Clinical outcomes of baloxavir versus oseltamivir in immunocompromised patients

BACKGROUND

Neuraminidase inhibitors, including oseltamivir, are the treatment standard for influenza. Baloxavir, a novel antiviral, demonstrated comparable outcomes to oseltamivir in outpatients with influenza. Baloxavir was equally effective as oseltamivir in a retrospective study of hospitalized patients with influenza at our institution. However, the efficacy of baloxavir in immunocompromised patients is unclear.

METHODS

We conducted a retrospective cohort study of immunocompromised adult patients hospitalized with influenza A who received baloxavir from January 2019 to April 2019 or oseltamivir from January 2018 to April 2018. Demographic and clinical outcomes were assessed. Primary outcomes were time from antiviral initiation to resolution of hypoxia and fever. Secondary outcomes were length of stay (LOS), intensive care unit (ICU) care, ICU LOS, and 30-day mortality.

RESULTS

Of 95 total patients, 52 received baloxavir and 43 received oseltamivir. Other than younger age (57.5 vs. 65; p = .035) and longer duration between vaccination and symptom onset (114 vs. 86 days; p = .001) in the baloxavir group, baseline characteristics did not differ. H1 was the predominant subtype in the baloxavir group (65.3%) versus H3 in the oseltamivir group (85.7%). When comparing baloxavir to oseltamivir, there was no significant difference in median time from antiviral initiation to resolution of hypoxia (59.9 vs. 42.5 h) and to resolution of fever (21.6 vs. 26.6 h). There were no differences in secondary outcomes.

CONCLUSION

Baloxavir was not associated with longer time to resolution of hypoxia or fever in comparison to oseltamivir. Results must be taken in context of variations in seasonal influenza subtype and resistance rates.

Immunomodulatory Agents for Coronavirus Disease-2019 Pneumonia

Morbidity and mortality from COVID-19 is due to severe inflammation and end-organ damage caused by a hyperinflammatory response. Multiple immunomodulatory agents to attenuate this response have been studied. Corticosteroids, specifically dexamethasone, have been shown to reduce mortality in hospitalized patients who require supplemental oxygen. Interleukin-6 antagonist, tocilizimab, and Janus kinase inhibitors have also been shown to reduce mortality. However, patients who have severe pulmonary end-organ damage requiring mechanical ventilation or extracorporeal membrane oxygenation appear not to benefit from immunomodulatory therapies. This highlights the importance of appropriate timing to initiate immunomodulatory therapies in the management of severe COVID-19 disease.

Outcomes of pregnant women exposed to Sotrovimab for the treatment of COVID-19 in the BA.1 Omicron predominant era (PRESTO)

BACKGROUND

Sotrovimab, a monoclonal antibody with efficacy against SARS-CoV-2 including certain Omicron variants, has been used in treatment of mild-moderate COVID-19. Limited data exists regarding its use in pregnant women.

METHODS

Electronic medical record review of pregnant COVID-19 patients treated with sotrovimab from 12/30/21 - 1/31/22 (Yale New Haven Health Hospital System [YNHHS]) was performed. Included were pregnant individuals ≥ 12 years, weighing ≥ 40 kg, with positive SARS-CoV-2 test (within 10 days). Those receiving care outside YNHHS or receiving other SARS-CoV-2 treatment were excluded. We assessed demographics, medical history, and Monoclonal Antibody Screening Score (MASS). The primary composite clinical outcome assessed included emergency department (ED) visit < 24 h, hospitalization, intensive care unit (ICU) admission, and/or death within 29 days of sotrovimab. Secondarily, adverse feto-maternal outcomes and events for neonates were assessed at birth or through the end of the study period, which was 8/15/22.

RESULTS

Among 22 subjects, median age was 32 years and body mass index was 27 kg/m2. 63% were Caucasian, 9% Hispanic, 14% African-American, and 9% Asian. 9% had diabetes and sickle cell disease. 5% had well-controlled HIV. 18%, 46%, and 36% received sotrovimab in trimester 1, 2, and 3, respectively. No infusion/allergic reactions occurred. MASS values were < 4. Only 12/22 (55%) received complete primary vaccination (46% mRNA-1273; 46% BNT162b2; 8% JNJ-78,436,735); none received a booster.

CONCLUSIONS

Pregnant COVID-19 patients receiving sotrovimab at our center tolerated it well with good clinical outcomes. Pregnancy and neonatal complications did not appear sotrovimab-related. Though a limited sample, our data helps elucidate the safety and tolerability of sotrovimab in pregnant women.

589. Clinical Outcomes of Twice versus Thrice daily Metronidazole Dosing for Bacteroides Bloodstream Infections

Background

The optimal metronidazole dose for the treatment of Bacteroides spp. has not been defined. The purpose of this study was to evaluate the utility of a twice (BID), rather than thrice (TID) daily metronidazole dosing strategy among patients with bacteremia due to Bacteroides spp.

Methods

Adult, hospitalized patients with bacteremia secondary to Bacteroides spp. between October 2010 and June 2021 were assessed across 11 hospitals. The primary endpoint was clinical failure which was a composite of all-cause 30-day mortality, escalation of antimicrobial therapy, 30-day readmission or recurrence due to an anaerobic infection, positive repeat blood cultures for Bacteroides spp., or failure to resolve leukocytosis or fever.

Results

208 patients were included; 68 received metronidazole 500mg BID and 140 patients received metronidazole 500mg TID (Figure). Patient age, Charlson comorbidity index, and Pitt Bacteremia score were similar among patients receiving BID vs TID dosing (Table 1). On balance, patients who received BID dosing were more likely to receive oral metronidazole and had shorter lengths of hospitalization prior to bacteremia. Overall, there was no significant difference between rates of clinical failure or other outcomes between patients who received BID versus TID metronidazole dosing (Table 2). In the multivariate model, neither the use of TID dosing (OR = 0.74; 95% CI = 0.33–1.65; P=0.457), time to treatment initiation (OR = 1; 95% CI = 0.81–1.22; P=0.968), days of initial non-metronidazole anaerobic therapy (OR = 0.91; 95% CI = 0.59–1.34; P=0.646), pre-infection length of stay (OR = 1.02; 95% CI = 0.99–1.05; P=0.106), admission prior to 2016 (OR = 1.09; 95% CI = 0.49–2.39; P=0.829), or initial oral metronidazole use (OR = 0.45; 95% CI = 0.18–1.03; P=0.066) were significantly associated with clinical failure. Figure 1:Inclusion and exclusion

Non-metronidazole anaerobic coverage consisted of a beta-lactam/beta-lactamase inhibitor, cefoxitin, or a carbapenem Table 1:Demographics and baseline characteristicsTable 2:Clinical outcomes*Patients were considered to have escalated antimicrobial therapy if, in the setting of ongoing signs of infections, antimicrobial therapy was either broadened or the frequency of metronidazole was increased from twice daily to thrice daily.

Conclusion

In the largest study to date of patients with Bacteroides spp. bacteremia treated with metronidazole, there was no significant difference between BID and TID metronidazole dosing strategies. In the absence of a clear benefit, metronidazole 500mg BID is a reasonable dosing strategy in lieu 500mg TID for infections due to Bacteroides spp.

Disclosures

Ryan K. Shields, PharmD, MS, Infectious Disease Connect: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Roche: Grant/Research Support.

588. A Safety analysis of High Dose Intrawound Vancomycin in Arthroplasty

Background

There is a paucity of data to support the efficacy and safety of placing vancomycin powder into and around the joint in total hip arthroplasty (THA), total knee arthroplasty (TKA), and shoulder arthroplasty (SA).

Methods

This was a retrospective chart review of patients undergoing THA, TKA, or SA who received intrawound (IW) vancomycin powder placed into and around the joint with a vancomycin impregnated bone cement spacer (VIBCS) compared to patients who received a VIBCS alone (usual care).

Results

There were 24 patients who met inclusion criteria. Of the 14 patients who received IW vancomycin, the median dose (Range) was 5g (4-10). While there were no statistically significant differences in baseline demographics, those who received IW vancomycin were more likely to experience vancomycin induced nephrotoxicity (VIN) compared to those who received usual care (42.9% vs. 0%, P=0.02) (Table 1).

Conclusion

Our experience with IW vancomycin at a median dose of 5g in combination with VIBCS was associated with an increased risk of nephrotoxicity in our patients. Therefore, re-evaluation of the use of IW vancomycin at these doses is warranted.

Disclosures

All Authors: No reported disclosures.

LB1577. Outcomes of Pregnant Women Exposed to Sotrovimab for the Treatment of COVID-19 in the Omicron Predominant Era (PRESTO)

Background

Sotrovimab, a monoclonal antibody with efficacy against SARS-CoV-2 including certain Omicron variants, has been used in treatment of mild-moderate COVID-19. Limited data exists regarding its use in pregnant women.

Methods

Electronic medical record review of pregnant COVID-19 patients treated with sotrovimab from 12/30/21-1/31/22 (Yale New Haven Health Hospital System [YNHHS]) was performed. Included were pregnant individuals ≥ 12 years, weighing ≥ 40 kg, with positive SARS-CoV-2 test (within 10 days). Those receiving care outside YNHHS or receiving other SARS-CoV-2 treatment were excluded. We assessed demographics, medical history, and Monoclonal Antibody Screening Score (MASS). Clinical outcomes assessed included emergency department (ED) visit < 24 hours, hospitalization, ICU admission, and/or death within 29 days of sotrovimab. Pregnancy and neonatal outcomes were assessed until 8/15/22.

Results

Among 22 subjects, median age was 32 years and body mass index was 27 kg/m². Sixty-three percent were Caucasian, 9% Hispanic, 14% African-American, and 9% Asian. Nine percent had diabetes and sickle cell disease. Five percent had well-controlled HIV. Eighteen percent, 46%, and 36% received sotrovimab in trimester 1, 2, and 3, respectively. No infusion/allergic reactions occurred. MASS values were < 4. Only 12/22 (55%) received complete primary vaccination (46% mRNA-1273; 46% BNT162b2; 8% JNJ-78436735); none received a booster.

There were no ICU admissions nor deaths. One subject was hospitalized for post-partum pyelonephritis; another had an ED visit for post-partum vaginal bleeding. Median gestational age at birth was 38.9 weeks. Nine percent had premature labor and premature rupture of membranes, respectively. Median infant birth weight was 3220 g. One neonate required an ICU stay due to prenatally diagnosed omphalocele (before sotrovimab) in a mother with congenital defect history. There were no abortions, fetal loss, or other birth/neurodevelopmental defects.

Conclusion

Pregnant COVID-19 patients receiving sotrovimab at our center tolerated it well with good clinical outcomes. Pregnancy and neonatal complications did not appear sotrovimab-related. Though a limited sample, our data helps elucidate the safety and tolerability of sotrovimab in pregnant women.

Disclosures

All Authors: No reported disclosures.

195. Reducing Time to Optimal Antimicrobial Therapy (OAT) for Bloodstream Infections (BSI) due to Gram Positive Cocci (GPC) in Chains Using Rapid Diagnostics Paired with Antimicrobial Stewardship (ASP) Efforts

Background

Rapid microbiology diagnostic results paired with immediate ASP intervention have been shown to decrease time to OAT and improve patient outcomes. For Gram positive (GP) BSI, studies have primarily focused on Staphylococci. However, the value of using rapid diagnostics for GPC in chains is not well studied. With the use of BioFire® FilmArray® Blood Culture Identification 2 (BCID2) to identify GPC in chains, we aimed to compare the time to OAT between pre- and post- implementation.

Methods

In May 2021, our institution implemented the use of BCID2 for GPC in chains, which detects 5 types of GPC in chains to the species level and the van A/B gene. Positive results were communicated in real time 24/7 to ASP who provided recommendations on OAT to the treatment team.

A retrospective chart review compared the pre-implementation cohort (Jan - Sept 2019) to the post-implementation cohort (May 2021 - Jan 2022). The following patients were excluded from analysis: < 18 years of age, presence of polymicrobial infection or Streptococci with unidentified species by BCID2, discharged or deceased before rapid diagnostic result, on comfort measures or left against medical advice within 72 hours of result.

The primary study endpoint was time to OAT which was defined as time from positive Gram stain to OAT. Secondary outcomes included percentage of ASP recommendations accepted, length of stay (LOS), and 30-day mortality.

Results

A total of 199 patients met inclusion criteria, 117 pre-cohort vs. 82 post-cohort. Baseline demographics were similar in both groups with the exception of the post-cohort having a numerically higher Charlson Comorbidity Index (Table 1). The most common sources of the bacteremias were intra-abdominal, skin and soft tissue, and endovascular (Table 2).

The primary endpoint, average time to OAT, was 35 hours in the pre-cohort and 18 hours in the post-cohort with a difference of 16.8 hours (95% CI 9.8 – 23.8; p < 0.0001) (Table 3). ASP recommendations were accepted 91% of the time. The median LOS was 9 days (IQR 6 - 21) in the pre-cohort vs. 13 days (IQR 7-32) in the post-cohort (p = 0.07). The 30-day mortality rate was numerically lower in the pre-cohort (6.1% vs. 10.3%; p = 0.79).

Conclusion

For BSI due to GPC in chains, rapid diagnostics via BCID2 paired with 24/7 ASP led to markedly decreased time to OAT.

Disclosures

David Peaper, MD, Tangen Biosciences: Stocks/Bonds.

Mucocutaneous Leishmaniasis in a Pregnant Immigrant

Cutaneous leishmaniasis is a parasitic infection that causes significant maternal morbidity, and even fetal mortality, during pregnancy, yet there are limited therapeutic options. Here, we report a case of leishmaniasis in a pregnant immigrant with exuberant mucocutaneous lesions with favorable response to liposomal amphotericin B.

Combination Therapy of Chloramphenicol and Daptomycin for the Treatment of Infective Endocarditis Secondary to Multidrug Resistant Enterococcus faecium

A 38-years-old female with an aortic valve replacement presented to an outside hospital (OSH) with fevers and malaise. Blood cultures revealed VRE which was resistant to linezolid, resistant to ampicillin, non-susceptible to daptomycin (MIC of 8 mcg/mL), and exhibited susceptibility to gentamicin. The patient was therefore initiated on intravenous (IV) daptomycin 6 mg/kg q24h and gentamicin IV 1 mg/kg q8h. However, after 14 days of therapy with daptomycin and gentamicin, the patient was transferred to our institution for the management of cardiogenic shock and hypoxemic respiratory failure. Given the concern for treatment failure, her antimicrobial regimen was changed to IV chloramphenicol 12.5 mg/kg every 6 hours with IV daptomycin 10 mg/kg every 48 hours given an estimated creatinine clearance of 30 mL/minutes. In vitro susceptibilities for chloramphenicol were performed which confirmed susceptibility. A transesophageal echocardiogram revealed a possible abscess at the left coronary cusp and aortic valve dehiscence. The patient underwent aortic valve replacement with aortic root reconstruction. The aortic valve culture grew VRE susceptible to linezolid but resistant to ampicillin and doxycycline. The patient was deemed clinically cured after 42 days of combination therapy with daptomycin and chloramphenicol. After 6 years of follow-up, the patient has not had a recurrent VRE infection. To our knowledge, this is the first case of endocarditis secondary to VRE that was successfully managed with the combination of daptomycin and chloramphenicol.

An outbreak of SARS-CoV-2 on a transplant unit in the early vaccination era

Solid organ transplant recipients are at increased risk of COVID-19 associated morbidity and mortality. We describe the first nosocomial outbreak investigation on an immunocompromised inpatient unit aided by SARS-CoV-2 whole genome sequencing. Two patients were identified as potential index cases; one presented with diarrhea and the other tested positive on hospital day 18 after developing hypoxemia and subsequently testing positive for SARS-CoV-2. Following identification of the SARS-CoV-2 cluster, the unit was closed to new admissions, and the remaining patients and staff members underwent surveillance SARS-CoV-2 testing. Four additional patients and four staff members tested positive for SARS-CoV-2. Asymptomatic patients with COVID-19 were treated with bamlanivimab and all were alive at discharge. The unit was then re-opened with no additional positives reported since the initial outbreak. Preventing SARS-CoV-2 outbreaks in transplant units poses unique challenges as patients may have atypical presentations of COVID-19. Immunocompromised patients who test positive for SARS-CoV-2 while asymptomatic may benefit from monoclonal antibody therapy to prevent disease progression. All hospital staff members working with immunocompromised patients should be promptly encouraged to receive SARS-CoV-2 vaccination. This article is protected by copyright. All rights reserved.

947. Nocardiosis in Renal Transplant Recipients Linked to Decreased Utilization of Trimethoprim/Sulfamethoxazole During COVID-19

Background

The renal transplant population is at increased risk of Nocardiosis due to impaired T-cell mediated immunity with immunosuppression. Pneumocystis jirovecii (PJP) prophylaxis with trimethoprim/sulfamethoxazole (TMP/SMX) provides coverage against Nocardia spp. unlike alternative agents such as atovaquone (ATQ), aerosolized pentamidine (AP), and dapsone. During the COVID-19 pandemic, patients receiving AP were transitioned to ATQ to avoid the use of nebulized medication. This, in turn, led to decreased use of TMP/SMX as patients on oral ATQ were not reassessed for the use of TMP/SMX as would have occurred while on AP. Additionally, an increased incidence of Nocardia infections was observed during this time. The objective of this study was to determine the association between the incidence of Nocardia infections and number of TMP/SMX prophylaxis-days in pre- versus COVID-19 cohorts.

Methods

This was a single center retrospective chart review of all renal transplant recipients between September 2018 – August 2019 (pre-COVID-19 cohort) and April 2020 – March 2021 (COVID-19 cohort). Patients were included if they were at least 18 years of age and a recipient of a cadaveric or living donor kidney transplant. Exclusion criteria included multi-organ transplant, pediatric patients, and repeat transplants. The primary outcome was incidence of Nocardiosis within the first 6 months post-transplant in the pre- and COVID-19 cohorts.

Results

A total of 218 patients were included (Table 1). Induction therapy and initial immunosuppression did not differ significantly between groups, nor did rates of rejection within 180 days of transplant (Table 2). Although the pre-COVID-19 cohort had a higher rate of neutropenia, there was no difference in median absolute lymphocyte count between the two groups. The COVID-19 cohort had a decreased percentage of TMP/SMX prophylaxis-days (59.2% vs. 72.5%, p < 0.0001) and an increased incidence of Nocardia infections in the first 6 months post-transplant (4% vs. 0%, p=0.0292). All 4 cases of Nocardia infections occurred in patients receiving ATQ.

Conclusion

The increased incidence of Nocardiosis was associated with a decreased use of TMP/SMX for PJP prophylaxis which may have been an unintended consequence of increased use of ATQ in lieu of AP during COVID-19.

Disclosures

All Authors: No reported disclosures

Renal and Hepatic Toxicity Analysis of Remdesivir Formulations: Does What Is on the Inside Really Count?

It has been postulated that the injectable solution formulation of remdesivir could be more nephrotoxic than the lyophilized powder since it contains twice as much sulfobutylether-β-cyclodextrin (SBECD). Therefore, we evaluated 1,000 hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who received remdesivir lyophilized powder or solution. A logistic regression model accounting for baseline confounders identified that neither the use of the injectable solution (odds ratio [OR], 1.05; 95% confidence interval [CI], 0.49 to 2.29; P = 0.901) nor a creatinine clearance of <30 ml/min at the time of remdesivir initiation (OR, 1.39; 95% CI, 0.51 to 3.5; P = 0.499) was significantly associated with acute kidney injury. Regarding hepatoxicity, there was no significant difference in early discontinuation of remdesivir due to abnormal liver function tests between patients who received the lyophilized powder versus those who received solution (0.9% versus 2.3%, P = 0.09).

Clinical outcomes of baloxavir versus oseltamivir in patients hospitalized with influenza A

OBJECTIVES

To date, clinical trials evaluating baloxavir have excluded patients hospitalized with influenza infection and therefore this study sought to evaluate the efficacy of baloxavir in inpatients with influenza A.

METHODS

This study was a multicentre, retrospective chart review of adult patients admitted to the hospital within the Yale New Haven Health System who received oseltamivir or baloxavir for the treatment of influenza A. Patients were screened for inclusion between January 2018 and April 2018 in the oseltamivir group, while patients in the baloxavir group were screened for inclusion between January 2019 and April 2019. Influenza A diagnosis was confirmed by RT-PCR using a nasopharyngeal swab specimen.

RESULTS

Of the 2392 patients assessed, 790 met the inclusion criteria. There were 359 patients who received baloxavir and 431 patients who received oseltamivir. Patients who received baloxavir were younger compared with those who received oseltamivir [median = 69 (IQR = 57-81) years versus 77 (IQR = 62-86) years; P < 0.001]. Patients who received baloxavir had no significant difference in hospital length of stay [median = 4 (IQR = 3-6) days versus 5 (IQR = 3-6)  days; P = 0.45] or 30 day all-cause mortality [12 (3.3%) versus 26 (6%); P = 0.079] compared with those who received oseltamivir. However, patients who received baloxavir had a significantly faster time to hypoxia resolution [median = 51.7 (IQR = 25.3-89.3) h versus 72 (IQR = 37.5-123) h; P < 0.001].

CONCLUSIONS

The results of this study support the use of baloxavir for the treatment of influenza A in hospitalized patients with the potential benefit of a faster time to resolution of hypoxia.

A Novel Dosing Strategy of Ceftolozane/Tazobactam in a Patient Receiving Intermittent Hemodialysis

We describe the case of a 54-year-old male receiving intermittent hemodialysis (iHD) who was found to have Pseudomonas aeruginosa bacteremia secondary to osteomyelitis of the calcaneus bone. The patient was clinically cured without recurrence using a ceftolozane/tazobactam (CTZ) dosing strategy of 100/50 mg every 8 hours (standard dosing) and 1000/500 mg thrice weekly following iHD. Utilizing a susceptibility breakpoint of ≤4 µg/mL for P. aeruginosa, the T > MIC for standard dosing and the 1000/500-mg thrice-weekly following iHD regimen were calculated to be 92.7% and 94.1%, respectively. Ceftolozane total body clearance for the standard q 8 h dosing and the 1000/500-mg thrice-weekly following iHD regimen were calculated to be 0.196 L/h and 0.199 L/h, respectively. To our knowledge, this is the first report to illustrate the administration of CTZ at a dose of 1000/500 mg thrice weekly following iHD.

Cytokine Profiles Before and After Immune Modulation in Hospitalized Patients with COVID-19

We describe the cytokine profiles of a large cohort of hospitalized patients with moderate to critical COVID-19, focusing on IL-6, sIL2R, and IL-10 levels before and after receiving immune modulating therapies, namely, tocilizumab and glucocorticoids. We also discuss the possible roles of sIL2R and IL-10 as markers of ongoing immune dysregulation after IL-6 inhibition. We performed a retrospective chart review of adult patients admitted to a tertiary care center with moderate to critical SARS-CoV-2 infection. Disease severity was based on maximum oxygen requirement during hospital stay to maintain SpO2 > 93% (moderate, 0-3 L NC; severe, 4-6 L NC or non-rebreather; critical, HFNC, NIPPV, or MV). All patients were treated using the institution's treatment algorithm, which included consideration of tocilizumab for severe and critical disease. The most common cytokine elevations among all patients included IL-6, sIL2R, IFN-γ, and IL-10; patients who received tocilizumab had higher incidence of IL-6 and sIL2R elevations. Pre-tocilizumab IL-6 levels increased with disease severity (p = .0151). Both IL-6 and sIL2R levels significantly increased after administration of tocilizumab in all severity groups; IL-10 levels decreased in severe (p = .0203), but not moderate or critical, patients after they received tocilizumab. Cluster analysis revealed association between higher admission IL-6, sIL2R, and CRP levels and disease severity. Mean IL-6, sIL2R, and D-dimer were associated with mortality, and tocilizumab-treated patients with elevated IL-6, IL-10, and D-dimer were more likely to also receive glucocorticoids. Accessible clinical cytokine panels may be useful for monitoring response to treatment in COVID-19. The increase in sIL2R post-tocilizumab, despite administration of glucocorticoids, may indicate the need for combination therapy in order to modulate more than one hyperinflammatory pathway in COVID-19. We also discuss the role of cytokines as potential biomarkers for use of adjunct glucocorticoid therapy.

Pharmacists leadership in a medication shortage response: Illustrative examples from a health system response to the COVID-19 crisis

As medication experts, clinical pharmacists play an active and dynamic role in a medication shortage response. Supplementing existing guidelines with an actionable framework of discrete activities to support effective medication shortage responses can expand the scope of pharmacy practice and improve patient care. Dissemination of best practices and illustrative, networked examples from health systems can support the adoption of innovative solutions. In this descriptive report, we document the translation of published shortage mitigation guidelines into system success through broad pharmacist engagement and the adaption and implementation of targeted strategies. The profound, wide‐reaching medication shortages that accompanied the coronavirus disease 2019 (COVID‐19) pandemic are used to highlight coordinated but distinct practices and how they have been combined to expand the influence of the pharmacy enterprise.

Orally Administered Human Immunoglobulin Therapy for Norovirus Enteritis in Solid Organ Transplant Recipients: A Case Series at a Single Academic Transplant Center

Norovirus enteritis can cause intractable diarrhea in solid organ transplant (SOT) recipients, for which there are no established treatments. We reviewed medical records of 9 SOT recipients at our center who received orally administered human immunoglobulin for norovirus enteritis, and it appeared to be an effective treatment modality.

577. Incidence and Outcomes of Positive Outpatient Surveillance Blood Cultures in Hematopoietic Stem Cell Transplant (HSCT) Patients with Graft Versus Host Disease (GvHD) On High Dose ≥ 0.5 mg/kg/day (HD) and Low Dose &lt; 0.5mg/kg/day (LD) Steroid Therapy

Background

Treatment of GvHD with steroids increases the risk of infection in HSCT patients due to additive immunosuppression and may delay the diagnosis of infection due to lack of symptoms. Outpatient surveillance blood cultures in HSCT with GvHD being treated with HD steroids has demonstrated a blood culture positivity rate of 3.5%. Currently, the utility of surveillance cultures in patients receiving LD steroid therapy is unknown. Our practice includes weekly outpatient surveillance cultures for all GvHD patients treated with steroids regardless of the dose. The primary endpoint of this study was to assess the incidence of positive surveillance blood cultures in GvHD patients receiving HD or LD steroids. Secondary endpoints included number of patients treated, hospitalization, 30 day mortality due to infection, and organisms isolated.

Methods

This was a single-center, retrospective review of GvHD patients at Yale New Haven Hospital between January 2013 and May 2019. Patients were excluded if: lack of signs or symptoms of GvHD, treatment with steroids for any indication other than GvHD, and active GvHD without central line. Cultures from patients receiving antibiotics for concurrent infection were also excluded.

Results

A total of 71 patients met criteria with 901 blood cultures. On HD, eight patients (14%) had 12 positive cultures (4%), and on LD, 16 patients (25%) had 22 positive cultures (4%) (p=0.15). Treatment occurred in six patients (75%) with four (24%) requiring hospitalization on HD, and 12 patients (75%) with 10 (83%) requiring hospitalization on LD (p=0.45). The median duration of steroid therapy was 93 and 236 days with a median dose of steroids of 1mg/kg/day and 0.15mg/kg/day, respectively. The number of positive cultures/1000 steroid days was 1.2 on HD and 0.5 on LD (RR 2.2). 30 day mortality was only noted in one patient (8%) on LD. The most common organism in both groups was Coagulase-negative staphylococci with all six cultures on HD classified as contaminants and 6/10 cultures requiring treatment on LD.

Conclusion

Although the relative risk of positive surveillance blood cultures in HD patients compared to LD was twofold higher, there were clinically significant infections identified in the LD group.

Disclosures

All Authors: No reported disclosures

116. Leveraging the Use of the PCR-based Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Swab in the Emergency Department to Optimize Vancomycin Use in the Inpatient Setting

Background

The MRSA nasal swab has been shown to have a negative predictive value of 97–100% for an MRSA infection. Therefore, a negative MRSA swab can be an important antimicrobial stewardship tool to stop unnecessary empiric anti-MRSA therapy. Prolonged anti-MRSA therapy may increase hospital length stay, adverse effects, antimicrobial resistance, and increase the risk of acute kidney injury. Timely obtainment of the MRSA nasal swab is paramount to prevent these complications. To improve the timely collection at our institution, we linked the MRSA nasal swab order with the initial order for vancomycin in the ED using the electronic medical record.

Methods

This was a single-center, retrospective review of adult ED patients (≥ 18 years) who recieved vancomycin at Yale New Haven Hospital, New Haven, CT, USA and had an MRSA nasal swab collected. The pre-intervention cohort were patients who met inclusion criteria between September 2018 and October 2018. The post-intervention cohort, following the linking of the MRSA nasal swab with the vancomycin order included patients between June 2019 and July 2019. The primary endpoint was the time from the ED visit to vancomycin discontinuation in patients with a negative MRSA nasal swab. The secondary endpoint was a comparison of inpatient vancomycin usage before and after implimentation of the intervention.

Results

In the pre-intervention cohort 665 patients were reviewed with 100 meeting inclusion criteria and in the post-intervention cohort 242 patients were reviewed with 100 meeting inclusion criteria. Baseline demographic characteristics were similar between the two cohorts. For the primary endpoint, the time from ED visit until vancomycin discontinuation was 61 hours in the pre-intervention cohort versus 34 hours in the post-intervention cohort (p< 0.001). The secondary endpoint of the impact of the intervention on vancomycin usage is depicted figure attached.

Vancomycin IV Days of Therapy/1000 Patient Days Before and After Intervention

Conclusion

Linking the MRSA nasal swab order with the order for vancomycin in the ED led to a significantly shorter time of empiric vancomycin which in turn resulted in an overall reduction in the use of vancomycin.

Disclosures

All Authors: No reported disclosures

308. Re-purposing Beta-lactam Antibiotics as Fluoroquinolone Sparing Stepdown Therapy for the Treatment of Enterobacteriales Bloodstream Infections

Background

Oral antimicrobial therapy for Enterobacteriales bloodstream infection (EB-BSI) is advantageous to reduce the risk of central line complications, cost of care, and length of stay. Fluoroquinolones (FQ) given their high bioavailability have been utilized as the standard for stepdown therapy (SDT) for EB-BSI. Given the recent increased warnings around FQ use including Clostridioides difficile infection (CDI) and the increasing FQ resistance alternative oral options for treatment are warranted. Recent literature has suggested beta-lactams (BLM) may be an option for EB-BSI. To enhance the antimicrobial stewardship goal of reducing FQ use, our team began recommending de-escalation to a BLM for EB-BSI and the objective of this study is to evaluate the outcomes of this approach.

Methods

This study was a retrospective chart review of patients with EB-BSI due to ceftriaxone sensitive monomicrobial E. coli, Klebsiella spp., or P. mirabilis who received a BLM or a FQ as SDT. Patients were excluded if < 18 years of age; pregnant; ANC < 1000 cells/µL; had endocarditis, a bone/joint, or a CNS infection; discharged to hospice or expired prior to discharge; anaphylactic BLM allergy; or prior kidney transplant. SDT was defined as a switch to a definitive oral antibiotic after empiric IV therapy. The primary outcome was clinical cure defined as completion of therapy without signs of infection (increase in WBC > 2000 cells/mL if WBC was ≥ 12,000 cells/mL, fever (>38°C), or change in antibiotic due to failure). Secondary outcomes included 30 day re-admission rates, reinfection rate defined as positive culture within 30 days of completion of therapy, antibiotic associated adverse events defined as side effects leading to discontinuation and/or CDI within 90 days from start of treatment.

Results

A total of 159 patients were included in the study (Figure 1). The BLM patients had a higher median age (78 vs 72, p=0.008), higher median PITT bacteremia score (2 vs 1, p=0.037), were less likely to be immunosuppressed (9% vs 25%, p=0.045), and had shorter median duration of therapy (13 vs 14, p=0.034). There was no difference in the primary or secondary outcomes (Table 2).

Conclusion

BLM may enhance stewardship efforts as a FQ sparing option for treatment of EB-BSI; however, prospective studies in this area are warranted.

Disclosures

All Authors: No reported disclosures

729. Real World Efficacy of Bezlotoxumab for Prevention of Clostridioides Difficile Recurrence in Immunosuppressed Patients

Background

Bezlotoxumab has been shown to prevent recurrent episodes of C. difficile infection (CDI) in high risk patients. Current studies define therapeutic efficacy within the first 12 weeks when the risk of recurrence is greatest. However, the risk of recurrent CDI can occur beyond the 12-week window in the immunosuppressed population. Given that bezlotoxumab has detectable serum levels for up to 24 weeks after infusion, the primary endpoint is to determine overall efficacy in immunosuppressed patients with recurrent CDI at 4 weeks, 12 weeks, and 24 weeks after initial infusion. Secondary endpoints consist of risk factors for recurrent CDI, treatment of CDI, and antibiotics usage before and after bezlotoxumab.

Methods

This analysis included immunosuppressed patients at high risk for CDI recurrence who received bezlotoxumab from February 2017 to December 2019. Patients were excluded if they were not immunosuppressed, had no follow-up appointments, and/or without a C. difficile positive test. High risk antibiotics included fluoroquinolones, beta lactamase inhibitors, third generation cephalosporins, or carbapenems.

Results

Twenty-seven bezlotoxumab doses were given to 26 patients. Baseline characteristics for CDIs prior to bezlotoxumab is reported in Table 1. The overall CDI recurrence rate at all intervals after bezolotoxumab was 4 (15%), one recurrent CDIs occurred at < 4 weeks, two recurrent CDIs occurred at 5-12 weeks, and one recurrent CDI at 13-24 weeks. High risk antibiotics were given in 2/4 (50%) of CDIs recurrences and 22/75 (29%) in the non-recurrence group. Of the four CDI recurrences, all were mild to moderate in disease severity given no evidence of colitis was seen on CT scan and a median Zar score of 1 (range 0-1) due to age > 60 years.

Table 1: Baseline Characteristics

Conclusion

In immunosuppressed patients with CDI, bezlotoxumab is effective at reducing CDI episodes up to 24 weeks. Additionally, this highly antibiotic exposed population continued to receive benefit up to 24 weeks after bezlotoxumab.

Disclosures

All Authors: No reported disclosures

574. De-escalation of Broad Spectrum Antibiotics during Cytokine Release Syndrome with Haploidentical Hematopoietic Stem Cell Transplantation

Background

Fever is a common component of cytokine release syndrome (CRS) occurring in 90% of patients undergoing haploidentical hematopoietic stem cell transplantation (Haplo-HSCT). Fevers typically occur between the stem cell infusion (Day 0) and initiation of post-transplant cyclophosphamide and are often confused with febrile neutropenia (FN). Due to longer time to engraftment in Haplo-HSCT, CRS/FN exposes patients to prolonged courses of empiric broad spectrum antibiotic (BSA) therapy increasing the risk for multi-drug resistant organisms. Recently, at Yale New Haven Health, our practice has changed to now recommend antibiotic de-escalation to prophylaxis after 7 days of BSA if no infection is identified. The objective of this study was to assess the incidence of breakthrough infections with the de-escalation of BSA in CRS/FN. Secondary endpoints include rate of FN, rate of de-escalation, rate of recurrent fevers, duration of BSA, and positive blood culture data.

Methods

The patient population included those undergoing Haplo-HSCT between July 2016 and February 2020 and who developed CRS/FN between Day 0 and Day +5. Patients were excluded if they had prolonged hospitalization due to non-infectious complications or engraftment failure. Bacteremia was defined using NHSN definitions.

Results

Of the 53 Haplo-HSCTs assessed, 43 experienced CRS/FN. Thirty-five Haplo-HSCT (81%) with CRS/FN had negative cultures and 23 (66%) of these were de-escalated back to antibacterial prophylaxis. The median duration of BSA in the de-escalated group was 7 days (range 5–13) compared to 16.5 days range (13–21) in the non-de-escalated group (p< 0.001). Among those de-escalated, 7 (30%) had recurrent fever occurring at a median of 4 days (range 2–14) and were placed back on BSA. Two Haplo-HSCT (9%) that had fever after de-escalation developed a breakthrough bacteremia. No Haplo-HSCT after de-escalation had fever or re-admission for bacteremia 30 days after engraftment. Four Haplo-HSCT (9%) with CRS/FN had positive blood cultures; however, three (7%) were still able to be de-escalated from BSA to narrower agents based on susceptibilities.

Conclusion

De-escalation of BSA in FN/CRS in Haplo-HSCT patients reduced unnecessary, prolonged antibiotic exposure with a low incidence of breakthrough infections.

Disclosures

All Authors: No reported disclosures

Implications for medication dosing for transgender patients: A review of the literature and recommendations for pharmacists

PURPOSE

Transgender patients face considerable healthcare disparities. Improved means of recognizing transgender patients and understanding their medical needs is important to provide optimal care. The electronic medical record (EMR) of our health system allows for differentiation of gender identity, legal sex, and sex at birth. With EMR recognition of transgender patients, a recommendation for estimating creatinine clearance (CLcr) and ideal body weight (IBW) was needed to standardize medication dosing.

SUMMARY

The literature was reviewed for evidence on the effect of gender-affirming hormone therapy on serum creatinine concentration and lean body mass. Findings informed a recommendation for drug dosing based on CLcr and IBW in transgender patients. Four studies that reported the effect of hormone therapy on biometric laboratory values were found. Three studies reported that values of transgender patients more closely resembled the standard values of their gender identity vs sex at birth after hormone therapy; 1 study reported a range of values that more closely resembled those associated with sex at birth while still overlapping with values associated with gender identity. Consequently, it was recommended that pharmacists dose medications based on CLcr and IBW calculations consistent with gender identity after a patient has been on hormone therapy for 6 months or longer.

CONCLUSION

Providing optimal care to transgender patients includes considering the effect of gender-affirming hormone therapy on overall physiology. Consistently using the appropriate CLcr and IBW calculations for each patient ensures safe and effective care. Additional studies are needed to confirm the effect of hormone therapy on renal clearance and lean body mass.

Case Report: Disseminated Strongyloidiasis in a Patient with COVID-19

The SARS-CoV-2 virus has emerged and rapidly evolved into a current global pandemic. Although bacterial and fungal coinfections have been associated with COVID-19, little is known about parasitic infection. We report a case of a COVID-19 patient who developed disseminated strongyloidiasis following treatment with high-dose corticosteroids and tocilizumab. Screening for Strongyloides infection should be pursued in individuals with COVID-19 who originate from endemic regions before initiating immunosuppressive therapy.

Optimizing the correct timing of vancomycin level collection utilizing a vancomycin medication administration record (MAR) level order

OBJECTIVE

Vancomycin, a commonly used antimicrobial, has a narrow therapeutic index; therefore, Therapeutic Drug Monitoring (TDM) is required. Although the Electronic Medical Record (EMR) may improve patient care, without appropriate optimization, it can contribute to incorrectly drawn vancomycin levels. For medication administration, nurses utilize the Medication Administration Record (MAR) for medication administration documentation and medication workflow guidance. Therefore, we hypothesized creating a MAR level order which would be incorporated into this already established medication workflow may improve the rate of correctly drawn vancomycin levels.

MATERIALS AND METHODS

This was a multicenter, retrospective, pre-and post-intervention study which evaluated the effect of a Medication Administration Record (MAR) level order within the EMR on the correct timing of vancomycin level collection. Vancomycin levels were classified into pre-and post-intervention groups. The primary endpoint was the rate of incorrectly drawn levels, defined as a level being drawn early, a level being drawn late, a level drawn while infusing, or a missed level.

RESULTS

A total of 1353 vancomycin levels were assessed, and 628 levels met inclusion criteria. Of the levels eligible for inclusion, 331 were in the pre-intervention period and 297 were in the post-intervention period. Levels in the post-intervention group utilizing the vancomycin MAR level order were less likely to be missed or drawn at an incorrect time (11.1 % vs 36 %, P < 0.01) and were less likely to require rescheduling (3.4 % vs 8.5 %, P < 0.01).

CONCLUSION

Utilization of a vancomycin MAR level order was associated with a significant decrease in incorrectly drawn vancomycin levels.

Tocilizumab Treatment for Cytokine Release Syndrome in Hospitalized Patients With Coronavirus Disease 2019: Survival and Clinical Outcomes

Background

Tocilizumab, an IL-6 receptor antagonist, can be used to treat cytokine release syndrome (CRS), with observed improvements in a coronavirus disease 2019 (COVID-19) case series.

Research Question

The goal of this study was to determine if tocilizumab benefits patients hospitalized with COVID-19.

Study Design and Methods

This observational study of consecutive COVID-19 patients hospitalized between March 10, 2020, and March 31, 2020, and followed up through April 21, 2020, was conducted by chart review. Patients were treated with tocilizumab using an algorithm that targeted CRS. Survival and mechanical ventilation (MV) outcomes were reported for 14 days and stratified according to disease severity designated at admission (severe, ≥ 3 L supplemental oxygen to maintain oxygen saturation > 93%). For tocilizumab-treated patients, pre/post analyses of clinical response, biomarkers, and safety outcomes were assessed. Post hoc survival analyses were conducted for race/ethnicity.

Results

Among the 239 patients, median age was 64 years; 36% and 19% were black and Hispanic, respectively. Hospital census increased exponentially, yet MV census did not. Severe disease was associated with lower survival (78% vs 93%; P < .001), greater proportion requiring MV (44% vs 5%; P < .001), and longer median MV days (5.5 vs 1.0; P = .003). Tocilizumab-treated patients (n = 153 [64%]) comprised 90% of those with severe disease; 44% of patients with nonsevere disease received tocilizumab for evolving CRS. Tocilizumab-treated patients with severe disease had higher admission levels of high-sensitivity C-reactive protein (120 vs 71 mg/L; P < .001) and received tocilizumab sooner (2 vs 3 days; P < .001), but their survival was similar to that of patients with nonsevere disease (83% vs 91%; P = .11). For tocilizumab-treated patients requiring MV, survival was 75% (95% CI, 64-89). Following tocilizumab treatment, few adverse events occurred, and oxygenation and inflammatory biomarkers (eg, high-sensitivity C-reactive protein, IL-6) improved; however, D-dimer and soluble IL-2 receptor (also termed CD25) levels increased significantly. Survival in black and Hispanic patients, after controlling for age, was significantly higher than in white patients (log-rank test, P = .002).

Interpretation

A treatment algorithm that included tocilizumab to target CRS may influence MV and survival outcomes. In tocilizumab-treated patients, oxygenation and inflammatory biomarkers improved, with higher than expected survival. Randomized trials must confirm these findings.

Intravenous (IV) cefazolin with oral probenecid: A novel daily regimen for the management of Methicillin Sensitive Staphylococcus aureus (MSSA) bacteremia in a patient with renal dysfunction

A 78 year old man developed a methicillin sensitive Staphylococcus aureus (MSSA) post-operative wound infection following an elective L2-L4 laminectomy. He was treated with surgical debridement which was to be followed by a planned 6 weeks course of cefazolin. However, two weeks post debridement, a follow-up MRI revealed an L3-L5 epidural abscess, septic arthritis and vertebral osteomyelitis prompting repeat surgical debridement. No purulence was noted, and operative cultures were negative for growth. His hospital course was complicated by acute kidney injury and a renal biopsy reveled crescentic glomerulonephritis consistent with post infectious glomerulonephritis. He was treated with daptomycin, followed by oral linezolid. Five months after his original laminectomy, he developed purulent drainage from his back wound. Blood cultures grew MSSA and a repeat aspirate done by interventional radiology also grew MSSA. He improved with nafcillin and was transitioned to telavancin on discharge to facilitate once daily treatment. While on telavancin he developed increasing back pain and fever. Therefore, the regimen was changed to IV cefazolin and oral probenecid for five weeks followed by oral cephalexin to complete a total of 12 weeks of therapy. There is no evidence of disease recurrence one year after completion of therapy. IV cefazolin with oral probenecid may represent a once daily IV treatment option for patients with MSSA bacteremia and kidney disease.

2688. The Clinical Impact of Early De-escalation of Broad-Spectrum Antibiotics in Acute Myeloid Leukemia Patients with Febrile Neutropenia

Background

In patients with febrile neutropenia (FN) the initiation of broad-spectrum antibiotics (BSA), an anti-pseudomonal agent +/− vancomycin, is recommended by national guidelines. BSA should be continued until absolute neutrophil count (ANC) recovery (ANC > 500 cells/mm3). With increasing antimicrobial resistance, clinicians are reassessing the need to continue BSA until count recovery; new data are emerging that patients may be able to have their BSA de-escalated if stable and afebrile. At our institution, some patients are de-escalated from BSA to a fluoroquinolone before ANC recovery and others are continued on BSA. The purpose of this study was to evaluate the efficacy and safety of early de-escalation compared with the standard of care.

Methods

We retrospectively reviewed acute myeloid leukemia patients receiving induction chemotherapy who developed FN while at Yale New Haven Hospital from March 2013 to August 2018. Patients were excluded if they developed a culture documented infection, received incomplete or multiple induction chemotherapy treatments, or died from underlying disease during hospitalization. The primary outcome was recurrent fever during admission and secondary outcomes included incidence of breakthrough infections (BI), duration of hospital stay, early discharge (discharge before ANC recovery), duration of BSA, and readmission within 7 days of discharge.

Results

A total of 210 patients were evaluated and 91 patients were included (de-escalation, n = 45; BSA, n = 46). Baseline characteristics are noted in Table 1. There was no statistical difference in rate of recurrent fever in patients who were de-escalated from BSA compared with those that were continued (P = 0.05). De-escalated patients had a shorter duration of BSA therapy (P < 0.05), earlier discharge (P = 0.05) and no difference in readmission rates (P = 0.39) (Table 2). There was no difference in rate of BI between both groups and all BI were bacteremias. (Table 3) No patients who experienced a BI died from infection.

Conclusion

The results of this study revealed no difference in the primary outcome of recurrent fever between the BSA and de-escalation groups. De-escalation led to a reduced duration of BSA and facilitated earlier discharge without increasing readmission rates and BI.

Disclosures

All authors: No reported disclosures.

2645. Clinical Outcomes of Oseltamivir vs. Baloxavir in Patients Hospitalized with Influenza A

Background

Baloxavir marboxil is a new antiviral agent for the treatment of acute uncomplicated influenza in patients > 12 years of age who have been symptomatic for no more than 48 hours. However, clinical trials to date have excluded patients hospitalized with influenza infection.

Methods

This study was a multi-center, retrospective chart review of adult patients admitted to the hospital who received oseltamivir or baloxavir for the treatment of influenza A. Patients were screened for inclusion between January 2018 and February 2018 in the oseltamivir group while patients in the baloxavir group were screened for inclusion between January 2019 and February 2019. Patients who had influenza diagnosed after 48 hours from hospital admission, were not admitted to the hospital, received baloxavir and > 2 doses of oseltamivir during their hospital stay, received > 1 dose of baloxavir during admission for influenza, received influenza therapy prior to admission, died within 48 hours of presentation to the hospital, were asymptomatic at the time of antiviral therapy, or who had left the hospital against medical advice were excluded. Influenza A diagnosis was confirmed by RT–PCR using a nasopharyngeal swab specimen. The primary outcome was hospital length of stay (LOS).

Results

Of the 699 patients reviewed, 359 met inclusion criteria. There were 221 patients who received baloxavir and 138 patients who received oseltamivir. Patients who received oseltamivir were older (65 years [55–78] vs. 82 years [69–88], P < 0.01) and were less likely to have a Body Mass Index > 40 kg/m² (26 [12%] vs. 7 [5%], P = 0.03) compared with the baloxavir group. For the primary outcome of LOS, the baloxavir group had a shorter LOS compared with oseltamivir (4 days [3–6] vs. 5 days [3–8], P = 0.02). Of the 272 patients who were hypoxic at the time of antiviral administration, the baloxavir group was more likely to resolve their hypoxia (145 [88%] vs. 84 [79%], P = 0.04) and had a shorter time to resolution of hypoxia (43 hours [22–78] vs. 81 hours [33–135], P < 0.001) compared with oseltamivir.

Conclusion

This study supports the use of baloxavir for the treatment of influenza A in hospitalized patients with possible benefits of reduced length of stay and faster time to resolution of hypoxia compared with oseltamivir.

Disclosures

All authors: No reported disclosures.

1150. Evaluating the Impact of Antibiotic Prophylaxis on the Microbiology and Incidence of Ventriculitis in Patients with External Ventricular Drains

Background

External ventricular drains (EVDs) are frequently used in acute brain injuries for continuous intracranial pressure monitoring and cerebrospinal (CSF) fluid diversion. EVDs are associated with a 0–22% risk of ventriculitis. The evidence for antibiotic prophylaxis (AP) for ventriculitis prevention is not robust. This study aimed to delineate the incidence of EVD-related ventriculitis and causative organisms in patients receiving AP.

Methods

A retrospective chart review from 2013 to 2018 at Yale New Haven Hospital was performed. Patients were included if ≥18 years of age, admitted to the neurosciences intensive care unit (ICU), and had AP with cefazolin, vancomycin, sulfamethoxazole/trimethoprim, or clindamycin. Patients were excluded if they had a diagnosis of meningitis or ventriculitis prior to EVD placement, on multiple agents for AP, on antibiotics for indications other than AP, CSF leak, or skull fracture. The primary endpoint was the incidence of ventriculitis per 1,000 EVD-days. Secondary endpoints were causative organisms of ventriculitis, EVD duration, ICU length of stay (LOS), hospital LOS, and 30-day mortality.

Results

Five hundred ninety-nine patients were reviewed and 249 patients were included. Baseline demographics are noted in Table 1. Cefazolin was the most common agent for AP (98%). There were 7 cases of ventriculitis with an incidence rate of 2.8% (4 infections per 1000 EVD-days). All of the causative organisms were resistant to the prophylactic agents administered (Table 2). Patients with ventriculitis had a significantly longer duration of EVD placement (10 ± 3 vs. 7 ± 6 days, P = 0.03), hospital LOS (30 ± 19 days vs. 15 ± 12, P = 0.04), ICU LOS (22 ± 14 vs. 10 ± 7, P = 0.03). Two patients with ventriculitis (28%) died within 30 days of admission compared with 46 patients without ventriculitis (19%, P = 0.53) (Table 3).

Conclusion

The rate of ventriculitis in our study was similar to previous studies that did not utilize AP. All of the causative organisms were resistant to the prophylactic agent. Patients who had ventriculitis had a longer duration of EVD placement, hospital LOS, and ICU LOS; however, 30-day mortality was not impacted. Based on our findings, the use of AP to prevent EVD-related ventriculitis should be reconsidered.

Disclosures

All authors: No reported disclosures.

2683. Evaluation of the Negative Predictive Value (NPV) of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Swab Screening in Acute Myeloid Leukemia Patients

Background

Methicillin-Resistant Staphylococcus aureus (MRSA) nasal swabs are utilized to guide discontinuation of empiric MRSA therapy. In multiple studies, MRSA nasal swabs has been shown to have a negative predictive value (NPV) of ~99% in non-oncology patients with pneumonia and other infections. At Yale New Haven Hospital (YNHH), a negative MRSA nasal swab is utilized in acute myeloid leukemia (AML) patients to de-escalate empiric MRSA antibiotic therapy. The primary endpoint was to assess the percentage of patients with a negative MRSA nasal swab who developed a culture documented (CD) MRSA infection during their admission. Secondary endpoints included the number of MRSA nasal swabs that were initially negative but converted to positive, and the types of MRSA infections.

Methods

This was a retrospective chart review of AML patients with a suspected infection and a MRSA nasal swab collected at YNHH between 2013 and 2018. Patients were excluded if < 18 years old, prior confirmed MRSA infection or positive MRSA nasal swab within the past year.

Results

194 patients were identified with 484 discrete encounters analyzed. Hematopoietic stem cell transplantation occurred in 83 (43%) patients. A total of 468 (97%) encounters had a negative MRSA nasal swab upon admission with no CD MRSA infection during their hospitalization. Three encounters (0.6%) had a negative MRSA nasal swab with a subsequent CD MRSA infection during their admission. Identified infections were bacteremia (2) and pneumonia (1). Median duration from the negative MRSA nasal swab to CD infection was 16 days. Thirteen encounters (3%) had a positive MRSA nasal swab, 5 of which had a CD MRSA infection. Infections included bacteremia (3), pneumonia (2), and sputum with negative chest X-ray (1). MRSA nasal swab had a sensitivity of 57% (CI 0.56–0.58), specificity of 98% (CI 0.98–0.98) positive predictive value of 31% (CI 0.3–0.32), and NPV of 99% (CI 0.99–0.99).

Conclusion

The results of this retrospective study demonstrate that a negative MRSA nasal swab has a 99% NPV for subsequent MRSA infections in AML patients with no prior history of MRSA colonization or infection. Based on these findings, a negative MRSA nasal swab can help guide de-escalation of empiric MRSA antibiotic therapy in this immunosuppressed population.

Disclosures

All authors: No reported disclosures.

2385. Evaluating the Antibiotic Risk for Clostridioides difficile Infection (CDI): Comparing Piperacillin/Tazobactam to Cefepime and Ceftazidime

Background

Clostridioides difficile infection (CDI) is a common healthcare-associated infection (HAI). Past studies have revealed that anti-pseudomonal cephalosporins such as cefepime (FEP) and ceftazidime (CTZ) are associated with a higher CDI risk than β-lactam/β-lactamase inhibitors (BLBLI) such as piperacillin/tazobactam (PTZ). However, there is limited data evaluating the comparative healthcare-associated CDI (HA-CDI) risk associated with BLBLI and anti-pseudomonal cephalosporin therapy.

Methods

An observational cohort study was performed with patients who received PTZ, FEP, or CTZ at Yale New Haven Hospital and Bridgeport Hospital from February 1, 2013 to June 1, 2018. Patients who received ≥ 3 days of PTZ, FEP, or CTZ therapy were included. Patients under the age of 18, those admitted to oncology, transplant, or pediatric units, and those with < 2 or ≥ 120 days of hospital admission were excluded. Multivariate logistic regression models were constructed to control and to adjust for underlying comorbidities.

Results

A total of 11,909 patient encounters met the study criteria. The median patient-days of therapy for both the PTZ and FEP/CTZ groups was 4 days (Table 1). FEP/CTZ exposure was associated with a higher CDI risk than PTZ exposure (P = 0.03) (Figure 1) even with higher C. difficile testing frequency in the PTZ group (P < 0.001) (Table 1). Using a multivariate logistic regression model controlling for high-risk antibiotic therapy (ciprofloxacin, clindamycin, ertapenem, meropenem, moxifloxacin), acid suppression therapy (famotidine, lansoprazole, pantoprazole), sex, Charlson comorbidity index score, age, and duration of hospital admission, FEP/CTZ exposure was independently associated with a higher CDI risk than PTZ exposure (Table 2) (Table 3).

Conclusion

FEP/CTZ exposure was associated with a higher CDI risk than PTZ exposure. PTZ may be associated with a higher risk for non-CDI antibiotic-associated diarrhea which may lead to an increased frequency of testing for CDI. The findings from this study may justify additional antibiotic stewardship efforts to limit the use of empiric FEP/CTZ therapy.

Disclosures

All authors: No reported disclosures.

2694. Incidence of Pneumocytis jiroveci (PJP) Infection with 3-Month Prophylaxis of Aerosolized Pentamidine (AP) in Autologous Hematopoietic Stem Cell Transplantation (HSCT)

Background

HSCT patients are at an increased risk of developing PJP after transplant due to treatment induced immunosuppression. Given the risk of cytopenias with co-trimoxazole, AP is utilized as an alternative for PJP prophylaxis. A prior study revealed a 0% (0/19 patients) incidence when AP prophylaxis was given for one year post autologous HSCT. Current guidelines recommend a duration of 3 – 6 months for PJP prophylaxis in autologous HSCT. The primary endpoint of this study was to assess the incidence of PJP infection within one year post autologous HSCT in patients who received 3 months of AP. Secondary endpoint was a cost comparison of 3 months compared with 6 months of AP.

Methods

A single-center, retrospective study of adult autologous HSCT patients at Yale New Haven Hospital between February 2013 and December 2017 was performed. Patients were excluded if: <18 years of age, received < or >3 months of AP, changed to alternative PJP prophylactic agent or received no PJP prophylaxis, received tandem HSCT, deceased prior to one year post-transplant from a non PJP-related infection, HIV positive, or lost to follow-up. Pentamidine was given as a 300 mg inhalation monthly for 3 months starting Day +15 after autologous HSCT.

Results

A total of 288 patients were analyzed, no PJP infections occurred within one year post HSCT. Additionally, 187 (65%) patients received treatment post HSCT with 135/215 (63%) receiving maintenance immunomodulatory drugs for myeloma and 40/288 (14%) patients developing relapsed disease. 43% of the chemotherapy regimens for relapsed disease included high dose corticosteroids. The cost difference of using 3 months vs. 6 months of AP is $790, reflecting the cost of drug and its administration. Applying our incidence of 0%, potential cost savings of 3 months vs. 6 months of AP would be $330,000 over 5 years or $66,000 per year.

Conclusion

Three months of AP for PJP prophylaxis in autologous HSCT patients is safe and effective as well as cost-effective compared with a 6 month regimen.

Disclosures

All authors: No reported disclosures.

Telavancin for refractory MRSA bacteraemia in intermittent haemodialysis recipients

Background

Patients with end-stage renal disease (ESRD) requiring intermittent haemodialysis (IHD) are at high risk of MRSA bacteraemia (MRSA-B) and often fail first-line therapy. The safety, effectiveness and optimal dosing of telavancin for MRSA-B in this patient population are unclear.

Objectives

We aimed to describe clinical outcomes of telavancin in the treatment of refractory MRSA-B in patients with ESRD requiring IHD.

Patients and methods

This was a retrospective study of hospitalized patients at two tertiary care academic medical centres with recurrent or persistent (≥3 days) MRSA-B treated with telavancin monotherapy. Outcomes included duration of MRSA-B (pre-telavancin versus post-telavancin) and microbiological failure (duration of MRSA-B ≥3 days after initiation of telavancin).

Results

Telavancin dosed 10 mg/kg three times weekly post-IHD or 10 mg/kg every 48 h resulted in microbiological cure in 7/8 (87.5%) refractory MRSA-B cases. Telavancin monotherapy was associated with a significant reduction in median duration of bacteraemia [16 days pre-telavancin (IQR 8-19 days) versus 1 day post-telavancin (IQR 0-2 days); P = 0.018]. Telavancin was well tolerated by all patients and no adverse events were reported.

Conclusions

Telavancin was very safe and highly effective in the treatment of refractory MRSA-B in a cohort of patients with ESRD requiring IHD. These data support the utility of telavancin in the armamentarium against refractory MRSA-B, particularly in the high-risk IHD-dependent population.

The impact of a multimodal approach to vancomycin discontinuation in hematopoietic stem cell transplant recipients (HSCT) with febrile neutropenia (FN)

BACKGROUND

Current guidelines recommend adding vancomycin to empiric treatment of FN in patients who meet specific criteria. After 48 hours, the guidelines recommend discontinuing vancomycin if resistant Gram-positive organisms are not identified. Based on these recommendations, a vancomycin stewardship team defined criteria for discontinuation of vancomycin at 48 hours and increased surveillance of vancomycin usage through a multimodal approach. The purpose of this retrospective analysis is to assess the impact of this multimodal approach on the discontinuation of empiric vancomycin at 48 hours in FN.

METHODS

This retrospective analysis included a pre- and post-intervention cohort of 200 HSCT recipients with FN from 2015 to 2018. Criteria for continued vancomycin use beyond 48 hours included culture-documented resistant Gram-positive infection, positive Methicillin-Resistant S aureus (MRSA) nasal swab with evidence of pneumonia, or hemodynamic instability with concern for sepsis. The following patient characteristics were collected: previous MRSA infection, MRSA nasal swab collection and results, culture results, duration of vancomycin use, rationale for continuation of vancomycin beyond 48 hours, and re-initiation of vancomycin.

RESULTS

In the post-intervention cohort, vancomycin discontinuation at 48 hours increased from 31% (95% CI 21.94-40.05) to 70% (95% CI 61.02-78.97; P < 0.0001). An additional 23% of vancomycin orders were discontinued at 72 hours. Off criteria vancomycin use decreased from 33% in pre to 1% in the post-implementation cohort.

CONCLUSION

Establishing define criteria for vancomycin use in FN patients with a multimodal approach of physicians from hematology and infectious diseases, clinical pharmacists and the antibiotic stewardship team significantly improved vancomycin discontinuation.

Evaluating a voriconazole dose modification guideline to optimize dosing in patients with hematologic malignancies

BACKGROUND

Voriconazole is an azole antifungal utilized for prophylaxis and treatment of invasive fungal infections in hematologic patients. Previous studies have revealed decreased efficacy and increased toxicity with subtherapeutic <1 mcg/mL and supratherapeutic > 4 mcg/mL levels. A voriconazole dose modification guideline was introduced in July 2014 based on a retrospective analysis.

OBJECTIVE

The primary objective was to evaluate the voriconazole dose modification guideline. Secondary objectives were to identify patient-specific characteristics that contribute to inadequate levels, adverse effects, and breakthrough invasive fungal infections.

METHODS

This prospective study included 128 patients with 250 admissions who received voriconazole from July 2014 to February 2016. Eligible adult patients receiving voriconazole for prophylaxis or treatment with at least one trough level, drawn appropriately, were included. Demographics, adverse effects, and breakthrough invasive fungal infections were documented.

RESULTS

Voriconazole use was categorized as: new start, new start with loading dose, or continuation of home therapy. The median initial levels were 1.5, 3.5, and 1.7 mcg/mL with 62% (73/119), 55% (6/11), and 60% (72/120) within the therapeutic range, respectively. Using the voriconazole dose modification guideline, 80% were within goal by the second dose adjustment. Age ≤ 30 and BMI ≤ 25 kg/m² had higher rates of subtherapeutic levels in the new start cohorts (p = 0.024 and p = 0.009). Approximately 7.6% of patients experienced an adverse effect with neurologic/psychological being the most common. A total of 8.5% of patients had a possible, probable or proven breakthrough invasive fungal infections while on voriconazole.

CONCLUSION

Using the voriconazole dose modification guideline, the number of patients that reached therapeutic range improved from 36% to 80% by the second dose adjustment (p = 0.007). This voriconazole dose modification guideline can be utilized to help dose and adjust voriconazole in order to achieve therapeutic levels.

Utility of fosfomycin as antibacterial prophylaxis in patients with hematologic malignancies

PURPOSE

Prolonged and profound neutropenia is common among hematology and hematopoietic stem cell transplant (HSCT) patients as a result of chemotherapy. The National Comprehensive Cancer Network (NCCN) and Infectious Diseases Society of America (IDSA) currently recommend antibacterial prophylaxis in patients who are deemed at intermediate or high risk for infection. Specifically, fluoroquinolone prophylaxis should be considered for high-risk neutropenic patients. However, with prolonged and frequent exposure to fluoroquinolones, these high-risk patients may develop resistance to these agents. Patients may also have allergies or other contraindications which prohibit the use of fluoroquinolones for antibacterial prophylaxis. Unfortunately, there is no standard recommendation for alternative antimicrobial therapy in this patient population, as well as there is a lack of data to support the use of potential alternative agents.

METHODS

Currently, Yale-New Haven Hospital utilizes fosfomycin for antibacterial prophylaxis in patients who are not eligible for fluoroquinolone therapy. The primary objective of this study was to assess the incidence of breakthrough infections in this population receiving fosfomycin. Secondary objectives included organisms identified, types of breakthrough infections, resistance patterns, and time from initiation to onset of fever.

RESULTS

Of the 42 patients who received fosfomycin, 25 patients with 42 admissions met inclusion criteria. A total of 8 (19%) breakthrough infections occurred during the 42 admissions. Organisms included Klebsiella spp. (5), Streptococcus mitis/viridans (2), Pseudomonas aeruginosa (1), and coagulase-negative staphylococcus (1). Infections included the following: bacteremia (7), cellulitis (1), and urine (1).

CONCLUSION

Given the low rate of breakthrough infections, fosfomycin may be a potential alternative option for antibacterial prophylaxis.

Combination liposomal amphotericin B, posaconazole and oral amphotericin B for treatment of gastrointestinal Mucorales in an immunocompromised patient

Mucormycosis is a life threatening infection caused by fungi in the order Mucorales. Mucormycosis can affect any organ system with rhino-orbital-cerebral and pulmonary infections being the most predominant infection types. Gastrointestinal mucormycosis is rare and accounts for only 4-7% of all cases. Here, we present a case of invasive gastrointestinal mucormycosis in an immunocompromised host treated with systemic and topical anti-mold therapy.

Listeria monocytogenes bacteremia in a pancreas transplant recipient

We report a case of Listeria monocytogenes bacteremia in a patient 12 years after his pancreas transplant, during which time he received a steroid-free immunosuppressive regimen. To our knowledge, there are no reported cases describing L monocytogenes bacteremia after pancreas transplant. In addition, although typically identified as a complication shortly after transplant or after treatment for organ rejection, this case demonstrates that it is still possible for a patient to develop a L monocytogenes infection far removed from transplant.

Molecular Adsorbent Recirculating System (MARS(®)) removal of piperacillin/tazobactam in a patient with acetaminophen-induced acute liver failure

The objective of this study was to illustrate the pharmacokinetic removal of piperacillin/tazobactam in an anuric patient on Molecular Adsorbent Recirculating System (MARS(®)). The patient was a 32-year-old woman who presented to a medical intensive care unit with acute liver failure secondary to an acetaminophen overdose. While awaiting transplant, she was started on MARS therapy as a bridge to liver transplant and empirically started on piperacillin/tazobactam therapy. MARS is an extracorporeal hemofiltration device, which incorporates a continuous venovenous hemofiltration (CVVHD) machine linked to an albumin-enriched dialysate filter to normalize excess electrolytes, metabolic waste, and protein-bound toxins. In addition to protein-bound waste, MARS removes water-soluble, low molecular-weight molecules. The patient received piperacillin/tazobactam 4.5 g infused intravenously over 3 h. A steep decline in serum levels occurred between hours 4 and 6 while MARS continued and no antibiotic was infused. The elimination rate constant (k(e)) for the removal of piperacillin in this patent was 0.453 h(-1) and the half-life (λ) was 1.53 h. The k(e) was 2.9-fold higher than with CVVHD alone and the λ was 3.7-fold shorter. Low levels of piperacillin are achieved during MARS therapy, but in the treatment of more resistant organisms, such as Pseudomonas aeruginosa, these low levels may not be adequate to achieve bactericidal activity. Drug levels following a standard infusion of 30 min would likely be even lower. Formalized pharmacokinetic studies of piperacillin/tazobactam removal in patients on MARS therapy are necessary to make clear dosing recommendations.

Vancomycin-induced thrombocytopenia without isolation of a drug-dependent antibody

Vancomycin is a glycopeptide antibiotic used in the treatment of gram-positive infections including methicillin-resistant Staphylococcus aureus (MRSA). The most common adverse reaction to vancomycin is red man syndrome, which is a histaminergic reaction causing a rash on the upper torso, neck, and face after rapid infusion of the drug. Less commonly, vancomycin has been associated with thrombocytopenia. The etiology is believed to be the induction of drug-dependent antibodies, which in turn cause immune-mediated destruction of platelets. We describe a 41-year-old man who received two courses of vancomycin for the treatment of MRSA pneumonia and then experienced a decline in platelet count to a nadir of 15 x 10³/mm³. Vancomycin was discontinued, doxycycline was started, and the patient's platelet count rebounded over the next 6 days. The patient was readmitted to the hospital 2 months later for MRSA bacteremia and was rechallenged with vancomycin. He again experienced a decline in platelet count. Vancomycin was discontinued, and daptomycin was started. The patient's platelet count rebounded to normal levels over the next 5 days. Although the patient experienced acute thrombocytopenia after vancomycin exposure, no bleeding complications occurred, and the patient's platelet count rebounded to normal after the discontinuation of vancomycin. The patient had no other known risk factors for the development of rapid thrombocytopenia. Use of the Naranjo adverse drug reaction probability scale indicated a definite relationship (score of 9) between the patient's development of thrombocytopenia and vancomycin therapy. Although vancomycin was the presumed cause of thrombocytopenia in this patient, no drug-dependent antibody was isolated from blood samples collected after both exposures to vancomycin (analyzed by using a screening assay to identify drug-dependent antibodies to vancomycin [developed by the BloodCenter of Wisconsin]). Although the evidence supporting vancomycin induction of antibody-mediated destruction of platelets was lacking, further studies delineating alternate mechanisms of platelet destruction are warranted. Therefore, even in the absence of a positive antibody test, vancomycin should still be considered in the differential diagnosis as a cause of drug-induced thrombocytopenia.

Use of Corporate Six Sigma Performance-Improvement Strategies to Reduce Incidence of Catheter-Related Bloodstream Infections in a Surgical ICU

BACKGROUND

Corporate performance-improvement methodologies can outperform traditional ones in addressing ICU-based adverse events. My colleagues and I used Six Sigma methodology to address our catheter-related bloodstream infection (CR-BSI) rate, which considerably exceeded the nationally established median over a 9-year period. We hypothesized that use of Six Sigma methodology would result in a substantial and sustainable decrease in our CR-BSI rate.

STUDY DESIGN

All patients were directly cared for by a geographically localized surgical ICU team in an academic tertiary referral center. CR-BSIs were identified by infection control staff using CDC definitions. Personnel trained in Six Sigma techniques facilitated performance-improvement efforts. Interventions included barrier precaution kits, new policies for catheter changes over guide wires, adoption of a new site-preparation antiseptic, direct attending supervision of catheter insertions, video training for housestaff, and increased frequency of dressing changes. After additional data analysis, chlorhexidine-silver catheters were used selectively in high-risk patients. The impact of interventions was assessed by monitoring the number of catheters placed between CR-BSIs.

RESULTS

Before the intervention period, 27 catheters were placed, on average, between individual CR-BSIs, a CR-BSI rate of 11 per 1,000 catheter days. After all operations were implemented, 175 catheters were placed between line infections, and average CR-BSI rate of 1.7/1,000 catheter days, a 650% improvement (p < 0.0001). Compared with historic controls, adoption of chlorhexidine-silver catheters in high-risk patients had a considerable impact (50% reduction; p < 0.05).

CONCLUSIONS

This represents the first successful application of Six Sigma corporate performance-improvement method impacting purely clinical outcomes. CR-BSI reduction was highly substantial and sustained after other traditional strategies had failed.

Correlation between healthcare workers' knowledge of influenza vaccine and vaccine receipt

OBJECTIVE

Influenza vaccine receipt by healthcare workers (HCWs) is important because HCWs are at risk for occupational exposure to influenza and may act as vectors in the nosocomial transmission of influenza. HCWs were surveyed to determine whether belief in commonly held influenza vaccine misconceptions was associated with influenza vaccine acceptance.

DESIGN

Cross-sectional study.

SETTING

A large urban teaching hospital.

METHOD

A self-administered survey was used to assess nursing and physician staff influenza vaccine knowledge, current vaccination status, and potential reasons for vaccine declination.

RESULTS

Two hundred twelve of 215 surveys were completed. The overall influenza vaccination rate was 73%. Physician staff were significantly more likely to have been vaccinated compared with nursing staff (82% vs 62%, respectively; P = .0009). HCWs answering the 5 influenza vaccine basic knowledge questions correctly were significantly more likely to have been vaccinated than those responding incorrectly to any question (84% vs 64%, respectively; P = .002). This association was present in the nursing group where 80% of those answering the knowledge questions correctly were vaccinated, but only 49% of those answering incorrectly were vaccinated (P = .000005). However, in the physician group, there was no significant difference in the influenza vaccination rates between those answering correctly and those answering incorrectly (P = .459).

CONCLUSION

Belief in commonly held influenza vaccine misconceptions was significantly associated with influenza vaccine declination among nursing staff and may act as a barrier to greater rates of influenza vaccination. Reasons for influenza vaccine nonreceipt may differ between nursing and physician staff.