Positive Surveillance Cultures Research Articles

Risk factors for the development of candidemia in patients with positive urine surveillance culture for Candida spp.

The objective of the study was to characterize candiduria in patients admitted to a tertiary hospital and establish the risk factors associated with the development of candidemia. To this end, a laboratory and clinical surveillance study was carried out with samples of Candida spp. previously isolated from urine surveillance cultures of patients admitted to the Intensive Care Unit, during the period from 2019 to 2020. It was demonstrated that the incidence of candidemia in patients with positive urine cultures for Candida spp. it was 17.7 per 1000 admissions and 80% of patients who developed candidemia died. The chance of developing candidemia was eight times greater in patients who had diseases of the digestive system that caused hospitalization and 26 times greater in those who had Coronary Artery Disease (CAD), compared to patients who did not have the comorbidity. We concluded that the possibility of developing candidemia from candiduria is 4.5%, however, the onset of candidemia, regardless of the source, worsens the patient's prognosis.

Impact of the COVID-19 Pandemic on Candida auris Infections: A Retrospective Analysis in an Academic Medical Center in New York City.

Candida auris (C. auris), a multidrug-resistant fungus first described in Japan in 2009, has since spread rapidly around the world. More recently, cases of C. auris have increased substantially, which may have been affected by the strain the coronavirus disease 2019 (COVID-19) pandemic placed on health care resources. We describe the epidemiology of C. auris infection and colonization at a tertiary care hospital in New York City before, during, and after the peak of the COVID-19 pandemic and describe our approach to surveillance. We performed a retrospective chart review for all incident cases of C. auris, defined as a patient without a known history of infection or colonization who had a positive surveillance or clinical culture detected at our institution from 2019 through 2022. Clinical and demographic data were collected using the electronic medical record. Sixty-four incident cases of C. auris were identified. Thirty-four of these were identified by surveillance and 30 by clinical culture. There was a statistically significant increase in the number of cases identified in 2022 compared with 2019, with incidence rates of 2.6 cases per 10 000 admissions in 2019 and 7.8 cases per 10 000 admissions in 2022 (p = .002), respectively. The incidence of C. auris colonization or infection increased significantly at our institution during the COVID-19 pandemic, reflecting the potential impact the pandemic had on C. auris transmission. Targeted admission surveillance allows for the early identification of C. auris cases and can serve as a valuable tool to combat the increasing transmission of C. auris.

Vancomycin vs metronidazole use for the treatment of Clostridioides difficile infection in a tertiary care hospital in Saudi Arabia

BackgroundThe 2017 Infectious Diseases Society of America (IDSA) Clostridioides difficile infection (CDI) guidelines recommendation for oral vancomycin as preferred treatment was based on studies conducted in North America, Australia, and Europe. According to recent published data, metronidazole remains a reasonable option. No studies have been conducted in Saudi Arabia to compare prescribing patterns before and after the release of the guidelines. Due to low CDI burden in Saudi Arabia, the aim is to assess the effectiveness and outcomes of vancomycin vs metronidazole treatment options. MethodsThis was a retrospective cohort study conducted in a tertiary care hospital in Jeddah which was approved by the Institutional Review Board (IRB 2020–53). Data was collected from January 2017 to April 2020. Eligible patients were adults (>18 years old) diagnosed with CDI who either received oral metronidazole (500 mg 3 times daily) or oral vancomycin (125–500 mg 4 times daily). Patients who received a combination of treatment or who were diagnosed with fulminant CDI were excluded. Demographic data were collected. The primary outcome was to assess treatment response to initial therapy with oral metronidazole versus oral vancomycin. Secondary outcomes included assessing early treatment response, time to discharge after diagnosis, proportion of patients with a positive VRE surveillance culture within 6 months of diagnosis, 30-day recurrence and 30-day all-cause mortality. Chi-square or Fisher's exact test were used to examine differences in categorical variables while student t-test or Mann–Whitney test, were used to examine differences in continuous variables. P value < 0.05 was considered as significant. ResultsA total of 166 patients were included in the analysis. Demographic characteristics were not significantly different between the two groups. There was no difference in treatment response between vancomycin and metronidazole (96.4 % versus 94.3 %, p = 0.682). However, compared with metronidazole, vancomycin treatment was significantly associated with better early response (94.0 % versus 77.8 %, p = 0.008). Other outcomes were not significantly different between the two drug groups for time to discharge after diagnosis (P = 0.522), 30-day recurrence (P > 0.99) and 30-day all-cause mortality (P = 0.782). Of note, the vancomycin versus metronidazole use before the 2017 IDSA guidelines (26 % versus 74 %) was completely reversed after the release of the guidelines (83.3 % versus 16.7 %), p < 0.001). ConclusionThe results of this study demonstrate that vancomycin and metronidazole have comparable outcomes in regards to treatment response for non-fulminant CDI. The study also reveals the high and quick impact of international guidelines on local prescription patterns. Further studies are needed in Saudi Arabia to guide the treatment of CDI.

Predictive Role of Targeted, Active Surveillance Cultures for Detection of Methicillin-Resistant Staphylococcus aureus.

IntroductionMethicillin-resistant Staphylococcus aureus (MRSA) colonisation is an important source of healthcare-acquired infections. Reliable screening strategies for MRSA colonisation are essential for the timely implementation of infection control measures.AimThis study determined reliable MRSA screening sites to predict colonisation in resource-limited settings and estimated the impact of missed MRSA cases when shifting from multi- to single-site screening.MethodologyA cross-sectional study was conducted in patients with positive MRSA surveillance cultures from the routinely screened sites (nasal, axillary, groin, and throat) from January 2009 to December 2019.ResultsA total of 1906 screening tests were positive for MRSA cultures (n = 1345 patients). As a single site, the nasal cavity showed the highest MRSA detection, with a sensitivity of 66.8% (95% CI = 64–69) with 277.9 missed isolation days. Screening three or more anatomical sites detected 97–100% of MRSA cases, with 0–24.5 missed isolation days. Screening the axilla and groin separately or in combination showed a good clinical utility index (CUI) of >0.6 to <0.8, while an excellent CUI was obtained upon screening other site samples (>0.8). The combined nasal and throat cultures demonstrated a sensitivity of 93.2 (95% CI = 91–94) with 57.2 missed isolation days.ConclusionMulti-site screening is the optimal strategy for minimising MRSA exposure within a healthcare facility. For active MRSA surveillance, a combination of nasal and throat cultures can provide a practical approach in low-resource settings compared to nasal sampling alone.

Spa Typing of Staphylococcus aureus in a Neonatal Intensive Care Unit During Routine Surveillance.

Staphylococcus aureus protein A (spa) typing can be used to expand characterization of the epidemiology of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in neonatal intensive care units (NICU). From January 2017 to June 2018, twice-monthly surveillance for S. aureus was performed in an academically affiliated NICU. Decolonization of infants colonized with S. aureus included chlorhexidine gluconate bathing and/or mupirocin for those with mupirocin-susceptible strains. Spa typing and mupirocin-resistance testing were performed. Demographic and clinical characteristics were compared between infants colonized with MSSA vs MRSA and infants with and without the most common MSSA spa type, MSSA-t279. Overall, 14% and 2% of 1556 hospitalized infants had positive surveillance cultures for MSSA and MRSA, respectively. Thirty-six infants harbored unique MSSA spa types, 5 infants harbored unique MRSA spa types, and 30 MSSA and 6 MRSA spa types were identified in ≥2 infants. No outbreaks were identified during the study period. MSSA-t279 was isolated from 3% of infants and largely detected from infants hospitalized in one section of the NICU; 96% of t279 isolates were mupirocin resistant. Infection rates, length of hospitalization, and mortality were similar among infants initially colonized with t279 vs other MSSA spa types. The MSSA colonization burden was 5-fold larger than that of MRSA. Numerous unique spa types were identified. The most common spa type, MSSA-t279, was not associated with increased morbidity or mortality but was mupirocin resistant and associated with clustered NICU beds. This suggests potential transmission from the environment, shared staff, and/or workflow issues requiring further study. Other decolonization strategies for S. aureus in the NICU are needed.

Surveillance Cultures and Infection in 230 Pacemaker and Defibrillator Generator Changes in Pediatric and Adult Congenital Patients.

Postoperative infections can occur during surgical replacement of pulse generators for pacemakers and implantable cardioverter-defibrillators. The incidence of infection is poorly documented in children and patients with adult congenital heart disease. The utility of surveillance cultures obtained from device pocket swabs is unknown in this group. We reviewed surgical replacements of cardiovascular implantable pulse generators from 2010 to 2017. Two cohorts were defined. In a surveillance cohort (123 patients), aerobic and anaerobic culture swabs of the device pocket were obtained at the time of generator change. In a nonsurveillance cohort (107 patients), generator change occurred without obtaining cultures. During 230 generator changes (mean patient age 19 years; 77% with structural congenital heart disease), two clinical infections occurred at the surgical site (0.9% incidence). Neither infection occurred in the surveillance cohort. Cultures were positive in 12 (9.8%) of 123 patients in the surveillance cohort, but 11 of 12 were likely contaminants and none were subsequently associated with clinical disease. There was no association between clinical infection or positive surveillance cultures and the location of pulse generator, the presence of other concurrent surgeries, or a history of prior pocket infection. Clinical infection was rare after pulse generator change in children and young adults. No cases required reintervention on the pocket. Surveillance cultures did not improve clinical care. These data extend current recommendations that surveillance cultures are not required during generator change to the pediatric and young adult population.

Effectiveness of surveillance cultures for high priority multidrug-resistant bacteria in hematopoietic stem cell transplant units.

ABSTRACTSurveillance strategies to detect colonization are an important tool to prevent and control the spread of microorganisms in hematopoietic stem cell transplant (HSCT) units. The aim of this study was to evaluate routine surveillance cultures for screening colonization and infection by carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Pseudomonas aeruginosa (CRPa), and vancomycin-resistant enterococci (VRE). Surveillance cultures were collected (1,323 samples) from 200 patients admitted to an HSCT unit over one year; swabs were taken on admission and then weekly. We compared the positivity of cultures for each site, agent, clinical and epidemiological data according to the colonization status. Infection due to multidrug-resistant organisms (MDROs) occurred in 52 (21.5%) patients, 45 (86.5%) due to blood stream infection; 12 (23%) patients had a positive surveillance culture before the infection. Cultures of 554 (41.8%) samples were performed for CRPa, 413 (31.2%) for VRE and 356 (27%) for CRE. Of these, 179 (13.5%) were positive. Colonization by any MDRO, CRE or CRPa was associated with increased risk of infection (P < 0.05), but not with death. Previous colonization by an MDRO was a significant risk for infection by these pathogens, specially by CRE. Overall, rectal swabs had the highest positivity rate compared with other sites, oropharynx swabs were an option for CRPa, and fecal cultures showed low positivity. Although the impact of the strategy on the mortality of patients undergoing HSCT is not clear, routine VRE surveillance should be questioned with regard to patients undergoing auto-HSCT due to the additional cost and little impact on survival rates.

Contamination of Healthcare Worker Personal Protective Equipment with MRSA Outside the Intensive Care Unit Setting

Background: Estimates of contamination of healthcare personnel (HCP) gloves and gowns with methicillin-resistant Staphylococcus aureus (MRSA) following interactions with colonized or infected patients range from 17% to 20%. Most studies were conducted in the intensive care unit (ICU) setting where patients had a recent positive clinical culture. The aim of this study was to determine the rate of MRSA transmission to HCP gloves and gown in non-ICU acute-care hospital units and to identify associated risk factors. Methods: Patients on contact precautions with history of MRSA colonization or infection admitted to non-ICU settings were randomly selected from electronic health records. We observed patient care activities and cultured the gloves and gowns of 10 HCP interactions per patient prior to doffing. Cultures from patients’ anterior nares, chest, antecubital fossa and perianal area were collected to quantify bacterial bioburden. Bacterial counts were log transformed. Results: We observed 55 patients (Fig. 1), and 517 HCP–patient interactions. Of the HCP–patient interactions, 16 (3.1%) led to MRSA contamination of HCP gloves, 18 (3.5%) led to contamination of HCP gown, and 28 (5.4%) led to contamination of either gloves or gown. In addition, 5 (12.8%) patients had a positive clinical or surveillance culture for MRSA in the prior 7 days. Nurses, physicians and technicians were grouped in “direct patient care”, and rest of the HCPs were included in “no direct care group.” Of 404 interactions, 26 (6.4%) of providers in the “direct patient care” group showed transmission of MRSA to gloves or gown in comparison to 2 of 113 (1.8%) interactions involving providers in the “no direct patient care” group (P = .05) (Fig. 2). The median MRSA bioburden was 0 log 10CFU/mL in the nares (range, 0–3.6), perianal region (range, 0–3.5), the arm skin (range, 0-0.3), and the chest skin (range, 0–6.2). Detectable bioburden on patients was negatively correlated with the time since placed on contact precautions (rs= −0.06; P &lt; .001). Of 97 observations with detectable bacterial bioburden at any site, 9 (9.3%) resulted in transmission of MRSA to HCP in comparison to 11 (3.6%) of 310 observations with no detectable bioburden at all sites (P = .03). Conclusions: Transmission of MRSA to gloves or gowns of HCP caring for patients on contact precautions for MRSA in non-ICU settings was lower than in the ICU setting. More evidence is needed to help guide the optimal use of contact precautions for the right patient, in the right setting, for the right type of encounter.Funding: NoneDisclosures: None

Effect of Contact Precautions on Staphylococcus aureus and Clinical Outcomes of Colonized Patients in the Neonatal Intensive Care Unit.

Staphylococcus aureus is a common pathogen in neonatal intensive care units (NICUs), yet little is known about the effect of contact precautions and clinical outcomes of colonized patients. Retrospective cohort study of all neonates from August 2014 to November 2018 colonized with either methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus (MSSA) and select noncolonized patients at two neonatal intensive care units at the University of California, Los Angeles. Outcomes during two time periods (during and after the use of contact precautions) were assessed. A total of 234 patients were included in the study: 83 colonized and 151 noncolonized patients. There was a fourfold higher incidence of MSSA colonization versus MRSA (P < 0.001). There was a higher incidence of positive surveillance cultures after contact precautions were discontinued (P = 0.01), but this did not correlate with a higher incidence of invasive cultures (P = 0.475). There were twice as many MSSA invasive cultures than MRSA, but a higher rate of invasion with MRSA (P < 0.05). Colonized patients were more likely to develop an invasive infection than noncolonized (P = 0.003 MRSA; P = 0.004 MSSA). When controlling for gestational age and surgical interventions, colonization was more likely to be associated with skin and soft tissue infections (P < 0.001) and a longer length of stay by a mean of 27.8 days (P < 0.0001). Contact precautions resulted in a lower incidence of colonization without a difference in invasive cultures in our NICUs. Those colonized with S. aureus had a higher incidence of skin and soft tissue infections and a longer NICU length of stay.

The Role of Healthcare Worker-Mediated Contact Networks in the Transmission of Vancomycin-Resistant Enterococci.

BackgroundUser- and time-stamped data from hospital electronic health records (EHRs) present opportunities to evaluate how healthcare worker (HCW)-mediated contact networks impact transmission of multidrug-resistant pathogens, such as vancomycin-resistant enterococci (VRE).MethodsThis is a retrospective analysis of incident acquisitions of VRE between July 1, 2016 and June 30, 2018. Clinical and demographic patient data were extracted from the hospital EHR system, including all recorded HCW contacts with patients. Contacts by an HCW with 2 different patients within 1 hour was considered a “connection”. Incident VRE acquisition was determined by positive clinical or surveillance cultures collected ≥72 hours after a negative surveillance culture.ResultsThere were 2952 hospitalizations by 2364 patients who had ≥2 VRE surveillance swabs, 112 (4.7%) patients of which had incident nosocomial acquisitions. Patients had a median of 24 (interquartile range [IQR], 18–33) recorded HCW contacts per day, 9 (IQR, 5–16) of which, or approximately 40%, were connections that occurred <1 hour after another patient contact. Patients that acquired VRE had a higher average number of daily connections to VRE-positive patients (3.1 [standard deviation {SD}, 2.4] versus 2.0 [SD, 2.1]). Controlling for other risk factors, connection to a VRE-positive patient was associated with increased odds of acquiring VRE (odds ratio, 1.64; 95% confidence interval, 1.39–1.92).ConclusionsWe demonstrated that EHR data can be used to quantify the impact of HCW-mediated patient connections on transmission of VRE in the hospital. Defining incident acquisition risk of multidrug-resistant organisms through HCWs connections from EHR data in real-time may aid implementation and evaluation of interventions to contain their spread.

Limited Utility of Outpatient Surveillance Blood Cultures in Hematopoietic Cell Transplant Recipients on High-Dose Steroids for Treatment of Acute Graft-versus-Host-Disease.

Steroids used to treat acute graft-versus-host-disease (GVHD) are believed to blunt clinical symptoms of infection. We aimed to assess the value of weekly surveillance blood cultures (SBCs) drawn in an outpatient setting from hematopoietic cell transplant (HCT) patients receiving high-dose steroids. We hypothesized that most positive outpatient surveillance cultures would be low-pathogenicity, gram-positive organisms and would lead to excess vancomycin therapy. We conducted a retrospective review of blood cultures collected from a cohort of adult HCT patients enrolled in a clinical trial of acute GVHD therapy with high-dose steroids (prednisone-equivalent doses ≥ .5 mg/kg/day) between April 2009 and May 2013. SBCs were defined as those collected weekly from central venous catheters in the outpatient setting while patients were receiving high-dose steroids. Cultures obtained as part of a symptom workup or as follow-up for documented bacteremia were excluded. Clinical data were collected using center databases supplemented by medical record review. One hundred twenty-seven HCT recipients were eligible for inclusion in the study. A total of 1015 SBCs were obtained, with a median of 8 cultures (interquartile range, 5 to 10) per patient. Forty-two organisms were isolated from 36 of 1015 cultures (3.5%) in 30 unique patients, or 1 positive culture per 28 blood cultures drawn. The most frequently detected organisms were coagulase-negative Staphylococci (25/1015 [2.5%]). Gram-negative organisms were rare (4/1015 [.4%]. Antibiotics were administered to most patients with positive surveillance cultures (33/36 [92%]). Six were admitted to the hospital for treatment; none needed intensive care or died from their bacteremia. Vancomycin was the most frequently administered antibiotic, comprising 256 of 376 total days (68%) of antibiotic received by the cohort with a median duration of 10 days ((interquartile range, 7 to 14). Weekly outpatient SBCs obtained from asymptomatic patients on high-dose glucocorticoids for treatment of acute GVHD after allogeneic HCT were infrequently positive, and most organisms were low-pathogenicity organisms. SBCs also led to excess antibiotic exposure and costs, suggesting benefits of such ambulatory screening may be of limited value in this setting.

Colonization and Infection With Extensively Drug Resistant Gram-Negative Bacteria in Liver Transplant Recipients

BackgroundInfections due to extensively drug resistant Gram-negative bacteria (GNB) after solid organ transplantation are increasing in prevalence and are associated with high morbidity and mortality. Surveillance culture (SC) seems to be an important tool for extensively drug resistant GNB control. The aim of this study was to evaluate colonization rates and subsequent infections by XDR-GNB in liver transplant recipients. Material and MethodsThis was a prospective cohort study in patients who underwent liver transplantation (LT) between January 2016 and January 2018. Data on demographics, extensively drug resistant colonization, and 3-month clinical outcomes were obtained. Colonization was defined as a positive surveillance culture (SC-perirectal) immediately before transplantation, once weekly after LT, and after intensive care unit discharge, with emphasis to carbapenem-resistant Gram-negative bacteria (CR-GNB). ResultsForty-four patients who underwent LT were included in the study. Ten patients (22.72%) were colonized with CR-GNB prior to transplantation, and 7/10 (70%) developed infection due to the same pathogen (5 patients bloodstream infections, 2 patients pneumonia) during the study period. Intensive care unit length of stay was significantly longer in colonized with CR-GNB patients (P < .05). Mortality rate was higher in colonized patients (30%) than in noncolonized (11.76%) (P = .2). ConclusionOur study results suggest an overall 70% risk of CR-GNB infection among colonized patients. Given the high mortality rate and the difficulty in treating these infections, further research to investigate and develop strategies to eliminate the colonization is needed.

Avaliação da colonização por bactérias multirresistentes em pacientes admitidos via central de regulação do estado em um hospital filantrópico em Salvador, Bahia

Justificativa e objetivos: Infecções Relacionadas à Assistência à Saúde (IRAS) são consideradas um problema de saúde pública cujo controle pode minimizar a morbimortalidade dos pacientes. A instituição precoce de isolamento de contato para pacientes possivelmente colonizados por microrganismos multirresistentes (MR), pode reduzir sua disseminação os casos de IRAS e custos hospitalares. O objetivo deste estudo foi avaliar a frequência e impacto de culturas de vigilância positivas com microrganismos multirresistentes (MR) após um surto de Enterococcus spp. resistentes à vancomicina (VRE). Métodos: Foram implementadas rotinas de coleta de culturas de vigilância a partir de abril de 2014 para pacientes procedentes de outras unidades de saúde via Central de Regulação do Estado e Município em um hospital filantrópico em Salvador – BA. Resultados: Foram avaliados 663 pacientes no período de dezembro de 2014 a dezembro de 2015, sendo que 42 destes apresentaram cultura de vigilância positiva para microrganismos gram positivos e negativos MR. Após a implementação da rotina de realização de culturas de vigilância, não foram mais detectados surtos na nossa unidade. Conclusão: A rotina de culturas de vigilância pode funcionar como um importante instrumento na prevenção da disseminação de MR. Descritores: Isolamento de Pacientes. Resistência Microbiana a Medicamentos; Monitoramento Epidemiológico.

923. Rapid Emergence of Candida auris in the Chicago Region

BackgroundIn 2016, Candida auris was first reported in the United States, with 2 Illinois patients among the first cases. In response, the state and 3 Chicago-area health departments (HDs) investigated clinical cases and performed point prevalence surveys (PPSs) to identify colonized cases.MethodsClinical cases had positive C. auris cultures obtained for clinical care; colonized cases had positive surveillance cultures during PPSs. In August 2016–January 2018, PPSs were performed in Chicago-area acute care hospital (ACH) intensive care units, long-term acute-care hospitals (LTACHs), and high-acuity floors of skilled nursing facilities (SNFs) and SNFs caring for ventilated patients (vSNFs). Facility and HD staff obtained composite axilla/groin swabs from assenting patients to detect colonization. Facilities with an epidemiologic link to a clinical case or a shared patient population with a facility housing a clinical case were prioritized for PPSs.ResultsDuring May 2016–January 2018, Chicago-area facilities reported 24 clinical cases, including 10 bloodstream infections. HDs performed 33 PPSs at 20 facilities (5 ACHs, 5 LTACHs, 3 SNFs, and 7 vSNFs) during August 2016–January 2018. Of 1,364 patients screened, 92 (6.7%) were colonized with C. auris; 10 (50%) facilities had ≥1 colonized patient. A significantly higher proportion screened positive from September 2017 to January 2018 (84/822, 10.2%) than in August 2016–August 2017 (8/542, 1.5%; z-test P < 0.01). Prevalence of C. auris colonization was highest in vSNFs (median: 7.7%; range: 0%–43.3%), compared with ACHs (0%; 0%–6.3%), LTACHs (0%; 0%–14.3%), and SNFs (0%, 0%–1.5%). PPSs in vSNFs identified 91% (84/92) of colonized cases. Among 5 vSNFs with repeat PPSs, 4 had higher prevalence on repeat screening (median: 26.1%; range: 0%–43.3%) than at baseline (1.2%; 0%–17.0%).Conclusion C. auris has rapidly emerged in the Chicago area. Increasing prevalence of C. auris colonization during repeat PPSs indicates transmission and amplification within vSNFs. To prevent spread, state and local HDs provided infection control recommendations, disseminated health alerts, and recommended placing vSNF patients from high-acuity floors on transmission-based precautions.Disclosures All authors: No reported disclosures.

1251. Contaminated Sinks May be an Environmental Source for Serial Transmission of Carbapenem-Resistant Enterobacteriaceae (CRE) to ICU Patients

BackgroundWe performed an investigation after noting an increase in hospital-onset (HO) KPC-producing Enterobacteriaceae (KPC-E) infections in patients admitted to a tertiary referral hospital in North Carolina.MethodsWe defined pre-outbreak (January 1, 2017–June 30, 2017), outbreak (July 1, 2017–October 31, 2017), and post-outbreak (November 1, 2017–March 31, 2018) phases. A clinical case was defined as any positive clinical culture for KPC-E. HO was defined as a positive clinical or surveillance culture collected on hospital day ≥3. Patients were mapped in space and time to inform targeted environmental sampling. Whole-genome sequencing (WGS) was performed on selected KPC K. pneumoniae environmental and patient isolates to determine relatedness.In October 2017, a CRE prevention bundle was implemented that included daily communication of CRE patient movement, increased audits/feedback of HCW compliance with hand hygiene, enhanced cleaning and disinfection in CRE rooms and high-risk units with bleach and UVC disinfection, and weekly rectal surveillance screens in four adult ICUs.Results0.67 clinical cases of KPC-E per month were observed during the pre-outbreak period compared with 3.75 clinical cases of KPC-E per month during the outbreak period. K. pneumoniae was the most common species (Figure 1). Mapping of patients revealed probable direct and indirect transmission between patients in multiple hospital units (Figure 2). three patients who were non-sequentially admitted to the same ICU room over a 12-week span acquired KPC K. pneumoniae (Figure 2). Environmental cultures from the in-room sink drain and P-trap grew KPC K. pneumoniae that was related to the patient isolates by WGS; the sink was removed. Although no additional clinical cases of KPC-E occurred after full implementation of the bundle and sink removal, we continued to observe acquisition of KPC-E rectal colonization in all four ICUs (Figure 3).ConclusionWe describe a multispecies outbreak of KPC-E that was mitigated through evidence-based CRE control measures and removal of a colonized sink. However, ongoing low-level presumed transmission of KPC points to persistent environmental sources. Additional study is needed to understand the prevalence of CRE in hospital sinks, factors that drive drain colonization, and contribution of CRE in a sink to nosocomial transmission. Disclosures All authors: No reported disclosures.

1217. Staphylococcus Protein A (spa) Typing Demonstrates Genetic Heterogeneity of Methicillin-Susceptible Staphyloccus aureus (MSSA) in a Neonatal Intensive Care Unit (NICU)

BackgroundIn the NICU, MSSA is a more prevalent pathogen than MRSA, but optimal infection prevention and control strategies for MSSA are not yet well understood. There are likely multiple routes of MSSA acquisition given its role as normal flora and its detection in the anovaginal tract of pregnant women. We describe the molecular epidemiology of MSSA in our NICU during a yearlong surveillance effort.MethodsIncluded infants were hospitalized in a university-affiliated level III-IV NICU from January to December 2017 (1032 admissions) and had positive clinical and/or surveillance cultures for MSSA. Infants admitted at ≥7 days of age were screened for MSSA colonization by culturing the anterior nares and three skin sites. All infants in the NICU were screened twice monthly. Spa typing was performed to genetically characterize isolates.ResultsDuring the study period, MSSA was identified in 187 infants (18 at admission, 145 by twice monthly surveillance, and 24 from clinical cultures). In all, 269 MSSA isolates (245 surveillance and 24 clinical isolates) from 166 infants were spa typed. Sixty-two MSSA spa types were identified; 31 (50%) were each detected in only one infant. The incidence of the nine most common spa types is shown (Figure 1); t279 (13%), t002 (8%), and t1451 (6%) had the highest incidence. t1451 and t571 belong to ST398, a common MSSA clone in the local community. The epidemiology of spa types varied; e.g., incident cases of t279 was detected in 10 months, t1451 was detected in 6 months and t148 in 3 months. Among the 14 sets of twins and triplets with MSSA isolates, 12 (86%) shared the same spa type as their sibling(s). Of the 58 infants with >1 MSSA isolate, 12 (21%) acquired new spa-types. No spa type(s) predominated in the 19 episodes of invasive infections. In 6 infants with both colonizing and invasive isolates, colonizing and invasive isolates were the same spa type(s) in 5.ConclusionSpa typing demonstrated that MSSA isolates in our NICU exhibited substantial genetic heterogeneity. While these data do not elucidate acquisition route(s), they suggest infants are acquiring MSSA from multiple sources, likely including family members and the local community. Ongoing sequencing studies are examining common spa types to further understand transmission dynamics.Figure 1.Disclosures A. C. Uhlemann, Merck: Investigator, Grant recipient

2303. Differential Effects on MRSA and MSSA Epidemiology in a Neonatal Intensive Care Unit (NICU) During a Year-Long Surveillance and Decolonization Effort

Background Staphylococcus aureus (SA) causes morbidity and mortality in the NICU. While surveillance, with decolonization, is recommended for MRSA outbreak control, the impact of such strategies on endemic MSSA infections is less known. We compare the impact of a year-long surveillance and decolonization effort on MRSA and MSSA colonization dynamics and invasive infection rates in the NICU.MethodsAll infants hospitalized in our academically affiliated, regional perinatal NICU (1032 annual admissions) between January and December 2017 were screened twice monthly for SA colonization by culturing the anterior nares and three skin sites. Eligible patients with positive SA cultures underwent decolonization with mupirocin and/or chlorhexidine bathing. The following parameters for MRSA and MSSA were compared using frequencies and Fisher’s exact tests: 1) Colonization density (proportion of positive surveillance cultures; 2) rates of effective decolonization (proportion of successful decolonization efforts); 3) rates of invasive infections; and 4) mupirocin resistance.ResultsOverall, 25 twice monthly surveillance efforts were undertaken from which 1351/1375 (98%) screening cultures were obtained. Screening identified newly detected MSSA vs. MRSA in 145 vs. 20 infants, respectively. Colonization density decreased more for MRSA (Q1 vs. Q4 decrease of 67%) vs, MSSA (Q1 vs. Q4 decrease of 5%). Decolonization was more effective for MRSA (78%) vs. MSSA (71%). Compared with 2016, rates of invasive infections decreased more for MRSA (2.4 vs. 1.6 /10,000 patient-days, 33%) than MSSA (9.4 vs. 7.8 /10,000 patient-days, 17%). Prevalence of mupirocin resistance through study period was higher for MSSA (24% vs. 10%). No outbreaks were detected.ConclusionA year- long surveillance and decolonization effort was more successful in decreasing MRSA colonization density and invasive infections compared with MSSA. These results are likely due to continual importation of MSSA into the NICU from the community. Since MSSA caused more invasive infections than MRSA, strategies primarily aimed to decrease the burden of MRSA need to be modified to decrease the burden of MSSA in NICUs.Disclosures All authors: No reported disclosures.

Liberal Use of Delayed Sternal Closure in Children Is Not Associated With Increased Morbidity

Delayed sternal closure (DSC) is often employed to optimize hemodynamics following pediatric cardiac surgery. Prior reports have suggested that DSC may be associated with increased morbidity. We sought to analyze the impact of a liberal policy of DSC on surgical outcomes at our center. We retrospectively evaluated the clinical course of 1,000 consecutive patients between July 2005 and June 2015 whose sternum was electively left open following pediatric cardiac surgery. Data are presented as mean and standard error (parametric) or median and quartiles (nonparametric). Receiver-operating characteristic curve analysis was undertaken to identify significant points of inflection. A p less than 0.05 was considered significant. An a priori decision to leave the sternum open is made when complex surgery, especially in neonates and usually involving circulatory arrest, is expected to result in postoperative hemodynamic instability. Age at index surgery for the 1,000 patients was 7 (interquartile range [IQR], 3 to 19) days and weight 3.3 (IQR, 2.8 to 3.7) kg. There were 816 (82%) neonates and 569 (57%) boys. Index operations included 332 (33%) Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) category 5, 483 (48%) STAT category 4, and 185 (19%) STAT category 3 procedures. A total of 103 (10%) patients required postoperative extracorporeal support. Following hemodynamic recovery, DSC was undertaken 3 (IQR, 2 to 4) days postoperatively and in 98.3% patients was performed in the intensive care unit. Overall, mortality was 6.3% and major Society of Thoracic Surgeons morbidity was 21.6%. There were 42(4.2%) positive mediastinal surveillance cultures at the time of DSC, with the most common organism being coagulase-negative staphylococcus. Fifty-nine (5.9%) clinical sternal and mediastinal wound infections and a total of 117 infectious complications were encountered in 94 patients. Using Society of Thoracic Surgeons database outcome as benchmark, mortality and length of stay in our patients were comparable when analyzed by STAT categories or for the 2 most common index procedures (eg, Norwood and arterial switch operations). Receiver-operating characteristic curve analysis showed that 5 days of open sternum had a weak, but statistically significant, correlation with incidence of infectious complications (area under the curve, 0.56; p=0.002). The need for DSC 5 or more days after theindex procedure was observed in 177 (18%) patients and was not associated with increased wound infection.It was, however, independently associated on multiple regression analysis with major morbidity (odds ratio, 1.7; 95% confidence interval, 1.2 to 2.5; p= 0.002) and, in the subset of 897 patients who did not requireextracorporeal support, with increased mortality (odds ratio, 2.2; 95% confidence interval, 1.3 to 3.6; p=0.003). A liberal policy of DSC does not adversely affect surgical outcomes, including infectious complications and length of stay. We submit that need for DSC should not, by itself, be considered a source of morbidity.

Bacterial Burden in Critically Injured Ventilated Patients Does Not Correlate with Progression to Pneumonia.

Ventilator-associated pneumonia (VAP) is common in critically injured patients. The pathogenesis of VAP is not completely understood. We hypothesized that mechanically ventilated trauma patients who develop pneumonia have a progressive increase in pathogen burden over the course of ventilation until a threshold for symptomatic pneumonia is reached, leading to clinical suspicion of VAP. Critically injured adults ventilated for more than two successive days were enrolled. Patients underwent daily surveillance mini-bronchoscopic alveolar lavage (mBAL) while ventilated for 14 days or until extubation. Standard semi-quantitative cultures were performed, and the investigators were blinded to the results. Standard patient management was performed by the clinical team. Patients suspected of having VAP by the clinical team underwent bronchoscopic bronchoalveolar lavage (bBAL) and semi-quantitative culture, with VAP defined as clinical symptoms plus >104 colony-forming units (CFU) of bacteria. Standard statistical analysis for non-parametric data was performed. The 37 patients enrolled were ventilated for a median of nine days. While ventilated, 23 patients met the criteria for a clinical suspicion of VAP, of which two were too ill for bronchoscopy. Thus, 21 patients underwent bBALs because of a suspicion of VAP, and 13 (35%) were positive, with >104 CFU of one or more pathogens, and were treated for pneumonia. The bacterial burden on mBAL remained <104 CFU during ventilation for 32% of patients. None developed clinical symptoms of VAP. Two-thirds (67%) had an mBAL bacterial burden of >104 CFU without clinical suspicion of VAP. Half (56%) of positive surveillance cultures were followed by clinical VAP, confirmed by bBAL, all of which had identical pathogens on mBAL and bBAL. Almost half (44%) of the patients with positive surveillance mBALs never developed clinical VAP. A significant percentage of critically injured, ventilated adults develop high bacterial burdens in the lungs early in their course, and many clear these bacteria without developing VAP. Further study is needed to identify the factors causing progression to VAP.

Microbiological and functional outcomes after open extremity fractures sustained overseas: The experience of a UK level I trauma centre

BackgroundOpen extremity fractures carry a high risk of limb loss and poor functional outcomes. Transfer of extremity trauma patients from developing countries and areas of conflict adds further layers of complexity due to challenges in the delivery of adequate care. The combination of extensive injuries, transfer delays and complex microbiology presents unique challenges. MethodsA retrospective review was conducted to analyse the surgical and microbiological themes of patients with open extremity fractures transferred from overseas to our institution (Imperial College NHS Trust) between January 2011 and January 2016. ResultsTwenty civilian patients with 21 open extremity fractures were referred to our unit from 11 different countries. All patients had poly-microbial wound contamination on initial surveillance cultures. Five patients (25%) underwent amputation depending on the extent of osseous injury; positive surveillance cultures did not preclude limb reconstruction, with seven patients undergoing complex reconstruction and eight undergoing simple reconstruction to achievewound coverage. Hundred percent of patients demonstrated infection-free fracture union on discharge. ConclusionPatients with open extremity fractures transferred from overseas present the unique challenge of poly-microbial infection in addition to extensive traumatic wounds. Favourable outcomes can be achieved despite positive microbiological findings on tissue culture with adequate antimicrobial therapy. The decision to salvage the limb and the complexity of reconstruction used should be based on the chance of achieving meaningful functional recovery, mainly determined by the extent of bony injury. The complexity of reconstruction was based on the predicted long-term functionality of the salvaged limb.