Machine Learning To Stratify Methicillin-Resistant Staphylococcus aureus Risk among Hospitalized Patients with Community-Acquired Pneumonia.

Methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon but serious cause of community-acquired pneumonia (CAP). A lack of validated MRSA CAP risk factors can result in overuse of empirical broad-spectrum antibiotics. We sought to develop robust models predicting the risk of MRSA CAP using machine learning using a population-based sample of hospitalized patients with CAP admitted to either a tertiary academic center or a community teaching hospital. Data were evaluated using a machine learning approach. Cases were CAP patients with MRSA isolated from blood or respiratory cultures within 72 h of admission; controls did not have MRSA CAP. The Classification Tree Analysis algorithm was used for model development. Model predictions were evaluated in sensitivity analyses. A total of 21 of 1,823 patients (1.2%) developed MRSA within 72 h of admission. MRSA risk was higher among patients admitted to the intensive care unit (ICU) in the first 24 h who required mechanical ventilation than among ICU patients who did not require ventilatory support (odds ratio [OR], 8.3; 95% confidence interval [CI], 2.4 to 32). MRSA risk was lower among patients admitted to ward units than among those admitted to the ICU (OR, 0.21; 95% CI, 0.07 to 0.56) and lower among ICU patients without a history of antibiotic use in the last 90 days than among ICU patients with antibiotic use in the last 90 days (OR, 0.03; 95% CI, 0.002 to 0.59). The final machine learning model was highly accurate (receiver operating characteristic [ROC] area = 0.775) in training and jackknife validity analyses. We identified a relatively simple machine learning model that predicted MRSA risk in hospitalized patients with CAP within 72 h postadmission.

Innate Immune System Activation, Inflammation and Corneal Wound Healing.

Corneal wounds resulting from injury, surgeries, or other intrusions not only cause pain, but also can predispose an individual to infection. While some inflammation may be beneficial to protect against microbial infection of wounds, the inflammatory process, if excessive, may delay corneal wound healing. An examination of the literature on the effect of inflammation on corneal wound healing suggests that manipulations that result in reductions in severe or chronic inflammation lead to better outcomes in terms of corneal clarity, thickness, and healing. However, some acute inflammation is necessary to allow efficient bacterial and fungal clearance and prevent corneal infection. This inflammation can be triggered by microbial components that activate the innate immune system through toll-like receptor (TLR) pathways. In particular, TLR2 and TLR4 activation leads to pro-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) activation. Similarly, endogenous molecules released from disrupted cells, known as damage-associated molecular patterns (DAMPs), can also activate TLR2, TLR4 and NFκB, with the resultant inflammation worsening the outcome of corneal wound healing. In sterile keratitis without infection, inflammation can occur though TLRs to impact corneal wound healing and reduce corneal transparency. This review demonstrates the need for acute inflammation to prevent pathogenic infiltration, while supporting the idea that a reduction in chronic and/or excessive inflammation will allow for improved wound healing.

Getting to Zero: A Demonstration Project of Partner HIV Testing in the Prenatal Setting in Chicago, Illinois.

Women who experience HIV seroconversion during pregnancy are missed during early routine pregnancy HIV screening and are at high risk of perinatal HIV transmission. Male partner HIV testing during routine prenatal care may be an effective primary prevention strategy by identifying women at risk of seroconversion and mitigating their risk. Our objective was to assess interest in and uptake of male partner HIV testing services offered during prenatal care. This demonstration project included all pregnant, English-speaking, HIV-negative women receiving publicly funded prenatal care in an urban hospital-based practice located in a high HIV prevalence area. Women were offered free HIV screening for their male sexual partners. From April 2017 to June 2018, enrolled women completed surveys on social demographics, medical access characteristics, and HIV testing history. Women were invited to bring their partners to a prenatal visit where HIV testing was offered to their male partners. Factors associated with women's interest in testing and completion of partner testing were assessed using bivariable and multivariable analyses. Of 392 women approached, 70% (N = 274) completed study surveys. Although the majority (76%, N = 200 of 264 respondents) of women desired their partner undergo HIV testing, testing was underutilized as only 18 (7%) male partners completed testing. While neither maternal characteristics nor male social or attitudinal factors were associated with interest in or completion of partner HIV testing, sensitivity analyses, performed with multiple imputation, demonstrated some association between interest and completion of partner testing and partner medical care access and utilization. In conclusion, although the majority of low-income women in an urban prenatal clinic expressed interest in having their partners undergo HIV testing, uptake of free partner HIV testing services was uncommon. A focused assessment of implementation and uptake barriers is needed to optimize partner testing and eliminate HIV transmission to mothers and their babies.

Impact of early antimicrobial stewardship intervention in patients with positive blood cultures: results from a randomized comparative study.

BACKGROUND: Antimicrobial stewardship intervention (ASI) appears to be necessary to realize the full benefits of rapid diagnostic technologies in clinical practice. This study aimed to compare clinical outcomes between early ASI paired with matrix-associated laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) compared with MALDI-TOF with standard of care (SOC) reporting in patients with positive blood cultures. METHODS: Adult patients with positive blood cultures and organism speciation via MALDI-TOF admitted between February 2015 and September 2015 were randomized to ASI or SOC in a 1:1 fashion. Patients admitted for at least 48 h following positive culture were included in analyses. ASI was defined as a clinical assessment by a stewardship team member with non-binding treatment recommendations offered to the primary team. The primary outcome was time to definitive therapy. Secondary outcomes included post-culture length of stay (LOS), time to first change in antibiotics, and in-hospital mortality. RESULTS: In total, 149 patients were included in the analyses (76 in the ASI group and 73 in the SOC group). ASI and SOC arms did not differ according to age, sex, comorbidities or severity of illness. Gram-positive organisms were common in both SOC and ASI arms (74.0 vs. 61.8%, P=0.11). Time to definitive therapy was reduced, on average, by 30.3 h in the ASI group (71.6 vs. 41.3 h, P=0.01). Hospital LOS following the first positive blood culture was significantly shorter in the ASI group (8.7 vs. 11.2 days, P=0.049). CONCLUSIONS: ASI combined with MALDI-TOF reduced the time to definitive therapy and time to first change in antibiotics, and was associated with a shorter post-culture LOS.

Characterizing Risk Factors for Clostridioides difficile Infection among Hospitalized Patients with Community-Acquired Pneumonia.

Hospitalized patients with community-acquired pneumonia (CAP) are at risk of developing Clostridioides difficile infection (CDI). We developed and tested clinical decision rules for identifying CDI risk in this patient population. The study was a single-center retrospective, case-control analysis of hospitalized adult patients empirically treated for CAP between 1 January 2014 and 3 March 2018. Differences between cases (CDI diagnosed within 180 days following admission) and controls (no test result indicating CDI during the study period) with respect to prehospitalization variables were modeled to generate propensity scores. Postadmission variables were used to predict case status on each postadmission day where (i) ≥1 additional case was identified and (ii) each model stratum contained ≥15 subjects. Models were developed and tested using optimal discriminant analysis and classification tree analysis. Forty-four cases and 181 controls were included. The median time to diagnosis was 50 days postadmission. After weighting, three models were identified (20, 117, and 165 days postadmission). The day 20 model yielded the greatest (weighted [w]) accuracy (weighted area under the receiver operating characteristic curve [wROC area] = 0.826) and the highest chance-corrected accuracy (weighted effect strength for sensitivity [wESS] = 65.3). Having a positive culture (odds, 1:4; P = 0.001), receipt of ceftriaxone plus azithromycin for a defined infection (odds, 3:5; P = 0.006), and continuation of empirical broad-spectrum antibiotics with activity against P. aeruginosa when no pathogen was identified (odds, 1:8; P = 0.013) were associated with CDI on day 20. Three models were identified that accurately predicted CDI in hospitalized patients treated for CAP. Antibiotic use increased the risk of CDI in all models, underscoring the importance of antibiotic stewardship.

Home Birth in the Era of COVID-19: Counseling and Preparation for Pregnant Persons Living with HIV.

With the coronavirus disease 2019 (COVID-19) pandemic in the United States, a majority of states have instituted "shelter-in-place" policies effectively quarantining individuals-including pregnant persons-in their homes. Given the concern for COVID-19 acquisition in health care settings, pregnant persons with high-risk pregnancies-such as persons living with HIV (PLHIV)-are increasingly investigating the option of a home birth. Although we strongly recommend hospital birth for PLHIV, we discuss our experience and recommendations for counseling and preparation of pregnant PLHIV who may be considering home birth or at risk for unintentional home birth due to the pandemic. We also discuss issues associated with implementing a risk mitigation strategy involving high-risk births occurring at home during a pandemic. KEY POINTS: · Coronavirus disease 2019 pandemic has increased interest in home birth.. · Women living with HIV are pursuing home birth.. · Safe planning is paramount for women living with HIV desiring home birth, despite recommending against the practice..

Cutaneous manifestations of Campylobacter jejuni infection: A case report and review of the literature.

A 51 year old man with active follicular lymphoma presented with several days of erythematous skin nodules on all extremities two weeks after a self-limited diarrheal illness. All serum immunoglobulin levels were found to be low. Blood cultures grew Campylobacter jejuni. The patient was given one week of azithromycin with complete resolution of his skin nodules. The literature of skin manifestations seen in active Campylobacter jejuni infection are reviewed. The majority of cases occur in immunocompromised hosts, many with low or no serum immunoglobulin levels. Postulated mechanisms include a lack of secretory IgA in intestinal mucosa predisposing susceptible patients to translocated enteric pathogens however the precise pathogenesis underlying cutaneous manifestations are unknown.

Diagnostic stewardship of C. difficile testing: a quasi-experimental antimicrobial stewardship study.

OBJECTIVE: We evaluated whether a diagnostic stewardship initiative consisting of ASP preauthorization paired with education could reduce false-positive hospital-onset (HO) Clostridioides difficile infection (CDI). DESIGN: Single center, quasi-experimental study. SETTING: Tertiary academic medical center in Chicago, Illinois. PATIENTS: Adult inpatients were included in the intervention if they were admitted between October 1, 2016, and April 30, 2018, and were eligible for C. difficile preauthorization review. Patients admitted to the stem cell transplant (SCT) unit were not included in the intervention and were therefore considered a contemporaneous noninterventional control group. INTERVENTION: The intervention consisted of requiring prescriber attestation that diarrhea has met CDI clinical criteria, ASP preauthorization, and verbal clinician feedback. Data were compared 33 months before and 19 months after implementation. Facility-wide HO-CDI incidence rates (IR) per 10,000 patient days (PD) and standardized infection ratios (SIR) were extracted from hospital infection prevention reports. RESULTS: During the entire 52 month period, the mean facility-wide HO-CDI-IR was 7.8 per 10,000 PD and the SIR was 0.9 overall. The mean ± SD HO-CDI-IR (8.5 ± 2.0 vs 6.5 ± 2.3; P < .001) and SIR (0.97 ± 0.23 vs 0.78 ± 0.26; P = .015) decreased from baseline during the intervention. Segmented regression models identified significant decreases in HO-CDI-IR (Pstep = .06; Ptrend = .008) and SIR (Pstep = .1; Ptrend = .017) trends concurrent with decreases in oral vancomycin (Pstep < .001; Ptrend < .001). HO-CDI-IR within a noninterventional control unit did not change (Pstep = .125; Ptrend = .115). CONCLUSIONS: A multidisciplinary, multifaceted intervention leveraging clinician education and feedback reduced the HO-CDI-IR and the SIR in select populations. Institutions may consider interventions like ours to reduce false-positive C. difficile NAAT tests.

Understanding the Components, Calculation, and Impact of Monthly and Seasonal Variation of the Standardized Antimicrobial Utilization Ratio (SAAR).

This study sought to characterize the impact of 3 types of variation on the Standardized Antimicrobial Administration Ratio (SAAR) utilizing local National Healthcare Safety Network (NHSN) data. SAAR and antimicrobial days per 1,000 days present (AD/1000DP) were compiled monthly for Northwestern Memorial Hospital from 2014 to 2016. Antimicrobial consumption was aggregated into agent categories (via NHSN criteria). Month-to-month changes in SAAR and AD/1000DP were evaluated. Azithromycin and oseltamivir AD/1000DP from 2012 through 2017 were explored for seasonal variation. A sensitivity analysis was performed to explore the effect of seasonality and altered consumption at other hypothetical hospitals on the SAAR. Across agent categories for both the intensive care unit (n = 4) and general wards (n = 4), the average matched-month percent change in AD/1000DP was correlated with the corresponding change in SAAR (coefficient of determination of 0.99). The monthly mean ± standard deviation (SD) AD/1000DP was 235 (range, 47.2 to 661.5), and the mean ± SD SAAR was 1.09 ± 0.26 (range, 0.79 to 1.09) across the NHSN agent categories. Five seasons exhibited seasonal variation in AD/1000DP for azithromycin with a mean percent change of 26.76% (range, 22.27 to 30.69). Eight seasons exhibited seasonal variation in AD/1000DP for oseltamivir with a mean percent change of 129.1% (range, 32.01 to 352.74). The sensitivity analyses confirm that antimicrobial usage at comparator hospitals does not impact the local SAAR, and seasonal variation of antibiotics has the potential to impact SAAR. Month-to-month changes in the SAAR mirror monthly changes in an institution's AD/1000DP. Seasonal variation is an important variable for future SAAR consideration, and the variable antibiotic use at peer hospitals is not currently captured by the SAAR methodology.

Understanding HIV-Related Pill Aversion as a Distinct Barrier to Medication Adherence.

Pill aversion, defined as difficulty swallowing pills without identifiable medical cause, is a poorly characterized barrier to sustained viral suppression for many HIV-infected persons. We aimed to quantify the frequency of self-reported pill aversion, characterize its symptoms, and measure the association between self-reported pill aversion and missing antiretroviral doses. This is a prospective, observational, exploratory survey study of English-speaking persons living with HIV (PLHIV) at a single urban tertiary outpatient clinic. Participants completed anonymous questionnaires about their experiences of swallowing antiretroviral pills. The primary outcome was skipping pills due to pill aversion symptoms. Of 384 participants, a quarter (25.5%) skipped pills due to pill aversion symptoms. Younger age, being Non-Hispanic Black or Hispanic, not being married or partnered, having public insurance, not being employed, having less than a college education, and having a mental health diagnosis were associated with skipping pills due to pill aversion. On multivariable regression analyses, PLHIV who skipped pills were more likely to report symptoms of gagging, nausea at the time of swallowing, and heavy feeling in the stomach, as well as being bothered by the taste, smell, and size of the pills. PLHIV who skipped pills were also more likely to report negative and fear-based emotions about pill-taking than PLHIV who did not skip pills due to pill aversion. HIV-related pill aversion may represent a significant and frequent barrier to adherence in an adult HIV population.

Going for the Gold: A Description of the Centers of Excellence Designation by the Infectious Diseases Society of America.

Antimicrobial stewardship programs (ASPs) are recommended by the Centers for Disease Control and Prevention and World Health Organization and mandated by the Joint Commission to curb antimicrobial resistance. However, <50% of institutions have optimal ASPs in place. Building on its experience of antimicrobial stewardship (AMS) advocacy, the Infectious Diseases Society of America (IDSA) developed the AMS Centers of Excellence (CoE) program, which will serve as a conduit to share best practices and highlight the standards for other hospitals to achieve in order to advance the field of AMS. A designation of CoE signifies that these institutions deliver high-quality care consistently, serve as the "gold" standard for executing novel AMS principles, and demonstrate commitment to their ASP. Here, we describe the process and purpose of designating institutions as AMS CoEs, provide awareness to clinicians on opportunities available through IDSA with this CoE designation, and discuss the evolution of the program.

Measuring the impact of varying denominator definitions on standardized antibiotic consumption rates: implications for antimicrobial stewardship programmes.

Objectives: To quantify the impact of varying the at-risk days definition on the overall report of at-risk days and on the calculated standardized consumption rates (SCRs) for piperacillin/tazobactam, amikacin, daptomycin and vancomycin. Methods: Data were evaluated for two system hospitals, an 894 bed academic centre and a 114 bed community hospital. Aggregate inpatient antibiotic administration and occupancy data were extracted from electronic databases at the facility-wide level. Occupancy data were reported from admission-discharge-transfer systems. At-risk days were defined as hospital days present (DP), patient days (PD), persons present (PP) and billing days (BD). Inpatient antimicrobial days of therapy (DOT) across four major antimicrobial agents were used to calculate facility-wide SCRs using each denominator and were evaluated by least-squares regression and R2 values. Results: Within the 894 bed academic hospital, the average monthly facility-wide days were 28 424, 22 198, 15 957 and 14 789 by the DP, PP, PD and BD definitions, respectively. Within the 114 bed community hospital, the average monthly facility-wide days were 5175, 3523 and 2816 by the DP, PP and PD definitions, respectively. Strong concordance was observed between facility-wide SCRs using the DP and PP definitions in both the academic (R2 = 0.99, y = 0.78x - 0.001) and community (R2 = 0.99, y = 0.68x - 0.03) centres across all four inpatient antibiotics evaluated. In an analysis of piperacillin/tazobactam SCRs, rates were over-predicted by 28%-93% at the facility-wide level across centres using alternative denominators. Conclusions: We found that data source and definitions of at-risk denominator days meaningfully impact antibiotic SCRs. Centres should carefully consider these potential sources of variation when setting consumption benchmarks and internally evaluating use.

Association between maternal HIV disclosure and risk factors for perinatal transmission.

OBJECTIVE: To determine whether maternal disclosure of HIV serostatus is associated with uptake of perinatal HIV transmission prevention interventions. STUDY DESIGN: Retrospective cohort study of women living with HIV enrolled in a perinatal HIV clinic. Women who disclosed their HIV serostatus to sexual partner(s) prior to delivery were compared to non-disclosers. Multivariable logistic regression was performed. RESULTS: Of 209 women, 71.3% (N = 149) disclosed. Non-disclosers were more likely to attend <10 prenatal visits, demonstrated worse antiretroviral therapy adherence, required more time to achieve virologic suppression, and were less likely to have an undetectable viral load. On multivariable analyses, disclosure status did not remain associated with these factors. However, compared to non-disclosers, disclosers had lower odds of preterm delivery (OR: 0.43, 95% CI: 0.19-0.94) and greater odds of postpartum visit attendance (aOR: 5.10, 95% CI: 1.65-15.72). CONCLUSIONS: Non-disclosure of HIV status to sexual partner(s) during pregnancy may be a risk factor for preterm birth and poorer postpartum visit attendance.

Correlation between hospital-level antibiotic consumption and incident health care facility-onset Clostridium difficile infection.

BACKGROUND: The purpose of this single-center, ecologic study is to characterize the relationship between facility-wide (FacWide) antibiotic consumption and incident health care facility-onset Clostridium difficile infection (HO-CDI). METHODS: FacWide antibiotic consumption and incident HO-CDI were tallied on a monthly basis and standardized, from January 2013 through April 2015. Spearman rank-order correlation coefficients were calculated using matched-months analysis and a 1-month delay. Regression analyses were performed, with P < .05 considered statistically significant. RESULTS: FacWide analysis identified a matched-months correlation between ceftriaxone and HO-CDI (ρ = 0.44, P = .018). A unit of stem cell transplant recipients did not have significant correlation between carbapenems and HO-CDI in matched months (ρ = 0.37, P = .098), but a significant correlation was observed when a 1-month lag was applied (ρ = 0.54, P = .014). DISCUSSION: Three statistically significant lag associations were observed between FacWide/unit-level antibiotic consumption and HO-CDI, and 1 statistically significant nonlagged association was observed FacWide. Antibiotic consumption may convey extended ward-level risk for incident CDI. CONCLUSIONS: Consumption of antibiotic agents may have immediate and prolonged influence on incident CDI. Additional studies are needed to investigate the immediate and delayed associations between antibiotic consumption and C difficile colonization, infection, and transmission at the hospital level.

Switch to atovaquone and subsequent re-challenge with trimethoprim-sulfamethoxazole for Pneumocystis prophylaxis in a kidney transplant population.

Kidney transplant recipients who are switched to atovaquone (ATO) from trimethoprim-sulfamethoxazole (TMP/SMX) for Pneumocystis jirovecii pneumonia (PJP) prophylaxis because of adverse events or complications may miss opportunities to be re-challenged with TMP/SMX, the first-line agent. This single-site, retrospective study assessed kidney transplant recipients for documented reasons for switching from TMP/SMX to alternate PJP prophylaxis and outcomes of TMP/SMX re-challenge. Out of 166 patients, 155 initially received TMP/SMX; of these, 31 were switched to ATO for various reasons. Fourteen patients receiving ATO were re-challenged with TMP/SMX; all were successfully re-initiated on TMP/SMX therapy. Most patients switched to ATO post kidney transplant secondary to non-hypersensitivity reasons should be re-challenged with TMP/SMX because of the advantages it provides over other agents.

A Simple Microsoft Excel Method to Predict Antibiotic Outbreaks and Underutilization.

Benchmarking strategies are needed to promote the appropriate use of antibiotics. We have adapted a simple regressive method in Microsoft Excel that is easily implementable and creates predictive indices. This method trends consumption over time and can identify periods of over- and underuse at the hospital level. Infect Control Hosp Epidemiol 2017;38:860-862.

Treating complicated carbapenem-resistant enterobacteriaceae infections with ceftazidime/avibactam: a retrospective study with molecular strain characterisation.

Ceftazidime/avibactam (CAZ/AVI) is the first antimicrobial agent with activity against carbapenem-resistant Enterobacteriaceae (CRE) approved by the US Food and Drug Administration (FDA). Notably, human clinical outcome data for this indication are limited. Therefore, a retrospective study was performed to evaluate the clinical outcomes and bacterial genomic characteristics of patients hospitalised at a tertiary medical centre with CRE infections treated for the first time with CAZ/AVI. From a total of 44 patients with CRE infections, 6 patients were treated with CAZ/AVI. The duration of CAZ/AVI treatment ranged from 7 days to 28 days. Five patients achieved clinical cure, however two relapsed with the same carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strain within 3 weeks of completion of CAZ/AVI treatment. In addition, one patient with CR-Kp pneumonia experienced clinical failure despite having a documented CAZ/AVI-susceptible CR-Kp strain [minimum inhibitory concentration (MIC) = 2 mg/L]. Consequently, the overall rate of unsuccessful outcome in this small cohort of patients was 50%. All strains carried KPC-3, OXA-9 and different TEM and SHV ß-lactamases, but none carried the intrinsically avibactam-resistant class B metallo-ß-lactamases. No obvious differences in antibiotic resistance genes were observed. This study provides an early glimpse of the clinical outcomes of patients with CR-Kp infections treated with CAZ/AVI. Findings of clinical failure and relapse in patients with no prior exposure to CAZ/AVI and with documented susceptibility to CAZ/AVI highlight the urgent need for well-designed clinical studies evaluating the effectiveness of CAZ/AVI in the treatment of CRE infections.

Use of High-Dose Oral Valacyclovir During an Intravenous Acyclovir Shortage: A Retrospective Analysis of Tolerability and Drug Shortage Management.

INTRODUCTION: In late 2011, a shortage of IV acyclovir led to the need to empirically substitute high-dose oral valacyclovir (HDVA) to conserve IV acyclovir for patients with confirmed herpes simplex virus (HSV) meningitis or encephalitis. This report describes the management of the most recent national IV acyclovir shortage by the Antimicrobial Stewardship Program (ASP) at Northwestern Memorial Hospital (NMH), Chicago, IL, USA, and the use of HDVA. Secondarily, we assessed the safety and tolerability of HDVA as an alternate to IV acyclovir during this shortage. METHODS: We report the step-wise management, restrictions, and guidelines implemented at NMH during a protracted IV acyclovir shortage. The assessment of HDVA was a retrospective, observational cohort study of hospitalized patients receiving HDVA between 1 January 2012 and 31 December 2013. Appropriate demographic and treatment variables were collected. The primary outcome was percentage of patients experiencing an adverse event. RESULTS: There were 15 adult patients included in the study on a median daily dose of HDVA of 3 g (IQR 2-8). There were four patients with microbiologically confirmed viral CNS infections (n = 1 HSV-1, n = 2 HSV-2, n = 1 VZV encephalitis) and eleven patients with unknown causative pathogens. Six (40%) patients experienced at least one adverse drug reaction (ADR) to HDVA (thrombocytopenia, 33.3%, n = 5; headache, 6.7%, n = 1; nausea, 6.7%, n = 1; rash, 6.7%, n = 1). One patient (6.7%) was readmitted within 30 days with a suspected non-CNS infection. There were no treatment discontinuations or symptomatic therapy necessary to treat any of the ADRs. CONCLUSIONS: The shortage of IV acyclovir was successfully managed by the ASP and HDVA appeared to be well tolerated when used as an alternative to IV acyclovir.

Implementation of a cefazolin-based stewardship pathway for methicillin-susceptible Staphylococcus aureus bloodstream infections paired with infectious diseases consultation.

Methicillin-susceptible Staphylococcus aureus (MSSA) infections have been successfully treated both with cefazolin and antistaphylococcal penicillins; cefazolin appears effective in MSSA bloodstream infections (BSIs). Thus, our antimicrobial stewardship programme (ASP) implemented a clinical pathway supporting cefazolin use in MSSA-BSIs and restricting oxacillin use to infectious diseases (ID) consultation due to cefazolin's lower cost and more convenient dosing. This before and after quasi-experimental study was conducted to describe the impact on outcomes and process of care measures associated with implementing this pathway among patients with MSSA-BSI. Definitive treatment with cefazolin increased over the study period from 17.3% to 69.8% post-implementation. Clinical failure (5.8% vs. 2.3%; P = 0.62) and in-hospital mortality (3.8% vs. 0%; P = 0.50) were rare pre- and post-implementation. Median hospital length of stay among survivors was similar between pre- and post-implementation periods (P = 0.31). Duration of bacteraemia [median (IQR) 3 (2-4) days vs. 2 (2-3) days; P = 0.002] and rates of re-infection after culture clearance (9.6% vs. 0%; P = 0.06) were reduced post-implementation. Frequency of source control (P = 0.71) and time to source control (P = 0.52) were similar between study periods. Significant increases in ID consultations (33.3% [3/9] vs. 73.3% [22/30]; P = 0.047) and median (IQR) 24-h daily doses [2 (1-3) g vs. 6 (3-6) g; P < 0.01] were seen for patients treated with cefazolin post-implementation. ASPs may find implementation of a similar pathway to be an effective means of improving the care of patients infected with MSSA.