The Penn Medicine COVID-19 Therapeutics Committee-Reflections on a Model for Rapid Evidence Review and Dynamic Practice Recommendations During a Public Health Emergency

The Penn Medicine COVID-19 Therapeutics Committee-an interspecialty, clinician-pharmacist, and specialist-front line primary care collaboration-has served as a forum for rapid evidence review and the production of dynamic practice recommendations during the 3-year coronavirus disease 2019 public health emergency. We describe the process by which the committee went about its work and how it navigated specific challenging scenarios. Our target audiences are clinicians, hospital leaders, public health officials, and researchers invested in preparedness for inevitable future threats. Our objectives are to discuss the logistics and challenges of forming an effective committee, undertaking a rapid evidence review process, aligning evidence-based guidelines with operational realities, and iteratively revising recommendations in response to changing pandemic data. We specifically discuss the arc of evidence for corticosteroids; the noble beginnings and dangerous misinformation end of hydroxychloroquine and ivermectin; monoclonal antibodies and emerging viral variants; and patient screening and safety processes for tocilizumab, baricitinib, and nirmatrelvir-ritonavir.

168. Syndrome-Based Analysis of Oral Antimicrobial Stewardship Opportunities at Hospital Discharge

Background

Suboptimal oral antibiotic prescriptions (OAPs) are prevalent at discharge and contribute to treatment failure, resistance, toxicity, and excess costs. Syndrome-specific prescribing patterns have not been widely described at discharge, nor have specific reasons for excessive treatment durations (the most commonly cited prescribing error).

Methods

Retrospective cohort of patients discharged from a general medicine service at an academic hospital with ≥1 OAP for urinary tract infection (UTI), skin and soft tissue infection (SSTI), or lower respiratory tract infection (LRTI). Study period varied to include a random sample of encounters occurring after the most recent institutional guideline update for each syndrome. Exclusions: multiple infectious indications, discharge against medical advice, parenteral antibiotics at discharge, pregnancy, cystic fibrosis, and immunocompromising conditions. Discharge OAPs were assessed for suboptimal selection, dose, frequency, or duration according to institutional guidelines (with secondary adjudication).

Results

Analysis included 160 encounters: 70 UTIs, 66 SSTIs, and 24 LRTIs. Of 71 (44%) culture-positive infections, Enterobacterales (61%) and Streptococcus spp. (15%) were most often identified. In total, 180 OAPs were issued – most commonly cefpodoxime (21%), cefadroxil (18%), and doxycycline (17%). Overall, 99 (62%) encounters were associated with a suboptimal discharge OAP. Of 138 suboptimal characteristics identified, suboptimal duration was most frequent (57%), specifically excessive duration (45%). Proportion of suboptimal OAPs and their underlying reasons are analyzed by syndrome in Figures 1 and 2, respectively. Miscalculation (39%), intentional selection of guideline-discordant duration (29%), and omission of inpatient antibiotic days (19%) were the most frequent reasons for suboptimal duration (Fig. 3).

Conclusion

Suboptimal discharge OAPs were common for all studied syndromes, most notably SSTI. Excessive duration was a key driver, with reasons for inappropriate duration previously undescribed. Duration miscalculation and selection of appropriate treatment duration are key areas to focus electronic health record enhancements, provider education, and antimicrobial stewardship efforts.

Disclosures

All Authors: No reported disclosures

622. Evaluation of Vascular Access Device Selection in Patients Discharged on Outpatient Parenteral Antimicrobial Therapy

Background

Selection of a vascular access device (VAD) is an important consideration for patients receiving outpatient parenteral antimicrobial therapy (OPAT). Midline catheters (MC) and peripherally inserted central catheters (PICC) are the most commonly placed VADs, with the former recommended by national guidelines to be used for durations no longer than two weeks. These recommendations, however, are based on limited data from heterogeneous populations. As such, we aim to further characterize VAD-associated complications specifically in patients receiving antimicrobials.

Methods

We conducted a retrospective cohort study that included adult patients discharged on OPAT with a newly inserted MC or PICC between January 2020 and August 2020. Patients with non-OPAT VAD indications were excluded. The primary outcome was the incidence of VAD-associated complications, which was further assessed by type and severity. The secondary outcome was time to complication. Multivariable Poisson regression was used to assess the association between VAD type and incidence of VAD-associated complications.

Results

A total of 190 encounters from 181 patients were included for analysis. Baseline demographics are detailed in Table 1. Despite a higher number of complications in the PICC group, rates per 1000 VAD days were not significantly different between VAD types (Table 2). Median time to first complication was 17 days in the overall cohort. Multivariable regression analysis showed those with a dermatologic history had a four-fold increased risk for VAD-associated complications (Table 3). VAD type was not independently associated with the risk of developing a complication.

Conclusion

Our results suggest that the development of VAD-associated complications was strongly associated with patients’ dermatologic history. To our knowledge, dermatologic history has not been previously identified as a risk factor for VAD-associated complications. Thorough assessment of patient-specific risk factors can inform optimal VAD selection for patients discharged on OPAT. Further studies are needed to assess the safety of MC for extended OPAT use.

Disclosures

All Authors: No reported disclosures

82. Assessment of Clinical Outcomes and Antibiotic Prescribing Patterns Following Implementation of the GenMark ePlex® Blood Culture Identification Panel for Gram-positive Bloodstream Infections

Background

Rapid diagnostic testing (RDT) of bloodstream pathogens provides key information sooner than conventional identification and susceptibility testing. The GenMark ePlex® blood culture identification gram-positive (BCID-GP) panel is a molecular-based multiplex platform, with 20 Gram-positive target pathogens and 4 bacterial resistance genes that can be detected within 1.5 hours of blood culture positivity. Published studies have evaluated the accuracy of the ePlex® BCID-GP panel compared to traditional identification methods; however, studies evaluating the impact of this panel on clinical outcomes and prescribing patterns are lacking.

Methods

This multi-center, quasi-experimental study evaluated clinical outcomes and prescribing patterns before (December 2018 – June 2019) and after (August 2019 – January 2020) implementation of the ePlex® BCID-GP panel in June 2019. Hospitalized, adult patients with growth of Enterococcus faecalis, Enterococcus faecium, or Staphylococcus aureus from blood cultures were included. The primary endpoint was time to targeted antibiotic therapy, defined as time from positive Gram-stain to antibiotic adjustment for the infecting pathogen.

Results

A total of 200 patients, 100 in each group, were included. Time to targeted therapy was 47.9 hours in the pre-group versus 24.8 hours in the post-group (p< 0.0001). Time from Gram-stain to organism identification was 23.03 hours (pre) versus 2.56 hours (post), p< 0.0001. There was no statistically significant difference in time from Gram-stain to susceptibility results, hospital length of stay (LOS), or all-cause 30-day mortality.

Conclusion

Implementation of the GenMark ePlex® BCID-GP panel reduced time to targeted antibiotic therapy by nearly 24 hours. Clinical outcomes including hospital LOS and all-cause 30-day mortality did not show a statistical difference, although analysis of a larger sample size is necessary to appropriately assess these outcomes. This study represents the effect of RDT implementation alone, in the absence of stewardship intervention, on antibiotic prescribing patterns. These findings will inform the design of a dedicated RDT antimicrobial stewardship intervention at our institution, while also being generalizable to other institutions with RDT capabilities.

Disclosures

All Authors: No reported disclosures

751. Impact of Changing from a Three-step to Two-step Testing Algorithm for the Diagnosis of Clostridioides difficile

Background

The optimal method for laboratory diagnosis of Clostridioides difficile infection (CDI) remains undefined and national guidelines do not make a recommendation for a preferred diagnostic algorithm. Aiming to improve infection control measures, the Hospital of the University of Pennsylvania changed its testing process for the diagnosis of CDI from a 3-step to a 2-step algorithm (Figure 1) in September 2018. Starting an algorithm with nucleic acid amplification testing (NAAT) has been hypothesized to lead to potential diagnostic uncertainty if the result is positive by NAAT alone, as this test cannot distinguish between active infection and colonization.

Three-Step and Two-Step Diagnostic Testing Algorithms

Methods

This retrospective, single-center, quasi-experimental study included patients ≥ 18 years of age that tested positive for C. difficile between May 1^st, 2018 and January 31^st, 2019. The study period encompassed 4 months prior to the algorithm change, a 1-month washout immediately following the change, and the subsequent 4 months. The primary outcome was proportion of patients who tested positive for C. difficile and received targeted treatment for CDI. Secondary outcomes included total number of patients who tested positive for C. difficile and received targeted treatment for CDI, duration of treatment for CDI, and hospital length of stay.

Results

Sixty-nine patients in the pre-group (3-step) and 75 patients in the post-group (2-step) tested positive for C. difficile. A higher proportion of patients in the post-group tested positive by NAAT alone (59.4% vs. 73.3%). CDI severity and prior history of CDI were similar between groups. The primary outcome occurred in 89.9% of patients in the pre-group and 83.8% in the post-group (p=0.213). Sixty-two patients in each group received targeted treatment for CDI (p=0.213), median treatment duration was 15 (IQR 11.25-25.75) and 14 (IQR 11-25) days (p=0.505), and median hospital length of stay was 9 (IQR 3-15) and 6 (IQR 3-20) days (p=0.690) in the pre-group and post-group, respectively.

Conclusion

Although there was a higher percentage of patients in the post-group that tested positive for C. difficile by NAAT alone, there was no difference in the proportion or total number of patients who received targeted CDI treatment between time periods.

Disclosures

All Authors: No reported disclosures

Real-world, Multicenter Experience With Meropenem-Vaborbactam for Gram-Negative Bacterial Infections Including Carbapenem-Resistant Enterobacterales and Pseudomonas aeruginosa

Background

We aimed to describe the clinical characteristics and outcomes of patients treated with meropenem-vaborbactam (MEV) for a variety of gram-negative infections (GNIs), primarily including carbapenem-resistant Enterobacterales (CRE).

Methods

This is a real-world, multicenter, retrospective cohort within the United States between 2017 and 2020. Adult patients who received MEV for ≥72 hours were eligible for inclusion. The primary outcome was 30-day mortality. Classification and regression tree analysis (CART) was used to identify the time breakpoint (BP) that delineated the risk of negative clinical outcomes (NCOs) and was examined by multivariable logistic regression analysis (MLR).

Results

Overall, 126 patients were evaluated from 13 medical centers in 10 states. The most common infection sources were respiratory tract (38.1%) and intra-abdominal (19.0%) origin, while the most common isolated pathogens were CRE (78.6%). Thirty-day mortality and recurrence occurred in 18.3% and 11.9%, respectively. Adverse events occurred in 4 patients: nephrotoxicity (n = 2), hepatoxicity (n = 1), and rash (n = 1). CART-BP between early and delayed treatment was 48 hours (P = .04). MEV initiation within 48 hours was independently associated with reduced NCO following analysis by MLR (adusted odds ratio, 0.277; 95% CI, 0.081–0.941).

Conclusions

Our results support current evidence establishing positive clinical and safety outcomes of MEV in GNIs, including CRE. We suggest that delaying appropriate therapy for CRE significantly increases the risk of NCOs.

54. Effectiveness of a Venous Catheter Stewardship Intervention Targeting Parenteral Antimicrobial Therapy at Hospital Discharge

Background

Peripherally inserted central catheters (PICCs) and midlines are often used in hospitalized patients who require outpatient parenteral antimicrobial therapy (OPAT) upon discharge. PICCs/midlines offer ease of insertion but still carry the risks of venous thrombosis, phlebitis, and catheter-associated infection. We report the results of a prospective audit and feedback (PAF) intervention targeting the placement of PICCs/midlines for OPAT at our institution.

Methods

We prospectively identified a cohort of patients identified by a real-time PICC/midline alert from 5/20/2019 through 5/29/2020 at two large academic medical centers. Alerts were generated by a third-party interface with the electronic health record and identified new line orders with an antimicrobial indication selected. Patients without infectious diseases (ID) consult underwent PAF by the antimicrobial stewardship team. Descriptive statistics were used to characterize patients, interventions, and outcomes.

Results

During the study period, 1267 PICC/midline alerts were identified. Most were excluded due to ID consult (85.4%). After exclusions, 113 alerts underwent full review. Median patient age was 64 years with female predominance (54.2%). Reviewable alerts most commonly originated from Pulmonary (36.5%) and Hospitalist (26.0%) services. The most frequent antimicrobial indications were pneumonia (37.5%) and bloodstream infection (28.1%), and the most frequently ordered antimicrobials were cefepime (27.1%) and piperacillin-tazobactam (17.7%). Median time from line order to insertion was 22 hours and from line insertion to discharge was 48 hours. Of 113 alerts reviewed by the stewardship team, 26 (23.0%) resulted in a recommendation to avoid line placement and 45 (39.8%) resulted in at least one specific stewardship recommendation (Table 1). Recommendations were fully or partially accepted in 58.3% of instances.

TABLE 1. Interventions Resulting from Prospective Venous Catheter Stewardship

Conclusion

Prospective audit of PICC/midline orders for OPAT identified a line-sparing opportunity in nearly 1 in 4 cases. Where line avoidance was not possible, other opportunities for antimicrobial optimization were common. This high-yield intervention should be considered for institutions that do not mandate infectious diseases consult for all OPAT discharges.

Disclosures

All Authors: No reported disclosures

275. Comparison of Cefazolin versus Nafcillin for Methicillin-Susceptible Staphylococcus aureus Bacteremia with a Deep-Seated Source

Background

Historically, anti-staphylococcal penicillins have been the treatment of choice for methicillin-susceptible Staphylococcus aureus (MSSA) infections. However, cefazolin may have advantages over these agents including convenience and tolerability. Despite several studies finding similar rates of clinical efficacy using cefazolin with fewer adverse drug events, some prescribers remain hesitant to use this agent due to concern for an inoculum effect in deep-seated infections. The purpose of this study was to compare cefazolin and nafcillin for the treatment of MSSA bacteremia with exclusively deep-seated sources.

Methods

Adult patients who were admitted with MSSA bloodstream infections (BSI) treated with cefazolin or nafcillin between March 2017 and October 2019 were identified. Patients were included if their BSI had a deep-seated source, defined as endocarditis, osteomyelitis, septic arthritis, pneumonia, prosthetic material, mediastinitis, or abscess. Patients were excluded if they had polymicrobial BSI, central nervous system infection, or received less than 7 days of therapy. The primary efficacy outcome (PEO) was a composite of treatment failure, 60-day mortality, and 60-day infection relapse, and was assessed using multivariate logistic regression. The primary safety outcome (PSO) was discontinuation of therapy due to adverse drug events, which was assessed with a chi-square test.

Results

A total of 164 patients were included in this analysis (141 treated with cefazolin and 23 with nafcillin). There were no significant differences in the baseline characteristics collected (Table 1), and the most common deep-seated sources were prosthetic material and endocarditis. Treatment with nafcillin was not found to be protective against the PEO in multivariate analysis (aOR, 1.19; 95% CI, 0.42 to 3.39; P = 0.75), and the PSO was reached significantly more often among nafcillin recipients compared to those treated with cefazolin (7/23 [30.4%] versus 8/141 [5.7%], P < 0.0001).

Conclusion

Though the sample size was smaller than desired, cefazolin and nafcillin appeared to have similar efficacy for the treatment of MSSA BSIs with deep-seated sources. Nafcillin was associated with significantly more adverse drug events leading to discontinuation of therapy.

Disclosures

All Authors: No reported disclosures

Clinical evaluation of serological IgG antibody response on the Abbott Architect for established SARS-CoV-2 infection

OBJECTIVE

This study aimed to evaluate the diagnostic performance of the Abbott Architect SARS-CoV-2 IgG assay in COVID-19 patients.

METHODS

Residual sera from 177 symptomatic SARS-CoV-2-positive patients and 163 non-COVID-19 patients were tested for antibody with the Abbott SARS-CoV-2 IgG assay (Abbott Diagnostics, Chicago, USA). Clinical records for COVID-19 patients were reviewed to determine the time from onset of clinical illness to testing.

RESULTS

Specificity of the assay was 100.0% (95%CI: 97.1-100.0%). The clinical sensitivity of the assay varied depending on time from onset of symptoms, increasing with longer periods from the onset of clinical illness. The clinical sensitivity at ≤6 days was 8.6% (7/81; 95%CI: 3.8-17.5%), at 7-13 days 43.6% (17/39; 95%CI: 28.2-60.2%), at 14-20 days 84.0% (21/25; 95%CI: 63.1-94.7%), and at ≥21 days 84.4% (27/32; 95%CI: 66.5-94.1%). Clinical sensitivity was higher in the ≥14-day group compared to <14 days. There were no differences between the 14-20-day and ≥21-days groups; the combined clinical sensitivity for these groups (≥14 days) was 84.2% (49/57; 71.6-92.1%).

CONCLUSION

The Abbott SARS-CoV-2 IgG test has high specificity. Clinical sensitivity was limited in the early stages of disease but improved from 14 days after the onset of clinical symptoms.

Assessing an intervention to improve the safety of automatic stop orders for inpatient antimicrobials

Background

Automatic stop orders (ASOs) for antimicrobials have been recommended as a component of antimicrobial stewardship programs, but may result in unintentional treatment interruption due to failure of providers to re-order an antimicrobial medication. We examined the impact of a multifaceted intervention designed to reduce the potential harms of interrupting antimicrobial treatment due to ASOs.

Methods

An intervention was implemented that included pharmacist review of expiring antimicrobials as well as provider education to encourage use of a long-term antimicrobial order set for commonly used prophylactic antimicrobials. Pharmacist interventions and antimicrobial re-ordering was recorded. Percent of missed doses of a commonly used prophylactic antimicrobial, single strength co-trimoxazole, was compared pre- and post-intervention using a chi-squared test.

Results

From November 1, 2015 to November 30, 2016, there were 401 individual pharmacist interventions for antimicrobial ASOs, resulting in 295 instances of antimicrobial re-ordering. The total percent of presumed missed single strength co-trimoxazole doses was reduced from 8.4% to 6.2% post-intervention (P<0.001).

Conclusions

This study found that a targeted intervention was associated with a reduction in unintended antimicrobial treatment interruption related to ASOs.

Real-world Multicenter Analysis of Clinical Outcomes and Safety of Meropenem-Vaborbactam in Patients Treated for Serious Gram-Negative Bacterial Infections

Fourty patients were treated with meropenem-vaborbactam (MEV) for serious Gram-negative bacterial (GNB) infections. Carbapenem-resistant Enterobacteriaceae (CRE) comprised 80.0% of all GNB infections. Clinical success occurred in 70.0% of patients. Mortality and recurrence at 30 days were 7.5% and 12.5%, respectively. One patient experienced a probable rash due to MEV.

High prevalence and incidence of tuberculosis in people living with the HIV in Mandalay, Myanmar, 2011-2017

SETTING

Two human immunodeficiency virus (HIV) clinics providing antiretroviral therapy (ART), Mandalay, Myanmar.

OBJECTIVE

To assess prevalent TB at enrolment, incident TB during follow-up and associated risk factors in adult people living with HIV (PLHIV) between 2011 and 2017.

DESIGN

Cohort study using secondary data.

RESULTS

Of 11 777 PLHIV, 2911 (25%) had prevalent TB at or within 6 weeks of enrolment. Independent risk factors for prevalent TB were being male or single/widowed, daily alcohol consumption, CD4 count 200 cells/μl and anaemia. During 6 years follow-up in 8866 PLHIV with no prevalent TB, the rate of new TB was 2.9 per 100 person-years (95%CI 2.6-3.1). Cumulative TB incidence was 9.6%, with 370 (72%) of 517 new TB cases occurring in the first year. Independent risk factors for incident TB were being male and anaemia. Incident TB was highest in the first year of ART, in PLHIV with CD4 counts 200 cells/μl and those not receiving isoniazid preventive therapy (IPT). Incident TB declined with time on ART and rising CD4 counts.

CONCLUSION

Prevalent and incident TB were high in PLHIV in the Mandalay clinics. Consideration should be given to earlier TB diagnosis using more sensitive diagnostic tools, effective ART and scaling up IPT.

Childhood TB in Myanmar: trends in notification, profile and treatment outcomes in the private sector

SETTING

Myanmar National Tuberculosis (TB) programme (NTP).

OBJECTIVE

To describe 1) the trends in childhood TB (aged ⩾ 14 years) notification from 2014 to 2017 and quantify the private sector contribution to this notification; and 2) the profile and treatment outcomes of childhood TB managed in the private sector in 2016.

STUDY DESIGN

This was an observational study involving the review of routine records and reports of the NTP public-private mix (PPM) projects managed by the Myanmar Medical Association and Population Service International.

RESULTS

The total number of childhood TB notified has declined from 36 314 in 2014 to 28 723 in 2017 (average annual decline = 2607 cases per year). The private sector contribution to the notification remained between 17% and 19%. Of the 5616 childhood TB cases diagnosed and treated under the two PPM projects in 2016, 99% were clinically diagnosed and 5459 (97.7%) had successful treatment outcomes. Children aged ⩾10 years, males, those with bacteriologically confirmed TB, those treated in the regions or states of Mandalay, Chin and Shan had a higher risk of an unfavourable outcome (lost to follow-up, death, move to second-line treatment and not evaluated).

CONCLUSION

Childhood TB notification is showing a declining trend. One of five notified childhood TB cases was diagnosed and treated in the private sector, where the successful treatment rate was high.

1012. Characterization of Antibiotic Superutilizers in the Inpatient Setting

Background

Inappropriate use of antibiotics is a major public health concern that contributes to increased antibiotic resistance, adverse effects, and healthcare costs. Little is known about the highest utilizers, or superutilizers, who may be appropriate targets for antibiotic stewardship efforts. The purpose of this study was to characterize superutilizers at an academic hospital.

Methods

All adult patients who were admitted to the Hospital of the University of Pennsylvania and received at least one day of antibiotics between July 1, 2017 and June 30, 2018 were identified. All inpatient administrations for systemic antibacterial agents were identified. Antibiotics given in procedural areas and the emergency department were excluded, as were any antifungals and antivirals. Usage was reported as days of therapy (DOT). We compared the demographics and DOT among the superutilizers (defined as the top 1% of patients) to different groupings of the rest of the population.

Results

Overall, 13,559 patients (and 183,082 DOT) were included in the analysis, including 136 superutilizers. The superutilizers received 15% of the total antibacterial DOT and a median of 56 DOT during the 12-month period. (table)

Conclusion

Inpatient antibiotic use is unevenly distributed across the population. Higher meropenem and sulfamethoxazole/trimethoprim DOT suggest that treatment of multidrug-resistant organisms and opportunistic infection prophylaxis are more common in the superutilizer group. Additional study is needed to determine whether antimicrobial stewardship efforts could impact antibiotic use in the superutilizer population.

Disclosures

All authors: No reported disclosures.

124. Impact of Levofloxacin MIC on Outcomes with Levofloxacin Step-down Therapy in Enterobacteriaceae Bloodstream Infections

Background

The Clinical and Laboratory Standards Institute reduced the levofloxacin minimum inhibitory concentration (MIC) breakpoint from ≤2 to ≤0.5 mg/L for Enterobacteriaceae in 2019 guidelines. The reduction is based on Monte Carlo simulations for a levofloxacin dose of 750 mg daily. The aim of this study was to determine whether there was a difference in clinical outcomes in the treatment of Enterobacteriaceae bacteremia with levofloxacin step-down therapy retrospectively comparing patients with isolates with low levofloxacin MICs (≤0.5 mg/L) to high MICs (1–2 mg/L).

Methods

This retrospective, two-center cohort study included patients ≥18 years of age with a monomicrobial Enterobacteriaceae bacteremia with a levofloxacin MIC ≤2 mg/L from March 2017 through December 2018. Patients had to have received treatment with ≥3 days of levofloxacin step-down therapy, initial intravenous therapy with an agent active against the isolated organism, and total duration not exceeding 16 days from first negative blood culture. A subset of patients whose isolates had low levofloxacin MICs were randomly selected for comparison to all patients with high levofloxacin MICs in a 3:1 ratio. The primary outcome was a composite endpoint of recurrence and mortality within 30 days of completion of the antibiotic course. Secondary outcomes included post-culture length of stay (LOS) and 30-day readmission rate.

Results

Thirty-three patients with high MIC and 99 with low MIC were included. Urinary source was predominant and occurred in 44% of patients, and Escherichia coli was the infecting organism in 48%. Over 80% of patients experienced source resolution or control. The composite endpoint occurred in 8.1% of the low MIC group and 9.1% of the high MIC group (P = 0.856). Median LOS was 4.9 days (IQR 3.7–8.0) in the low MIC group and 4.3 days (IQR 3.2–6.8) in the high MIC group (P = 0.384), and readmission rate was 17.2% in the low MIC group and 15.2% in the high MIC group (P = 0.787).

Conclusion

There was no between-group difference in the primary outcome of recurrence and mortality, with a low overall event rate and short LOS post-culture. These results suggest that levofloxacin effectiveness may be sustained in patients with MICs of 1 or 2 despite levofloxacin not meeting susceptibility criteria by new definitions.

Disclosures

All authors: No reported disclosures.

Rifampicin-resistant tuberculosis patients in Myanmar in 2016: how many are lost on the path to treatment?

SETTING

Regional tuberculosis (TB) centres of the Yangon and Mandalay Regions of Myanmar, which account for 65% of all notified rifampicin-resistant tuberculosis (RR-TB) cases countrywide.

OBJECTIVE

To determine 1) initial loss to follow-up (LTFU), 2) treatment delay, and 3) factors associated with initial LTFU and treatment delay among RR-TB patients residing in the Yangon and Mandalay regions diagnosed using Xpert® during January-August 2016.

DESIGN

This was a retrospective cohort study. Each diagnosed patient was tracked in the drug-resistant TB treatment registers of the Yangon and Mandalay regional treatment centres for January-December 2016 using patient name, age, sex, township and date of diagnosis. If the diagnosed patient was not found in the treatment register by 31 December 2016, he/she was considered 'initial LTFU'.

RESULTS

Of the 1037 RR-TB patients diagnosed, 310 (30%) experienced initial LTFU, which was significantly higher among patients aged 55 years and among those diagnosed in the Mandalay Region. A treatment delay of >1 month was observed in 440 (70%) patients (median delay 41 days). Delay was uniformly high across patient subgroups, and was not associated with any factor.

CONCLUSION

Initial LTFU and treatment delays among RR-TB patients were high. Future studies using qualitative research methods are needed to ascertain the reasons for this observation.

How many sputum samples should be examined during follow-up of tuberculosis patients in Myanmar: two or one?

Setting: Ten selected microscopy centres in Sagaing Region, Myanmar, functioning under an external quality assurance system with no reported major errors. Objective: To assess the pattern of serial sputum results (NN, both smear-negative; NP, first smear-negative and second smear-positive; PN, first smear-positive and second smear-negative; and PP, both smear-positive) among follow-up sputum microscopy examinations of tuberculosis (TB) patients (end of intensive phase, mid-continuation phase and end of treatment) conducted from 1 November 2017 to 15 April 2018. Design: Cross-sectional study using secondary data (laboratory registers). Results: Of 2001 examinations, 94 (4.7%) were smear-positive: 66 PP (3.3%), 12 PN (0.6%) and 16 NP (0.8%); 75% of NP results were scanty. The proportion of NP results was 0.8% (95%CI 0.5-1.3), i.e., 125 smears (95%CI 77-200) were required to detect one additional smear-positive result in the second sample. Of the 16 NP results (15 patients), 14 were tested using Xpert^® MTB/RIF and none had rifampicin resistance. During the continuation phase of treatment, 13 became smear-negative, one remained smear-positive and one had unknown follow-up smear status. Conclusion: The benefit of the second sputum sample for monitoring anti-tuberculosis treatment was negligible. Given the favourable resource implications (reduced laboratory workload and costs), we recommend changing the policy from two sputum smears to one during follow-up sputum examinations of TB patients.

1814. External Validation of Precision Antibiotic Therapy for Enterococcal Bloodstream Infections

Background

ILÚM Heath Solutions, an infectious diseases software platform, developed precision antibiotic therapy (PAT) software to guide selection of therapy using data science, patient-specific factors, as well as historical patient, pharmacy, and microbiologic data. PAT reports percentages reflecting likelihood of susceptibility across a panel of antibiotics, identifying patients at high risk for resistant organisms. PAT has previously demonstrated high accuracy for predicting susceptibility of Enterobacteriaceae in bloodstream infections (BSIs) and risk for multi-drug resistance. The objective of this study was to validate PAT predictive capabilities in enterococcal BSIs and to assess accuracy in risk-stratifying patients for vancomycin-resistant Enterococcus spp. (VRE).

Methods

This retrospective cohort study included patients with an index enterococcal BSI from January 2016 through December 2016. The primary outcome was the performance characteristics of PAT in accurately predicting the risk of VRE, elaborated with sensitivity and specificity rates across varying PAT thresholds. Receiver operating characteristics (ROC) curve analyses were performed to identify an acceptable PAT threshold to define high risk for VRE. Brier score calculations were used to compare accuracy of PAT predictions to that of the institutional antibiogram.

Results

ROC curve analysis (Figure 1) demonstrated an area under the curve of 0.94, indicating excellent discrimination. The Brier scores for the institutional antibiogram and PAT software were 0.067 and 0.075, respectively, representing a similar degree in accuracy. Species-level Brier scores for the institutional antibiogram and PAT were 0.043 and 0.065, respectively, for E. faecalis and 0.093 and 0.073, respectively, for E. faecium.

Conclusion

PAT software was able to discriminate enterococcal BSIs resistant and susceptible to vancomycin. Similar to previous results seen with Enterobacteriaceae, PAT may be useful to accurately predict susceptibilities for Enterococcus spp., particularly for E. faecium.

Disclosures

S. Overly, ILÚM Health Solutions: Consultant, Salary. J. Mehta, ILUM Health Solutions: Consultant, Salary.

Intravenous Vancomycin Associated With the Development of Nephrotoxicity in Patients With Class III Obesity

Background:A consensus statement recommends initial intravenous (IV) vancomycin dosing of 15-20 mg/kg every 8- 24 hours, with an optional 25- to 30-mg/kg loading dose. Although some studies have shown an association between weight and the development of vancomycin-associated nephrotoxicity, results have been inconsistent. Objective: To evaluate the correlation between incidence of nephrotoxicity associated with weight-based IV vancomycin dosing strategies in nonobese and obese patients. Methods: This retrospective cohort study evaluated hospitalized adult patients admitted who received IV vancomycin. Patients were stratified into nonobese (body mass index [BMI] <25 kg/m2), obesity class I and II (BMI 30-39.9kg/m2), and obesity class III (BMI≥40 kg/m2) groups; patients who were overweight but not obese were excluded. Incidence of nephrotoxicity and serum vancomycin trough concentrations were evaluated. Results: Of a total of 62 documented cases of nephrotoxicity (15.1%), 13 (8.7%), 23 (14.3%), and 26 (26.3%) cases were observed in nonobese, obesity class I and II, and obesity class III groups, respectively ( P=0.002). Longer durations of therapy ( P<0.0001), higher initial maintenance doses in both total milligrams/day ( P=0.0137) and milligrams/kilogram ( P=0.0307), and any trough level >20 mg/L ( P<0.0001) were identified as predictors of development of nephrotoxicity. Concomitant administration of piperacillin/tazobactam, diuretics, and IV contrast were associated with development of nephrotoxicity ( P<0.005, all). Patients with class III obesity were 3-times as likely to develop nephrotoxicity when compared with nonobese patients (odds ratio [OR]=2.99; CI=1.12-7.94) and obesity class I and II patients (OR=3.14; CI=1.27-7.75). Conclusions: Obesity and other factors are associated with a higher risk of vancomycin-associated nephrotoxicity.

Psychosis prevalence and physical, metabolic and cognitive co-morbidity: data from the second Australian national survey of psychosis

BACKGROUND

There are insufficient data from nationwide surveys on the prevalence of specific psychotic disorders and associated co-morbidities.

METHOD

The 2010 Australian national psychosis survey used a two-phase design to draw a representative sample of adults aged 18-64 years with psychotic disorders in contact with public treatment services from an estimated resident population of 1 464 923 adults. This paper is based on data from 1642 participants with an International Classification of Diseases (ICD)-10 psychotic disorder. Its aim is to present estimates of treated prevalence and lifetime morbid risk of psychosis, and to describe the cognitive, physical health and substance use profiles of participants.

RESULTS

The 1-month treated prevalence of psychotic disorders was 3.10 cases per 1000 population aged 18-64 years, not accounting for people solely accessing primary care services; lifetime morbid risk was 3.45 per 1000. Mean premorbid intelligence quotient was approximately 0.5 s.d.s below the population mean; current cognitive ability (measured with a digit symbol coding task) was 1.6 s.d.s below the population mean. For both cognitive tests, higher scores were significantly associated with better independent functioning. The prevalence of the metabolic syndrome was high, affecting 60.8% of participants, and pervasive across diagnostic groups. Of the participants, two-thirds (65.9%) were current smokers, 47.4% were obese and 32.4% were sedentary. Of the participants, half (49.8%) had a lifetime history of alcohol abuse/dependence and 50.8% lifetime cannabis abuse/dependence.

CONCLUSIONS

Our findings highlight the need for comprehensive, integrative models of recovery to maximize the potential for good health and quality of life for people with psychotic illness.

135 EXPRESSION OF APOPTOSIS-RELATED GENES IN BUFFALO (BUBALUS BUBALIS) EMBRYOS PRODUCED THROUGH IN VITRO FERTILIZATION AND PARTHENOGENETIC ACTIVATION

Apoptosis, a highly conserved evolutionary mechanism that allows an organism to tightly control cell numbers, tissue size, and protect itself from dangerous cells and unfavourable environments that threaten homeostasis, is generally directed by specific genes involved in the regulation of a series of pro-apoptotic (BAX) and anti-apoptotic (BCL-XL) proteins that are expressed during early development. All mammalian species show the highest level of spontaneous apoptotic processes at the blastocyst stage. These proteins prevent apoptosis by maintaining the cell survival by interfering with the release of cytochrome-C from mitochondria. In this study, immature oocytes were obtained from buffalo slaughterhouse ovaries and were subjected to in vitro maturation (IVM) in TCM-199 + 10% FBS + 5 μg mL–1 porcine FSH for 24 h in a CO2 incubator (5% CO2, 90 to 95% relative humidity) at 38.5°C. The mature oocytes were used for IVF, and the cleaved embryos were cultured for 8 days in culture medium (CR2 medium containing 0.6% BSA and 10% FBS) for production of embryos at different stages. The parthenotes were produced with exposure of 7% ethanol, 6-dimethyl aminopurine and cultured for 8 days in culture medium. The total RNA was isolated from oocytes and embryos and transcribed using Cell-to-cDNA-II (Ambion, Austin, TX, USA), according to manufacturer protocol. The PCR cycle included heating to 94°C for 5 min, followed by 35 cycles of 94°C for 30 s, 60 (BAX) and 62°C (BCL) for 30 s, and 72°C for 45 s with a final extension at 72°C for 10 min. The amplified product of both genes were separated on agarose gel and densitometry data for band intensities were generated using AlphaDigiDocTM AD-1201 software under a WindowsTM environment and data analysed with the help of SYSTAT software. Relative abundance of BCL-XL transcripts in immature, mature oocytes and embryos produced through IVF (i.e. 2-cell, 4-cell, 8- to 16-cell, morula, and blastocyst stage) were 25.33 ± 0.90, 12.67 ± 1.20, 37.67 ± 0.90, 30.67 ± 0.30, 23.67 ± 0.90, 18.33 ± 0.90, and 27.00 ± 1.20, respectively, whereas in parthenogenesis these values were 23.67 ± 0.88, 13.67 ± 1.20, 23.67 ± 1.20, 22.34 ± 0.88, 24.34 ± 0.88, 33.67 ± 0.88, and 45.34 ± 1.20, respectively. Relative abundance of BAX transcripts by IVF were 23.0 ± 0.60, 0.33 ± 0.10, 4.00 ± 0.60, 5.00 ± 0.60, 0.37 ± 0.06, 13.0 ± 0.66, and 56.7 ± 0.90; and by parthenonenesis were 22.3 ± 0.90, 0.13 ± 0.03, 13.67 ± 0.90, 14.0 ± 0.60, 15.33 ± 0.90, 64.67 ± 2.20, and 55.0 ± 2.10, respectively. In conclusion, the expression pattern of the apoptosis-related genes revealed that the incidence of apoptosis was significantly higher in IVF and parthenogenetically produced buffalo embryos at stages such as immature oocytes, morula, and blastocyst than the early cleavage stage embryos.

Comparison of the technical and clinical performance of the Elecsys HBsAg II assay with the Architect, AxSym, and Advia Centaur HBsAg screening assays

South East Asia has some of the highest prevalence rates of hepatitis B virus (HBV) infection (>or=8%) in the world, and the emergence of hepatitis B surface antigen (HBsAg) mutant strains is a growing problem. Assays with the highest levels of sensitivity, including mutant detection, should be used for routine HBsAg screening. In this large multicenter study, the clinical and technical performance of the fully automated Elecsys HBsAg II assay was compared with the Architect, AxSYM, and Advia Centaur HBsAg assays for HBsAg screening. Nine laboratories (three each from Thailand, Korea, and Singapore) compared the Elecsys HBsAg II assay with their routine HBsAg screening assay against a range of stored and routine clinical samples, including recombinant mutants. The Elecsys HBsAg II assay demonstrated equivalent sensitivity and specificity to the Architect HBsAg assay. However, the Elecsys HBsAg II assay recognized a native mutant sample (L94S, L97V, L98V, T123A) that the Architect HBsAg assay failed to detect. The AxSYM and Advia Centaur HBsAg assays appeared less sensitive for the detection of early HBV infection and also failed to detect some of the recombinant mutant strains. There was almost complete agreement between the Elecsys HBsAg II assay and comparator assays with respect to routine serum samples. The results of this study demonstrate that the Elecsys HBsAg II assay is a highly sensitive and specific screening assay for HBsAg and detects reliably the most important and clinically relevant HBV mutants and genotypes. It is suitable for routine HBsAg screening in Asia.

Combined adenocarcinoid and mucinous cystadenoma of the appendix: a case report

INTRODUCTION

Adenocarcinoid of the appendix is a rare malignant tumour with features of both adenocarcinoma and carcinoid, showing both epithelial and endocrine differentiation. Mucinous cystadenoma is the commonest of the benign neoplasms of the appendix, with an incidence of 0.6% in appendicectomy specimens. We report a rare combination of these tumours and discuss the latest treatment options. To the best of our knowledge, only six cases have been reported in the literature to date.

CASE PRESENTATION

A 71-year-old Caucasian man presented to our department with a right iliac fossa mass associated with pain. Laparoscopy revealed an adenocarcinoid of the appendix in combination with mucinous cystadenoma. He underwent a radical right hemicolectomy with clear margins and lymph nodes.

CONCLUSION

Adenocarcinoids account for 2% of primary appendiceal malignancies. Most tumours are less than 2 cm in diameter and 20% of them metastasize to the ovaries. The mean age for presentation is 59 years and the 5-year survival rate ranges from 60% to 84%. Right hemicolectomy is generally advised if any of the following features are present: tumours greater than 2 cm, involvement of resection margins, greater than 2 mitoses/10 high-power fields on histology, extension of tumour beyond serosa. Chemotherapy mostly with 5-Fluorouracil and Leucovorin is advised for remnant disease after surgery. Cytoreductive surgery with intraperitoneal chemotherapy can offer improved survival for advanced peritoneal dissemination.

The effect of the InterLink cannula on fluid flow rates and haemolysis

OBJECTIVE

To examine the effect of the InterLink cannula system (Becton Dickinson, New Jersey, NY, USA) on intravenous fluid flow rates and red blood cell haemolysis.

METHODS

An in vitro study was performed with crystalloid and packed red blood cells run through intravenous catheters of various sizes, with and without the InterLink cannula. Data recorded and analysed included fluid flow rates and plasma free haemoglobin concentration.

RESULTS

The InterLink cannula significantly reduced flow of crystalloid through a 14G catheter (reduction of median flow rate by 0.72 L/h, 12.3%, P < 0.001). There was a reduction of flow of packed red blood cells through a 14G catheter (0.11 L/h) but this was not statistically significant. There was no significant reduction of flow through smaller catheters and no significant effect on red blood cell haemolysis.

CONCLUSIONS

The InterLink cannula reduced flow rates through large diameter intravenous catheters. Because of other factors affecting fluid infusion in vivo this is of minor clinical significance. No increased haemolysis of red blood cells occurred with the InterLink cannula.

Urine laminin and kallikrein, markers of tubulointerstitial damage in experimental protein overload on pre-existing renal damage

We studied the response of urinary protein overload on preexisting tubulointerstitial nephritis (TIN), which was induced in male Sprague Dawley rats by hexachloro-1,3-butadiene (HCBD). Five days after the development of TIN, puromycin aminonucleoside (PAN) was administered to induce urinary protein overload. Urinary laminin and kallikrein were measured. Urine specimens were collected daily for 14 days and on day 21; and tissue specimens were collected on days 1, 4, 7, 10, 14 and 21. Urinalysis was correlated with the renal pathology at the light microscopic level. Laminin excretion was increased on day 4; one day before total protein, indicating damage to the basement membrane. Kallikrein levels also fell early indicating distal tubular damage. There is clear evidence that urine protein overload in a previously damaged kidney with tubulointerstitial injury leads to accelerated and more severe renal damage. Laminin and kallikrein are early and sensitive markers of renal injury.

Age-related reference intervals for free and total prostate-specific antigen in a Singaporean population

Cancer of the prostate is the sixth most frequently found cancer in Singapore. Prostate-specific antigen (PSA) is the most clinically useful tumour marker available today for the diagnosis and management of prostate cancer. To enhance the value of PSA as a screening test we developed age-specific intervals for our ethnic population. The measurement of free PSA was included in the study to calculate the free:total ratio which enhances the differential diagnosis of prostate cancer from benign prostatic hyperplasia or prostatitis. The total PSA upper limits of 10-year intervals, beginning at 30-years-old, were 1.4, 1.7, 2.3, 4.0, 6.3 and 6.6 microg/l. Free PSA cut-off limits were 0.4, 0.5, 0.5, 1.0, 1.5 and 1.6 microg/l. The free:total ratio of PSA was not age dependent. Abbott AxSym standardised their calibration material for both free and total PSA assays with the Stanford 90:10 reference material. This laboratory has implemented these age-specific reference intervals and are currently following up their pick-up rate in the detection of prostate cancer.

Muslim divorce trends and patterns in Singapore

"This paper attempts to discuss the general trends in the incidence of divorce among the Muslim population in Singapore since 1921 and the patterns of divorce in the 1980s when detailed statistics were made available.... The Singapore Muslims experienced an extremely high and steady incidence of divorce during the period up to 1958 when the procedures for processing divorce petitions were not well organised. Following the introduction of new legislation and the creation of the Syariah Court to handle marital disputes in 1958, there occurred an immediate and dramatic downturn in the rate of Muslim divorce. By 1970 the decline appeared to have stalled and a slight upturn has even taken place in the 1980s." The impact of rapid social and economic development is assessed. (SUMMARY IN FRE AND ITA)

Population and labour force growth and patterns in ASEAN countries

"The paper shows that the diverse labor dimensions prevailing in the ASEAN region can be attributed to changes in the structure of the society and economy in the course of recent economic development. It observes the considerable variety in the growth of the population and its effect on the labor force in the ASEAN region.... The paper details the similarity and diversity in the level and type of labor force participation rates. A common feature shared by ASEAN countries is a general pattern in the age-specific participation rate of men. In contrast, the women, aside from participating in the labor force at a much lower level than men at almost all ages, display diverse patterns of participation over the working age range. Lastly, the distribution of the labor force according to major industrial sectors in the six ASEAN countries is presented...."

Seventeen years of legalized abortion in Singapore

"In this paper we first discuss the two-stage process of legalizing induced abortion in Singapore, the initial legalization to make it available on a restrictive basis in 1970 and the complete liberalization to make it available on demand from 1975 onwards. The incidence of abortions registered in the last seventeen years and the major characteristics of aborters are analysed. The impact of abortion on the rapid decline of fertility to below-replacement level is highlighted, and the need to reduce abortion by amending the more liberal aspects of the law are considered at the end of the paper."