Hepatitis C Virus Reflex Testing Protocol in an Emergency Department.

INTRODUCTION: Our aim was to measure hepatitis C virus (HCV) screening and linkage-to-care rates in an urban emergency department (ED) before and after implementing an HCV viral RNA (vRNA) reflex testing protocol within a HCV screening program for at-risk patients. Our hypothesis was that using a reflex testing protocol would increase HCV testing rates of at-risk patients in the ED, which would increase the linkage-to-care rate. METHODS: In August 2018, our institution implemented an automated, electronic health record-based HCV screening protocol in the ED for at-risk patients. In January 2019, we implemented an HCV vRNA reflex testing protocol (reflex testing) for all positive HCV antibody (Ab) tests that were initiated through the screening protocol. We compared completion rates of HCV vRNA testing and the rate of linkage to care for patients with positive HCV Ab test results before and after implementation of reflex testing (five months per study period). RESULTS: Prior to reflex testing implementation, 233/425 (55%) patients with a positive HCV Ab test had an HCV vRNA test performed, whereas 270/323 (84%) patients with a positive HCV Ab test result had vRNA testing after reflex testing implementation (odds ratio [OR], 4.2; 95% confidence interval (CI): 3.0-6.0; P < 0.001). Of the eligible patients with positive HCV Ab test results who could be linked to care, 45 (10.6%) were linked to care before HCV reflex implementation and 46 (14.2%) were linked to care with reflex testing (OR, 1.4; 95% CI: 0.9-2.2; P = 0.13). CONCLUSION: Implementing a reflex testing initiative into an HCV screening program in the ED can result in an increase of the percentage of patients who receive an HCV vRNA test after having had a positive HCV Ab. Hepatitis C virus vRNA reflex testing was not associated with a statistically significant increase in linkage-to-care rates for HCV Ab-positive patients; however, further studies are required.

Evaluation of the selection of cerebrospinal fluid testing in suspected meningitis and encephalitis.

Diagnostic stewardship interventions can decrease unnecessary antimicrobial therapy and microbiology laboratory resources and costs. This retrospective cross-sectional study evaluated factors associated with inappropriate initial cerebrospinal fluid (CSF) testing in patients with suspected community-acquired meningitis or encephalitis. In 250 patients, 202 (80.8%) and 48 (19.2%) were suspected meningitis and encephalitis, respectively. 207 (82.8%) patients had inappropriate and 43 (17.2%) appropriate testing. Any inappropriate CSF test was greatest in the immunocompromised (IC) group (n = 54, 91.5%), followed by non-IC (n = 109, 80.1%) and HIV (n = 44, 80%). Ordering performed on the general ward was associated with inappropriate CSF test orders (adjOR 2.81, 95% CI [1.08-7.34]). Laboratory fee costs associated with excessive testing was close to $300,000 per year. A stepwise algorithm defining empiric and add on tests according to CSF parameters and patient characteristics could improve CSF test ordering in patients with suspected meningitis or encephalitis.

SARS-CoV-2 RT-PCR positivity and antibody prevalence among asymptomatic hospital-based health care workers.

BACKGROUND: The level of asymptomatic infection with SARS-CoV-2 could be substantial and among health care workers (HCWs) a source of continuing transmission of the virus to patients and co-workers. OBJECTIVES: Measure the period prevalence of SARS-CoV-2 PCR positivity and seroprevalence of SARS-CoV-2 IgG antibodies among a random sample of asymptomatic health system hospital-based health care workers (HCWs) 6½ -15½ weeks after 4/5/2020, the peak of the first surge of COVID-19 admissions. RESULTS: Of 524 eligible and consented participants from four metropolitan hospitals, nasopharyngeal swabs were obtained from 439 (83.8 %) and blood from 374 (71.4 %). Using PCR nucleic acid-based amplification (NAAT) methods, the period prevalence of SARS-CoV-2 infection was 0.23 % (95 % confidence interval (CI) 0.01 %-1.28 %; 1/439) from 5/21/20-7/16/20. The seroprevalence of SARS-CoV-2 IgG antibodies from June 17-July 24, 2020 was 2.41 % (95 % CI 1.27 %-4.51 %; 9/374). Those who were reactive were younger (median age 36 versus 44 years; p = 0.050), and those with self-reported Hispanic/Latino ethnicity had a higher seroprevalence (2/12 = 16.7 % versus 7/352 = 2.0 %; p = 0.051). There were no significant differences by sex, race, residence, hospital, unit or job type. The one employee who was found to be PCR test positive in this study was also reactive for IgG antibodies, tested 27 days later. CONCLUSIONS: The period prevalence of PCR positivity to SARS-CoV-2 and IgG seroprevalence was unexpectedly low in asymptomatic HCWs after a peak in COVID-19 admissions and the establishment of state and institutional infection control policies, suggesting that routine screening tests while community prevalence is relatively low would produce a minimal yield.

The Need for Dedicated Microbiology Leadership in the Clinical Microbiology Laboratory.

Clinical microbiology laboratories play a crucial role in patient care using traditional and innovative diagnostics. Challenges faced by laboratories include emerging pathogens, rapidly evolving technologies, health care-acquired infections, antibiotic-resistant organisms, and diverse patient populations. Despite these challenges, many clinical microbiology laboratories in the United States are not directed by doctoral level microbiology-trained individuals with sufficient time dedicated to laboratory leadership. The manuscript highlights the need for medical microbiology laboratory directors with appropriate training and qualifications.

Improving care for critically ill patients with community-acquired pneumonia.

PURPOSE: The purpose of this study was to improve antimicrobial management and outcomes of critically ill patients with community-acquired pneumonia (CAP) through implementation of a pharmacist-driven bundle for ordering evidence-based diagnostic tests in a medical intensive care unit (MICU). METHODS: An inpatient collaborative practice agreement (CPA) was established for MICU pharmacists to order criteria-driven diagnostic testing for CAP from November 2017-March 2018. Adults admitted to the MICU and started on empiric antibiotics for CAP were included. The intervention arm was compared with a standard of care (SOC) group from November 2016-March 2017. RESULTS: Ninety-one patients were included in each group. There was no difference in the median antibiotic duration between SOC and CPA, at 7 days (interquartile range [IQR], 6-10) versus 7 days (IQR, 6-8), respectively. The overall use of evidence-based diagnostic tests increased in the CPA group. Patients in the CPA group had more frequent pathogen identification (SOC and CPA, respectively: 31 [34%] versus 46 [51%], p = 0.035) and antimicrobial deescalation (24 [26%] versus 53 [58%], p < 0.001). There was no significant difference in length of intensive care unit stay, at 4 days for SOC (IQR, 2-10) versus 6 days for CPA (IQR, 3-10), and no significant difference in inpatient all-cause mortality (13 [14%] versus 7 [8%]), retreatment 14 [15%] versus 11 [12%]), or 30-day readmission 16 ([18%] versus 13 [14%]) for SOC and CPA, respectively. The CPA was the only variable that was independently associated with antimicrobial deescalation (odds ratio, 4.030; 95% confidence interval, 2.101-7.731) in a multiple logistic regression. CONCLUSION: Implementation of a pharmacy-driven pneumonia diagnostic stewardship bundle improved the use of evidence-based diagnostics and increased the frequency of pathogen identification. This intervention was associated with increased antimicrobial deescalation without a negative impact on patient safety outcomes.

T2 Candida versus beta-D-glucan to facilitate antifungal discontinuation in the intensive care unit.

T2 Magnetic Resonance Candida Panel (T2MR) detects Candida directly in blood. Rapid turnaround time and high negative predictive value make it a useful diagnostic test to support antifungal discontinuation. This retrospective quasi-experiment compared empiric anidulafungin days of therapy (DOTs) in intensive care unit (ICU) patients with suspected candidemia that had negative blood cultures and negative 1,3-ß-D-glucan (BDG) versus negative blood cultures and negative T2MR. In 206 ICU patients, median anidulafungin DOTs were 2 (1, 5) compared to 1 (1, 2), respectively (P < 0.001); T2MR was associated with early discontinuation, AdjOR 3.0 95% CI (1.7-5.6), P < 0.001. Proven candidemia after discontinuation of anidulafungin occurred in 3% of BDG and 2% of T2MR patients at a median of 8 and 21 days, respectively. T2MR testing supports safe, early discontinuation of empiric antifungal therapy in ICU patients with suspected candidemia. Prospective studies to better define the role of T2MR in antifungal stewardship are warranted.

Multicenter Assessment of Gram Stain Error Rates.

Gram stains remain the cornerstone of diagnostic testing in the microbiology laboratory for the guidance of empirical treatment prior to availability of culture results. Incorrectly interpreted Gram stains may adversely impact patient care, and yet there are no comprehensive studies that have evaluated the reliability of the technique and there are no established standards for performance. In this study, clinical microbiology laboratories at four major tertiary medical care centers evaluated Gram stain error rates across all nonblood specimen types by using standardized criteria. The study focused on several factors that primarily contribute to errors in the process, including poor specimen quality, smear preparation, and interpretation of the smears. The number of specimens during the evaluation period ranged from 976 to 1,864 specimens per site, and there were a total of 6,115 specimens. Gram stain results were discrepant from culture for 5% of all specimens. Fifty-eight percent of discrepant results were specimens with no organisms reported on Gram stain but significant growth on culture, while 42% of discrepant results had reported organisms on Gram stain that were not recovered in culture. Upon review of available slides, 24% (63/263) of discrepant results were due to reader error, which varied significantly based on site (9% to 45%). The Gram stain error rate also varied between sites, ranging from 0.4% to 2.7%. The data demonstrate a significant variability between laboratories in Gram stain performance and affirm the need for ongoing quality assessment by laboratories. Standardized monitoring of Gram stains is an essential quality control tool for laboratories and is necessary for the establishment of a quality benchmark across laboratories.

Outcomes of Aminopenicillin Therapy for Vancomycin-Resistant Enterococcal Urinary Tract Infections.

Vancomycin-resistant urinary tract infections are often challenging to treat. This retrospective cohort study compared outcomes between patients treated for vancomycin-resistant enterococcal urinary tract infection with an aminopenicillin and those treated with a non-ß-lactam antibiotic. Inpatients treated with an enterococcus-active agent for their first symptomatic vancomycin-resistant enterococcal urinary tract infection between 1 January 2012 and 31 December 2013 were considered for inclusion. Patients with colonization, on hospice, or receiving comfort care only were excluded. The primary endpoint of clinical cure was defined as resolution of clinical symptoms, or symptom improvement to the extent that no additional antibacterial drug therapy was necessary, and lack of microbiologic persistence. Secondary endpoints of 30-day readmission or retreatment and 30-day all-cause mortality were also compared. A total of 316 urinary isolates were screened, and 61 patients with symptomatic urinary tract infection were included. Twenty (35%) of the 57 isolates tested were ampicillin susceptible. Thirty-one patients received an aminopenicillin, and 30 received a non-ß-lactam. Rates of clinical cure for aminopenicillin versus non-ß-lactam treatment were 26/31 (83.9%) and 22/30 (73.3%) (P = 0.315), respectively. Rates of 30-day readmission (6/31, or 19.4%, versus 9/30, or 30%, respectively; P = 0.334), 30-day retreatment (4/31, or 12.9%, versus 4/30, 13.3%, respectively; P = 0.960), and 30-day all-cause mortality (2/31, or 6.5%, versus 1/30, or 3.3%, respectively; P = 0.573) were also not significantly different between groups. Aminopenicillins may be a viable option for treating vancomycin-resistant urinary tract infection regardless of the organism's ampicillin susceptibility. Prospective validation with larger cohorts of patients should be considered.

Evaluation of a microarray-based assay for rapid identification of Gram-positive organisms and resistance markers in positive blood cultures.

Rapid identification of pathogens directly from positive blood cultures can play a major role in reducing patient mortality rates. We evaluated the performance of the Verigene Gram-Positive Blood Culture (BC-GP) assay (Nanosphere Inc., Northbrook, IL) for detection of commonly isolated Gram-positive organisms as well as associated resistance markers from positive blood cultures. Positive blood cultures (VersaTREK; Trek Diagnostic Systems, Independence, OH) from 203 patients with Gram-positive organism infections were analyzed using the BC-GP assay within 12 h for the detection of 12 different organisms, including staphylococci, streptococci, and enterococci, as well as for the presence of 3 resistance markers (mecA, vanA, and vanB). Results were compared to those of routine laboratory methods for identification and susceptibility testing. For identification of organisms and detection of resistance markers in 178 monomicrobial positive blood cultures, the BC-GP assay showed 94% and 97% concordance, respectively, with routine methods. After 25 polymicrobial cultures were included, the results showed 92% and 96% agreement for identification and resistance markers, respectively, for a total of 203 positive cultures. In 6/25 polymicrobial cultures, at least 1 isolate was not detected. Concordance levels for detection of major pathogens such Staphylococcus aureus (n = 45) and enterococci (n = 19) were 98% and 95%, respectively. Agreement levels for detection of resistance markers such as mecA and vanA/B were 92% and 100%, respectively. The BC-GP assay is capable of providing rapid identification of Gram-positive cocci as well as detection of resistance markers directly from positive blood cultures at least 24 to 48 h earlier than conventional methods.

Discordant Streptococcus agalactiae (Group B streptococcus) gestational infection in monochorionic/diamniotic and dichorionic/diamniotic twins.

Infection due to Streptococcus agalactiae or Group B streptococcus may be acquired during parturition or gestation. Discordant twin gestational Group B streptococcus infections are rarely reported. We describe two cases of fatal discordant gestational Group B streptococcus infection in both a monochorionic/diamniotic pregnancy and in a dichorionic/diamniotic pregnancy. In both instances, cultures, examination of the placentae, and autopsy findings demonstrated infection by Group B streptococcus in only the presenting fetus. Despite the ubiquity of this organism, this is the first documented case of discordant gestational Group B streptococcus infection in monochorionic/diamniotic twins and only the third case documented in dichorionic/diamniotic twins.

Comparison of time to positivity of the VersaTREK® REDOX 80-mL and the REDOX EZ draw 40-mL blood culture bottles for common bacterial bloodstream pathogens.

The VersaTREK(®) microbial detection system offers 2 media formulations, an aerobic and an anaerobic bottle available in a 40-mL direct draw format and an 80-mL format. The 40-mL EZ Draw(®) bottle can be inoculated with a maximum volume of 5 mL, while the REDOX 80-mL bottle accommodates a 10-mL volume. The effect of volume of blood inoculum on time to positivity (TTP) has not been clearly established with these bottle types. This study utilized simulated blood cultures seeded with clinically relevant microorganisms in human blood to evaluate the impact of inoculum volume and organism load on TTP for the 2 bottle types. For 13/15 organisms, the EZ Draw bottle flagged positive earlier than the REDOX 80-mL bottles. The lower volume of blood inoculum did not negatively impact TTP using the EZ Draw blood culture bottles as compared to REDOX 80-mL bottles.

Expression, production and release of the Eis protein by Mycobacterium tuberculosis during infection of macrophages and its effect on cytokine secretion.

The eis gene of Mycobacterium tuberculosis has been shown to play a role in the survival of the avirulent Mycobacterium smegmatis within the macrophage. In vitro and in vivo analysis of Deltaeis deletion mutants and complemented strains showed no effect on survival of M. tuberculosis in U-937 macrophages or in a mouse aerosol infection model, respectively. Further studies were done in an attempt to determine the role of eis in M. tuberculosis intracellular survival and to define a phenotypic difference between wild-type and the Deltaeis deletion mutant. Bioinformatic analysis indicated that Eis is an acetyltransferase of the GCN5-related family of N-acetyltransferases. Immunofluorescence microscopy and Western blot analysis studies demonstrated that Eis is released into the cytoplasm of M. tuberculosis-infected U-937 macrophages. Eis was also found in the extravesicular fraction and culture supernatant of M. tuberculosis-infected macrophages. The effect of Eis on human macrophage cytokine secretion was also examined. Eis modulated the secretion of IL-10 and TNF-alpha by primary human monocytes in response both to infection with M. tuberculosis and to stimulation with recombinant Eis protein. These results suggest that Eis is a mycobacterial effector that is released into the host cell to modulate inflammatory responses, possibly via transcriptional or post-translational means.