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ObjectiveTo quantify the frequency and outcomes of receiving an antibiotic prescription upon discharge from the hospital to long-term care facilities (LTCFs).DesignRetrospective cohort study.SettingA 576-bed, academic hospital in Portland, Oregon.PatientsAdult inpatients (≥18 years of age) discharged to an LTCF between January 1, 2012, and June 30, 2016.MethodsOur primary outcome was receiving a systemic antibiotic prescription upon discharge to an LTCF. We also quantified the association between receiving an antibiotic prescription and 30-day hospital readmission, 30-day emergency department (ED) visit, and Clostridium difficile infection (CDI) on a readmission or ED visit at the index facility within 60 days of discharge.ResultsAmong 6,701 discharges to an LTCF, 22.9% were prescribed antibiotics upon discharge. The most prevalent antibiotic classes prescribed were cephalosporins (20.4%), fluoroquinolones (19.1%), and penicillins (16.7%). The medical records of ~82% of patients included a diagnosis code for a bacterial infection on the index admission. Among patients prescribed an antibiotic upon discharge, the incidence of 30-day hospital readmission to the index facility was 15.9%, the incidence of 30-day ED visit at the index facility was 11.0%, and the incidence of CDI on a readmission or ED visit within 60 days of discharge was 1.6%. Receiving an antibiotic prescription upon discharge was significantly associated with 30-day ED visits (adjusted odds ratio [aOR], 1.2; 95% confidence interval [CI], 1.02–1.5) and with CDI within 60 days (aOR, 1.7; 95% CI, 1.02–2.8) but not with 30-day readmissions (aOR, 1.01; 95% CI, 0.9–1.2).ConclusionsAntibiotics were frequently prescribed upon discharge to LTCFs, which may be associated with increased risk of poor outcomes post discharge. more...

OBJECTIVETo examine self-reported practices and policies to reduce infection and transmission of multidrug-resistant organisms (MDRO) in healthcare settings outside the United States.DESIGNCross-sectional survey.PARTICIPANTSInternational members of the Society for Healthcare Epidemiology of America (SHEA) Research Network.METHODSElectronic survey of infection control and prevention practices, capabilities, and barriers outside the United States and Canada. Participants were stratified according to their country’s economic development status as defined by the World Bank as low-income, lower-middle-income, upper-middle-income, and high-income.RESULTSA total of 76 respondents (33%) of 229 SHEA members outside the United States and Canada completed the survey questionnaire, representing 30 countries. Forty (53%) were high-, 33 (43%) were middle-, and 1 (1%) was a low-income country. Country data were missing for 2 respondents (3%). Of the 76 respondents, 64 (84%) reported having a formal or informal antibiotic stewardship program at their institution. High-income countries were more likely than middle-income countries to have existing MDRO policies (39/64 [61%] vs 25/64 [39%],P=.003) and to place patients with MDRO in contact precautions (40/72 [56%] vs 31/72 [44%],P=.05). Major barriers to preventing MDRO transmission included constrained resources (infrastructure, supplies, and trained staff) and challenges in changing provider behavior.CONCLUSIONSIn this survey, a substantial proportion of institutions reported encountering barriers to implementing key MDRO prevention strategies. Interventions to address capacity building internationally are urgently needed. Data on the infection prevention practices of low income countries are needed.Infect Control Hosp Epidemiol.2016:1–8 more...

Objective.To quantify the association between admission to an intensive care unit (ICU) room most recently occupied by a patient positive for extended-spectrumβ-lactamase (EBSL)-producing gram-negative bacteria and acquisition of infection or colonization with that pathogen.Design.Retrospective cohort study.Setting and Patients.The study included patients admitted to medical and surgical ICUs of an academic medical center between September 1, 2001, and June 30, 2009.Methods.Perianal surveillance cultures were obtained at admission to the ICU, weekly, and at discharge from the ICU. Patients were included if they had culture results that were negative for ESBL-producing gram-negative bacteria at ICU admission and had an ICU length of stay longer than 48 hours. Pulsed-field gel electrophoresis (PFGE) was performed on ESBL-positive isolates from patients who acquired the same bacterial species (eg,Klebsiellaspecies orEscherichia coli) as the previous room occupant.Results.Among 9, 371 eligible admissions (7, 651 unique patients), 267 (3%) involved patients who acquired an ESBL-producing pathogen in the ICU; of these patients, 32 (12%) were hospitalized in a room in which the prior occupant had been positive for ESBL. Logistic regression results suggested that the prior occupant's ESBL status was not significantly associated with acquisition of an ESBL-producing pathogen (adjusted odds ratio, 1.39 [95% confidence interval, 0.94-2.08]) after adjusting for colonization pressure and antibiotic exposure in the ICU. PFGE results suggested that 6 (18%) of 32 patients acquired a bacterial strain that was the same as or closely related to the strain obtained from the prior occupant.Conclusions.These data suggest that environmental contamination may not play a substantial role in the transmission of ESBL-producing pathogens among ICU patients. Intensifying environmental decontamination may be less effective than other interventions in preventing transmission of ESBL-producing pathogens. more...

Risk factors for development of intestinal colonization by imipenem-resistant Pseudomonas aeruginosa (IRPA) may differ between those who acquire the organism via patient-to-patient transmission versus by antibiotic selective pressure. The aim of this study was to quantify potential risk factors for the development of IRPA not due to patient-to-patient transmission. more...

Background.The anterior nares are the most sensitive single site for detecting methicillin-resistantStaphylococcus aureus(MRSA) colonization. Colonization patterns of USA300 MRSA colonization are unknown.Objectives.To assess whether residents of extended care facilities who are colonized with USA300 MRSA have different nares or skin colonization findings, compared with residents who are colonized with non-USA300 MRSA strains.Methods.The study population included residents of 5 extended care units in 3 separate facilities who had a recent history of MRSA colonization. Specimens were obtained weekly for surveillance cultures from the anterior nares, perineum, axilla, and skin breakdown (if present) for 3 weeks. MRSA isolates were categorized as USA300 MRSA or non-USA300 MRSA.Results.Of the 193 residents who tested positive for MRSA, 165 were colonized in the anterior nares, and 119 were colonized on their skin. Eighty-four percent of USA300 MRSA-colonized residents had anterior nares colonization, compared with 86% of residents colonized with non-USA300 MRSA (P= .80). Sixty-six percent of USA300 MRSA–colonized residents were colonized on the skin, compared with 59% of residents colonized with non-USA300 MRSA (P= .30).Conclusions.Colonization patterns of USA300 MRSA and non-USA300 MRSA are similar in residents of extended care facilities. Anterior nares cultures will detect most—but not all—people who are colonized with MRSA, regardless of whether it is USA300 or non-USA300 MRSA. more...

Objective.Recognition of seasonal trends in hospital infections may improve diagnosis, use of empirical therapy, and infection prevention interventions. There are very few data available regarding the seasonal variability of these infections. We quantified the seasonal variation in the incidences of hospital infection caused by common bacterial pathogens and estimated the association between temperature changes and infection rates.Methods.A cohort of all adult patients admitted to the University of Maryland Medical Center during the period from 1998 through 2005 was analyzed. Time-series analyses were used to estimate the association of the number of infections per month caused by Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Staphylococcus aureus, and enterococci with season and temperature, while controlling for long-term trends.Results.There were 218,594 admissions to the index hospital, and analysis of 26,624 unique clinical cultures that grew the organisms of interest identified increases in the mean monthly rates of infection caused by P. aeruginosa (28% of isolates recovered; P < .01), E. cloacae (46%; P < .01), E. coli (12%; P < .01), and A. baumannii (21%; P = .06). For each 10°F increase, we observed a 17% increase in the monthly rates of infection caused by P. aeruginosa (P = .01) and A. baumanii (P = .05).Conclusion.Significantly higher rates of gram-negative infection were observed during the summer months, compared with other seasons. For some pathogens, higher temperatures were associated with higher infection rates, independent of seasonality. These findings have important implications for infection prevention, such as enhanced surveillance during the warmer months, and for choice of empirical antimicrobial therapy among hospitalized adults. Future, quasi-experimental investigations of gram-negative infection prevention initiatives should control for seasonal variation. more...

Background.Severity of illness is an important confounder in outcome studies involving infectious diseases. However, it is unclear whether the time at which severity of illness is measured is important.Methods.We performed a retrospective study of 328 episodes of gram-negative bacteremia in adult patients to assess the impact of the time of measurement of severity of illness on the association between empirical antimicrobial therapy received and in-hospital mortality. Using a modified Acute Physiology Score (APS), severity of illness was measured at 2 time points: (1) hospital admission and (2) 24 hours before the first culture-positive blood sample was collected. Multivariate logistic regression was used to estimate the impact of adjusting for the APS on the relationship between empirical therapy received (ie, the exposure) and in-hospital mortality (ie, the outcome).Results.The mean APS ( ± standard deviation) of patients with bacteremia increased during their hospital stay (from 19.2 ± 11.6 at admission to 24.2 ± 13.6 at the second time point; P < .01). When examining the association between empirical antimicrobial therapy received and in-hospital mortality, and controlling for the APS, there was a trend toward a decreased impact of appropriate therapy received on in-hospital mortality. The unadjusted odds ratio (OR) for the association between appropriate therapy received and in-hospital mortality was 0.83 (95% confidence interval [CI], 0.51-1.34). After controlling for the APS at admission, this association was attenuated (OR, 0.94 [95% CI, 0.57-1.55]), and when a change in the APS was also included in the multivariate logistic regression model, the association was further attenuated (OR, 0.99 [95% CI, 0.58-1.69]).Conclusions.The magnitude of the association between appropriate antimicrobial therapy received and in-hospital mortality among patients with gram-negative bacteremia was sensitive to the timing of adjustment for severity of illness. more...

Background.The occurrence of nosocomial infections due to third-generation cephalosporin–resistant gram-negative bacteria is increasing. Gastrointestinal colonization is an important reservoir for antibiotic-resistant bacteria, and it often precedes clinical infection.Objective.To estimate the prevalence of gastrointestinal colonization with ceftazidime-resistant gram-negative bacteria among intensive care unit (ICU) patients at a university-affiliated tertiary-care hospital during 2 distinct periods and to assess whether, at any time during the index hospitalization, colonized patients had a clinical culture positive for the same organism that was recovered from surveillance culture.Setting.Two ICUs at the University of Maryland Medical Center, a 656-bed tertiary-care hospital located in Baltimore, Maryland. Both ICUs provide care to adult patients.Methods.We performed a cross-sectional study of adult patients admitted to the medical ICU or the surgical ICU from June 14 to July 14, 2003, and from June 14 to July 14, 2006. Perirectal swab samples were obtained for surveillance culture on admission to the intensive care unit, weekly thereafter, and at discharge. Each culture sample was plated onto MacConkey agar supplemented with ceftazidime.Results.In 2003, a total of 33 (18.8%) of 176 patients were colonized with ceftazidime-resistant gram-negative bacilli; in 2006, 60 (31.4%) of 191 patients were (PKlebsiellaisolates (which accounted for 6.4% of isolates in 2003 and for 22.8% in 2006;PP= .28).Conclusion.Our data suggest that gastrointestinal colonization with ceftazidime-resistant gram-negative bacilli is common, that its prevalence is increasing, and that colonization may result in clinical cultures positive for these bacilli. more...

The ability to recover bacteria from frozen culture specimens has important implications. The purpose of this study was to validate the utility of frozen specimens for recovery of several gram-positive and gram-negative bacterial species by culture. Results demonstrate that 98% of 250 bacterial isolates identified on initial culture were subsequently recovered by culture of frozen specimens after a median storage period of 564 days. more...

Objective.To quantify the value of performing active surveillance cultures for detection of methicillin-resistantStaphylococcus aureus(MRSA) on intensive care unit (ICU) discharge.Design.Prospective cohort study.Setting.Medical ICU (MICU) and surgical ICU (SICU) of a tertiary care hospital.Participants.We analyzed data on adult patients who were admitted to the MICU or SICU between January 17, 2001, and December 31, 2004. All participants had a length of ICU stay of at least 48 hours and had surveillance cultures of anterior nares specimens performed on ICU admission and discharge. Patients who had MRSA-positive clinical cultures in the ICU were excluded.Results.Of 2,918 eligible patients, 178 (6%) were colonized with MRSA on ICU admission, and 65 (2%) acquired MRSA in the ICU and were identified by results of discharge surveillance cultures. Patients with MRSA colonization confirmed by results of discharge cultures spent 853 days in non-ICU wards after ICU discharge, which represented 27% of the total number of MRSA colonization-days during hospitalization in non-ICU wards for patients discharged from the ICU.Conclusions.Surveillance cultures of nares specimens collected at ICU discharge identified a large percentage of MRSA-colonized patients who would not have been identified on the basis of results of clinical cultures or admission surveillance cultures alone. Furthermore, these patients were responsible for a large percentage of the total number of MRSA colonization-days during hospitalization in non-ICU wards for patients discharged from the ICU. more...

We assessed methicillin-resistantStaphylococcus aureus(MRSA) infection and colonization in hospitalized prisoners. Of 434 admission surveillance cultures, 58 (13%) were positive for MRSA. The sensitivity of admission surveillance cultures of samples from the anterior nares was 72% and increased to 84% when the calculation included cultures of wound samples. Hospitalized prisoners are at high risk for MRSA infection and colonization, and surveillance should include cultures of nares and wound samples. more...

Background.Institutions such as hospitals, prisons, and long-term care facilities have been identified as focal points for the transmission of emerging infections. Cost-effective control of these infections in large populations requires the identification of optimal subpopulations for targeted infection control interventions. Our objective was to quantify and compare the relative impact that individual institutions or subpopulations have on wider population-level outbreaks of emerging pathogens.Design.We describe a simple mathematical model to compute the epidemiologic weight (EW) of an institution or subpopulation. The EW represents the rate at which newly infectious individuals exit the institution under consideration.Setting.A hypothetical academic tertiary-care hospital (700 beds, 5-day length of stay [LOS]) and prison (3098 inmates, 27-day LOS).Patients.Individuals entering a hospital in-patient prison ward and nonprisoners entering both medical and surgical intensive-care units and those admitted to the general medical and surgical wards.Results.The recent example of the community-acquired methicillin-resistantStaphylococcus aureusepidemic is used to illustrate the EW calculation. Hospitals and prisons, which often have vastly dissimilar populations sizes and LOSs and might have differing transmission rates, can have comparable EWs and thus contribute equally to an epidemic in the community.Conclusions.This method highlights the importance of measuring entrance and exit colonization prevalences for the optimal targeting of prevention measures. The EW not only identified superspreader institutions but also ranks them, enabling public health workers to optimize the allocation of resources to places where they are likely to be of most benefit. more...

The medical ICU implemented aggressive control measures following an outbreak of multidrug-resistant, clonalAcinetobacter baumannii.Multivariable regression analyses comparing acquisition (6 months preceding to 6 months during or following the outbreak) revealed decreased VRE and MRSA acquisition. Aggressive control measures can reduce VRE, and perhaps MRSA, transmission. more...