Post-COVID-19 Vaccine Thromboembolic Complication in the Setting of Newly Diagnosed May-Thurner Syndrome

May-Thurner syndrome (MTS) can lead to deep venous thrombosis (DVT) in the left lower extremity, and it is often triggered by factors such as surgery or pregnancy. We present a rare case where the risk factor for thromboembolism in MTS is a complication from COVID-19 vaccination. A 44-year-old female who presented with fatigue, fever, and myalgia had developed thromboembolism as a complication of the Johnson & Johnson COVID-19 vaccine. Diagnostic criteria for vaccine-induced immune thrombotic thrombocytopenia (VITT) should be considered in such cases that include symptoms within 5-30 days post vaccination, elevated D-dimer, and thrombosis. Treatment involved anticoagulants and intervention for MTS included thrombectomy and stent placement. Recognition of post-COVID-19 vaccination complications such as VITT is crucial for early intervention and patient awareness during vaccination decisions.

Cardiogenic Shock in a Patient With 4G/4G PAI Polymorphism and MTHFR A1298C Mutation

Myocardial infarction (MI) remains a common cause of morbidity and mortality. Although many well-known risk factors exist, the association between inherited thrombophilia disorders and acute MI is not well described. Here, we present a case of a 75-year-old male with known 4G/4G PAI-1 polymorphism, methylenetetrahydrofolate reductase (MTHFR) mutation, and peripheral artery disease (PAD) post stent placement who presented with cardiogenic shock in the setting of acute MI with no prior significant cardiac history.

COVID-19 convalescent plasma therapy decreases inflammatory cytokines: a randomized controlled trial

IMPORTANCE

This study examined the role that cytokines may have played in the beneficial outcomes found when outpatient individuals infected with SARS-CoV-2 were transfused with COVID-19 convalescent plasma (CCP) early in their infection. We found that the pro-inflammatory cytokine IL-6 decreased significantly faster in patients treated early with CCP. Participants with COVID-19 treated with CCP later in the infection did not have the same effect. This decrease in IL-6 levels after early CCP treatment suggests a possible role of inflammation in COVID-19 progression. The evidence of IL-6 involvement brings insight into the possible mechanisms involved in CCP treatment mitigating SARS-CoV-2 severity.

Pulmonary Renal Syndrome in ANCA-Negative Vasculitis

Below we highlight a rare case of anti-neutrophil cytoplasmic antibody (ANCA)-negative vasculitis, unique in its own right, as the diagnosis was hard to make and the respiratory decline rapid, with the patient going from a 23% fraction of inspired oxygen (FiO2) on admission to 100% FiO2 within four days for what was initially presumed to be community-acquired pneumonia. Precise data on the incidence or prevalence of ANCA-associated vasculitis are lacking. However, a 20-year population-based study in the United States found that, of 58 incident cases, 9% were ANCA-negative. We present the case of a 69-year-old Egyptian male with worsening shortness of breath who was found to have elevated inflammatory markers and an ANCA-negative panel and was later diagnosed with ANCA-negative vasculitis. By highlighting this case, we aim to increase awareness and point out the need to keep the disease high on the list of differential diagnoses in order to allow for timely intervention. Though there isn't a lot of data available on definitive treatment or the disease itself, there are studies that point to rituximab, cyclophosphamide, plasmapheresis, and hemodialysis as useful interventions for treatment.

Analysis of seasonal variation of antibiotic prescribing for respiratory tract diagnoses in primary care practices

Objective

To determine antibiotic prescribing appropriateness for respiratory tract diagnoses (RTD) by season.

Design

Retrospective cohort study.

Setting

Primary care practices in a university health system.

Patients

Patients who were seen at an office visit with diagnostic code for RTD.

Methods

Office visits for the entire cohort were categorized based on ICD-10 codes by the likelihood that an antibiotic was indicated (tier 1: always indicated; tier 2: sometimes indicated; tier 3: rarely indicated). Medical records were reviewed for 1,200 randomly selected office visits to determine appropriateness. Based on this reference standard, metrics and prescriber characteristics associated with inappropriate antibiotic prescribing were determined. Characteristics of antibiotic prescribing were compared between winter and summer months.

Results

A significantly greater proportion of RTD visits had an antibiotic prescribed in winter [20,558/51,090 (40.2%)] compared to summer months [11,728/38,537 (30.4%)][standardized difference (SD) = 0.21]. A significantly greater proportion of winter compared to summer visits was associated with tier 2 RTDs (29.4% vs 23.4%, SD = 0.14), but less tier 3 RTDs (68.4% vs 74.4%, SD = 0.13). A greater proportion of visits in winter compared to summer months had an antibiotic prescribed for tier 2 RTDs (80.2% vs 74.2%, SD = 0.14) and tier 3 RTDs (22.9% vs 16.2%, SD = 0.17). The proportion of inappropriate antibiotic prescribing was higher in winter compared to summer months (72.4% vs 62.0%, P < .01).

Conclusions

Increases in antibiotic prescribing for RTD visits from summer to winter were likely driven by shifts in diagnoses as well as increases in prescribing for certain diagnoses. At least some of this increased prescribing was inappropriate.

Dynamics of inflammatory responses after SARS-CoV-2 infection by vaccination status in the USA: a prospective cohort study

BACKGROUND

Cytokines and chemokines play a critical role in the response to infection and vaccination. We aimed to assess the longitudinal association of COVID-19 vaccination with cytokine and chemokine concentrations and trajectories among people with SARS-CoV-2 infection.

METHODS

In this longitudinal, prospective cohort study, blood samples were used from participants enrolled in a multi-centre randomised trial assessing the efficacy of convalescent plasma therapy for ambulatory COVID-19. The trial was conducted in 23 outpatient sites in the USA. In this study, participants (aged ≥18 years) were restricted to those with COVID-19 before vaccination or with breakthrough infections who had blood samples and symptom data collected at screening (pre-transfusion), day 14, and day 90 visits. Associations between COVID-19 vaccination status and concentrations of 21 cytokines and chemokines (measured using multiplexed sandwich immunoassays) were examined using multivariate linear mixed-effects regression models, adjusted for age, sex, BMI, hypertension, diabetes, trial group, and COVID-19 waves (pre-alpha or alpha and delta).

FINDINGS

Between June 29, 2020, and Sept 30, 2021, 882 participants recently infected with SARS-CoV-2 were enrolled, of whom 506 (57%) were female and 376 (43%) were male. 688 (78%) of 882 participants were unvaccinated, 55 (6%) were partly vaccinated, and 139 (16%) were fully vaccinated at baseline. After adjusting for confounders, geometric mean concentrations of interleukin (IL)-2RA, IL-7, IL-8, IL-15, IL-29 (interferon-λ), inducible protein-10, monocyte chemoattractant protein-1, and tumour necrosis factor-α were significantly lower among the fully vaccinated group than in the unvaccinated group at screening. On day 90, fully vaccinated participants had approximately 20% lower geometric mean concentrations of IL-7, IL-8, and vascular endothelial growth factor-A than unvaccinated participants. Cytokine and chemokine concentrations decreased over time in the fully and partly vaccinated groups and unvaccinated group. Log10 cytokine and chemokine concentrations decreased faster among participants in the unvaccinated group than in other groups, but their geometric mean concentrations were generally higher than fully vaccinated participants at 90 days. Days since full vaccination and type of vaccine received were not correlated with cytokine and chemokine concentrations.

INTERPRETATION

Initially and during recovery from symptomatic COVID-19, fully vaccinated participants had lower concentrations of inflammatory markers than unvaccinated participants suggesting vaccination is associated with short-term and long-term reduction in inflammation, which could in part explain the reduced disease severity and mortality in vaccinated individuals.

FUNDING

US Department of Defense, National Institutes of Health, Bloomberg Philanthropies, State of Maryland, Mental Wellness Foundation, Moriah Fund, Octapharma, HealthNetwork Foundation, and the Shear Family Foundation.

Plasmapheresis vs Conventional Insulin Therapy in Hypertriglyceridemia-Induced Acute Pancreatitis

Hypertriglyceridemia is a rare yet firm etiology of pancreatitis, with an incidence of 2-4% in the general population. The etiology of hypertriglyceridemia itself consists of both primary and secondary causes. We discuss the case of a 37-year-old female with a strong family history of hypertriglyceridemia (primary cause) along with daily alcohol consumption (secondary cause) who initially presented to the emergency department with tingling and numbness of her bilateral upper extremities, bilateral lower extremity cramping and spasm and pins, and needles sensation in all extremities. She was found to have acute pancreatitis (AP) as a cause of hypocalcemia with elevated triglycerides of 5,823 mg/dl responsive to plasmapheresis combined with insulin drip. We explore the pathophysiology of hypertriglyceridemia-induced acute pancreatitis and the different modalities used to treat it which are still largely debated. The choice of therapy has been influenced by the cost, perceived effectiveness, and availability.

Transfusing Convalescent Plasma as Post-Exposure Prophylaxis Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection: A Double-Blinded, Phase 2 Randomized, Controlled Trial

BACKGROUND

The efficacy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) convalescent plasma (CCP) for preventing infection in exposed, uninfected individuals is unknown. CCP might prevent infection when administered before symptoms or laboratory evidence of infection.

METHODS

This double-blinded, phase 2 randomized, controlled trial (RCT) compared the efficacy and safety of prophylactic high titer (≥1:320 by Euroimmun ELISA) CCP with standard plasma. Asymptomatic participants aged ≥18 years with close contact exposure to a person with confirmed coronavirus disease 2019 (COVID-19) in the previous 120 hours and negative SARS-CoV-2 test within 24 hours before transfusion were eligible. The primary outcome was new SARS-CoV-2 infection.

RESULTS

In total, 180 participants were enrolled; 87 were assigned to CCP and 93 to control plasma, and 170 transfused at 19 sites across the United States from June 2020 to March 2021. Two were excluded for screening SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) positivity. Of the remaining 168 participants, 12/81 (14.8%) CCP and 13/87 (14.9%) control recipients developed SARS-CoV-2 infection; 6 (7.4%) CCP and 7 (8%) control recipients developed COVID-19 (infection with symptoms). There were no COVID-19-related hospitalizations in CCP and 2 in control recipients. Efficacy by restricted mean infection free time (RMIFT) by 28 days for all SARS-CoV-2 infections (25.3 vs 25.2 days; P = .49) and COVID-19 (26.3 vs 25.9 days; P = .35) was similar for both groups.

CONCLUSIONS

Administration of high-titer CCP as post-exposure prophylaxis, although appearing safe, did not prevent SARS-CoV-2 infection.

CLINICAL TRIALS REGISTRATION

NCT04323800.

932. Analysis of Seasonal Variation of Antibiotic Prescribing for Respiratory Tract Diagnoses in Primary Care Practices

Background

Seasonal fluctuations in antibiotic prescribing for respiratory tract diagnoses (RTDs) have been identified, but characteristics and appropriateness of these variations have not been well described. The objectives of this study were to describe seasonal variations for RTDs and to determine whether seasonal variation in prescribing is associated with inappropriate use.

Methods

From July 1, 2016 through June 30, 2017, antibiotic prescribing was analyzed for 31 primary care practices comparing winter (October-March) and summer (April-September) months. ICD-10 codes for RTDs were described as tier 1, 2, or 3 based on whether antibiotics are almost always, sometimes, or almost never indicated, respectively. Twenty visits from each of 60 providers were randomly selected and manually reviewed to determine a gold standard of antibiotic appropriateness in order to characterize the appropriateness of these seasonal variations. Associations between season and diagnosis tier, season and appropriateness, and individual provider seasonal changes in antibiotic prescribing and provider characteristics were determined.

Results

There was a lower proportion of visits with tier 3 diagnoses in winter months (68% v. 74%, p&lt; 0.01), but a greater proportion of tier 2 diagnoses (29% v. 23%, p&lt; 0.01). There were greater proportions of visits in which an antibiotic was prescribed for both tier 2 (80% vs 74%, p&lt; 0.01) and tier 3 diagnoses (23% v. 16%, p&lt; 0.01) in winter months. Using medical record review, inappropriate antibiotics were prescribed more frequently for RTDs in winter compared to summer months (73% v. 64%, p&lt; 0.01). Greater individual provider difference in proportion of RTD visits in which an antibiotic was prescribed from summer to winter was associated with family medicine v. internal medicine specialty (8.2% v. 5.1%, p&lt; 0.01), nonteaching v. teaching practice (8.1% v. 2.9%, p&lt; 0.01), and nonurban v. urban setting (9.1% v. 3.9%, p&lt; 0.01).

Conclusion

Although there was a greater proportion of tier 2 compared to tier 3 RTDs in winter months, winter months were associated with more inappropriate prescribing than in summer months. More investigation is needed to understand the drivers for seasonal variations in RTDs and inappropriate prescribing.

Disclosures

Kathleen Degnan, MD, Gilead: Grant/Research Support Michael Z. David, MD PhD, Contrafect: Grant/Research Support|GSK: Advisor/Consultant|Johnson and Johnson: Advisor/Consultant.

1305. PrEParing for success: An intervention to increase HIV prevention awareness among internal medicine residents

Background

PrEP (Pre-Exposure Prophylaxis) is a strategy that involves a combination of antiretrovirals medications aimed to reduce HIV transmission among at-risk individuals. The purpose of this quality improvement project is to increase internal medicine residents' knowledge and prescribing of PrEP.

Methods

We administered an anonymous paper survey to internal medicine residents at all stages of training at our suburban community hospital in the Hudson Valley, NY in the summer of 2021 during the academic half-day of their ambulatory block rotation. The survey consisted of questions about the residents’ demographics, PrEP knowledge, and previous prescribing of PrEP. Following the survey participants were given a 1-hour lecture by the authors on sexual history and PrEP including indications, available options, dosing, monitoring, side effects, and access to the therapy. Six months later we reissued the same survey to the residents. Surveys were analyzed using descriptive statistics.

Results

All 74 eligible residents completed the survey. Out of the 74, 35 (47.3%) identified as male and 40 (52.7%) identified as female. Medical school graduation year range between 2007 to 2021. Only 69 residents completed the post-survey. To Q1 “which medications are FDA approved to be used as PrEP,” 40 (54.05%) answered correctly prior to the intervention, whereas 51 (73.91%) did after. When they were asked Q3 “How effective was PrEP at reducing the risk of contracting HIV through sex,” 21 (28.38%) responded correctly, which improved to 46 (66.67%) after. To the other knowledge-based questions there was no significant improvement (see table). The number of people who reported prescribing PrEP increased from 2 (2.7%) to 7 (10.14%).

PrEP survey Pre and Post results

Conclusion

Although experiencing this educational intervention did not improve long-term retention of knowledge among the participants, there was a substantial increase in the number of residents who prescribed PrEP. One of the limitations that can contribute to these results; is the short time frame between the intervention and post-survey. These findings demonstrate the need for early introduction of this topic into medical school and residency program curricula.

Disclosures

All Authors: No reported disclosures.

Takotsubo Cardiomyopathy as a Cardiovascular Manifestation of COVID-19: A Case Report and Literature Review

Coronavirus disease 2019 (COVID-19) has a wide range of clinical manifestations, affecting multiple organ systems. Cardiovascular manifestations of COVID-19 that have been reported include arrhythmias, myocarditis, and an increased predisposition to acute myocardial infarction. Takotsubo cardiomyopathy (TCM), which is characterized by apical ballooning of the heart leading to acute left ventricular dysfunction, is scarcely seen in COVID-19 patients. We present a case of COVID-19-associated TCM in a 68-year-old man.  A 68-year-old man with no significant past medical history presented with sudden-onset midsternal pressure-like chest pain at rest, associated with diaphoresis and shortness of breath. This occurred ten days after diagnosis of COVID-19 with mild symptoms, with no other recent physical or emotional stressors. At presentation, he was afebrile (98.5 °F), hypertensive (177/108 mmHg), tachycardic (HR 118 bpm), and saturating 100% on room air. Labs were significant for leukocytosis with 15.1 × 103 WBCs/mcL, elevated creatinine (1.46 g/dL), brain natriuretic peptide (BNP) of 156, troponin of 4 ng/mL that peaked at 16.28 ng/mL. The rapid COVID-19 test was positive. EKG showed anterolateral ST elevation and QTc interval of 446 ms. Echo showed severe hypokinesis of mid and apical segments and severely decreased left ventricular ejection fraction (LVEF)of <30%. Emergent left heart catheterization showed 75% mid left anterior descending coronary artery (LAD) stenosis and moderate right coronary artery (RCA) disease, while the ventriculogram showed a left ventricular ejection fraction of 35% with anteroapical and inferoapical akinesia suggestive of Takotsubo cardiomyopathy. The patient was placed on aspirin, ticagrelor, and atorvastatin, carvedilol, and lisinopril. EKG the next day showed a prolonged QTc of 526 ms with T-wave inversion and no ST elevations. The patient had no findings consistent with myocarditis or pheochromocytoma. He was discharged two days later. Within the next few weeks, his symptoms improved, and a follow-up echo confirmed normalization of left ventricular function.  There has been an increased incidence of Takotsubo cardiomyopathy during the COVID-19 pandemic compared to the pre-pandemic period. There is only a slight female preponderance in COVID-19-induced TCM, possibly because males are predominantly affected by COVID-19. Our patient satisfied all four Mayo Clinic criteria required for the diagnosis of TCM. Pathophysiology of TCM in COVID-19 is linked with cytokine storm and consequent catecholamine surge. Most patients improve within succeeding weeks or months. Nonetheless, the case fatality rate is high 36.5%, which is significantly higher compared to TCM patients without COVID-19. COVID-19 has a multisystem involvement with various clinical presentations. New cardiomyopathy in COVID-19 patients should raise suspicion among clinicians regarding stress-induced cardiomyopathy.

An Unusual Presentation of Clostridioides Difficile Colitis in a Patient on Opioids

Clostridioides difficile colitis is an inflammation of the colon due to toxins produced by a gram-positive bacterium called Clostridioides difficile (also known as Clostridium difficile). Clostridioides difficile colitis is associated with an increased risk of morbidity and mortality in elderly patients. The infection develops because of the disruption of the microbiome that usually suppresses the overgrowth of Clostridioides difficile. Testing for Clostridium difficile infection is routinely recommended in patients with at least three loose bowel movements in a day. We present an unusual case of a 74-year-old woman on chronic opioids who presented with a three-day history of lower abdominal pain, constipation, hematochezia, with no diarrhea. Radiologic imaging showed evidence of colitis, and the patient was found to have Clostridium difficile colitis.

Randomized controlled trial transfusing convalescent plasma as post-exposure prophylaxis against SARS-CoV-2 infection

BACKGROUND

The efficacy of SARS-CoV-2 convalescent plasma (CCP) for preventing infection in exposed, uninfected individuals is unknown. We hypothesized that CCP might prevent infection when administered before symptoms or laboratory evidence of infection.

METHODS

This double-blinded, phase 2 randomized, controlled trial (RCT) compared the efficacy and safety of prophylactic high titer (≥1:320) CCP with standard plasma. Asymptomatic participants aged ≥18 years with close contact exposure to a person with confirmed COVID-19 in the previous 120 hours and negative SARS-CoV-2 test within 24 hours before transfusion were eligible. The primary outcome was development of SARS-CoV-2 infection.

RESULTS

180 participants were enrolled; 87 were assigned to CCP and 93 to control plasma, and 170 transfused at 19 sites across the United States from June 2020 to March 2021. Two were excluded for SARS-CoV-2 RT-PCR positivity at screening. Of the remaining 168 participants, 12/81 (14.8%) CCP and 13/87 (14.9%) control recipients developed SARS-CoV-2 infection; 6 (7.4%) CCP and 7 (8%) control recipients developed COVID-19 (infection with symptoms). There were no COVID-19-related hospitalizations in CCP and 2 in control recipients. There were 28 adverse events in CCP and 58 in control recipients. Efficacy by restricted mean infection free time (RMIFT) by 28 days for all SARS-CoV-2 infections (25.3 vs. 25.2 days; p=0.49) and COVID-19 (26.3 vs. 25.9 days; p=0.35) were similar for both groups.

CONCLUSION

In this trial, which enrolled persons with recent exposure to a person with confirmed COVID-19, high titer CCP as post-exposure prophylaxis appeared safe, but did not prevent SARS-CoV-2 infection.

TRIAL REGISTRATION

Clinicaltrial.gov number NCT04323800 .

A Rare Case of Hepatic Abscess That Resolved after Drainage of Pleural Empyema

Empyema has rarely been associated with hepatic abscess. In patients with concurrent empyema and hepatic abscess, hepatic abscess drainage is usually required after drainage of the pleura. We present a rare case of a 91-year-old Caucasian man who presented with a 2-week history of productive cough, fever, shortness of breath, and generalized malaise. The patient was found to have concurrent streptococci empyema and hepatic abscess, and, interestingly, the hepatic abscess resolved after the drainage of the empyema and initiation of antibiotics.

Improving Outpatient Antibiotic Prescribing for Respiratory Tract Infections in Primary Care; a Stepped-Wedge Cluster Randomized Trial

BACKGROUND

Inappropriate antibiotic prescribing is common in primary care (PC), particularly for respiratory tract diagnoses (RTDs). However, the optimal approach for improving prescribing remains unknown.

METHODS

We conducted a stepped-wedge study in PC practices within a health system to assess the impact of a provider-targeted intervention on antibiotic prescribing for RTDs. RTDs were grouped into tiers based on appropriateness of antibiotic prescribing: tier 1 (almost always indicated), tier 2 (may be indicated), and tier 3 (rarely indicated). Providers received education on appropriate RTD prescribing followed by monthly peer comparison feedback on antibiotic prescribing for (1) all tiers and (2) tier 3 RTDs. Chi-squared testing was used to compare the proportion of visits with antibiotic prescriptions before and during the intervention. Mixed-effects multivariable logistic regression analysis was performed to assess the association between the intervention and antibiotic prescribing.

RESULTS

Across 30 PC practices and 185,755 total visits, overall antibiotic prescribing was reduced with the intervention, from 35.2% to 23.0% of visits (p<0.001). In multivariable analysis, the intervention was associated with a reduced odds of antibiotic prescription for tiers 2 (OR 0.57; 95% CI 0.52 - 0.62) and 3 (OR 0.57; 95% CI 0.53 - 0.61), but not for tier 1 (OR 0.98; 95% CI 0.83 - 1.16).

CONCLUSION

A provider-focused intervention reduced overall antibiotic prescribing for RTDs without affecting prescribing for infections that likely require antibiotics. Future research should examine the sustainability of such interventions, potential unintended adverse effects on patient health or satisfaction, and provider perceptions and acceptability.

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.

The Impact of Reported Beta-Lactam Allergy in Hospitalized Patients With Hematologic Malignancies Requiring Antibiotics

Background

Patients hospitalized with hematologic malignancy are particularly vulnerable to infection. The impact of reported beta-lactam (BL) allergy in this population remains unknown.

Methods

This was a retrospective cohort study of adult inpatients with hematologic malignancy admitted at 2 tertiary care hospitals from 2010 through 2015. The primary outcome was hospital length of stay (LOS) after administration of the first antibiotic. Secondary outcomes included readmission, mortality, complications, hospital charges, and antibiotic usage. Our goal was to define the impact of BL-only allergy (BLOA) label on clinical outcomes compared to those with no BL allergy (NBLA) in hematologic malignancy inpatients who required systemic antibiotics.

Results

In our cohort (n = 4671), 38.3% had leukemia, 4.9% had Hodgkin lymphoma, 36.1% had non-Hodgkin lymphoma, and 20.7% had multiple myeloma. Among patients, 35.1% reported antibiotic allergy, and 14.1% (n = 660) had BLOA (including 9.3% with penicillin-only allergy and 3.3% cephalosporin-only allergy). Patients with BLOA had longer median LOS compared to patients with NBLA (11.3 vs 7.6 days, P < .001), which remained significant after multivariable adjustment. Patients with BLOA also had significantly worse outcomes in terms of mortality rate at 30 days (7.6% vs 5.3%, P = .017) and 180 days (15.8% vs 12.2%, P = .013), 30-day readmission rate, Clostridium difficile rate, hospital charges ($223 046 vs $173 256, P < .001), antibiotic classes used, and antibiotic duration.

Conclusions

In hospitalized patients with hematologic malignancy, patients with reported BL allergy had worse clinical outcomes and higher healthcare cost than those without BL allergy label.

2067. Improving Outpatient Antimicrobial Prescribing for Respiratory Tract Infections

Background

Antimicrobial stewardship often focuses on inpatients, yet inappropriate antimicrobial use is common in the outpatient setting. We performed a prospective, stepped wedge interventional study to assess the impact of an educational and feedback-based intervention on prescribing practices for respiratory tract infections (RTIs) in the adult primary care ambulatory setting.

Methods

Family and internal medicine practices were randomly placed into 6 cohorts, which received the intervention in a stepped wedge fashion at monthly intervals. The study period was July 1, 2016 to October 31, 2018, with the intervention occurring from October 1, 2017 to October 31, 2018. The intervention consisted of a 20-minute in-person educational session on appropriate antimicrobial prescribing for RTIs followed by monthly feedback to individual providers on their proportion of antibiotic prescriptions in comparison to their peers for (1) visits with a primary diagnosis of any RTI and (2) visits with a primary diagnosis of an RTI for which an antibiotic should rarely be prescribed (tier 3 diagnoses). The outcome of interest was whether an antibiotic was prescribed in RTI visits. Chi squared testing and logistic regression were used for analysis.

Results

Thirty-two practices participated, with 197,814 unique visits with a primary RTI diagnosis. Of these, 141,888 (71.7%) were physician visits and 55,926 (28.3%) were advanced practitioner visits (Figure 1). The proportion of visits with antibiotic prescriptions dropped from 37.2% to 24.0% following the intervention (P < 0.0001). Antibiotic prescriptions were significantly reduced for all primary RTI visits, OR 0.53 (95% CI 0.52 to 0.54), as well as for visits with tier 3 RTI diagnoses, OR 0.64 (95% CI 0.60 to 0.68). The proportion of visits with antibiotic prescriptions also exhibited a marked seasonal variation, another finding of the study (Figure 2).

Conclusion

An educational intervention with provider feedback successfully reduced antibiotic prescribing for RTIs in the ambulatory setting. Additional study is necessary to assess the sustainability of response over time after discontinuation of the monthly feedback.

Disclosures

All authors: No reported disclosures.

1813. Development and Validation of Novel Ambulatory Antibiotic Stewardship Metrics

Background

Over 260 million antibiotic courses are prescribed in ambulatory settings per year in the United States: 41% of which are for acute respiratory tract infections (ARTI). Over 50% of these antibiotic courses are inappropriate. However, interventions to improve ambulatory prescribing are little studied, and metrics to track antibiotic use are not well validated.

Methods

To validate metrics for ARTIs in adults, we conducted a retrospective cohort study from January 1, 2016 to December 31, 2016 at 32 primary care practices. We randomly selected 1,200 office visits with a coded respiratory tract diagnosis and determined by medical record review the proportion of visits in which antibiotic prescription was inappropriate using modified Infectious Diseases Society of America treatment guidelines. We determined clinic and provider characteristics associated with inappropriate prescribing. By linear regression, we also determined the aggregate metrics best correlated with inappropriate antibiotic prescribing.

Results

An antibiotic was prescribed in 37% of visits in which a respiratory tract diagnosis was coded. Of these prescriptions, 69% were inappropriate. Demographics associated with inappropriate prescribing included advance practice provider vs. physician (72% vs. 58%, P = 0.02), family medicine vs. internal medicine (75% vs. 63%, P = 0.01), board certification after vs. before 1997 (75% vs. 63%, P = 0.02), and practice in a non-teaching vs. teaching clinic (73% vs. 51%, P < 0.001). Rate of antibiotic prescribing in visits where any respiratory tract diagnosis was coded (R² = 0.23, P < 0.001) and rate of antibiotic prescribing in visits where a respiratory tract diagnosis that almost never requires an antibiotic was coded (R² = 0.24, P < 0.0001) were most strongly correlated with inappropriate prescribing.

Conclusion

Rate of antibiotic prescribing in visits where any respiratory tract diagnosis was coded and rate of antibiotic prescribing in visits where a respiratory tract diagnosis that almost never requires an antibiotic was coded may be useful proxies to estimate the rate of inappropriate prescribing for ARTIs. This study could inform ambulatory antibiotic benchmarking metrics and interventions to decrease inappropriate antibiotic prescribing for ARTIs in ambulatory settings.

Disclosures

All authors: No reported disclosures.

1800. Clinical Impact of Real-Time Predictive Model to Facilitate Antibiotic Prescribing in Gram-Negative Bacteremia

Background

Delay in effective antibiotic administration in severe infections such as bacteremia is associated with worse clinical outcomes. We implemented previously validated software that uses real-time predictive modeling to determine patient-specific antibiograms (PS-ABG). The software allowed prescribers to run the model on their individual patients. It also automatically evaluated positive blood cultures, alerting the antibiotic stewardship team if there was <90% chance of the organism being susceptible to current antibiotic therapy.

Methods

We performed a quasi-experimental study to evaluate clinical outcomes in patients with Gram-negative rod (GNR) bacteremia 18 months before (PRE) and 6 months after (POST) implementation of the software. Primary outcome was median time to effective antibiotic. Secondary outcomes included in-hospital mortality, utilization of antibiotics used for multidrug-resistant GNRs (MDR-GNR), median time to effective antibiotic in organisms resistant to at least one first-line antibiotic for sepsis, and length of stay.

Results

The change per month in the primary outcome did not differ between the PRE and POST periods (P = 0.48) (figure). Time to effective antibiotics in GNR bloodstream infections that were resistant to at least one first-line antibiotic for sepsis (cefepime, piperacillin–tazobactam, or levofloxacin) was lower following the intervention (15.8 hours vs. 13.7 hours, P = 0.11), and mortality decreased following the intervention (14.6% vs. 10.0%, P = 0.11) although these differences were not statistically significant. There was no difference in other secondary outcomes between PRE and POST groups: length of stay (7.7 vs. 7.5 days, P = 0.74) and days of therapy of MDR-GNR agents per 30 days of hospitalization (3.5 vs. 2.5, P = 0.09).

Conclusion

There was no difference in median time to effective antibiotic in all patients with GNR bacteremia. There was lower in-hospital mortality in the POST group and shorter time to effective antibiotic therapy in GNR bacteremia resistant to at least one first-line antibiotic for sepsis, although these differences were not statistically significant. Additional study in larger cohorts over longer periods is warranted to determine whether PS-ABGs improve clinical outcomes in patients with more resistant GNR bacteremia.

Disclosures

All authors: No reported disclosures.

Use of a Precision Antibiotic Therapy (PAT) Prediction Model to Identify Multidrug-Resistant (MDR) Enterobacteriaceae

Background

Emergence of multidrug-resistant (MDR) Enterobacteriaceae complicates the selection of empiric antibiotic therapy. Software called Precision Antibiotic Therapy (PAT) (Teqqa, LLC; Jackson, WY) operationalizes a predictive model using patient factors to make real-time, personalized predictions of antibiotic susceptibility for each antibiotic, allowing prescribers to choose empiric therapy for patients at risk for resistant infections. The purpose of this study was to determine the performance of PAT software in identifying MDR Enterobacteriaceaebloodstream infections (BSI) as well as to determine optimal thresholds of predicted antibiotic susceptibility to choose a broader-spectrum antibiotic.

Methods

We conducted a retrospective cohort study including 475 unique patients with BSIs caused by Enterobacteriaceaefrom January 1, 2016 through December 31, 2016. First-line antibiotic therapy for BSI was defined as cefepime, piperacillin-tazobactam, levofloxacin, or aztreonam. Susceptibilities predicted by PAT were compared with known susceptibilities determined by routine laboratory testing. PAT thresholds for broadening antibiotics were assessed when predicted susceptibilities were 80%, 85%, 90%, and 95% using receiver-operating characteristic (ROC) curves. Performance characteristics were calculated for each threshold. Brier score calculations were then used to compare the accuracy of PAT predictions using the optimized predicted susceptibility threshold, to that of aggregate institutional susceptibility data.

Results

ROC curve analysis demonstrated an area under the curve of 0.82 for the 95% threshold. The sensitivity for the PAT prediction utilizing the 95% threshold was 91.7% with a specificity of 74.3%. The Brier score for the 2016 antibiogram to determine antibiotic therapy was 0.085, whereas the Brier score using PAT software was 0.071, representing a 16% improvement in accuracy.

Conclusion

PAT software demonstrated excellent capability to discriminate between Enterobacteriaceae BSIs resistant and susceptible to first-line therapy. A predicted susceptibility threshold of 95% should be used to indicate a need for escalation of empiric antibiotic therapy using PAT.

Disclosures

All authors: No reported disclosures.

Home Environmental Contamination Is Associated with Community-associated Methicillin-resistant Staphylococcus aureus Re-colonization in Treated Patients

Background

Strategies to interrupt household transmission of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) that target human colonization show mixed results. Our aim was to determine whether home environmental contamination and pet carriage with MRSA were associated with re-colonization or persistent colonization of index patients diagnosed with CA-MRSA skin or soft-tissue infection (SSTI).

Methods

Index patients from a randomized controlled trial (NCT00966446) that tested household-wide decolonization of people were eligible to participate in this substudy. Before randomization, eight environmental sites and all pets were sampled in the home. Patients were treated by their physician for the initial SSTI between diagnosis (visit 0) and the home visit (visit 1). They provided swabs every 2 weeks for 3 months (7 visits). After broth-enrichment culture, MRSA isolates were PCR-confirmed and spa-typed.

Results

Of 88 index patients recruited from the main trial, 64 (73%) provided swabs for ≥3 visits and were included in this analysis. At visit 1, 41 (64%) households were MRSA contaminated and 6 (9%) had MRSA-positive pet(s). All MRSA-positive pets lived in homes with MRSA environmental contamination. After visit 1, 42 (66%) index patients and their household members were block-randomized to nasal mupirocin and chlorhexidine body wash decolonization. Thirty-seven (58%) index patients had two consecutive negative swabs (de-colonized); 13 (35%) of these later were MRSA-positive (re-colonized). Patients with home contamination had higher rates of re-colonization than those without (Cox proportional hazard ratio 6.0 [95% CI: 1.2, 30.6], P < 0.03). Persistent colonization (all or all but one swab positive) was identified in 6 (9%) of index patients and was associated with identification of matching spa-types in environmental and subsequent human MRSA isolates (P < 0.05).

Conclusion

In patients with MRSA SSTI, MRSA-contaminated homes, and potentially MRSA-positive pets, are associated with re-colonization and persistent colonization. Future studies are needed to determine whether environmental decontamination can improve the success of household decolonization interventions.

Disclosures

All authors: No reported disclosures.