Impact of diagnostic procedures on patient management and hospitalization cost during the 2000 and 2005 enterovirus epidemics in Marseilles, France

Use, Safety Assessment, and Implementation of Two Point-of-Care Tests for COVID-19 Testing

Objectives

The Abbot ID NOW COVID-19 assay and Quidel Sofia 2 SARS Antigen FIA are point-of-care assays that offer rapid testing for severe acute respiratory syndrome coronavirus 2 viral RNA and nucleocapsid protein, respectively. Given the utility of these devices in the field, we investigated the feasibility and safety of using the ID NOW and Sofia assays in the public health response to the coronavirus disease 2019 pandemic and in future public health emergencies.

Methods

A combination of utilization and contamination testing in addition to a review of instrument workflows was conducted.

Results

Utilization testing demonstrated that both tests are intuitive, associated with high user test success (85%) in our study, and could be implemented by staff after minimal training. Contamination tests revealed potential biosafety concerns due to the open design of the ID NOW instrument and the transfer mechanisms with the Sofia. When comparing the workflow of the ID NOW and the Sofia, we found that the ID NOW was more user-friendly and that the transfer technology reduces the chance of contamination.

Conclusions

The ID NOW, Sofia, and other emerging point-of-care tests should be used only after careful consideration of testing workflow, biosafety risk mitigations, and appropriate staff training.

Economic analysis of rapid multiplex polymerase chain reaction testing for meningitis/encephalitis in adult patients

PURPOSE

Many patients with suspected meningitis do not require hospitalization yet are admitted, often resulting in unnecessary care and additional cost. We assessed the possible economic impact of a rapid multiplex test for suspected adult community-acquired meningitis/encephalitis.

METHODS

A model simulated diagnosis, clinical decisions, resource use/costs of standard of care (SOC) and two cerebrospinal fluid (CSF) testing strategies using the FDA-cleared BioFire® FilmArray® System (FA) which provides results in approximately one hour.

RESULTS

Pathogens detected by FA caused approximately 74% of cases, 97% of which would be accurately diagnosed with FA. False positives and false negatives more often led to extended/unnecessary admission than inappropriate discharge/missed admission. Mean cost per case ranged from 16829 to 20791. A strategy of testing all suspected cases yielded greater savings (2213/case) than testing only those with abnormal CSF (812/case) and both were less expensive than SOC.

CONCLUSION

This economic analysis demonstrates that FA can inform more appropriate clinician decisions resulting in cost savings with greater economic benefits achievable with syndromic testing of all cases, rather than SOC or targeted syndromic testing.

Can point-of-care testing shorten hospitalization length of stay? An exploratory investigation of infectious agents using regression modelling

This retrospective study investigates the potential benefits from the introduction of point-of-care tests for rapid diagnosis of infectious diseases. We analysed a sample of 441 hospitalized patients who had received a final diagnosis related to 18 pathogenic agents. These pathogens were mostly detected by standard tests but were also detectable by point-of-care testing. The length of hospital stay was partitioned into pre- and post-laboratory diagnosis stages. Regression analysis and elementary queueing theory were applied to estimate the impact of quick diagnosis on the mean length of stay and the utilization of healthcare resources. The analysis suggests that eliminating the pre-diagnosis times through point-of-care testing could shorten the mean length of hospital stay for infectious diseases by up to 34 per cent and result in an equal reduction in bed occupancy and other resources. Regression and other more sophisticated models can aid the financing decision-making of pilot point-of-care laboratories in healthcare systems.

Economic analysis of rapid multiplex polymerase chain reaction testing for meningitis/encephalitis in pediatric patients

AIM

We assessed the possible economic impact of a rapid test in pediatric patients with suspected community-acquired meningitis/encephalitis.

MATERIALS & METHODS

Modeling simulated diagnosis, clinical decisions, resource use/costs of standard of care (SOC) and two cerebrospinal fluid testing strategies using FilmArray^® (FA), a US FDA-cleared system that provides results in approximately 1 h.

RESULTS

Pathogens detected by FA caused approximately 75% of cases, 97% of which would be accurately diagnosed with FA.  Mean cost/case ranged from $17,599 to $22,025.  Syndromic testing is less expensive than SOC. Testing all suspected cases yielded greater savings ($3481/case) than testing only those with abnormal cerebrospinal fluid ($2157/case).

CONCLUSION

Greater economic benefits are achievable with syndromic testing of all cases, rather than SOC or targeted syndromic testing.

Comparison of enterovirus detection in cerebrospinal fluid with Bacterial Meningitis Score in children

Objective

To measure the role of enterovirus detection in cerebrospinal fluid compared with the Bacterial Meningitis Score in children with meningitis.

Methods

A retrospective cohort based on analysis of medical records of pediatric patients diagnosed as meningitis, seen at a private and tertiary hospital in São Paulo, Brazil, between 2011 and 2014. Excluded were patients with critical illness, purpura, ventricular shunt or recent neurosurgery, immunosuppression, concomitant bacterial infection requiring parenteral antibiotic therapy, and those who received antibiotics 72 hours before lumbar puncture.

Results

The study included 503 patients. Sixty-four patients were excluded and 94 were not submitted to all tests for analysis. Of the remaining 345 patients, 7 were in the Bacterial Meningitis Group and 338 in the Aseptic Meningitis Group. There was no statistical difference between the groups. In the Bacterial Meningitis Score analysis, of the 338 patients with possible aseptic meningitis (negative cultures), 121 of them had one or more points in the Bacterial Meningitis Score, with sensitivity of 100%, specificity of 64.2%, and negative predictive value of 100%. Of the 121 patients with positive Bacterial Meningitis Score, 71% (86 patients) had a positive enterovirus detection in cerebrospinal fluid.

Conclusion

Enterovirus detection in cerebrospinal fluid was effective to differentiate bacterial from viral meningitis. When the test was analyzed together with the Bacterial Meningitis Score, specificity was higher when compared to Bacterial Meningitis Score alone.

The Point-of-Care Laboratory in Clinical Microbiology

Point-of-care (POC) laboratories that deliver rapid diagnoses of infectious diseases were invented to balance the centralization of core laboratories. POC laboratories operate 24 h a day and 7 days a week to provide diagnoses within 2 h, largely based on immunochromatography and real-time PCR tests. In our experience, these tests are conveniently combined into syndrome-based kits that facilitate sampling, including self-sampling and test operations, as POC laboratories can be operated by trained operators who are not necessarily biologists. POC laboratories are a way of easily providing clinical microbiology testing for populations distant from laboratories in developing and developed countries and on ships. Modern Internet connections enable support from core laboratories. The cost-effectiveness of POC laboratories has been established for the rapid diagnosis of tuberculosis and sexually transmitted infections in both developed and developing countries.

Characteristics and outcomes of human parechovirus infection in infants (2008-2012)

Human parechoviruses (HPeVs) cause a spectrum of disease ranging from self-limiting illness to severe disease and, sometimes, death. We describe the clinical characteristics and outcomes of HPeV infection in infants. The study describes the clinical and laboratory characteristics and outcomes of infants with HPeV infection during 2008-2012, from three paediatric hospitals in London each with a paediatric intensive care unit. The infants were retrospectively identified through laboratory and patient discharge databases and diagnosed through HPeV PCR. Fifty infants were identified. Half required admission to PICU. Infants less than 3 months were more likely to require PICU (16/25: p < 0.01). Clinical signs at presentation were often indistinguishable from those of bacterial sepsis and meningitis, but inflammatory markers were nearly always (95 % of cases) within normal ranges. Brain MRI showed white matter changes in 10/12 infants. Three of 19 infants with follow-up data (16 %) had significant neurological sequelae.

CONCLUSION

HPeV may cause severe disease and long-term neurological sequelae in young infants. HPeV should be considered in infants with clinical features of sepsis/meningitis with normal CSF microscopy. Prospective observational studies are warranted to better define the epidemiology of infection and thus inform future treatment trials.

Rapid detection of enterovirus in cerebrospinal fluid by a fully-automated PCR assay is associated with improved management of aseptic meningitis in adult patients

BACKGROUND

Enterovirus (EV) is the most frequent cause of aseptic meningitis (AM). Lack of microbiological documentation results in unnecessary antimicrobial therapy and hospitalization.

OBJECTIVES

To assess the impact of rapid EV detection in cerebrospinal fluid (CSF) by a fully-automated PCR (GeneXpert EV assay, GXEA) on the management of AM.

STUDY DESIGN

Observational study in adult patients with AM. Three groups were analyzed according to EV documentation in CSF: group A = no PCR or negative PCR (n=17), group B = positive real-time PCR (n = 20), and group C = positive GXEA (n = 22). Clinical, laboratory and health-care costs data were compared.

RESULTS

Clinical characteristics were similar in the 3 groups. Median turn-around time of EV PCR decreased from 60 h (IQR (interquartile range) 44-87) in group B to 5h (IQR 4-11) in group C (p<0.0001). Median duration of antibiotics was 1 (IQR 0-6), 1 (0-1.9), and 0.5 days (single dose) in groups A, B, and C, respectively (p < 0.001). Median length of hospitalization was 4 days (2.5-7.5), 2 (1-3.7), and 0.5 (0.3-0.7), respectively (p < 0.001). Median hospitalization costs were $5458 (2676-6274) in group A, $2796 (2062-5726) in group B, and $921 (765-1230) in group C (p < 0.0001).

CONCLUSIONS

Rapid EV detection in CSF by a fully-automated PCR improves management of AM by significantly reducing antibiotic use, hospitalization length and costs.

Enterovirus infections in England and Wales, 2000-2011: the impact of increased molecular diagnostics

There have recently been significant changes in diagnostic practices for detecting enterovirus (EV) infections across England and Wales. Reports of laboratory-confirmed EV infections submitted by National Health Service (NHS) hospital laboratories to Public Health England (PHE) over a 12-year period (2000-2011) were analysed. Additionally, the PHE Virus Reference Department (VRD) electronic database containing molecular typing data from 2004 onwards was interrogated. Of the 13,901 reports, there was a decline from a peak of 2254 in 2001 to 589 in 2006, and then an increase year-on-year to 1634 in 2011. This increase coincided with increasing PCR-based laboratory diagnosis, which accounted for 36% of reported cases in 2000 and 92% in 2011. The estimated annual incidence in 2011 was 3.9/100,000 overall and 238/100,000 in those aged <3 months, who accounted for almost one-quarter of reported cases (n = 2993, 23%). During 2004-2011, 2770 strains were submitted for molecular typing to the VRD, who found no evidence for a predominance of any particular strain. Thus, the recent increase in reported cases closely reflects the increase in PCR testing by NHS hospitals, but is associated with a lower proportion of samples being submitted for molecular typing. The high EV rate in young infants merits further investigation to inform evidence-based management guidance.

Virological point-of-care testing for the developing world

ABSTRACT: 

The goal of point-of-care testing is to provide fast, convenient, and easy-to-use diagnostic assays that shorten the turnaround time of intervention. Several diagnostic tests have already migrated from the centralized laboratory to patients’ bedside, physician offices and domestic environments in more developed countries. However, the situation is dramatically different in countries of the developing world where lack of facilities and resources still results in diagnosis to be inferred mostly from the symptoms only. Reliable and rapid diagnosis is urgently needed particularly in case of viral diseases with the concrete risk of outbreaks going undetected in the early stages. In this article we will advocate the necessity to implement robust point-of-care testing for viral diseases to overcome the diagnostic gap of less developed countries.

[Aseptic meningitis in an adult population. Etiology and utility of molecular techniques in the clinical management of patients]

OBJECTIVE

This study describes the epidemiological, clinical and microbiological features of acute aseptic meningitis (AAM) in an adult population, and evaluates the impact of microbiological results on the clinical management of patients.

PATIENTS AND METHODS

Cases of AAM were prospectively collected between 2007 and 2010 among immunocompetent patients over 14 years-old. Enteroviruses and herpes viruses were determined using nucleic acids detection in CSF. Demographic and clinical data were retrospectively collected from medical records.

RESULTS

A total of 94 patients were included, of whom 84 were diagnosed with viral meningitis (VM). The annual incidence of VM ranged from 2.4 to 15.3 cases per 100,000 inhabitants. An aetiological diagnosis was obtained in 76.2% of the patients with VM, 55 enterovirus, 4 HSV-2, 3 VZV, one HSV-1, and one EBV. Forty five per cent of patients were admitted to hospital and 65.8% of them received antibiotic treatment. A positive result prompted immediate discharge of 80% of inpatients and discontinuation of antibiotic therapy in 94.1% of them. The median duration of admission to hospital in these patients was 2.8±2.9 days. Patients without available results during admission completed the antibiotic treatment, and the median hospital stay was 11.6±4.6 days.

CONCLUSIONS

The annual incidence of AAM is variable. Enteroviruses were the main aetiological agent. Molecular tests revealed the aetiology in 76.2% of cases. Almost half of the patients required hospitalisation, and in these cases a positive result can lead to the immediate discharge of patients, and the diagnostic and therapeutic interventions can be reduced.

Comparative detection of enterovirus RNA in cerebrospinal fluid: GeneXpert system vs. real-time RT-PCR assay

Enteroviruses (EVs) constitute the most common cause of aseptic meningitis in both children and adults. Molecular techniques have now been recognized as the reference standard for the diagnosis of EV infections, and the rapidity of the molecular diagnosis of EV meningitis has been shown to be a determining factor in the management of patients. The rapid documentation of EV RNA in cerebrospinal fluid (CSF) is key to adapting patient management and the therapeutic regimen. To shorten the time needed for virological documentation, we implemented EV RNA detection in two point-of-care (POC) laboratories. Here, we present the results of the POC detection of EV RNA with the Xpert EV kit on the GeneXpert integrated system, and a comparison with the real-time RT-PCR (rtRT-PCR) assay routinely used in the core virology laboratory. From January to September 2009, a total of 310 CSF samples were tested. The rtRT-PCR gave 81 positive, 225 negative and four 'indeterminate' results. POC results were concordant in 81.6% (253/310). Most of the discrepancies consisted of 'indeterminate' results at the POC level (16%). Calculated performances (excluding the indeterminate results) of the Xpert EV kit on the GeneXpert system in POC settings were 100%, 98.9%, 97.6% and 100% for Sensibility, Specificity, positive predictive value and negative predictive value, respectively. Taken together, these results indicate that the implementation of POC detection of EV RNA can provide robust results in <4 h, and may have a significant impact on patient management, therapeutic attitude, and hospitalization costs.

Revolutionizing clinical microbiology laboratory organization in hospitals with in situ point-of-care

BACKGROUND

Clinical microbiology may direct decisions regarding hospitalization, isolation and anti-infective therapy, but it is not effective at the time of early care. Point-of-care (POC) tests have been developed for this purpose.

METHODS AND FINDINGS

One pilot POC-lab was located close to the core laboratory and emergency ward to test the proof of concept. A second POC-lab was located inside the emergency ward of a distant hospital without a microbiology laboratory. Twenty-three molecular and immuno-detection tests, which were technically undemanding, were progressively implemented, with results obtained in less than four hours. From 2008 to 2010, 51,179 tests yielded 6,244 diagnoses. The second POC-lab detected contagious pathogens in 982 patients who benefited from targeted isolation measures, including those undertaken during the influenza outbreak. POC tests prevented unnecessary treatment of patients with non-streptococcal tonsillitis (n = 1,844) and pregnant women negative for Streptococcus agalactiae carriage (n = 763). The cerebrospinal fluid culture remained sterile in 50% of the 49 patients with bacterial meningitis, therefore antibiotic treatment was guided by the molecular tests performed in the POC-labs. With regard to enterovirus meningitis, the mean length-of-stay of infected patients over 15 years old significantly decreased from 2008 to 2010 compared with 2005 when the POC was not in place (1.43±1.09 versus 2.91±2.31 days; p = 0.0009). Altogether, patients who received POC tests were immediately discharged nearly thrice as often as patients who underwent a conventional diagnostic procedure.

CONCLUSIONS

The on-site POC-lab met physicians' needs and influenced the management of 8% of the patients that presented to emergency wards. This strategy might represent a major evolution of decision-making regarding the management of infectious diseases and patient care.

Routine use of point-of-care tests: usefulness and application in clinical microbiology

Point-of-care (POC) tests offer potentially substantial benefits for the management of infectious diseases, mainly by shortening the time to result and by making the test available at the bedside or at remote care centres. Commercial POC tests are already widely available for the diagnosis of bacterial and viral infections and for parasitic diseases, including malaria. Infectious diseases specialists and clinical microbiologists should be aware of the indications and limitations of each rapid test, so that they can use them appropriately and correctly interpret their results. The clinical applications and performance of the most relevant and commonly used POC tests are reviewed. Some of these tests exhibit insufficient sensitivity, and should therefore be coupled to confirmatory tests when the results are negative (e.g. Streptococcus pyogenes rapid antigen detection test), whereas the results of others need to be confirmed when positive (e.g. malaria). New molecular-based tests exhibit better sensitivity and specificity than former immunochromatographic assays (e.g. Streptococcus agalactiae detection). In the coming years, further evolution of POC tests may lead to new diagnostic approaches, such as panel testing, targeting not just a single pathogen, but all possible agents suspected in a specific clinical setting. To reach this goal, the development of serology-based and/or molecular-based microarrays/multiplexed tests will be needed. The availability of modern technology and new microfluidic devices will provide clinical microbiologists with the opportunity to be back at the bedside, proposing a large variety of POC tests that will allow quicker diagnosis and improved patient care.

Point of care strategy for rapid diagnosis of novel A/H1N1 influenza virus

BACKGROUND

Within months of the emergence of the novel A/H1N1 pandemic influenza virus (nA/H1N1v), systematic screening for the surveillance of the pandemic was abandoned in France and in some other countries. At the end of June 2009, we implemented, for the public hospitals of Marseille, a Point Of Care (POC) strategy for rapid diagnosis of the novel A/H1N1 influenza virus, in order to maintain local surveillance and to evaluate locally the kinetics of the pandemic.

METHODOLOGY/PRINCIPAL FINDINGS

Two POC laboratories, located in strategic places, were organized to receive and test samples 24 h/24. POC strategy consisted of receiving and processing naso-pharyngeal specimens in preparation for the rapid influenza diagnostic test (RIDT) and real-time RT-PCR assay (rtRT-PCR). This strategy had the theoretical capacity of processing up to 36 samples per 24 h. When the flow of samples was too high, the rtRT-PCR test was abandoned in the POC laboratories and transferred to the core virology laboratory. Confirmatory diagnosis was performed in the core virology laboratory twice a day using two distinct rtRT-PCR techniques that detect either influenza A virus or nA/N1N1v. Over a period of three months, 1974 samples were received in the POC laboratories, of which 111 were positive for nA/H1N1v. Specificity and sensitivity of RIDT were 100%, and 57.7% respectively. Positive results obtained using RIDT were transmitted to clinical practitioners in less than 2 hours. POC processed rtRT-PCR results were available within 7 hours, and rtRT-PCR confirmation within 24 hours.

CONCLUSIONS/SIGNIFICANCE

The POC strategy is of benefit, in all cases (with or without rtRT-PCR assay), because it provides continuous reception/processing of samples and reduction of the time to provide consolidated results to the clinical practitioners. We believe that implementation of the POC strategy for the largest number of suspect cases may improve the quality of patient care and our knowledge of the epidemiology of the pandemic.

Point of care strategy for rapid diagnosis of novel A/H1N1 influenza virus

In late June 2009, we implemented for public hospitals of Marseille Point Of Care strategy for rapid diagnosis of novel A/H1N1 influenza virus. During two months, we have tested more than 900 specimens in both Point Of Care laboratories. We believe that implementation of Point of Care strategy for the largest number of suspects cases may improve quality of patients care and our knowledge of the epidemiology of the pandemic.