Relative Contribution of Diagnostic Testing to the Diagnosis of Respiratory Syncytial Virus in Hospitalized Adults in the United States.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of acute respiratory illness (ARI) in older adults. Optimizing diagnosis could improve understanding of RSV burden. METHODS: We enrolled adults ≥50 years of age hospitalized with ARI and adults of any age hospitalized with congestive heart failure or chronic obstructive pulmonary disease exacerbations at two hospitals during two respiratory seasons (2018-2020). We collected nasopharyngeal (NP) and oropharyngeal (OP) swabs (n=1558), acute and convalescent sera (n=568), and expectorated sputum (n=153) from participants, and recorded standard-of-care (SOC) NP results (n=805). We measured RSV antibodies by two immunoassays and performed BioFire testing on respiratory specimens. RESULTS: Of 1,558 eligible participants, 92 (5.9%) tested positive for RSV by any diagnostic method. Combined NP/OP PCR yielded 58 positives, while separate NP and OP testing identified 11 additional positives (18.9% increase). Compared to Study NP/OP PCR alone, the addition of paired serology increased RSV detection by 42.9% (28 vs 40) among those with both specimen types, while the addition of SOC swab RT-PCR results increased RSV detection by 25.9% (47 vs 59). CONCLUSIONS: The addition of paired serology testing, SOC swab results, and separate testing of NP and OP swabs improved RSV diagnostic yield in hospitalized adults.

Evaluation of a BioFire multiplex PCR panel for detection of joint infections using retrospective and prospectively collected specimens.

The BioFire Joint Infection Panel (JI panel) is a newly FDA-approved multiplex PCR assay for detection of common bone and joint pathogens with 39 targets which include select Gram-positive and Gram-negative bacteria, yeast, and antimicrobial resistance genes. We evaluated the performance of the JI panel in detecting joint infections in our patient population. Sixty-three frozen, residual joint fluid specimens were retrospectively tested using the JI panel. An additional 104 residual joint fluid specimens were de-identified and prospectively tested within 1 week of collection. Results from routine bacterial cultures were used as the reference standard, which included inoculation to agar plates and blood culture bottles. For the frozen specimens, the JI panel showed a positive percent agreement (PPA) of 92.8% and a negative percent agreement (NPA) of 97.1%. PPA was 71.4% and NPA was 94.8% for fresh specimens. A total of 12 discrepancies were observed among the 167 specimens tested. The JI panel demonstrated good overall agreement with routine culture for the detection of joint infections and may improve timely diagnosis when used in conjunction with bacterial culture. However, potential false-positive and false-negative results were observed in both retrospective and prospective testing of specimens.IMPORTANCEThe BioFire JI panel is a new commercially available multiplex PCR assay for detecting common pathogens causing bone and joint infections. The test is performed directly on joint fluids with a fast turnaround time of 1 hour. Our study shows that while the JI panel overall shows good agreement with routine culture, discrepancies were observed in 7% of cases and results should be interpreted with appropriate clinical context.

Multiplex real-time PCR FilmArray performance in the diagnosis of meningoencephalitis: lights and shadows.

PURPOSE: We aimed to evaluate the performance of the FilmArray (FA) meningitis/encephalitis (ME) panel. Secondarily, we analyzed the false positive (FP) and false negative (FN) results, as well as the predictive values of the technique, regarding the cerebrospinal fluid (CSF) characteristics. METHODS: FA is a multiplex real-time PCR detecting 14 of the most common ME pathogens in CSF. All FA performed at our hospital (2018-2022) were retrospectively reviewed. FA was compared to conventional techniques and its performance was assessed based on the final diagnosis of the episode. RESULTS: FA was performed in 313 patients with suspicion of ME. Most patients had altered mental status (65.2%) and fever (61%). Regarding CSF characteristics, 49.8% and 53.7% presented high CSF proteins and pleocytosis, respectively. There were 84 (26.8%) positive FA results, mainly for HSV-1 (10.9%), VZV (5.1%), Enterovirus (2.6%), and S. pneumoniae (1.9%). In the 136 cases where both FA and routine methods were performed, there was a 25.7% lack of agreement. We identified 6.6% FN results, but 28.6% FP, mainly due to HSV-1. This resulted in a high negative predictive value (NPV) of 93.4%, but a positive predictive value (PPV) of 73%. Remarkably, PPV as low as 36.9%, and 70.2%, were found in cases without pleocytosis, or lack of high CSF protein levels, respectively. CONCLUSION: FA was associated with high NPV, but frequent FP results and low PPV, particularly for HSV-1, and especially in patients without high CSF protein levels or pleocytosis.

Evaluation of the clinical relevance of the Biofire© FilmArray pneumonia panel among hospitalized patients.

PURPOSE: Panel PCR tests provide rapid pathogen identification. However, their diagnostic performance is unclear. We assessed the performance of the Biofire© FilmArray pneumonia (PN)-panel against standard culture in broncho-alveolar lavage (BAL) samples. METHODS: Setting: University Hospital Basel (February 2019 to July 2020), including hospitalized patients with a BAL (± pneumonia). We determined sensitivity and specificity of the PN-panel against standard culture. Using univariate logistic regression, we calculated odds ratios (OR) for pneumonia according to PN-panel and culture status, stratifying by chronic pulmonary disease. We calculated ORs for pneumonia for different pathogens to estimate the clinical relevance. RESULTS: We included 840 adult patients, 60% were males, median age was 68 years, 35% had chronic pulmonary disease, 21% had pneumonia, and 36% had recent antibiotic use. In 1078 BAL samples, bacterial pathogens were detected in 36% and 16% with PN-panel and culture, respectively. The overall sensitivity and specificity of the PN-panel was high, whereas the positive predictive value was low. The OR of pneumonia was 1.1 (95% CI 0.7-1.6) for PN-panel-positive only; 2.6 (95% CI 1.3-5.3) for culture-positive only, and 1.6 (95% CI 1.0-2.4) for PN-panel and culture-positive. The detection rate of Haemophilus influenzae, Staphylococcus aureus, and Moraxella catarrhalis in the PN-panel was high but not associated with pneumonia. CONCLUSION: While sensitivity and specificity of PN-panel are high compared to culture, pathogen detection did not correlate well with a pneumonia diagnosis. Patients with culture-positive BAL had the highest OR for pneumonia-thus the impact of the PN-panel on clinical management needs further evaluation in randomized controlled trials.

Evaluation and clinical practice of pathogens and antimicrobial resistance genes of BioFire FilmArray Pneumonia panel in lower respiratory tract infections.

BACKGROUND: Existing panels for lower respiratory tract infections (LRTIs) are slow and lack quantification of important pathogens and antimicrobial resistance, which are not solely responsible for their complex etiology and antibiotic resistance. BioFire FilmArray Pneumonia (PN) panels may provide rapid information on their etiology. METHODS: The bronchoalveolar lavage fluid of 187 patients with LRTIs was simultaneously analyzed using a PN panel and cultivation, and the impact of the PN panel on clinical practice was assessed. The primary endpoint was to compare the consistency between the PN panel and conventional microbiology in terms of etiology and drug resistance, as well as to explore the clinical significance of the PN panel. The secondary endpoint was pathogen detection using the PN panel in patients with community-acquired pneumonia (CAP) or hospital-acquired pneumonia (HAP). RESULTS: Fifty-seven patients with HAP and 130 with CAP were included. The most common pathogens of HAP were Acinetobacter baumannii and Klebsiella pneumoniae, with the most prevalent antimicrobial resistance (AMR) genes being CTX-M and KPC. For CAP, the most common pathogens were Haemophilus influenzae and Staphylococcus aureus, with the most frequent AMR genes being CTX-M and VIM. Compared with routine bacterial culture, the PN panel demonstrated an 85% combined positive percent agreement (PPA) and 92% negative percent agreement (NPA) for the qualitative identification of 13 bacterial targets. PN detection of bacteria with higher levels of semi-quantitative bacteria was associated with more positive bacterial cultures. Positive concordance between phenotypic resistance and the presence of corresponding AMR determinants was 85%, with 90% positive agreement between CTX-M-type extended-spectrum beta-lactamase gene type and phenotype and 100% agreement for mecA/C and MREJ. The clinical benefit of the PN panel increased by 25.97% compared with traditional cultural tests. CONCLUSION: The bacterial pathogens and AMR identified by the PN panel were in good agreement with conventional cultivation, and the clinical benefit of the PN panel increased by 25.97% compared with traditional detection. Therefore, the PN panel is recommended for patients with CAP or HAP who require prompt pathogen diagnosis and resistance identification.

The impact of the BIOFIRE® Blood Culture Identification 2 Panel on antimicrobial treatment of children with suspected systemic inflammatory response syndrome and sepsis.

This study aimed to assess the therapeutic effects of implementing the BioFire® Blood Culture Identification 2 (BCID2) Panel (bioMérieux, Marcy l'Etoile, France) in the clinical practice of children with sepsis. This retrospective cross-sectional study included children from 15 days of age to 18 years old with sepsis and of whom the BCID2 Panel was studied from the positive blood culture. If the antimicrobial treatment was changed according to the results of BCID2 Panel, it was recorded and re-grouped as targeted antimicrobial therapy, de-escalation of the antimicrobial treatment and shifting to another antimicrobial drug if any antimicrobial resistance was detected. Seven-days and thirty-days mortality rate was recorded. Thirty-two patients with 36 septic episodes with positive BCID2 Panel results were included. The median age was 10 months 15 days (ranging from 15 days to 16.5 years). The mean difference between having positive results by the BCID2 Panel and conventional culture methods was 82.2 ± 45.4 h (ranging from 12.3 to 207 h). Effect of the BCID2 Panel on the antimicrobial treatment was detected in 69.4% of the episodes (n = 25). Glycopeptides were ceased at 6 patients, piperacillin/tazobactam was ceased at 6 patients, and cefotaxime was ceased at one patient and de-escalation was achieved in 13 episodes which formed the 36.1% of the initial antimicrobial treatment.   Conclusion: The BCID2 Panel had an important impact on the patients care and optimization according to the principles of antimicrobial stewardship. The BCID2 Panel may be one of the key items for rapid and accurate diagnosis in children with sepsis. Blood culture is still the mainstay for especially detection of antimicrobial drug resistance, while BCID2 tests had several advantages such as speed and diagnostic accuracy as good as blood culture. What is Known: • The BioFire® Blood Culture Identification 2 (BCID2) Panel (bioMérieux, Marcy l'Etoile, France) is a well-validated assay that allows for the simultaneous identification of 43 nucleic acid targets associated with bloodstream infections within about 1 h. What is New: • BCID2 Panel had a direct impact on the patient's treatment decision at the 69.4% of the sepsis episodes. • The clinicians received the microbiological results 82.2 h earlier with BCID2 panel compared to blood culture methods with antimicrobial resistance and de-escalation of the antimicrobial drugs was achieved at 13 episodes which formed the 36.1% of the initial treatment.

Impact of Rapid Molecular Multiplex Gastrointestinal Pathogen Testing in Management of Children during a Shigella Outbreak.

Fecal culture for isolation and identification of Shigella may take days. The BioFire FilmArray Gastrointestinal (GI) panel (bioMérieux, France) is a PCR-based assay that detects enteric pathogens including Shigella/enteroinvasive Escherichia coli (EIEC) in about an hour. The aim of this study was to evaluate the impact of GI panel detection of Shigella in a pediatric emergency department (ED) during an outbreak. Stool samples from children with acute gastroenteritis were tested by the GI panel. Test results were either withheld in preintervention (PRE) or reported to clinicians/families in the postintervention (POST) period. The impact of the GI panel testing on patient management and outcomes was measured. Shigella/EIEC was identified by the GI panel in the PRE (n = 30) and POST (n = 21) phase. The GI panel detected more Shigella infections than did culture; six of 31 (19.4%) Shigella GI panel-positive patients who also had stool cultures were missed by culture. Azithromycin therapy was prescribed for 20% of subjects in the PRE phase and 71.4% of subjects in the POST phase (P < 0.001). Time from the clinical encounter until starting azithromycin therapy was shorter in the POST phase (n = 9), 8.25 h (range, 6.37 to 52.37 h), than in the PRE phase (n = 1), 72 h. Six subjects in the PRE phase visited additional providers compared with one in the POST phase. Prompt diagnosis of shigellosis with the GI panel may provide the opportunity for prompt antimicrobial therapy and avoid additional visits to providers due to early definitive diagnosis. Prompt diagnosis of Shigella at an ED visit may optimize patient management and reduce transmission.

Diagnostic utility of oropharyngeal swabs as an alternative to lower respiratory tract samples for PCR-based syndromic testing in patients with community-acquired pneumonia.

Syndromic PCR-based analysis of lower respiratory tract (LRT) samples in patients with community-acquired pneumonia (CAP) improves the bacterial yield and time-to-results compared to culture-based methods. However, obtaining adequate sputum samples can be challenging and is frequently not prioritized in the emergency department (ED). In this study, we assess the concordance of microbiological detections between oropharyngeal- (OP) and LRT samples from patients presenting to the ED with CAP using a syndromic PCR-based respiratory panel [Biofire FilmArray Pneumonia plus (FAP plus)]. Paired OP- and high-quality LRT samples were collected from 103 patients with confirmed CAP, who had been included in a randomized controlled trial (NCT04660084) or a subsequent observational study at Haukeland University Hospital, and analyzed using the FAP plus. The LRT samples were obtained mainly by sputum induction (88%). Using the LRT samples as a reference standard, the positive percent agreement (PPA), negative percent agreement (NPA), and overall percent agreement for the most common bacterial pathogens in CAP, Streptococcus pneumoniae and Haemophilus influenzae, were 85%, 99% and 95%, and 86%, 98% and 93%, respectively. For Moraxella catarrhalis, the PPA was lower (74%), while the NPA was 100%. For bacteria that are less likely causes of uncomplicated CAP (e.g., Staphylococcus aureus and Enterobacterales) the results were more divergent. In conclusion, the FAP plus detects the most common CAP pathogens S. pneumoniae and H. influenzae from OP samples with high PPAs and excellent NPAs when compared with LRT samples. For these pathogens, the PPAs for OP samples were higher than previous reports for nasopharyngeal samples. This suggests that analysis of OP samples with syndromic PCR panels could represent an alternative approach for rapid microbiological testing in the ED, especially in patients where LRT samples are difficult to obtain. Divergent results for bacteria that are less likely to cause uncomplicated CAP do, however, emphasize the need for clinical evaluation of positive test results.

Performance and Hypothetical Impact on Joint Infection Management of the BioFire Joint Infection Panel: a Retrospective Analysis.

Pathogen identification is key in septic arthritis. Culture-based techniques are challenging, especially when patients have been pretreated with antibiotics or when difficult-to-culture bacteria are encountered. The BioFire joint infection assay (BJA) is a multiplex PCR panel which detects 31 of the most prevalent bacterial and fungal pathogens causing septic arthritis. Here, 123 cryoconserved contemporary synovial fluid samples from 120 patients underwent BJA analysis. Results were compared to those of culture-based diagnostics (standard of care [SOC]). Clinical data were collected, and the possible impact of the molecular diagnostic application on patient management was evaluated. Fifteen of 123 synovial fluid cultures grew bacterial pathogens. All on-panel pathogens (9/15) were correctly identified by the BJA. The BJA identified four additional bacterial pathogens in four SOC-negative cases. BJA sensitivity and specificity were 100% (95% confidence interval [CI], 69.2% to 100%) and 100% (95% CI, 96.8% to 100%), respectively. Compared to the SOC, the BJA would have resulted in faster provision of species identification and molecular susceptibility data by 49 h and 99 h, respectively. Clinical data analysis indicates that in BJA-positive cases, faster species ID could have led to timelier optimization of antibiotic therapy. This retrospective study demonstrates high sensitivity and specificity of the BJA to detect on-panel organisms in bacterial arthritis. The usefulness of the BJA in prosthetic-joint infections is limited, as important pathogens (i.e., coagulase negative staphylococci and Cutibacterium acnes) are not covered. Evidence from patient data analysis suggests that the assay might prove valuable for optimizing patient management in acute arthritis related to fastidious organisms or for patients who received antibiotics prior to specimen collection.

Comparison of bacterial culture with BioFire® FilmArray® multiplex PCR screening of archived cerebrospinal fluid specimens from children with suspected bacterial meningitis in Nigeria.

BACKGROUND: Diagnosis of bacterial meningitis remains a challenge in most developing countries due to low yield from bacterial culture, widespread use of non-prescription antibiotics, and weak microbiology laboratories. The objective of this study was to compare the yield from standard bacterial culture with the multiplex nested PCR platform, the BioFire® FilmArray® Meningitis/Encephalitis Panel (BioFire ME Panel), for cases with suspected acute bacterial meningitis. METHODS: Following Gram stain and bacterial culture on cerebrospinal fluid (CSF) collected from children aged less than 5 years with a clinical suspicion of acute bacterial meningitis (ABM) as defined by the WHO guidelines, residual CSF specimens were frozen and later tested by BioFire ME Panel. RESULTS: A total of 400 samples were analyzed. Thirty-two [32/400 (8%)] of the specimens were culture positive, consisting of; three Salmonella spp. (2 Typhi and 1 non-typhi), three alpha hemolytic Streptococcus, one Staphylococcus aureus, six Neisseria meningitidis, seven Hemophilus influenzae, 11 Streptococcus pneumoniae and 368 were culture negative. Of the 368 culture-negative specimens, the BioFire ME Panel detected at least one bacterial pathogen in 90 (24.5%) samples, consisting of S. pneumoniae, N. meningitidis and H. influenzae, predominantly. All culture positive specimens for H. influenzae, N. meningitidis and S. pneumoniae also tested positive with the BioFire ME Panel. In addition, 12 specimens had mixed bacterial pathogens identified. For the first time in this setting, we have data on the viral agents associated with meningitis. Single viral agents were detected in 11 (2.8%) samples while co-detections with bacterial agents or other viruses occurred in 23 (5.8%) of the samples. CONCLUSIONS: The BioFire® ME Panel was more sensitive and rapid than culture for detecting bacterial pathogens in CSF. The BioFire® ME Panel also provided for the first time, the diagnosis of viral etiologic agents that are associated with meningoencephalitis in this setting. Institution of PCR diagnostics is recommended as a routine test for suspected cases of ABM to enhance early diagnosis and optimal treatment.

Identification of microorganisms by a rapid PCR panel from positive blood cultures leads to faster optimal antimicrobial therapy - a before-after study.

BACKGROUND: The BioFire® FilmArray® Blood Culture Identification Panel 1 (BF-FA-BCIP) detects microorganisms with high accuracy in positive blood cultures (BC) - a key step in the management of patients with suspected bacteraemia. We aimed to compare the time to optimal antimicrobial therapy (OAT) for the BF-FA-BCIP vs. standard culture-based identification. METHODS: In this retrospective single-centre study with a before-after design, 386 positive BC cases with identification by BF-FA-BCIP were compared to 414 controls with culture-based identification. The primary endpoint was the time from BC sampling to OAT. Secondary endpoints were time to effective therapy, length of stay, (re-)admission to ICU, in-hospital and 30-day mortality. Outcomes were assessed using Cox proportional hazard models and logistic regressions. RESULTS: Baseline characteristics of included adult inpatients were comparable. Main sources of bacteraemia were urinary tract and intra-abdominal infection (19.2% vs. 22.0% and 16.8% vs. 15.7%, for cases and controls, respectively). Median (95%CI) time to OAT was 25.5 (21.0-31.2) hours with BF-FA-BCIP compared to 45.7 (37.7-51.4) hours with culture-based identification. We observed no significant difference for secondary outcomes. CONCLUSIONS: Rapid microorganism identification by BF-FA-BCIP was associated with a median 20-h earlier initiation of OAT in patients with positive BC. No impact on length of stay and mortality was noted. TRIAL REGISTRATION: Clinicaltrials.gov, NCT04156633, registered on November 5, 2019.

Diagnostic accuracy of the BioFire® FilmArray® pneumonia panel in COVID-19 patients with ventilator-associated pneumonia.

BACKGROUND: Ventilator-Associated pneumonia (VAP) is one of the leading causes of morbidity and mortality in critically ill COVID-19 patients in lower-and-middle-income settings, where timely access to emergency care and accurate diagnostic testing is not widely available. Therefore, rapid microbiological diagnosis is essential to improve effective therapy delivery to affected individuals, preventing adverse outcomes and reducing antimicrobial resistance. METHODS: We conducted a cross-sectional study of patients with suspected VAP and COVID-19, evaluating the diagnostic performance of the BioFire® FilmArray® Pneumonia Panel (FA-PP). Respiratory secretion samples underwent standard microbiological culture and FA-PP assays, and the results were compared. RESULTS: We included 252 samples. The traditional culture method detected 141 microorganisms, and FA-PP detected 277, resulting in a sensitivity of 95% and specificity of 60%, with a positive predictive value of 68% and negative predictive value of 93%. In samples with high levels of genetic material (> 10^5 copies/mL), the panel had a sensitivity of 94% and specificity of 86%. In addition, 40% of the culture-negative samples had positive FA-PP® results, of which 35% had > 10^5 copies/mL of genetic material. The most prevalent bacteria were Gram-negative bacilli, followed by Gram-positive cocci. The panel identified 98 genes associated with antimicrobial resistance, predominantly extended-spectrum beta-lactamases (28%). CONCLUSION: The FA-PP is a sensitive assay for identifying bacteria causing VAP in patients with COVID-19, with a greater capacity to detect bacteria than the conventional method. The timely microbiological recognition offered by this panel could lead to optimized decision-making processes, earlier tailored treatment initiation, and improved antibiotic stewardship practices.

Clinical impact of biofire gastrointestinal panel testing for hospitalised children with acute gastroenteritis.

AIM: To investigate the clinical impact of BioFire FilmArray Gastrointestinal Panel (FGP) testing in real-life diarrhoeal episodes of hospitalised paediatric patients. METHODS: Children hospitalised between October 2018 and September 2020 for whom stool specimens for FGP were submitted at the clinician's discretion were retrospectively observed. For each episode, demographics, clinical information and stool tests were collected. RESULTS: The clinical impact for each case was evaluated by changing the antibiotic prescription, following the result of the FGP testing. Out of 140 diarrhoeal episodes, 25 pathogens were found in 24 cases using conventional methods, whereas, FGP testing identified 75 pathogens in 56 cases (p < 0.05). The pathogens more frequently identified by FGP testing were Campylobacter, Shigella, Rotavirus, Giardia lamblia and Cryptosporidium. The clinical impact of FGP testing was observed in 17/140 (12%) diarrhoeal episodes, and higher rates in previously healthy (19%) and solid organ-transplanted children (15%). CONCLUSION: We found that using FGP testing for hospitalised children with diarrhoeal episodes could increase pathogen identification and impact clinical decisions, especially in healthy and transplant patients.

Multicenter Evaluation of the BioFire Respiratory Panel 2.1 (RP2.1) for Detection of SARS-CoV-2 in Nasopharyngeal Swab Samples.

As the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) begins to overlap with the traditional respiratory season in the Northern Hemisphere, simultaneous testing for SARS-CoV-2 and the other common causes of respiratory infections is imperative. This has led to the development of multiplex respiratory assays that include SARS-CoV-2 as a target. One such assay is the BioFire respiratory panel 2.1 (RP2.1), which is an expansion of the original BioFire FilmArray respiratory panel 2 (RP2) to include SARS-CoV-2. In this multicenter evaluation, we assessed the performance characteristics of the BioFire RP2.1 for the detection of SARS-CoV-2. One or more targets on the panel were detected in 19.3% (101/524) of specimens tested, with SARS-CoV-2 detected in 12.6% (66/524) of specimens. Human rhinovirus/enterovirus was also detected in 32.7% (33/101) and adenovirus in 3.0% (3/101) of positive specimens, with one dual positive for both SARS-CoV-2 and adenovirus being detected. A further breakdown of pathogens by age revealed a 4-fold predominance of human rhinovirus/enterovirus in subjects 0 to 18 years of age, whereas in all other age groups, SARS-CoV-2 was clearly the predominant pathogen. Overall, SARS-CoV-2 results obtained from the BioFire RP2.1 were highly concordant with the composite result, exhibiting 98.4% (61/62) positive percent agreement (95% confidence interval [CI], 91.4 to 99.7%) and 98.9% (457/462) negative percent agreement (95% CI, 97.5 to 99.5%) with further analysis of discordant results suggesting that the concentration of SARS-CoV-2 in the specimens was near the limit of detection (LoD) for both the BioFire RP2.1 and the comparator assays. Overall, the BioFire RP2.1 exhibited excellent performance in the detection of SARS-CoV-2.

Comparison of next generation diagnostic systems (NGDS) for the detection of SARS-CoV-2.

INTRODUCTION: The World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a pandemic in March 2020. Initially, supply chain disruptions and increased demand for testing led to shortages of critical laboratory reagents and inadequate testing capacity. Thus, alternative means of biosample collection and testing were essential to overcome these obstacles and reduce viral transmission. This study aimed to 1) compare the sensitivity and specificity of Cepheid GeneXpert® IV and BioFire® FilmArray® 2.0 next generation detection systems to detect SARS-CoV-2, 2) evaluate the performance of both platforms using different biospecimen types, and 3) assess saline as an alternative to viral transport media (VTM) for sample collection. METHODS: A total of 1,080 specimens consisting of nasopharyngeal (NP) swabs in VTM, NP swabs in saline, nasal swabs, oropharyngeal (OP) swabs, and saliva were collected from 216 enrollees. Limit of detection (LoD) assays, NP VTM and NP saline concordance, and saliva testing were performed on the BioFire® FilmArray® 2.0 Respiratory Panel 2.1 and Cepheid GeneXpert® Xpress SARS-CoV-2/Flu/RSV assays. RESULTS: LoD and comparative testing demonstrated increased sensitivity with the Cepheid compared with the BioFire® in detecting SARS-CoV-2 in NP VTM and saline, nasal, and OP swabs. Conversely, saliva testing on the Cepheid showed statistically significant lower sensitivity compared to the BioFire® . Finally, NP swabs in saline showed no significant difference compared with NP swabs in VTM on both platforms. CONCLUSION: The Cepheid and BioFire® NGDS are viable options to address a variety of public health needs providing rapid and reliable, point-of-care testing using a variety of clinical matrices.

A Hierarchical Genotyping Framework Using DNA Melting Temperatures Applied to Adenovirus Species Typing.

Known genetic variation, in conjunction with post-PCR melting curve analysis, can be leveraged to provide increased taxonomic detail for pathogen identification in commercial molecular diagnostic tests. Increased taxonomic detail may be used by clinicians and public health decision-makers to observe circulation patterns, monitor for outbreaks, and inform testing practices. We propose a method for expanding the taxonomic resolution of PCR diagnostic systems by incorporating a priori knowledge of assay design and sequence information into a genotyping classification model. For multiplexed PCR systems, this framework is generalized to incorporate information from multiple assays to increase classification accuracy. An illustrative hierarchical classification model for human adenovirus (HAdV) species was developed and demonstrated ~95% cross-validated accuracy on a labeled dataset. The model was then applied to a near-real-time surveillance dataset in which deidentified adenovirus detected patient test data from 2018 through 2021 were classified into one of six adenovirus species. These results show a marked change in both the predicted prevalence for HAdV and the species makeup with the onset of the COVID-19 pandemic. HAdV-B decreased from a pre-pandemic predicted prevalence of up to 40% to less than 5% in 2021, while HAdV-A and HAdV-F species both increased in predicted prevalence.

Performance of BioFire array or QuickVue influenza A + B test versus a validation qPCR assay for detection of influenza A during a volunteer A/California/2009/H1N1 challenge study.

BACKGROUND: Influenza places a significant burden on global health and economics. Individual case management and public health efforts to mitigate the spread of influenza are both strongly impacted by our ability to accurately and efficiently detect influenza viruses in clinical samples. Therefore, it is important to understand the performance characteristics of available assays to detect influenza in a variety of settings. We provide the first report of relative performance between two products marketed to streamline detection of influenza virus in the context of a highly controlled volunteer influenza challenge study. METHODS: Nasopharyngeal swab samples were collected during a controlled A/California/2009/H1N1 influenza challenge study and analyzed for detection of virus shedding using a validated qRT-PCR (qPCR) assay, a sample-to-answer qRT-PCR device (BioMerieux BioFire FilmArray RP), and an immunoassay based rapid test kit (Quidel QuickVue Influenza A + B Test). RESULTS: Relative to qPCR, the sensitivity and specificity of the BioFire assay was 72.1% [63.7-79.5%, 95% confidence interval (CI)] and 93.5% (89.3-96.4%, 95% CI) respectively. For the QuickVue rapid test the sensitivity was 8.5% (4.8-13.7%, 95% CI) and specificity was 99.2% (95.6-100%, 95% CI). CONCLUSION: Relative to qPCR, the BioFire assay had superior performance compared to rapid test in the context of a controlled influenza challenge study.

Point-of-care multiplex-PCR enables germ identification in haemolytic uremic syndrome 94 h earlier than stool culture.

Haemolytic uremic syndrome often affects children causing a relevant morbidity and mortality. We compared the time to diagnosis by multiplex-PCR and stool culture in 15 children from two centres. Multiplex-PCR accelerated the time to diagnosis by 94 (95% confidence interval, 80-119; P = 0.0007) hours. Multiplex-PCR offers a time advantage of stool culture that may aid in earlier identification of outbreak clusters.

Multinational evaluation of the BioFire® FilmArray® Pneumonia plus Panel as compared to standard of care testing.

This study compared standard of care testing (SOC) to BioFire® FilmArray® Pneumonia plus Panel (PNplus). PNplus detects 15 bacteria with semiquantitative log bin values, 7 antibiotic resistance markers, three atypical bacteria (AB), and eight viral classes directly from bronchoalveolar lavage-like specimens (BLS) and sputum-like specimens (SLS). Fifty-two laboratories from 13 European countries and Israel tested 1234 BLS and 1242 SLS with PNplus and SOC. Detection rates and number of pathogens/samples were compared for PNplus pathogens. PNplus bin values and SOC quantities were compared. Three thousand two hundred sixty-two bacteria in PNplus were detected by PNplus and/or SOC. SOC detected 57.1% compared to 95.8% for PNplus (p ≤ 0.0001). PNplus semiquantitative bin values were less than SOC, equal to SOC, or greater than SOC in 5.1%, 25.4%, and 69.6% of results, respectively. PNplus bin values were on average ≥ 1 log than SOC values (58.5% 1-2 logs; 11.0% 3-4 logs). PNplus identified 98.2% of MRSA and SOC 55.6%. SOC detected 73/103 AB (70.9%) and 134/631 viruses (21.2%). PNplus detected 93/103 AB (90.3%) and 618/631 viruses (97.9%) (p ≤ 0.0001). PNplus and SOC mean number of pathogens/samples were 1.99 and 1.44, respectively. All gram-negative resistance markers were detected. PNplus and SOC results were fully or partially concordant for 49.1% and 26.4% of specimens, respectively. PNplus was highly sensitive and detected more potential pneumonia pathogens than SOC. Semiquantification may assist in understanding pathogen significance. As PNplus generates results in approximately 1 h, PNplus has potential to direct antimicrobial therapy in near real time and improve antimicrobial stewardship and patient outcomes.

Rapid molecular detection of airway pathogens in lung transplant recipients.

BACKGROUND: Airway infections are difficult to distinguish from acute rejection in lung transplant recipients. Traditional culture techniques take time that may delay treatment. We hypothesized that a rapid multiplex molecular assay could improve time to diagnosis and appropriate clinical decision making. METHODS: In a prospective observational study of recipients undergoing bronchoscopy, we assessed the BioFire® FilmArray® Pneumonia Panel (BFPP) in parallel to standard of care (SOC) diagnostics. Research clinicians performed shadow (research only) clinical decision making in real time. Time to report and interpretation were reported as median and interquartile ranges and compared by Wilcoxon signed-ranked test. Agreement was defined based on detection of any species targeted in the molecular assay. RESULTS: For the 150 enrolled subjects, BFPP results were available 3.8 hours (IQR 2.8-5.1) following bronchoscopy, compared to 13 hours for viral SOC (IQR 10-34, P < .001) results and 48 hours for bacterial SOC (IQR 46-70, P < .001) results. Positive BFPP results were interpreted in 9 hours (IQR 5-20) following bronchoscopy, compared to 74 hours for SOC (IQR 37-110, P < .001). Assays agreed for 138 (92%) of the 150 subjects. Of 22 BFPP diagnoses, five (23%) resulted in a shadow antibiotic recommendation. Notable BFPP deficiencies included fungal species and H parainfluenzae, accounting for 15 (27%) and 13 (23%) of the 56 actionable SOC results, respectively. CONCLUSIONS: This molecular diagnostic including bacterial targets has the potential to shorten time to diagnosis and augment current clinical decision making but cannot replace SOC culture methods.