogen at an early stage of the disease in order to implement effective antimicrobial therapy and infection control. Over the last few years, diagnostics for respiratory infections have evolved substantially, with the development of novel assays and the availability of updated tests for newer strains of pathogens. Newer laboratory methods are rapid, highly sensitive and specific, and are gradually replacing the conventional gold standards, although the clinical utility of these assays is still under evaluation. This article reviews the current laboratory methods available for testing for respiratory pathogens and discusses the advantages and disadvantages of each approach.

Antibiotic Use in Febrile Children Presenting to the Emergency Department: A Systematic Review

Introduction: While fever is the main complaint among pediatric emergency services and high antibiotic prescription are observed, only a few studies have been published addressing this subject. Therefore this systematic review aims to summarize antibiotic prescriptions in febrile children at the ED and assess its determinants. Methods: We extracted studies published from 2000 to 2017 on antibiotic use in febrile children at the ED from different databases. Author, year, and country of publishing, study design, inclusion criteria, primary outcome, age, and number of children included in the study was extracted. To compare the risk-of-bias all articles were assessed using the MINORS criteria. For the final quality assessment we additionally used the sample size and the primary outcome. Results: We included 26 studies reporting on antibiotic prescription and 28 intervention studies on the effect on antibiotic prescription. In all 54 studies antibiotic prescriptions in the ED varied from 15 to 90.5%, pending on study populations and diagnosis. Respiratory tract infections were mostly studied. Pediatric emergency physicians prescribed significantly less antibiotics then general emergency physicians. Most frequent reported interventions to reduce antibiotics are delayed antibiotic prescription in acute otitis media, viral testing and guidelines. Conclusion: Evidence on antibiotic prescriptions in children with fever presenting to the ED remains inconclusive. Delayed antibiotic prescription in acute otitis media and guidelines for fever and respiratory infections can effectively reduce antibiotic prescription in the ED. The large heterogeneity of type of studies and included populations limits strict conclusions, such a gap in knowledge on the determining factors that influence antibiotic prescription in febrile children presenting to the ED remains.

Systematic review of the impact of point-of-care testing for influenza on the outcomes of patients with acute respiratory tract infection

Acute respiratory tract infections are a major cause of morbidity and mortality and represent a significant burden on the health care system. Laboratory testing is required to definitively distinguish infecting influenza virus from other pathogens, resulting in prolonged emergency department (ED) visits and unnecessary antibiotic use. Recently available rapid point-of-care tests (POCT) may allow for appropriate use of antiviral and antibiotic treatments and decrease patient lengths of stay. We undertook a systematic review to assess the effect of POCT for influenza on three outcomes: (1) antiviral prescription, (2) antibiotic prescription, and (3) patient length of stay in the ED. The databases Medline and Embase were searched using MeSH terms and keywords for influenza, POCT, antivirals, antibiotics, and length of stay. Amongst 245 studies screened, 30 were included. The majority of papers reporting on antiviral prescription found that a positive POCT result significantly increased use of antivirals for influenza compared with negative POCT results and standard supportive care. A positive POCT result also led to decreased antibiotic use. The results of studies assessing the effect of POCT on ED length of stay were not definitive. The studies assessed in this systematic review support the use of POCT for diagnosis of influenza in patients suffering an acute respiratory infection. Diagnosis using POCT may lead to more appropriate prescription of treatments for infectious agents. Further studies are needed to assess the effect of POCT on the length of stay in ED.

Clinical decision making in the emergency department setting using rapid PCR: Results of the CLADE study group

•

The influence of an influenza diagnosis on patient managed during ED visits is examined.

•

An influenza diagnosis in the ED is actionable, impacting empiric management in 61% of cases.

•

The clinical diagnosis of influenza, based on presenting symptoms, lacks sensitivity at 36%.

•

A 30 min result from collection to report could be achieved in the ED for 91.7%, of cases tested.

•

ED testing resulted in savings of $200.40/ED visit but is dependent on avoiding planned admissions.

Background

Emergency Departments (ED) are challenged during influenza season by patients who present acutely during sporadic ED visits. ED management is largely empiric, often occurring without reliable diagnostics needed for targeted therapies, safe outpatient discharge, or hospital admissions.

Objective

To evaluate the impact of the influenza diagnosis on physician decision making during ED visits using the Cobas Liat^® influenza A + B assay.

Study design

Prospective study assessing the impact of rapid (<30 min), reverse-transcriptase polymerase chain reaction (RT-PCR) influenza testing on physician decision making in the ED. Physician responses established pre-and post-diagnosis management courses which required confirmation via secondary documentation in the medical record. Changes in physician decision making were analyzed across four clinical touchpoints: (i) admission/discharge status, (ii) medical procedures, (iii) antiviral and antibiotic prescribing, and (iv) laboratory studies.

Results

An influenza diagnosis changed patient management courses, relative to empiric, pre-diagnosis plans, in in 61% of the cases resulting in cost savings of $49,420-to-$42,270 over 143 patients and 104 days during influenza season resulting in a cost savings of $200.40/ED visit. Evaluation over 2000 ED patient visits projects cost savings > $578,000 due to deferred admissions, and reduction in antiviral prescribing. Sensitivity of ED-based influenza testing using the Cobas Liat^® assay was equivalent to centralized lab testing at 98.8% sensitivity and 98.5% specificity respectively.

Conclusion

Providing rapid, RT-PCR influenza testing to ED settings is actionable and used to guide patient care decisions. Understanding the cascade of events linked to the influenza diagnosis in the ED provides overall cost savings which offset the cost of providing ED-based testing.

Influenza

Influenza is an acute viral respiratory disease that affects persons of all ages and is associated with millions of medical visits, hundreds of thousands of hospitalizations, and thousands of deaths during annual winter epidemics of variable severity in the United States. Elderly persons have the highest influenza-associated hospitalization and mortality rates. The primary method of prevention is annual vaccination. Early antiviral treatment has the greatest clinical benefit; otherwise, management includes adherence to recommended infection prevention and control measures as well as supportive care of complications.

The impact of commercial rapid respiratory virus diagnostic tests on patient outcomes and health system utilization

INTRODUCTION

Acute respiratory tract infections due to influenza A/B and respiratory syncytial virus (RSV) are major causes of morbidity and mortality globally. Rapid tests for detection of these pathogens include antigen detection point of care tests (POC) and newer easy to use molecular tests. From experience, these assays improve both laboratory workflow and assay interpretation issues. However, the question of the benefits of using rapid test technology compared to routine laboratory testing for respiratory viral pathogens is still often asked. Areas covered: Specifically, this review aims to; 1) identify clinical/patient indicators that can be measured prior to and following the implementation of rapid diagnostic test for influenza and RSV, 2) provide multiple perspectives on the extent of impact of a rapid diagnostic test, including direct and indirect outcomes, and 3) identify the technological advancements in the development of rapid testing, demonstrating a timeline that transitions from antigen-based assays to molecular assays. Expert commentary: Key benefits to the use of either antigen-based or molecular rapid tests for patient care, patient flow within institutions, as well as laboratory utilization are identified. Due to improved test characteristics, the authors feel that rapid molecular tests have greater benefits than antigen-based detection methods.

Right-Sizing Technology in the Era of Consumer-Driven Health Care

Technology for modern clinical and public health microbiology laboratories has evolved at an impressive rate over the last two decades. Contemporary diagnostics can rapidly provide powerful data that can impact patient lives and support infectious disease outbreak investigations. At the same time, dramatic changes to health care delivery are putting new pressures on a system that is now focusing on patient-centric, value-driven, convenient care. For laboratories, balancing all these demands in a cost-contained environment remains a challenge. This article explores the current and future directions of diagnostics in our dynamic health care environment.

Respiratory RNA Viruses

Acute upper and lower respiratory infections are a major public health problem and a leading cause of morbidity and mortality worldwide. At greatest risk are young children, the elderly, the chronically ill, and those with suppressed or compromised immune systems. Viruses are the predominant cause of respiratory tract illnesses and include RNA viruses such as respiratory syncytial virus, influenza virus, parainfluenza virus, metapneumovirus, rhinovirus, and coronavirus. Laboratory testing is required for a reliable diagnosis of viral respiratory infections, as a clinical diagnosis can be difficult since signs and symptoms are often overlapping and not specific for any one virus. Recent advances in technology have resulted in the development of newer diagnostic assays that offer great promise for rapid and accurate detection of respiratory viral infections. This chapter emphasizes the fundamental characteristics and clinical importance of the various RNA viruses that cause upper and lower respiratory tract diseases in the immunocompromised host. It highlights the laboratory methods that can be used to make a rapid and definitive diagnosis for the greatest impact on the care and management of ill patients, and the prevention and control of hospital-acquired infections and community outbreaks.

Clinical Mimics: An Emergency Medicine-Focused Review of Influenza Mimics

BACKGROUND

Influenza viruses are a significant cause of morbidity and mortality in the United States. Given the wide range of symptoms, emergency physicians must maintain a broad differential diagnosis in the evaluation and treatment of patients presenting with influenza-like illnesses.

OBJECTIVE

This review addresses objective and subjective symptoms commonly associated with influenza and discusses important mimics of influenza viruses, while offering a practical approach to their clinical evaluation and treatment.

DISCUSSION

Influenza-like symptoms are common in the emergency department (ED), and influenza accounts for > 200,000 hospitalizations annually. The three predominant types are A, B, and C, and these viruses are commonly transmitted through aerosolized viral particles with a wide range of symptoms. The most reliable means of identifying influenza in the ED is rapid antigen detection, although consideration of local prevalence is required. High-risk populations include children younger than 4 years, adults older than 50 years, adults with immunosuppression or chronic comorbidities, pregnancy, obesity, residents of long-term care facilities, and several others. The Centers for Disease Control and Prevention recommends treatment with neuraminidase inhibitors in these populations. However, up to 70% of patients with these symptoms may have a mimic. These mimics include infectious and noninfectious sources. The emergency physician must be aware of life-threatening mimics and assess for these conditions while beginning resuscitation and treatment.

CONCLUSIONS

The wide range of symptoms associated with influenza overlap with several life-threatening conditions. Emergency physicians must be able to rapidly identify patients at risk for complications and those who require immediate resuscitation.

Molecular point-of-care testing for respiratory viruses versus routine clinical care in adults with acute respiratory illness presenting to secondary care: a pragmatic randomised controlled trial protocol (ResPOC)

BACKGROUND

Respiratory viruses are associated with a huge socio-economic burden and are responsible for a large proportion of acute respiratory illness in hospitalised adults. Laboratory PCR is accurate but takes at least 24 h to generate a result to clinicians and antigen-based point-of-care tests (POCT) lack sensitivity. Rapid molecular platforms, such as the FilmArray Respiratory Panel, have equivalent diagnostic accuracy to laboratory PCR and can generate a result in 1 h making them deployable as POCT. Molecular point-of-care testing for respiratory viruses in hospital has the potential to improve the detection rate of respiratory viruses, improve the use of influenza antivirals and reduce unnecessary antibiotic use, but high quality randomised trials with clinically relevant endpoints are needed.

METHODS

The ResPOC study is a pragmatic randomised controlled trial of molecular point-of-care testing for respiratory viruses in adults with acute respiratory illness presenting to a large teaching hospital in the United Kingdom. Eligible participants are adults presenting with acute respiratory illness to the emergency department or the acute medicine unit. Participants are allocated 1:1 by internet-based randomisation service to either the intervention of a nose and throat swab analysed immediately on the FilmArray Respiratory Panel as a POCT or receive routine clinical care. The primary outcome is the proportion of patients treated with antibiotics. Secondary outcomes include turnaround time, virus detection, neuraminidase inhibitor use, length of hospital stay and side room use. Analysis of the primary outcome will be by intention-to-treat and all enrolled participants will be included in safety analysis.

DISCUSSION

Multiple novel molecular POCT platforms for infections including respiratory viruses have been developed and licensed in the last few years and many more are in development but the evidence base for clinical benefit above standard practice is minimal. This randomised controlled trial aims to close this evidence gap by generating high quality evidence for the clinical impact of molecular POCT for respiratory viruses in secondary care and to act as an exemplar for future studies of molecular POCT for infections. This study has the potential to change practice and improve patient care for patients presenting to hospital with acute respiratory illness.

TRIAL REGISTRATION

This study was registered with ISRCTN, number ISRCTN90211642 , on 14th January 2015.

Performance evaluation of a rapid molecular diagnostic, MultiCode based, sample-to-answer assay for the simultaneous detection of Influenza A, B and respiratory syncytial viruses

BACKGROUND

Clinical signs and symptoms of different airway pathogens are generally indistinguishable, making laboratory tests essential for clinical decisions regarding isolation and antiviral therapy. Immunochromatographic tests (ICT) and direct immunofluorescence assays (DFA) have lower sensitivities and specificities than molecular assays, but have the advantage of quick turnaround times and ease-of-use.

OBJECTIVE

To evaluate the performance of a rapid molecular assay, ARIES FluA/B & RSV, using laboratory developed RT-PCR assays (LDA), ICT (BinaxNOW) and DFA.

METHODS

Analytical and clinical performance were evaluated in a retrospective study arm (stored respiratory samples obtained between 2006-2015) and a prospective study arm (unselected fresh clinical samples obtained between December 2015 and March 2016 tested in parallel with LDAs).

RESULTS

Genotype inclusivity and analytical specificity was 100%. However, ARIES was 0.5 log, 1-2logs and 2.5logs less sensitive for fluA, RSV and fluB respectively, compared to LDA. In total, 447 clinical samples were included, of which 15.4% tested positive for fluA, 9.2% for fluB and 26.0% for RSV, in both LDA and ARIES. ARIES clinical sensitivity compared to LDA was 98.6% (fluA), 93.3% (fluB) and 95.1% (RSV). Clinical specificity was 100% for all targets. ARIES detected 10.6% (4 fluA, 8 fluB, 11 RSV) and 26.9% (7 fluA, 3 fluB, 22 RSV) more samples compared to DFA and ICT, all confirmed by LDA.

CONCLUSION

Although analytically ARIES is less sensitive than LDA, the clinical performance of the assay in our tertiary care setting was comparable, and significantly better than that of the established rapid assays.

Analytical performance of the BD veritor™ system for rapid detection of influenza virus A and B in a primary healthcare setting

Background

Infections with influenza A virus cannot be clinically differentiated from infections caused by influenza B virus or other respiratory viruses. Additionally, although antiviral treatment is available for influenza A virus, it is not effective for the other viruses and must be initiated early in the course of disease for it to be effective. For these reasons, there is a need for a rapid, accurate diagnostic test for use in physicians’ offices at the time patients are seen. We report the first field performance of BD Veritor™ System for Rapid Detection of Flu A + B test compared to real time PCR. The performance of this test was compared to real time PCR performed in the Istanbul University Influenza Reference Laboratory.

Method

A single-blinded cross sectional study was conducted in nine different family medicine centers in Istanbul, Turkey between 01 November 2014 and 01 May 2015. For every patient, two specimens were collected, one for real time PCR and one for the Veritor test. Specimens for the Veritor test were immediately tested at the participating clinic according to the manufacturer’s instructions. The specimens for real time PCR were transferred to the reference laboratory.

Results

A total of 238 persons were included in the study: 72 (30 %) of the patients included in the study were below 19 years old and accepted as childhood group. Mean age of adults was 42.4 and children 10.2 years. A total of 122 patients out of 238 were positive for influenza. The clinical sensitivity and specificity of the Veritor test in all age groups was determined to be 80 and 94 %, respectively. Positive predictive value was 93 % and the negative one was 81 %.

Conclusion

Field performance of the rapid influenza test was high and found to be useful with respect to rational antiviral use, avoiding unnecessary antibiotic usage and the management of cases by the family physicians.

Utility of early influenza diagnosis through point-of-care testing in children presenting to an emergency department

AIM

Influenza causes a large burden of disease in children. Point-of-care testing (POCT) can rapidly diagnose influenza with the potential to reduce investigation and hospital admission rates, but information on its use in an Australian setting is limited.

METHODS

Through a retrospective review of laboratory-confirmed influenza cases presenting at a paediatric emergency department (ED) in 2009, we evaluated children diagnosed by POCT versus standard testing (direct fluorescent antibody, polymerase chain reaction or viral culture) and assessed differences in investigations, admission requirements, length-of-stay (LOS) in ED/hospital and antibiotic/antiviral prescription. The rate of serious bacterial infection was examined.

RESULTS

Compared with standard testing (n = 65), children diagnosed by positive POCT (n = 236) had a shorter median hospital LOS by 1 day (P = 0.006), increased antiviral prescription (odds ratio 3.31, P < 0.001) and a reduction in the time to influenza diagnosis (2.4 vs. 24.4 h, P < 0.001); however, a negative POCT result (n = 63) resulted in delayed diagnosis (44.0 h, P = 0.001). POCT did not decrease LOS in ED. Interpretation of reductions in admission and investigations with POCT may be limited by possible confounding. Approximately 4% of influenza patients had a serious bacterial infection; urinary tract infections were commonest (2.7%), but no cerebrospinal fluid cultures were positive. A single positive blood culture was seen among 332 immunocompetent influenza patients.

CONCLUSIONS

Influenza diagnosis by POCT was quicker and reduced LOS of hospitalised children, whereas negative results delayed diagnosis. Negative POCT should not alter usual investigations if influenza remains suspected. A controlled prospective study during the influenza season is needed to clarify the direct benefits of POCT.

Performance of rapid SOFIA Influenza A+B test compared to Luminex x-TAG respiratory viral panel assay in the diagnosis of influenza A, B, and subtype H3

Influenza is an acute respiratory illness caused by influenza A or B viruses that occur in outbreaks, mainly during the winter season. Rapid laboratory diagnosis of influenza can help guide the clinical management of suspected patients effectively. Clinical sensitivities and specificities of the rapid influenza diagnostic tests have varied considerably in the literature. Most of these studies are evaluated using previously frozen or stored specimens that had previously tested positive. This study compares the performance of the rapid SOFIA Influenza A+B test to nucleic acid multiplex test x-TAG respiratory viral panel (RVP) assay in freshly collected nasal aspirates and measured simultaneously by both assays. Retrospective data from 1649 nasal aspirates (September 2014 to May 2015) collected from adults as well as from children tested simultaneously by both rapid SOFIA Influenza A+B FIA immunofluorescence (Quidel, San Diego, CA) and qualitative nucleic acid multiplex RVP assay X-TAG Luminex technology (Luminex, Austin, Texas, USA) were analyzed. Concordance, and analytical sensitivity and specificity were evaluated for influenza A, subtypes H1 and H3, and influenza B. Prevalence for influenza A by RVP was 15%, for subtype H3 it was 11.2%, and for influenza B, 2.9%. None of the aspirates were positive for influenza A subtype H1. SOFIA Influenza rapid test demonstrated good specificity and low sensitivity compared with a nucleic acid test for influenza A, subtype H3, and for influenza B. SOFIA Influenza A + B test performed well in providing a rapid diagnosis, however, confirmatory molecular testing is recommended for negative test results. Re-evaluation of test performance should be periodically carried out during outbreaks with the emergence and circulation of new influenza strains.

National Survey on the Impact of Viral Testing for the ED and Inpatient Management of Febrile Young Infants

OBJECTIVE

Well-appearing febrile infants with viral illnesses cannot be distinguished from those with occult life-threatening infections. Infants with respiratory viruses are less likely to have serious bacterial infections; however, current risk-stratification criteria predate widespread viral testing and there are limited data to safely inform physician management with this now common diagnostic tool. This study sought to explore the possible impact of respiratory virus testing on clinical decision-making for the management of febrile young infants<6 weeks old.

METHODS

A scenario-based survey was sent to emergency department (ED) and inpatient physicians at all 16 Canadian tertiary pediatric centers. Participants were asked questions regarding management decisions with and without results of respiratory virus testing.

RESULTS

Response rate was 78% (n=330; 190 ED, 140 inpatient). Detection of a respiratory virus reduced admission rates among 3-week-old (83% vs 95%, P<.001) and 5-week-old infants (36% vs 52%, P<.001). Similarly, empirical antibiotic treatment was decreased by detection of a respiratory virus for 3-week-old (65% vs 92%, P<.001) and 5-week-old infants (25% vs 39%, P<.001). Management of 5-week-old infants differed between ED and inpatient physicians, both in the presence and absence of a respiratory virus. There was no consensus among inpatient physicians regarding admission duration for well infants with a detectable respiratory virus and otherwise negative workup.

CONCLUSIONS

Respiratory virus testing appears to influence clinical decision-making for febrile infants<6 weeks, reducing both rates of admission and antimicrobial treatment. Important work is needed to better understand how to safely incorporate viral testing for the management of this vulnerable patient population.

Molecular diagnosis of respiratory viruses

The increasing availability of nucleic acid amplification tests since the 1980s has revolutionised our understanding of the pathogenesis, epidemiology, clinical and laboratory aspects of known and novel viral respiratory pathogens. High-throughput, multiplex polymerase chain reaction is the most commonly used qualitative detection method, but utilisation of newer techniques such as next-generation sequencing will become more common following significant cost reductions. Rapid and readily accessible isothermal amplification platforms have also allowed molecular diagnostics to be used in a ‘point-of-care’ format. This review focuses on the current applications and limitations of molecular diagnosis for respiratory viruses.

Antimicrobial Stewardship in the Emergency Department

The literature contains robust evidence on the positive impact of antimicrobial stewardship programs (ASP) in the inpatient setting. With national policies shifting toward provisions of quality health care, the impetus to expand ASP services becomes an important strategy for institutions. However data on stewardship initiatives in other settings are less characterized. For organizations with an established ASP team, it is rational to consider expanding these services to the emergency department (ED). The ED serves as an interface between the inpatient and community settings. It is often the first place where patients present for medical care, including for common infections. Challenges inherent to the fast-paced nature of the environment must be recognized for successful ASP implementation in the ED. Based on the current literature, a combination of strategies for initiating ASP services in the ED will be described. Furthermore, common scenarios and management approaches are proposed for respiratory tract, skin and soft tissue, and urinary tract infections. Expansion of ASP services across the health care continuum may improve patient outcomes with a potential associated decrease in health care costs while preventing adverse effects including the development of antibiotic resistance.