bluuebunny/crossref_metadata_2025 huggingface dataset:
A-205 Evaluating the Cost and Importance of Supply Chain Resilience in the Clinical Laboratory
Authors: Jurinic E
Published: October 2024

Background

Recent pandemics, epidemics and outbreaks continually underscore the critical importance of resilient supply chains in healthcare, particularly in clinical laboratories where timely access to supplies is essential for patient care. Supply chain disruptions, whether due to global crises or localized challenges, can significantly impact laboratory operations, leading to delayed diagnoses, compromised patient outcomes, and increased costs. It is estimated that 70%-80% of a patients’ EMR is clinical laboratory results. Despite this, supply chain resilience in clinical laboratories remains an under-addressed issue and remains a buzzword.

Methods

To evaluate the cost and importance of supply chain resilience in the clinical laboratory, we conducted a comprehensive review and interviews with 9 Healthcare Supply Chain experts analyzing the impact of supply chain disruptions on laboratory operations and patient care. Data was also collected from a diverse range of clinical laboratories, including hospitals, independent labs, and research institutions, spanning different geographic regions as well as a survey of 50 Laboratory experts with a 50% response rate. Key metrics assessed included: -Frequency and duration of supply chain disruptions. -Financial costs incurred due to disruptions, including expenses related to expedited shipping, alternative sourcing, and inventory management. -Impact on laboratory workflow, turnaround times, and patient care outcomes. -Strategies employed to mitigate supply chain risks and enhance resilience.

Results

Our review revealed findings regarding the cost and importance of supply chain resilience in the clinical laboratory: -Supply chain disruptions were frequent, with 85% of laboratories experiencing at least one significant disruption in the past year and 100% in experienced disruptions 2022. -The average duration of disruptions was 2-3 weeks, leading to substantial delays in test processing and patient care. -Financial costs associated with disruptions averaged $50,000 per laboratory per annum, including expenses for rush orders, and premium-priced alternatives. -Common strategies employed were increased inventory or safety stocks, multi-vendor sourcing, and supply chain mapping.

Conclusions

The findings of this study underscore the critical importance of supply chain resilience in the clinical laboratory. Supply chain disruptions are not just inconveniences; they pose significant risks to patient safety, operational efficiency, and financial sustainability. Investing in supply chain resilience is imperative for laboratories to fulfill their mission of delivering timely and accurate patient results. To continue to enhance supply chain resilience, laboratories must adopt a proactive approach, leveraging data-driven insights and collaborative partnerships. This includes diversifying supplier networks and fostering closer collaboration between laboratory and procurement teams.
A-210 Ldl-c to non-hdl-c ratio method: a simple way to determine bias for ldl-c methods on hypertriglyceridemic samples
Authors: Gcingca T A , Sampson M , Meeusen J W , Donato L J , Jaffe A S , Remaley A T
Published: October 2024

Background

Beta-quantification (BQ) is the reference method for LDL-C but is not widely available. It is difficult, therefore, for clinical laboratories to independently assess the accuracy of their methods for either calculating or directly measuring LDL-C. Our goal was to investigate if an interrelationship between the tests in the standard lipid panel could be used to compare the performance of different LDL-C methods against BQ, specifically in samples with hypertriglyceridemia, a major cause of bias for LDL-C testing.

Methods

BQ results from Mayo Medical Labs (n=39,667) and the NIH (n=18,338) were used to identify a linear relationship by least-squares regression analysis between lipid panel test results and LDL-C to facilitate a statistical comparison between different LDL-C methods.

Results

It is well established that the number of VLDL particles increases as TG increases, because VLDL is the main carrier of TG. As a consequence, the ratio of LDL-C to non-HDL-C is inversely related to TG, which can be made linear by taking the square root of TG (Figure). Nearly identical regression equations were found for this relationship, using two different BQ datasets. When LDL-C was calculated by either Sampson equation, the LDL-C/non-HDL-C regression lines nearly overlapped with the one for BQ. In contrast, the Martin equation showed a positive bias with increasing TG, whereas the Friedewald equation showed a negative bias, consistent with past reports on their LDL-C biases with hypertriglyceridemia. In the UKBiobank, the Beckman direct LDL-C showed a positive bias for TG, which was confirmed in CAP proficiency test surveys. By simulation analysis, approximately 80 samples with high (>200 mg/dL) and low (<100 mg/dL) TG is statistically sufficient to assess if the LDL-C/non-HDL-C regressions lines of LDL-C methods differ from BQ.

Conclusions

The LDL-C/non-HDL-C ratio method is a simple way to examine LDL-C methods for bias on hypertriglyceridemic samples.
A-213 Comparison of low-density lipoprotein cholesterol (LDL-c) estimates by in-lab and point-of-care devices in the context of emerging LDL-c equations
Authors: Hubler Z , Roper S
Published: October 2024

Background

Low-density lipoprotein cholesterol (LDL-c) and lipid measurements are used for hyperlipidemia diagnosis, cardiovascular disease risk classification, and medication management. Millions of lipid panels are performed annually. Given the widespread need for lipid testing, there are two CLIA-waived point-of-care (POC) lipid testing devices. These devices were FDA-approved using the Friedewald equation to estimate LDL-c based on measurements of (triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), and total cholesterol (TC). However, in laboratory-based testing, the Friedewald equation is being replaced by newer, more accurate equations such as the NIH-Sampson equation. These equations use the same lipid panel results to estimate LDL-c and only differ in the arithmetic of the estimation. The study objective is to evaluate how differences between the in-clinic POC machines and in-laboratory lipid measurements affect the estimated LDL-c results and are compounded by differences in the equations used for LDL-c estimation.

Methods

This retrospective observational study collected deidentified lipid results (TG, HDL-c, TC, LDL-c) and demographic data (age, gender) for all samples that had lipid panel results from in-lab and POC within twenty-four hours of each other in a single hospital system between 2014 and 2023. Three hundred twenty samples were identified; samples with non-numerical values or results outside of the reportable range for TG, HDL-c, or TC were not included in subsequent LDL-c calculations using the Friedewald and NIH-Sampson equations (69 results). Patients under the age of 18 were excluded (2 results). Two hundred and forty-nine samples met inclusion criteria; this cohort showed non-significant differences in lipid, age, and gender distributions relative to all POC results tested in the same time frame.

Results

Consistent with prior reports, we observed discordance between POC and the in-lab lipid measurements, particularly for TG (Bland-Altman: bias:-23.04 mg/dL, standard deviation:61.3 mg/dL). Regardless of the testing platform, LDL-c results are higher on an individual and population-based level with the NIH-Sampson equation. These analytical differences may not change clinical management if the cardiovascular risk classification using estimated LDL-c is unchanged. However, the risk classification based on the in-lab versus in-clinic testing differed for 20-30% of patients. The most pronounced difference in LDL-c estimation occurred when the POC machine used Friedewald and in-lab testing used NIH-Sampson, and resulted in 5% more patients differentially classified.

Conclusions

This study highlights the need for transparency in lipid panel reports regarding which LDL-c equation is used in both POC and in-lab testing formats, and the need for readily available tools for conversion between different LDL-c estimation equations.
A-216 Prevalence and status of Lipoprotein(a) in the Korean population visiting local clinics and hospitals
Authors: Jung S
Published: October 2024

Background

Lipoprotein a (Lp(a)) is a risk factor for cardiovascular disease (CVD) and has pro-atherogenic and pro-inflammatory effects. According to the Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) study, a sub-analysis was published showing that the risk of residual CVD after sufficiently lowering low-density lipoprotein cholesterol can be explained by Lp(a) concentration. The purpose of this study is to determine the prevalence of elevated Lp(a) and to analyze the characteristics of Lp(a) results by age, gender, and region in the Korean population visiting local clinics and hospitals.

Methods

We retrospectively reviewed Lp(a) test results from the Korean population who visited 117 local clinics and hospitals nationwide between February 2023 and January 2024. Serum levels of Lp(a) were measured by immunoturbidimetric assay. Lp(a) was analyzed to three age groups (<20, 20-59, ≥60 years) according to Lp(a) values (<30 or ≥30 mg/dl). One hundred seventeen local clinics and hospitals across the country were reclassified into 7 regions.

Results

A total of 15,523 patients (7,702 males and 7,821 females), aged 12-104 years, were included. The median (interquartile range, IQR) age of the population was 59 (49-69) years; the median (IQR) Lp(a) concentration was 9.7 (4.2-21.6) mg/dl. The prevalence of elevated Lp(a) levels (≥30 mg/dl) in this study was 16.7% (13.9% for males, 19.5% for females, p <0.001). Prevalence of elevated Lp(a) levels by age groups were as follows: <20 (8.9%, 5/56), 20-59 (13.9%, 1,071/7,724), ≥60 years (19.6%, 1,516/7,743). The correlation coefficient r between Lp(a) and age was 0.139 (p <0.001). No significant relationship was found between Lp(a) and region. Among 15,523 patients, the number of patients with Lp (a) level ≥100 mg/dl was 174 (n=70 for males, n=104 for females, p=0.128), and median (IQR) Lp(a) concentration was 115.1 (106.8-131.6) mg/dl. Of them, four patients showed extremely high Lp(a) levels (>180 mg/dL).

Conclusions

The prevalence of elevated Lp(a) in our population visiting local clinics and hospitals nationwide was 14.4% and differed by gender and age group. For successful management and establishment of the policy of CVD, it is important to identify the prevalence of elevated Lp(a). Future study is needed including the clinical information to confirm the present findings.
A-217 Estimation of the Prevalence and the Patterns of Dyslipidemia in the Korean population
Authors: Jung S , Hwang Y , Han G
Published: October 2024

Background

Dyslipidemia is one of the four major risk factors for the development of cardiovascular disease, along with hypertension, smoking, and diabetic mellitus. This countrywide study aimed to determine the prevalence and patterns of dyslipidemia and to describe their characteristics using data from the Korean population visiting local clinics.

Methods

We retrospectively reviewed the lipid profiles (total cholesterol (TC), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), and triglycerides (TG)) and fasting plasma glucose (FPG) test results from Korean patients visiting local clinics during December 2023. Dyslipidemia was defined as having one or more of TC ≥200 mg/dl, LDLC ≥100 mg/dl, HDLC <40 mg/dl for males and <50 mg/dl for females, or TG ≥150 mg/dl (National Cholesterol Education Program, Adult Training Program III, 2002). Glucose levels are considered hyperglycemic if blood glucose ≥126 mg/dl. The subjects comprised 1,232 patients who visited 57 local clinics nationwide were included. Lipid profile tests (except LDLC) and FPG were performed on Hitachi008AS automatic biochemistry analyzer and the LDLC test was calculated by the Friedewald equation. Data for TG ≥400 mg/dL were excluded.

Results

The study subject population comprised 610 males and 622 females aged 2 to 91 years. The overall prevalence of dyslipidemia was 53.3% (657/1,232), with 49.3% (301/657) males and 57.2 (356/657) females (p<0.001). TC, LDLC, and TG were high in 14.5% (95/657), 33.9% (184/657), and 23.6% (223/657) of patients, respectively; HDLC was low in 28.0% (155/657). The prevalence of dyslipidemia by age group was as follows: 2 to 19 years (36.4%, 4/11); 20 to 29 years (66.7%, 12/18); 30 to 39 years (52.5%, 52/99); 40 to 49 years (61.5%, 131/213); 50 to 59 years (57.0%, 167/293); 60 to 69 years (50.1%, 168/335); 70 to 79 years (48.4%, 91/188); 80 years or older, (42.7%, 32/75). There was a difference in the prevalence of dyslipidemia between the age group under 50 and the age group over 50 (p<0.001). The prevalence of dyslipidemia among males and females was TC (72.6% vs 28.4%), HDLC (55.4% vs 44.6%), LDLC (53.8% vs 46.2%), TG (42.6% vs 57.4%), respectively (p<0.001). Thirteen of the 1,232 patients had dyslipidemia accompanied by hyperglycemia. Seven of them had mixed dyslipidemia (including raised TC, LDLC, and TG (n=4), raised TG & Low HDLC (n=2), raised TC and LDLC (n=1)).

Conclusions

The prevalence of dyslipidemia in Korean patients visiting local clinics was 53.3% and differed by gender, age group, and lipid profile. Considering that the prevalence of dyslipidemia is higher in diabetic patients compared to patients without diabetes, additional studies targeting a large number of patients are needed to promote disease prevention and control.
A-222 Evaluation of the Analytical Performance of Apolipoprotein A-1, Apolipoprotein B, and Lipoprotein(a) Assays on the Atellica CI Analyzer
Authors: Huff J , Tyler C , Paudel P , Shalhoub V , Camacho J , Snyder J
Published: October 2024

Background

This study evaluated the analytical performance of the Atellica® CH Apolipoprotein A-1 (APO A1), Apolipoprotein B (APO B), and Lipoprotein(a) (Lp(a)) assays on the Atellica® CI Analyzer.

Methods

The Atellica CI assays use the same reagents and calibrators as the Atellica CH assays. Precision studies were performed according to CLSI EP05-A3 using human serum samples. Each sample was tested in duplicate in two runs per day for 20 days. MC studies were performed according to CLSI EP09-A3. Individual serum samples were analyzed using Atellica® CH and Atellica CI Analyzers.

Results

Across the three assays, repeatability CVs were <1.3%, within-lab CVs were <2.5%. Representative precision, and MC results observed for each assay across indicated sample ranges are presented in the table. Overall, slopes determined using the Deming linear regression model were approximately equal to 1.

Conclusions

Atellica CH APO A1, APO B, and Lp(a) Assays on the Atellica CI Analyzer demonstrated good precision and equivalent performance to the same assays on the Atellica CH Analyzer.
A-223 Direct LDL or not Direct-LDL, that is the question
Authors: Valaperta S , Apassiti Esposito S , Picciau A , Moioli V , Saiaci C , Marozzi R , Alessio M
Published: October 2024

Background

Management of Cardiovascular Disease (CVD) risk is dependent on Low Density Lipoprotein Cholesterol (LDL-C) levels; therefore LDL-C serves as the marker for the assessment of CVD risk and the focus of lipid lowering treatment. The gold standard reference method for measurement of LDL-C is beta-quantification. We compared calculated LDL-C with Friedewald (F-LDL-C), Martin-Hopkins (M-LDL-C) and Sampson (S-LDL-C) equations versus LDL-C directly measured (D-LDL-C). In CVD management also cholesterol ratios are evaluated. TC/HDL is associated with morbidity and mortality in the general population. Furthermore, several studies have stated that high triglycerides (TG) levels and low HDL-C (TG/HDL ratio) could function as an atherogenic index.

Methods

11399 samples were analyzed on Siemens Atellica Solution® for the lipid profile determination measuring Total Cholesterol (TC), D-LDL-C, HDL-C and TG. In the absence of additional clinical parameters, based on desirable levels for LDL-C recommended by guidelines, CVD risk was evaluated by assigning to LDL-C a cut-off of 100 mg/dL. In presence of misclassifications, we used two other parameters to assess LDL-C results: TG/HDL-C ratio and CT/HDL-C.

Results

Patients cohort had a mean age of 57.7 (±16.8) years of which 53% (age=58.6, ±15.9) were males and 47% (age=56.5, ±17.8 years) were females. Of these, the 57.7% were outpatients and 42.3% inpatients (42.1% of infectious diseases - 24.4% of the cardiovascular department). Data about LDL-C misclassification and ratio data parameters are shown in table 1. Discordant patients for D-LDL-C vs F-LDL-C are 8.5%, that of D-LDL-C vs M-LDL-C are 7.7% and D-LDL-C vs S-LDL-C are 7.2%.

Conclusions

Is known that LDL plays a central role in the pathogenesis of atherosclerosis. Accurate estimation of LDL-C is a fundamental point for the stratification of CVD risk and the achievement of the therapeutic goal; however, we are still uncertain about the best and accurate way to measure it.
A-224 Non HDL Cholesterol: could be e new cardiovascular disease risk stratification factor?
Authors: Valaperta S , Apassiti Esposito S , Moioli V , Picciau A , Saiaci C , Marozzi R , Alessio M
Published: October 2024

Background

A worldwide study demonstrated that among all modifiable risk factors of Cardiovascular Disease (CVD) to the abnormal cholesterol levels is attributable the highest risk of events. LDL-C is considered the most important lipoprotein risk factor. Some recent epidemiologic studies have suggested that non-HDL cholesterol (N-HDL-C) may be superior to LDL-C for identifying CVD risk. N-HDL-C is easily calculated from a lipid profile and represents all apolipoprotein B containing lipoproteins. Recent guidelines recommend LDL-C as a primary indicator and non-HDL-C as secondary. Moreover, cholesterol ratios are useful to stratification; the TC/HDL-C is associated with morbidity and mortality in the general population; in addition, several studies have stated that high triglycerides (TG) levels and low HDL-C are associated with increased risk and could function as atherogenic index.

Methods

11399 samples were analyzed on Atellica Solution for the determination of Total Cholesterol (TC), D-LDL-C, HDL-C and TG. In the absence of clinical parameters, based on the desirable levels recommended by the guidelines, CVD risk was evaluated by assigning a cut-off of 100 and 130 mg/dL for D-LDL-C and N-HDL-C respectively

Results

Patients cohort mean (±SD) for CT, D-LDL, HDL, TG and N-HDL-C are 180 mg/dL (±43.2), 113 mg/dL (± 38.5), 51.7 mg/dL (±15.6), 116 mg/dL (±73.8), 128 mg/dL (±39.5) respectively. Of the examined patients, the 57.7% were outpatients, 21.8% of infectious diseases and 12.6% of the cardiovascular department. Data about D-LDL-C and N-HDL-C comparison, evaluated on discordant patients, are shown in table 1.

Conclusions

The data obtained from evaluation would seem to confirm hypothesis according to which non-HDL cholesterol would have a greater power in the identification of CVD risk because of cholesterol ratios are suggestive of increased risk for patients with an LDL-C<100 and N-LDL-C>130 mg/dL. Further studies assessing CVD risk, not only through laboratory data, are necessary to confirm this supposition.
A-230 The Effect of Fasting on Serum Asymmetric Dimethylarginine (ADMA) and Symmetric Dimethylarginine (SDMA): A Report from a Large Reference Laboratory
Authors: Albeiroti S , Winchester T
Published: October 2024

Background

Asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) are metabolites of L-arginine that interfere with the production of nitric oxide (NO). NO deficiency can lead to endothelial dysfunction, which promotes atherosclerosis. High levels of ADMA are associated with increased risk for cardiovascular disease, while elevated SDMA levels correlate with reduced renal function. It is unknown whether fasting status influences ADMA and SDMA blood levels, and previously published studies are collectively inconclusive.

Methods

We performed retrospective analysis of previously reported serum ADMA and SDMA, measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). Results from self-reported fasting and non-fasting patients were compared. Fasting status was collected at the time of blood collection. Statistical significance was determined using unpaired Student's t-test.

Results

A total of 46,781 fasting and 3,136 non-fasting results were included in the analysis. The average of fasting ADMA results was 101.3 ± 17.0 ng/mL (mean ± SD) with a median of 100.0 ng/mL, while the average of non-fasting ADMA results was 100.3 ± 16.9 ng/mL with a median of 99.0 ng/mL. For SDMA, fasting and non-fasting patient averages were 107.9 ± 30.6 ng/mL and 106.6 ± 33.4 ng/mL, respectively, while fasting and non-fasting patient medians were 102.0 ng/mL and 101.0 ng/mL, respectively. Mean non-fasting ADMA and SDMA results were lower than fasting results (ADMA: %difference = -0.9% and p-value of <0.01; SDMA: %difference = -1.2% and p-value of <0.05).

Conclusions

The small difference between fasting and non-fasting ADMA and SDMA results, while statistically significant, is within analytical variation of the test, and is considered clinically insignificant. Using large sets of real patient results, we were able to demonstrate that fasting is not required for the determination of serum ADMA and SDMA. This finding simplifies ordering ADMA and SDMA along with other cardiovascular disease risk tests such as the lipid panel, which does not require fasting.
A-237 Analytical Performance Evaluation of Cytomegalovirus IgG and Syphilis Assays on the Atellica CI Analyzer
Authors: Quintanilla M , Valdivia B , Halik L , Arrode-Bruses G , Leipold H
Published: October 2024

Background

The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the Atellica IM Cytomegalovirus IgG (CMV IgG) and Syphilis (Syph) Assays on the Atellica CI Analyzer.

Methods

Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum samples. CMV IgG and Syph Assays were evaluated with one reagent lot on two Atellica CI analyzers. One aliquot of each sample was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Method comparison studies were performed according to CLSI EP12-A2. Individual native human serum samples were analyzed using the Atellica IM CMV IgG and Syph Assays on the Atellica IM and Atellica CI Analyzers. The results were assessed based on Index values distinguishing reactive (Index ≥cut-off value) and nonreactive (Index <cut-off value) specimens.

Results

As shown in table below, repeatability and within-lab %CVs for the two assays presented were <3.7% and <7.0%. Negative and positive agreement were 100% for the 111 nonreactive CMV IgG samples and the 169 CMV IgG reactive samples tested. Negative and positive agreement were 100% for the 103 Syph reactive samples and the 126 nonreactive Syph samples tested. Overall clinical agreement between each of the presented assays on the Atellica CI Analyzer and Atellica IM Analyzer was 100%.

Conclusions

Evaluation of the Atellica IM CMV IgG and Syph Assays using the Atellica CI Analyzer demonstrated acceptable precision and equivalent performance compared to the same assays on the Atellica IM Analyzer.
A-245 Evaluation of an Automated MALDI-TOF Target and Antimicrobial Susceptibility Suspension Preparation Instrument
Authors: Rice F M , Larsen J , Graf E
Published: October 2024

Background

Several studies have shown that the implementation of automation in microbiology laboratories may allow for increased volume growth without the need for additional staffing. One of the more recently available pieces of microbiology automation, the COPAN Colibri, automates the manual steps of colony spotting and preparation of targets for use on MALDI-TOF instruments for bacterial identification. This same instrument can also prepare a diluted bacterial inoculum for immediate use on automated susceptibility testing platforms. We wanted to evaluate the performance of both of these functions in real-time with clinical cultures, to determine if implementation would be beneficial over current workflows.

Methods

The COPAN Colibri was operated following the manufacturer’s recommendations with the exception of the identification of gram-positive organisms. The Colibri is FDA cleared for MALDI-TOF target spotting, however not with the use of formic acid, nor is it FDA cleared for susceptibility suspension preparation. Preliminary data suggested that addition of formic acid was necessary for accurate identification. A subset of cultures were digitally read in real-time as part of clinical workflows, selected for Colibri MALDI-TOF target spotting and Vitek2 suspension preparation using the COPAN WebApp software. Targets were run on the MALDI Bioptyper Sirius (Bruker) and suspensions were run on Vitek2 (BioMerieux) using the pre-dilution mode using GN-99 and GN-801 cards for appropriate organisms. All results were compared to standard manual workflows.

Results

A total of 145 gram-negative and 60 gram-positive organisms were picked for MALDI-target spotting on Colibri. Compared to standard testing, 144 (99%) gram-negative and 57 (95%) gram-positive Colibri spotted isolates matched expected species-level identifications. 97 Gram negative bacilli were run on Vitek 2 generating 95.52% categorical agreement across all drugs but with 13 major errors (MEs) and 2 very major errors (VMEs), which exceeded the acceptable percentage for certain drugs. The total number of failed runs was 13 (13.34% of total GNB isolates run), and all required complete resetting of MALDI-spotting and suspension preparation.

Conclusions

The Colibri performed well for MALDI-TOF target spotting with the addition of formic acid for gram-positive organisms. It did not perform within the acceptable range for susceptibility suspension preparation as it exceeded the recommended cutoffs for MEs and VMEs for certain drugs. The proportion of failed runs due to instrument errors may offset any advantages in labor savings due to the need for repeat set up.
A-246 Can CRP be used to rule in or rule out elevated procalcitonin concentrations in the emergency department?
Authors: Hawkins R
Published: October 2024

Background

C-reactive Protein (CRP) and procalcitonin (PCT) are commonly used sepsis biomarkers but have very different properties. PCT rises earlier, has a shorter half-life and is more specific for sepsis than CRP. It is however significantly more expensive. This study examined whether CRP measurement can be used to screen for the need for PCT measurement in emergency department patients.

Methods

This was a retrospective study of anonymized records of paired CRP and PCT requests from the emergency department during 2023. All testing was performed using Beckman Coulter AU 5800 (CRP) and Roche e601 (PCT). PCT results were interpreted using the 2023 AACC guidelines on PCT use (PCT<0.1 ug/L: strongly discourage antibiotic use; PCT 0.1-0.25: discourage antibiotic use; PCT 0.26-0.5: encourage antibiotic use; PCT>0.5: strongly encourage antibiotic use) and the ability of CRP to predict PCT exceeding the various cutoffs was calculated using Microsoft Excel and Analyse-It statistical add-on.

Results

There were 1645 paired results available. The CRP concentrations at 95% and 99% sensitivity and specificity levels for the various PCT cutoffs are shown in the table, together with the projected reductions in PCT testing volumes if PCT testing is restricted to samples with CRP within the ranges defined by the 95% or 99% sensitivity/specificity values. For example, from the table, for PCT>0.1 ug/L cutoff at 95% confidence, subsequent PCT measurement on the sample is only performed if CRP is between 3.4 and 90.5 mg/L.

Conclusions

Limiting PCT measurements to samples with CRP concentrations inside ranges based on the PCT cutoff of interest and the appropriate confidence level (95% or 99%) can potentially reduce PCT testing by 20-40% in emergency department patients. For laboratories which perform CRP and PCT analysis sequentially on different platforms, this approach allows significant reductions in PCT test volumes while ensuring testing is performed in equivocal cases.
A-253 Antimicrobial Susceptibility Pattern in Escherichia coli Isolated From Community-Acquired Urinary Tract Infections in the era Post-Covid-19
Authors: Ramadan-Boscolo D R , Nurmberger J M , Inoue F M , Lobo A P , de Andrade S S , Tufik S
Published: October 2024

Background

Urinary tract infections (UTI) are one of the most common infectious diseases diagnosed in the community as well as in hospitals. Community-acquired urinary tract infections caused by Escherichia coli represent the largest proportion of infectious diseases affecting women and a significant amount of oral antibiotics are prescribed daily to treat UTI in community outpatient clinics. Having knowledge of regional susceptibility data regarding E. coli is very important for selecting an appropriate empirical antibiotic. This study aimed to report the frequency and antimicrobial susceptibility of E. coli isolated from community-acquired urinary tract infections post-Covid-19 pandemic.

Methods

This study was a retrospective analysis from January to December 2023 based on the analysis of 24,019 uropathogens isolated from 182 outpatient health centers located in several regions of São Paulo city, Brazil. The urine samples were cultivated onto ChromID™CPS® agar plates by semi-quantitative technique using 1µL disposable loop, incubated at 35-37°C and the colony counting were read after 24h and 48h of incubation. The bacteria identification was performed by MALDI-TOF mass spectrometry (Vitek-MS), and the minimal inhibitory concentrations of antibiotics were determined using the Vitek®2 system, according to the manufacture’s recommendations. Only positive results with one bacterial species and a colony count ≥105 CFU/mL was considered for descriptive analysis.

Results

Of the 24,019 urine samples tested, 71.44% (17,159/24,019) were identified as Escherichia coli. The major frequency of E. coli infection occurred among women (90.48%) and the main age range was over 60 years (38.57%), while 21-30 comprised 16.5% of cases. The antimicrobial resistance profile for E. coli isolates showed 39.9% (6852/17158) of resistance to ciprofloxacin (MIC, >0.5 mg/L), 34.7% (5,921/17,075) to trimethoprim/sulfamethoxazole (MIC, >0.5 mg/L), 37.5% (6,371/17,002) to Amoxicillin/clavulanate (MIC, >8 mg/L), 8.75% (1,501/17,592) to ceftriaxone (MIC, >1 mg/L), 4.88% (837/17,138) to cefepime (MIC, >4 mg/L), 3.64% (616/16,901) to piperacillin/tazobactam (MIC, >8 mg/L), 11.07% (1,900/17,156) of gentamicin (MIC, >2 mg/L), 0.43% (74/17,158) of amikacin (MIC, >8 mg/L) and 2.23% (377/16,909) of fosfomycin (MIC, >16 mg/L). High-level of susceptibility was detected to carbapenems with 99.94% (10/17159) to ertapenem (MIC, ≤0.5 mg/L) and 99.8% (4/17,159) to meropenem (MIC, ≤2 mg/L). The rate of Extended-spectrum beta-lactamase production was 8.1% (1391/17159).

Conclusions

This data could be used locally with other related samples, to properly interpret significant resistance patterns and choose the most appropriate antimicrobial for empirical treatment of patients with community-acquired urinary tract infections.
A-254 Increase of Stenotrophomonas maltophilia Isolates Non-Susceptible to Trimethoprim-Sulfamethoxazole and/or Levofloxacin at Brazilian Hospitals
Authors: Ramadan-Boscolo D R , Nurmberger J M , Inoue F M , Lobo A P , de Andrade S S , Tufik S
Published: October 2024

Background

Stenotrophomonas maltophilia is an emerging multidrug-resistant pathogen that exhibits intrinsic and acquired resistance to a wide variety of antimicrobial agents such as β-lactams, aminoglycosides, quinolone, tetracyclines and disinfectants. In addition to that, the increased resistance to sulfamethoxazole/trimethoprim (SMX/TMP) and Levofloxacin has been reported in the past few years, leading to few therapeutic options. This study aimed to describe the increase of Stenotrophomonas maltophilia clinical isolates recovered from Brazilian hospitals over a 6-year analysis (January 2018 to December 2023).

Methods

This study design was a retrospective, observational analysis based on microbiological data of emergent BGN-NF isolates detected in several Brazilian tertiary hospitals. The bacterial identification was performed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF/MS) and the antimicrobial susceptibility profile to trimethoprim-sulfamethoxazole and levofloxacin was determined using disk-diffusion method and epsilometer method, respectively. Only one sample per patient was considered in this analysis.

Results

During the 6 year period, a total of 1,706 (2018; 221), (2019; 203), (2020; 294), (2021; 276), (2022; 294) and (2023; 418) Stenotrophomonas maltophilia strains were isolated from blood (n=626), respiratory tract (n=365), fluid and secretion (n=235), skin and soft tissue (n=162), urine (n=132), catheter tip (n=112), swab (n=36), bone fragment (n=29) and cerebrospinal fluid (n=9). The major frequency of S. maltophilia isolation occurred among man (52.6%) and the main age range was over 60 years (42.7%), while 0-10 comprised 16.6% of cases. Compared the 6-years period, the resistance rate to trimethoprim-sulfamethoxazole was 2.7%; 5.4%; 5.8%; 2.2%; 5.8%; 7.9% and levofloxacin was 3.6%; 3.4%; 3.1%; 3.3%; 1.7%; 2.9%, respectively. The resistance rate to trimethoprim-sulfamethoxazole and levofloxacin, simultaneously, was 0.23%.

Conclusions

The incidence rate of S. maltophilia infections has increased significantly, especially in the last year, followed by an increase in the pattern of resistance to trimethoprim-sulfamethoxazole. Regarding trimethoprim-sulfamethoxazole and levofloxacin co-resistance, very low rates were detected in our analysis. Our data point to a scenario wherein the presence of S. maltophilia may have been intensified by the covid-19 pandemic. Regional surveillance reports are extremely important and should be out to understand some aspects of the dynamics of bacterial resistance in both hospital and community settings.
A-262 Novel Hepatitis C Virus External Quality Control that is Stable at Ambient Temperature and Suitable For Use in Low-Resource Settings
Authors: Rivers S , Zhelev P , Alagic A , Gerbaba T , Patel R , Luscher M , Hughes K
Published: October 2024

Background

Notwithstanding the WHO’s initiative to eliminate viral hepatitis by 2030, there are currently 58 million individuals infected with Hepatitis C Virus (HCV). 73% of infected individuals live in low- and middle-income countries (LMIC) where conventional diagnostics are inaccessible due to high costs and lack of trained personnel. The emergence of low-complexity Point of Care tests is critical for improving accessibility and reducing the spread of infection. Additionally, there is a need for external quality controls (EQC) that monitor the accuracy of test results. Given that LMIC have limited access to laboratory equipment, EQC must have simplified handling procedures and storage conditions. Unfortunately, these materials are not available at scale. Microbix strived to develop HCV EQC swab formulations that are stable at ambient temperature. Since this format deviates from standard HCV diagnostic workflows, we sought to establish a simple yet reproducible workflow that can be followed by laboratories worldwide.

Methods

Microbix developed HCV swab-based EQC that are stable when stored at 2-30°C. The contrived specimens are formulated with protected synthetic HCV whole-genome nucleic acid and human cells. The formulation was quantified via ddPCR and benchmarked against the WHO HCV standard using Xpert® HCV Viral Load Fingerstick Assay. Sample performance was evaluated with various elution buffers (PrimeStore® MTM, eNAT®, TE buffer, Microbix’s proprietary buffer) and handling procedures that require minimal use of laboratory equipment. Each EQC workflow was assessed based on its ability to consistently demonstrate a viral load of 100-200 IU/mL when tested on Cepheid’s platform.

Results

The EQC tested positive for HCV when eluted in each buffer and processed using a hand-mixing procedure. Only the workflows that used PrimeStore® MTM or eNAT® consistently reported a viral load between 100-200 IU/mL.

Conclusions

Microbix developed an HCV swab-based EQC that is stable at ambient temperature; however, we observed that consistent elution conditions are imperative for achieving reproducible results. Our findings demonstrate that a universal workflow should be followed to standardize results across testing sites as deviations in elution buffers, volumes, and handling procedures can influence test outcomes.
A-278 Prevalence of Clostridium Difficile in Long-Term Care Facilities Using BD Max Cdiff Molecular Assay
Authors: Khoury R , Gudaitis P , Patel P , Gandhi A , Gudaitis D
Published: October 2024

Background

Clostridium difficile (C.Diff) is a gram positive anaerobe producing Enterotoxin and Cytotoxin (toxin A and B respectively); more than half of million infection is diagnosed yearly with more than 10% of the cases are in patients over 65 years old. Residents in Long-Term Care Facilities (LTCF) are more prone to have C. Diff infection (CDI) because of their age, the frequent use of antibiotics, fragilities, co-morbidity, and living environment. Diagnosing CDI is based on clinical signs and symptoms as well as laboratory tests; however, the enzyme immunoassays are reliable, the tissue culture cytotoxicity is labor intensive. The nucleic acid amplification tests are becoming more the standard as first step in the diagnosis. The BD MAX™ System is a PCR walkaway instrument that provides the sensitivity, specificity and faster turnaround for the C. diff.

Methods

The BD MAX™ System is an automated in-vitro diagnostic test for the direct qualitative detection of the C. difficile toxin B gene (tcdB) in human liquid or soft stool specimens from patients suspected of having Clostridium difficile Infection (CDI). Premier Toxins A & B is an enzyme immunoassay for the direct detection of Clostridium difficile toxin A and toxin B in stool samples. We collected data from 5,267 samples were collected from resident in LTCF and were run using the EIA assay, 275 samples were ran using the BD Max molecular assay. We had 31 samples that were run using both assays. Statistical analyses were done using Analyse-it.

Results

Female accounted for 60% of the patients tested; the positivity rate was 13.2% for female and 17.2 for male using the EIA. The positivity rate was 19.2% for female and 30.6% for male when using the molecular assay. The agreement between the EIA and the PCR was 87% based on 31 samples that were run for both assays.

Conclusions

The BD Max gave the benefit of a fully automated with high sensitivity and specificity for the presence of toxin B producing C. Diff. The difference between the methods could be due to the lack of the sensitivity in the EIA and the fact that the molecular assay might be picking up colonized specimen or the beginning or end of infection. However, the ability to diagnose CDI early and prevent spreading of the disease to other patients is a huge benefit to the facilities. We have to keep in mind also that C.diff infection can be prevented with appropriate use of antibiotics and implementing antibiotic stewardship and infection control plan to prevent and stop spreading of the infection.
A-279 Performance Evaluation of the Respiratory Viral for BD MAX™ System in Geriatric Population
Authors: Khoury R , Patel P , Gandhi A , Gudaitis D , Gudaitis P
Published: October 2024

Background

Respiratory Viral Infection is one of the most common infection in the geriatric population and cause major concern in the Long-Term Care Facilities. Influenza A and B, SARS-CoV-2, and respiratory syncytial virus (RSV) are responsible for most of the hospitalization and deaths among elderly patients. Rapid identification, treatment, and isolation are among the most important steps to fight the spreading of the infection.

Methods

The BD Respiratory Viral Panel for BD MAX™ System is an automated multiplexed real-time reverse transcriptase polymerase chain reaction (RT- PCR) test intended for the simultaneous, qualitative detection and differentiation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A, influenza B, and/or respiratory syncytial virus (RSV) nucleic acid in nasopharyngeal swab (NPS) and anterior nasal swab (ANS) specimens from individuals with signs and symptoms of respiratory tract infection. The assay is targeting RNA from the nucleocapsid phosphoprotein gene (N1 and N2 regions) of the SARS-CoV-2, a conserved region of the matrix protein M1 gene for influenza A, conserved regions of the matrix protein M1 gene and HA gene for influenza B, conserved regions of the N and M genes for RSV, and the human RNase P gene. The assay was evaluated for: precision, reproducibility, accuracy, and correlation with BioGx for SARS-CoV-2, Solana (Quidel) for influenza A, influenza B and RSV; the percentage agreement for the evaluation steps was calculated. We ran 86 samples collected from patients residing in Long-Term Care Facilities. Statistical analyses were done using Analyse-it.

Results

The percentage agreement for precision, reproducibility, and accuracy were 100%. The patients’ correlation was 100% when compared to the existing molecular testing in the laboratory. Female patients accounted for 62.8% (54 female and 32 male); 2 patients were positive for both influenza A and RSV, and one patient was positive for both influenza A and SAR-CoV-2.

Conclusions

The Respiratory Viral panel for BD MAX™ System gave the benefit of a fully automated, high precision, accuracy and acceptable sensitivity assay; in addition, it offers easier collection (one swabs versus multiple swabs), faster turnaround time for four targets in less than three hours which allow for earlier isolation to prevent the spreading of the infection and initiating treatment when needed. As with every molecular assay avoiding contamination is very important to eliminated false positive results.
A-283 Serologic and molecular testing for the diagnosis of Rickettsia, Ehrlicha, and Anaplasma infections in patients in Maryland
Authors: Mullins K , Hoti N
Published: October 2024

Background

Rickettsia, Anaplasma, and Ehrlichia are underrecognized tick-borne pathogens of increasing human importance. As tick habitats are expanding and populations are increasing, human exposure to these pathogens is also increased in recent years. Unfortunately, while treatment is usually simple, diagnosis can be difficult as it requires specialized testing for clinical diagnosis - generally performed only at reference laboratories.

Methods

To better understand the prevalence, diagnosis, and testing patterns for Rickettisal infections, Anaplasmosis, and Ehrlichiosis in Maryland, a retrospective analysis of all serologic and molecular testing for Rickettsia, Anaplasma, and Ehrlichia species performed for the University of Maryland Medical System from 2018-2022 was conducted. Eight hospitals within the University of Maryland Medical System (Central Maryland and Maryland’s Eastern Shore) diagnose Rickettsia, Anaplasma, and Ehrlichia infections using serologic and molecular testing.

Results

Between 2018-2022, an average of 413 individuals were tested for Rickettsia, Anaplasma, and Ehrlichia each year. On average 315 serologic tests for Rocky Mountain Spotted Fever (RMSF) group Rickettsia, 195 serologic tests for Ehrlichia chaffeensis (Anaplasma serology is not available), and 165 molecular tests for the detection of Anaplasma and Ehrlichia species were ordered each year. Clinical indications for testing included tick bite, fever, chills, severe headaches, muscle aches, and rash. Overall, 17% of individuals tested were positive for IgG antibodies to RMSF group Rickettsia, however only 1% were positive for IgM antibodies. Further, 20% of individuals tested were positive for IgG antibodies to Ehrlichia chaffeensis, while <1% were positive for IgM. Acute and convalescent samples were not tested for any individuals. Molecular evidence of infection was found in 8% of individuals tested. Nineteen precent were positive for Anaplasma phagocytophilum and the remaining 81% were positive for Ehrlichia chaffeensis. Interestingly, only two individuals had positive results from both molecular and serologic testing.

Conclusions

Results from serologic and molecular testing show that Rickettsia, Anaplasma, and Ehrlichia are important human pathogens with the potential to cause significant morbidity. However, lack of follow-up serology, and laboratory tests that confirm acute infection make definitive diagnosis difficult. Increased awareness of Rickettsial diseases and appropriate diagnostics is needed.
A-289 Multiple Gastric Polyps as an Unusual Presentation of Syphilitic Gastritis
Authors: de Andrade S S , Cilotti H P , Grecco L G , Agnol M D , Iriya K , Rigueiro M P , Yamassaki H O , Barata M C , Ramadan-Boscolo D R , Tufik S
Published: October 2024

Background

Syphilis is a sexually transmitted infection caused by Treponema pallidum and can clinically progress through four different stages. Syphilitic gastritis is one of the rare manifestations of the disease, harboring the potential to mimic several types of unrelated disorders such as malignant lymphomas, Langerhans cell histiocytosis, auto-immune gastritis and refractory Helicobacter pylori infection. The classics symptoms are weight loss, abdominal pain, and gastroparesis, nausea, vomiting and hematemesis. The most common endoscopic finding is gastric ulcers. The rising trends of syphilis in the last decade, detected in both developing and developed countries, calls for continued efforts for case detection on rare syphilis manifestations.

Methods

A 35-year-old male patient was submitted to gastric biopsy due to endoscopic findings of multiple polyps in the corpus and antrum of stomach. The material was processed and analyzed in a pathology laboratory in São Paulo, Brazil. Histological sections were stained with hematoxylin and eosin and immunohistochemical staining.

Results

The specimens exhibited intense inflammatory lympho-histiocytic infiltrate, rich in plasma cells, neutrophils and eosinophils affecting the gastric mucosa. Immunohistochemical staining revealed spiral-shaped bacteria consistent with T. pallidum affecting the gastric mucosa surface, adjacent to vessels, and permeating glands.

Conclusions

This case report has the goal of showing the occurrence of syphilitic gastritis, an uncommon extracutaneous manifestation of T. pallidum infection with the potential to mimic other etiologies. Due to the rarity of syphilitic gastritis and its non-specific symptoms, a combination of clinical, endoscopic, and histopathological findings is necessary to secure diagnosis of syphilitic gastritis. The advent of immunohistochemistry for T. pallidum has facilitated microscopic diagnosis, as special stains such as Warthin-Starry can still pose interpretation challenges.