Rapid PCR Test Research Articles

Predicting Antibiotic Resistance in Gram-Negative Bacilli from Resistance Genes.

We developed a rapid high-throughput PCR test and evaluated highly antibiotic-resistant clinical isolates of Escherichia coli (n = 2,919), Klebsiella pneumoniae (n = 1,974), Proteus mirabilis (n = 1,150), and Pseudomonas aeruginosa (n = 1,484) for several antibiotic resistance genes for comparison with phenotypic resistance across penicillins, cephalosporins, carbapenems, aminoglycosides, trimethoprim-sulfamethoxazole, fluoroquinolones, and macrolides. The isolates originated from hospitals in North America (34%), Europe (23%), Asia (13%), South America (12%), Africa (7%), or Oceania (1%) or were of unknown origin (9%). We developed statistical methods to predict phenotypic resistance from resistance genes for 49 antibiotic-organism combinations, including gentamicin, tobramycin, ciprofloxacin, levofloxacin, trimethoprim-sulfamethoxazole, ertapenem, imipenem, cefazolin, cefepime, cefotaxime, ceftazidime, ceftriaxone, ampicillin, and aztreonam. Average positive predictive values for genotypic prediction of phenotypic resistance were 91% for E. coli, 93% for K. pneumoniae, 87% for P. mirabilis, and 92% for P. aeruginosa across the various antibiotics for this highly resistant cohort of bacterial isolates.

748. The Impact of a Positive Respiratory Viral Panel Among Hospitalized Adult Patients with Negative Rapid Influenza Testing at an Academic Tertiary Care Facility: A-matched Cohort Study

BackgroundMultiplex nucleic acid amplification assays (NAATs) are increasingly used to evaluate respiratory illnesses. Viral diagnosis has the potential to change clinical management and, specifically, decrease antibiotic use. However, the assays are expensive, and their effect on clinical management is unknown. This study evaluated the incremental impact of a multiplex respiratory viral panel after negative rapid influenza testing.MethodsWe completed a retrospective review of all adult patients with respiratory viral panel (RVP; GenMark) and/or rapid influenza or RSV/influenza PCR tests (PCR; Cepheid Xpert) collected within 48 hours of admission to non-ICU, inpatient units from September 1, 2015 to April 15, 2016. We matched hospitalizations with a positive RVP simultaneously with or following negative PCR testing (PCR−RVP+) 1:1 with patient encounters with negative rapid PCR testing only (PCR−). Matching of the referent PCR-group occurred without replacement based on age (±10 years), sex, race, season of testing (±50 days), and any respiratory viral test in the prior 30 days. The primary outcome was a change in management, defined as antimicrobial de-escalation (discontinuation, switch from intravenous to oral administration, and/or narrowing of spectrum), antiviral initiation, and/or change in isolation precautions.ResultsDuring the study period, there were 153 PCR−RVP+ patient encounters and 524 with PCR− testing only from which we identified 134 matched pairs. In the matched cohort, the median age was 60 years (IQR: 41–71), 47.8% were female, and 34.3% were non-White. Respiratory viral testing was associated with management change in 3.7% of PCR− and 23.9% of PCR−RVP+ patients (risk difference 20.1%; 95% CI 12.2–28.0%). Antimicrobial de-escalation did not occur after testing for any PCR- patients but did occur for 15.7% of PCR−RVP+ patients (95% CI 9.5–21.8%).ConclusionAmong patients with negative rapid influenza testing, a subsequent or simultaneous positive RVP was associated with a higher frequency of antibiotic de-escalation. This suggests multiplex NAATs could play a role in improving antimicrobial stewardship in the setting of respiratory illness.Disclosures M. Miller, GenMark: Investigator, Research support. R. Jhaveri, GenMark: Investigator, Research support.

Simulation of four respiratory viruses and inference of epidemiological parameters.

While influenza has been simulated extensively to better understand its behavior and predict future outbreaks, most other respiratory viruses have seldom been simulated. In this study, we provide an overview of four common respiratory viral infections: respiratory syncytial virus (RSV), respiratory adenovirus, rhinovirus and parainfluenza, present specimen data collected 2004–2014, and simulate outbreaks in 19 overlapping regions in the United States. Pairing a compartmental model and data assimilation methods, we infer key epidemiological parameters governing transmission: the basic reproductive number R0 and length of infection D. RSV had been previously simulated, and our mean estimate of D and R0 of 5.2 days and 2.8, respectively, are within published clinical and modeling estimates. Among the four virus groupings, mean estimates of R0 range from 2.3 to 3.0, with a lower and upper quartile range of 2.0–2.8 and 2.6–3.2, respectively. As rapid PCR testing becomes more common, estimates of the observed virulence and duration of infection for these viruses could inform decision making by clinicians and officials for managing patient treatment and response.

Individual and household characteristics of persons with Plasmodium falciparum malaria in sites with varying endemicities in Kinshasa Province, Democratic Republic of the Congo

BackgroundThe Democratic Republic of the Congo (DRC) bears a large share of global malaria burden despite efforts to control and eliminate the disease. More detailed understanding of individual and household level characteristics associated with malaria are needed, as is an understanding of how these characteristics vary spatiotemporally and across different community-level malaria endemicities. An ongoing study in Kinshasa Province is designed to address gaps in prior malaria surveillance in the DRC by monitoring malaria across seasons, age groups and in high and low malaria sites. Across seven sites, 242 households and 1591 individuals are participating in the study. Results of the enrollment questionnaire, rapid diagnostic tests and PCR testing of dried blood spots are presented.ResultsOverall malaria prevalence in the study cohort is high, 27% by rapid diagnostic test and 31% by polymerase chain reaction, and malaria prevalence is highly varied across very small geographic distances. Malaria prevalence is highest in children aged 6–15. While the majority of households own bed nets, bed net usage is less than 50%.ConclusionsThe study cohort will provide an understanding of how malaria persists in populations that have varying environmental exposures, varying community-level malaria, and varying access to malaria control efforts.

The Impact of Biofire Filmarray Respiratory Panel on Antibiotic Usage in the Emergency Department at an Academic Medical Center

BackgroundBiofire respiratory panel is a multiplex PCR test designed to detect 17 pathogens within 1 hour. It has greater sensitivity, specificity, and number of pathogens detected compared with older testing methods. The aim of this research was to evaluate the impact of Biofire respiratory panel on antibiotic usage in the emergency department (ED) of an academic medical center.MethodsThis was an observational chart review. Patients with positive RSV or influenza rapid antigen test or PCR test, and patients with a positive Biofire test were included. RSV or influenza tests were reviewed from July to December 2015, and Biofire tests were reviewed from July to December 2016. The primary outcome was to evaluate the duration of antibiotic therapy in patients with viral respiratory infections diagnosed with RSV and influenza rapid antigen and PCR testing compared with Biofire viral respiratory panel. Secondary outcomes included virus type, antibiotic prescription rates on discharge, number of addmissions, procalcitonin levels, and oseltamivir usage.ResultsIn 2016, 67% (105/155) of biofire tests were positive. The most common pathogen was rhinovirus and enterovirus (42%). Of the positive results, 23/105 (22%) received antibiotics with 6 patients having antibiotics discontinued within 72 hours. Another 6 patients had bacterial coinfections. A total of 18/105 (17%) received antibiotic prescriptions on discharge. Median days of therapy (DOT) in hospital was 1 day and median DOT for prescriptions was 8.5 days. There were 5 procalcitonin tests and no oseltamivir usage. Overall 38/105 (36%) patients were admitted to inpatient. In 2015, 3% (20/1313) of RSV (14) and influenza (6) rapid antigen and PCR tests were positive. A total of 5/20 (25%) patients received antibiotics, with 3/20 (15%) patients receiving a prescription for outpatient antibiotics. Median DOT in the hospital was 3 days and median DOT for prescriptions was 10 days. There were 2 procalcitonin tests and 2 cases used oseltamivir. Overall 19 patients were admitted.ConclusionAntibiotics are witheld in the majority of patients with positive Biofire testing. Most patients were treated with supportive care measures only. Biofire continues to be a useful tool to identify candidates for antibiotic avoidance in the ED at our institution.Disclosures All authors: No reported disclosures.

Screening for group B Streptococcus (GBS) at labour onset using PCR: accuracy and potential impact – a pilot study

This pilot study assessed the diagnostic accuracy and potential impact of a rapid PCR-based screening test for the detection of group B Streptococcus (GBS) at the onset of labour for the purpose of optimising intrapartum antibiotic prophylaxis (IAP). Vaginal and rectal swabs from a convenience sample of 158 women were analysed by conventional broth-enriched culture and a rapid PCR test. Overall, GBS carriage was 18.98% by culture and 19.62% by PCR. PCR for the detection of GBS had a sensitivity of 93.1%, specificity of 96.67% and area under the curve (AUC) of 0.95. Only 19.3% GBS-positive women received IAP. Three-fourths of babies born to GBS-positive mothers did not receive surveillance for early-onset GBS disease. Of the women who received IAP, only 32.5% were GBS carriers. Seventy-four percent of the GBS-positive mothers delivered more than 5 h after recruitment, which gives adequate swab to delivery interval for appropriate antibiotic prophylaxis in labour.Impact statementWhat is already known about this subject: Appropriate intra-partum treatment of colonized mothers reduces the risk of GBS transmission to neonates. Universal ante partum screening of pregnant women or IAP based on risk factors in labour for GBS prevention fail to accurately identify and treat the woman who actually harbors GBS in the birth canal in labour. A PCR based rapid test, allows for real-time assessment of GBS carriage in labour.What this study adds: This study highlights the fact that a large number of GBS carriers in labour, who could potentially infect their babies, do not receive IAP, and most of their babies do not receive added surveillance in the neonatal period for EOGBS disease. It also confirms that PCR testing at onset of labour is a highly sensitive and reliable test that identifies the women who are GBS carriers in labour and hence need IAP.What the implications are of these findings for clinical practice and/or further research: Timely provision of IAP for the appropriate woman is possible by adopting universal GBS screening at the onset of labor using GBS-PCR. This would involve additional costs to health care facilities and added work to laboratory personnel.

Effects of Different Environmental Factors and Virulence Factors, dupA and iceA Genes, of Helicobacter pylori on Peptic Ulcer

Background: Helicobacter pylori is colonized in stomach and has a significant etiological role in different kinds of digestive diseases. Helicobacter pylori has the ability to devastate duodenal mucus causing peptic ulcer. Breakage of stomach lining is also seen more often among people who accustomed to consume tobacco, spicy (or sour) foods, alcohol, coffee, and tranquilizers as well as those who are exposed to heavy meals and stressful-life events (stress ulcer). Also, it seems dup A and ice A genes are involved in H. pylori etiology. Objectives: This study aimed to determine the relation of jhp0917 and jhp0918 genes, ABO blood type, and some environmental factors with peptic ulcer. Methods: In our study, 500 gastric mucosal biopsy samples from digestive tract were examined by rapid urease test (RUT) and 16s rDNA PCR test for H. pylori infection followed by histopathological examinations. The dup A and ice A genes were also evaluated by PCR. Results: In H. pylori colonized peptic ulcers, dup A gene showed no significant relation with peptic ulcer. On the other hand, iceA 1 (+)/ iceA 2 (-) genotype of H. pylori showed a strong association with peptic ulcer (P < 0.05). Conclusions: ABO blood group showed no association with H. pylori infection. Peptic ulcer had a significant relationship with consumption of tobacco (P < 0.05), consumption of tranquilizers (P < 0.05), and meteorism (P < 0.05).

Impact of introduction of xpert flu assay for influenza PCR testing on obstetric patients: a quality improvement project

Objective: The aim of this project was to assess the implementation of a quality improvement project regarding the introduction of on-site influenza PCR testing in a stand-alone obstetric hospital. Methods: As part of a quality improvement project on the management of influenza in obstetric patients, the Xpert Flu assay (Cepheid Inc., Sunnyvale, CA) was introduced on-site and it replaced the previous method of PCR testing which was off-site. The main outcome measures were duration of antimicrobials, rate of admission and administration of oseltamavir in the emergency department. Results: Twenty-eight patients were included in the pre-intervention period and 45 patients were included in the post-intervention period. Following the introduction of the test, there was a statistically significant reduction seen in commencement of antimicrobials (76% pre- and 33% post-intervention), and also rate of admission (88% pre- and 45% post-intervention) while there was a statistically significant improvement in the commencement of oseltamavir in the emergency department (72% pre-and 95% post-intervention) (p < .01 for all outcomes). Conclusion: Introduction of on-site rapid influenza PCR testing can lead to a significant improvement in patient management and should be considered for introduction to other sites.

Impact of a Rapid Herpes Simplex Virus PCR Assay on Duration of Acyclovir Therapy.

Herpes simplex virus (HSV) infections of the central nervous system (CNS) are associated with significant morbidity and mortality rates in children. This study assessed the impact of a direct HSV (dHSV) PCR assay on the time to result reporting and the duration of acyclovir therapy for children with signs and symptoms of meningitis and encephalitis. A total of 363 patients with HSV PCR results from cerebrospinal fluid (CSF) samples were included in this retrospective analysis, divided into preimplementation and postimplementation groups. For the preimplementation group, CSF testing was performed using a laboratory-developed real-time PCR assay; for the postimplementation group, CSF samples were tested using a direct sample-to-answer assay. All CSF samples were negative for HSV. Over 60% of patients from both groups were prescribed acyclovir. The average HSV PCR test turnaround time for the postimplementation group was reduced by 14.5 h (23.6 h versus 9.1 h; P < 0.001). Furthermore, 79 patients (43.6%) in the postimplementation group had dHSV PCR results reported <4 h after specimen collection. The mean time from specimen collection to acyclovir discontinuation was 17.1 h shorter in the postimplementation group (31.1 h versus 14 h; P < 0.001). The median duration of acyclovir therapy was also significantly reduced in the postimplementation group (29.2 h versus 14.3 h; P = 0.01). Our investigation suggests that implementation of rapid HSV PCR testing can decrease turnaround times and the duration of unnecessary acyclovir therapy.

Impact of Xpert MRSA/SA blood culture PCR assay on management of positive blood cultures in obstetric patients: a retrospective audit.

The Xpert MRSA/SA blood culture assay (Cepheid, USA) is a rapid PCR test which can be used for positive blood cultures where Gram-positive cocci in clusters are seen. It can detect Staphylococcus aureus and also the mecA gene, which encodes for β-lactam resistance. The assay was introduced into the Rotunda Hospital for positive blood cultures to allow earlier detection of MRSA and methicillin susceptible S. aureus. To assess the impact of the Xpert MRSA/SA blood culture assay on the management of obstetric patients with a positive blood culture where Gram-positive cocci in clusters were seen. The main outcome measures were duration of intravenous antimicrobials and length of admission. Pre-intervention and post-intervention groups were identified relating to whether or not the test was in use at the time. A standardised form was used to retrospectively review the medical notes and laboratory results. There were 35 obstetric patients with positive blood cultures with Gram-positive cocci in clusters in the pre-intervention group and 22 cases in the post-intervention group. All 22 positive blood cultures in the post-intervention period were correctly identified. The antimicrobial duration was reduced from a median of 55.5-43.5h and length of admission reduced from a median of 66.5-56h (Mann-Whitney U value=161, p=0.46 and U value=256, p=0.15, respectively). This study has shown a reduction in the median duration of intravenous antimicrobials and admission; however, larger multi-centre studies are needed to evaluate this potential benefit further.

A Retrospective Study of the Impact of Rapid Diagnostic Testing on Time to Pathogen Identification and Antibiotic Use for Children with Positive Blood Cultures.

IntroductionRapid identification of bloodstream pathogens provides crucial information that can improve the choice of antimicrobial therapy for children. Previous impact studies have primarily focused on adults. Our objective was to evaluate the impact of rapid testing in a children’s hospital on time to organism identification and antibiotic use in the setting of an established antimicrobial stewardship program.MethodsWe conducted a retrospective study over three consecutive time periods (spanning January 2013–August 2015) as our hospital sequentially introduced two rapid testing methods for positive blood cultures. An antimicrobial stewardship program was active throughout the study. In the baseline period, no rapid diagnostic methods were routinely utilized. In the second period (PNAFISH), a fluorescent in situ hybridization test was implemented for gram-positive organisms and in the third a rapid multiplex PCR (rmPCR) test was employed. For children with positive blood cultures, time to organism identification use and duration of select antimicrobial therapies were compared between periods.ResultsPositive blood cultures were analyzed. Median overall time to organism identification was 23, 11, and 0 h in the baseline, PNAFISH, and rmPCR periods, respectively (p < 0.001 for both PNAFISH and rmPCR vs. baseline). For gram-negative organisms, only rmPCR performed significantly faster than baseline (p < 0.001). The duration of vancomycin use for coagulase-negative staphylococci was shorter in both the PNAFISH and rmPCR periods (mean 31 h in the baseline period, 12 and 14 h in the PNAFISH and rmPCR periods, respectively). For MSSA bacteremia, use of vancomycin was significantly decreased only in the rmPCR period (32% of patients vs. 64 and 72% in the baseline and PNAFISH periods; mean duration of 9 h vs. 30 and 26 h). There was no difference in use or duration of broad-spectrum gram-negative therapy across the three time periods.ConclusionRapid diagnostic testing for children with positive blood cultures results in faster time to identification and can influence antibiotic prescribing in the setting of active antimicrobial stewardship particularly for gram-positive pathogens.FundingMerck.

Impact of rapid influenza PCR testing on hospitalization and antiviral use: A retrospective cohort study.

Rapid PCR-based influenza tests are increasingly used as point-of-care diagnostics in hospitals and clinics. To our knowledge, no prior studies have described clinical outcomes with implementation of rapid PCR-based influenza tests in hospitalized adult inpatients. Electronic medical records were used to assess differences in laboratory testing time and antiviral use among a subset of 175 consecutive adult inpatients tested for influenza in two respiratory seasons before and after implementation of rapid PCR-based influenza testing at an academic medical center. Of the 350 hospitalized inpatients included in this analysis, 96 (27%) were over 65 years of age and 308 (88%) had a comorbid condition. The overall time to result decreased significantly from 25.2 to 1.7 hr (P < 0.001) after implementation of rapid PCR-based influenza testing. Among influenza-negative patients, the frequency of oseltamivir initiation remained unchanged (before: 43% vs. after: 45%; P = 0.60), though the median duration of oseltamivir was significantly decreased from 1.1 to 0.0 days (P < 0.001). By providing an earlier result to clinicians, rapid PCR-based influenza tests may decrease unnecessary antiviral use among adult inpatients who test negative for influenza.

Quality Control of Widely Used Therapeutic Recombinant Proteins by a Novel Real-Time PCR Approach.

Background:Existence of bacterial host-cell DNA contamination in biopharmaceutical products is a potential risk factor for patients receiving these drugs. Hence, the quantity of contamination must be controlled under the regulatory standards. Although different methods such as hybridization assays have been employed to determine DNA impurities, these methods are labor intensive and rather expensive. In this study, a rapid real-time PCR test was served as a method of choice to quantify the E. coli host- cell DNA contamination in widely used recombinant streptokinase (rSK), and alpha interferon (IFN-α) preparations. Methods: A specific primer pair was designed to amplify a sequence inside the E. coli 16S rRNA gene. Serial dilutions of DNA extracted from E. coli host cells, along with DNA extracted from Active Pharmaceutical Ingredients of rSK, and IFN-α samples were subjected to an optimized real-time PCR assay based on SYBR Green chemistry. Results:The test enabled us to detect a small quantity of genomic DNA contamination as low as 0.0002 pg in recombinant protein-based drugs. For the first time, this study showed that DNA contamination in rSK and IFN-α preparation manufactured in Pasteur Institute of Iran is much lower than the safety limit suggested by the US FDA. Conclusion:Real-time PCR is a reliable test for rapid detection of host-cell DNA contamination, which is a major impurity of therapeutic recombinant proteins to keep manufacturers’ minds on refining drugs, and provides consumers with safer biopharmaceuticals.

Rapid multiplex PCR testing may be cost effective in infants

Rapid multiplex PCR testing may be cost effective in infants

First report of mecC MRSA in human samples from Austria: molecular characteristics and clinical data.

Reports of mecC methicillin-resistant Staphylococcus aureus (MRSA) strains have been published from several European countries. We describe the first six mecC MRSA isolates of human origin from Austria and report the application of a rapid PCR test. Candidate isolates (n = 295) received between 2009 and 2013 were investigated phenotypically by cefoxitin screening and streaking on ChromID MRSA plates. The presence of mecC was confirmed in six isolates from blood cultures, wound swabs and screening samples of four female and two male patients (age range 7–89 years) by an in-house PCR method and the new Genspeed MRSA test (Greiner Bio-One, Kremsmünster, Austria). The mecC MRSA were further characterized by whole genome sequencing, multilocus sequence and spa typing. Antimicrobial susceptibility testing was performed by Eucast disk-diffusion method and Vitek 2. The six mecC MRSA isolates were from two clonal lineages (CC130, including a new single-locus variant, and CC599) and four different spa types (t843, t1535, t3256, t5930). Analysis for virulence factor genes yielded lukED, eta, etd2 and edin-B (CC130 isolates) and tst, lukED, eta and sel (ST599 isolates). The Genspeed MRSA test identified mecC in all isolates whereas Vitek 2 failed to detect methicillin resistance in one isolate. The strains were susceptible to a wide range of non-β-lactam antibiotics. All patients were successfully treated or decolonized. mecC MRSA are present in Austria as colonizers but may also cause infections. Thus, laboratories must choose appropriate test methods such as cefoxitin screening and confirmation using molecular assays specifically targeting mecC.

PO-0209 Clinical Feature Of Hospitalised Children With Influenza Infection For Nine Years

The relation between influenza subtype and age, clinical symptoms, diagnosis, and clinical course was reviewed in hospitalised children in winter season annually since 2005 to 2014 respectively. The diagnosis of influenza was made by rapid diagnostic test kit or PCR test. The clinical features in each type of influenza were evaluated according to respiratory (R: pneumonia), neurological (N; seizure, abnormal behaviour), encephalopathy (E), and other symptoms (O;persistent fever, dehydration, gastroenteritis and others). The differential test for 2009 H1N1 was not performed in 2013–14 season. Results 292 (180 boys, and 112 girls) cases were admitted due to influenza antigen positive disease in this study period. Seasonal type A was 128 (R; 45, N44, E;5, O;33), 2009 H1N1 was 95 (R:55, N;23, E;3, O;14), and type B was 69 (R;27, N;21, E;2, O;19) cases. 2009 H1N1 virus was detected only in2009–10 and 2010–11 seasons. The age distribution (0y/1–5y/6–10y/11y-) of these children was 26/64/32/6 in seasonal A, 10/24/40/21 in 2009 H1N1, and 1/33/29/6in type B. All children recovered and discharged without major complication. In respiratory disorder, percutaneous Oxygen saturation at admission was lower in 2009 H1N1 (median 88%) than seasonal A (96) or B (98), but total admission period was not longer. Conclusion Rapid diagnostic kit is useful to know the origin of fever when patient should be admitted. The results support to understand the clinical picture of age related symptoms.

Multicriteria Evaluation of Classical Swine Fever Control Strategies Using the Choquet Integral

An outbreak of the highly contagious animal disease classical swine fever (CSF) requires the selection of an optimal control strategy. The choice of a control strategy is a decision process depending on different aspects. Besides epidemiology, economic and ethical/social aspects must be taken into account. In this study, multicriteria decision-making (MCDM) was used to evaluate six control strategies for two regions with different farm densities. A strategy including only the minimum EU control measures and the traditional control strategy based on preventive culling were compared to alternative control strategies using emergency vaccination and/or rapid PCR testing ('emergency vaccination', 'test to slaughter', 'test to control' and 'vaccination in conjunction with rapid testing'). The MACBETH approach was used in order to assess the three main criteria (epidemiology, economics and ethical/social aspects). Subcriteria with both quantitative and qualitative performance levels were translated into a normalized scale. The Choquet integral approach was adopted to obtain a ranking of the six CSF control strategies based on the three main criteria, taking interactions into account. Three different rankings of the importance of the main criteria, which were to reflect the potential perceptions of stakeholders, were examined. Both the region under investigation and the ranking of the main criteria had an influence on the 'best' choice. Alternative control strategies were favourable to the minimum EU control and the traditional control measures independent of the farm density. Because the choice of the 'best' control strategy does not solely depend on the epidemiological efficiency, MCDM can help to find the best solution. Both MACBETH and the Choquet integral approach are feasible MCDM approaches. MACBETH only needs a qualitative evaluation and is therefore a comparatively intuitive approach. The Choquet integral does not only take the importance of the criteria into account but also the interaction between them.

Intrapartum detection of Group B streptococci colonization by rapid PCR-test on labor ward

ObjectiveGroup B streptococci (GBS) may lead to early onset neonatal sepsis with severe morbidity and mortality of newborns. Intrapartum detection of GBS is needed. The objective was to compare a PCR-based test performed in the laboratory versus labor ward. Study design300 patients were included prospectively. In phase I, swabs were analyzed by selective culture and rapid PCR in the laboratory. In phase II, swabs were analyzed accordingly, but the PCR test was conducted in labor ward. Test performances were analyzed and compared. ResultsIn phase I the rapid PCR test had a sensitivity of 85.71% and a specificity of 95.9%. The GBS colonization rate was 18.67%. Overall 8.5% of the PCR results were invalid. In phase II the PCR test showed a sensitivity of 85.71% and a specificity of 95.65%. The GBS colonization rate was 23.3%. Overall 23.5% of swabs tested with PCR were invalid. Initiation of specific, short 2-hour training for operating personnel in the labor ward reduced the invalid test rate to 13.4%. ConclusionThe rapid PCR-based test yields adequate results to identify GBS colonization when performed in labor ward. In order to reduce the number of invalid tests a short training period is needed.

Comparison of different control strategies for classical swine fever using emergency vaccination and rapid PCR testing by using a Monte-Carlo simulation model

Abstract. Whenever an outbreak of classical swine fever has occurred in the European Union (EU), the basic control measures have usually been supplemented by preventive culling. This strategy has led to a great number of culled pigs and is discussed by general public and politics from both ethical and economic points of view. Emergency vaccination has been deemed to be an alternative control measure for some time now. PCR testing also provides a possible future strategy, since this method would allow a rapid and reliable testing of pigs in the vicinity of an outbreak farm. In this study, a spatial and temporal Monte-Carlo simulation model was used to compare alternative control strategies based upon these two measures (»Emergency Vaccination«, »Test To Slaughter«, »Test To Control« and »Vaccination in conjunction with Rapid Testing«) with the current control strategy. Two regions for investigation with different farm densities were used in the model. In a region with a low farm density, the basic EU control measures seemed to be sufficient to control an epidemic. In a region with a high farm density, additional measures would be necessary. »Emergency Vaccination« in a 3 km application zone and »Traditional Control« reached the same level of infected farms. Both »Test To Slaughter« and »Test To Control« combined with preventive culling led to a lower number of infected farms compared to the sole preventive culling strategy. The alternative control measures can reduce the number of culled farms significantly compared to »Traditional Control«.

Rapid detection of glycopeptide-resistant enterococci: impact on decision-making and costs

BackgroundAccording to French national recommendations, the detection of a patient colonized with glycopeptide-resistant enterococci (GRE) leads to interruption of new admissions and transfer of contact patients (CPs) to another unit or healthcare facility, with weekly screening of CPs.FindingsWe evaluated the medical and economic impact of a pragmatic adaptation of national guidelines associated with a real-time PCR (RTP) (Cepheid Xpert™ vanA/vanB) as part of the strategy for controlling GRE spread in two medical wards. Screening was previously performed using chromogenic selective medium (CSM). Turn around time (TAT), costs of tests and cost of missed patient days were prospectively collected. In February 2012, the identification of GRE in one patient in the diabetology ward led to the screening of 31 CPs using CSM; one secondary case was identified in a CP already transferred to the Nephrology ward. Awaiting the results of SCM (median TAT, 70.5 h), 41 potential patient days were missed, due to interruption of admissions. The overall cost (screening tests + missing patient.days) was estimated at 14, 302.20 €. The secondary case led to screening of 22 CPs in the Nephrology ward using RTP. Because of a short median TAT of 4.6 h, we did not interrupt admissions and patients’ transfers. Among 22 CPs, 19 (86%) were negative for vanA, 2 were positive for vanB and 3 had invalid results needing CSM. The overall cost of the strategy was estimated at 870.40 € (cost of screening tests only), without missing patient days.ConclusionThe rapid PCR test for vanA-positive GRE detection both allowed rapid decision about the best infection control strategy and prevented loss of income due to discontinuation of patient transfers and admissions.