Association between hospital-acquired infections and patients' transfers

States of Resistance: nosocomial and environmental approaches to antimicrobial resistance in Lebanon

Drawing on institutional historical records, interviews and student theses, this article charts the intersection of hospital acquired illness, the emergence of antimicrobial resistance (AMR), environments of armed conflict, and larger questions of social governance in the specific case of the American University of Beirut Medical Center (AUBMC) in Lebanon. Taking a methodological cue from approaches in contemporary scientific work that understand non-clinical settings as a fundamental aspect of the history and development of AMR, we treat the hospital as not just nested in a set of social and environmental contexts, but frequently housing within itself elements of social and environmental history. AMR in Lebanon differs in important ways from the settings in which global protocols for infection control or rubrics for risk factor identification for resistant nosocomial outbreaks were originally generated. While such differences are all too often depicted as failures of low and middle-income countries (LMIC) to maintain universal standards, the historical question before us is quite the reverse: how have the putatively universal rubrics of AMR and hospital infection control failed to take account of social and environmental conditions that clearly matter deeply in the evolution and spread of resistance? Focusing on conditions of war as an organized chaos in which social, environmental and clinical factors shift dramatically, on the social and political topography of patient transfer, and on a missing "meso" level of AMR surveillance between the local and global settings, we show how a multisectoral One Health approach to AMR could be enriched by an answering multisectoral methodology in history, particularly one that unsettles a canonical focus on the story of AMR in the Euro-American context.

Association between intrahospital transfer and hospital-acquired infection in the elderly: a retrospective case-control study in a UK hospital network

Background

Intrahospital transfers have become more common as hospital staff balance patient needs with bed availability. However, this may leave patients more vulnerable to potential pathogen transmission routes via increased exposure to contaminated surfaces and contacts with individuals.

Objective

This study aimed to quantify the association between the number of intrahospital transfers undergone during a hospital spell and the development of a hospital-acquired infection (HAI).

Methods

A retrospective case–control study was conducted using data extracted from electronic health records and microbiology cultures of non-elective, medical admissions to a large urban hospital network which consists of three hospital sites between 2015 and 2018 (n=24 240). As elderly patients comprise a large proportion of hospital users and are a high-risk population for HAIs, the analysis focused on those aged 65 years or over. Logistic regression was conducted to obtain the OR for developing an HAI as a function of intrahospital transfers until onset of HAI for cases, or hospital discharge for controls, while controlling for age, gender, time at risk, Elixhauser comorbidities, hospital site of admission, specialty of the dominant healthcare professional providing care, intensive care admission, total number of procedures and discharge destination.

Results

Of the 24 240 spells, 2877 cases were included in the analysis. 72.2% of spells contained at least one intrahospital transfer. On multivariable analysis, each additional intrahospital transfer increased the odds of acquiring an HAI by 9% (OR=1.09; 95% CI 1.05 to 1.13).

Conclusion

Intrahospital transfers are associated with increased odds of developing an HAI. Strategies for minimising intrahospital transfers should be considered, and further research is needed to identify unnecessary transfers. Their reduction may diminish spread of contagious pathogens in the hospital environment.

Transfer status in geriatric hip fracture surgery - An independent risk factor associated with 30-day mortality, re-operations and complications

BACKGROUND

A significant proportion of patients undergoing hip fracture surgery are transferred from other locations. With no current orthopedic literature present, we sought to study the impact of transfer location on 30-day outcomes following geriatric hip fracture surgery.

MATERIALS & METHODS

The 2015-2016 ACS-NSQIP database was queried using CPT codes to retrieve records of geriatric patients undergoing hip fracture surgery (total hip arthroplasty/THA, hemiarthroplasty/HA and open reduction internal fixation/ORIF). Transfer status was defined into four groups - 1) No transfer (admitted from home), 2) From acute care hospital, 3) From nursing home/chronic care facility and 4) From outside emergency department (ED). Patients with missing data were excluded. A total of 31,218 patients were included in the final cohort.

RESULTS

Out of 31,218 patients - 23,659 (75.8%) were admitted from home, 1574 (5.0%) from acute care hospitals, 3299 (10.6%) from nursing home/chronic care facilities and 2686 (8.6%) from outside EDs. Following adjusted analysis, transfer from nursing home vs. home was associated with higher odds of 30-day mortality (OR 1.57 [95% 1.36-1.80]; p < 0.001), 30-day re-operations (OR 1.36 [95% CI 1.10-1.68]; p = 0.005), septic shock (OR 1.58 [95% CI 1.07-2.32]; p = 0.021), sepsis (OR 1.45 [95% CI 1.05-1.99]; p = 0.023) and urinary tract infection (OR 1.21 [95% CI 1.02-1.42]; p = 0.025). Additionally, transfer from outside ED vs. home was also associated with higher odds of 30-day mortality (OR 1.26 [95% CI 1.06-1.50]; p = 0.010).Transfer from any location (acute care hospital, nursing home and outside ED) was significantly associated with higher odds of non-home discharge (p < 0.001).

CONCLUSION

Transfer status is an important risk factor associated with 30-day mortality and morbidity in geriatric patients undergoing hip fracture surgery. The findings stress the need for recognition of these patients as being a high-risk group to allow enhanced medical optimization in an attempt to minimize the risk of poor outcomes.

Hospital-acquired influenza in an Australian tertiary Centre 2017: a surveillance based study

Background

In 2017, Australia experienced its highest levels of influenza virus activity since the 2009 pandemic. This allowed detailed comparison of the characteristics of patients with community and hospital-acquired influenza, and infection control factors that contributed to influenza spread.

Methods

A surveillance based study was conducted on hospitalised patients with laboratory-confirmed influenza at the Canberra Hospital during April–October 2017. Differences between the hospital-acquired and community-acquired patient characteristics and outcomes were assessed by univariate analysis. Epidemiologic curves were developed and cluster distribution within the hospital was determined.

Results

Two hundred and ninety-two patients were included in the study. Twenty-eight (9.6%) acquired influenza in hospital, representing a higher proportion than any of the previous 5 years (range 0.9–5.8%). These patients were more likely to have influenza A (p = 0.021), had higher rates of diabetes (p = 0.015), malignancy (p = 0.046) and chronic liver disease (p = 0.043). Patients acquiring influenza in hospital met clinical criteria for influenza like illness in 25% of cases, compared with 64.4% for community-acquired cases (p < 0.001). Hospital-acquired influenza cases occurred in two distinct clusters. Patients were moved an average of 5 times after diagnosis. Mean length of stay following diagnosis was 13 days compared to 5 days for community-acquired cases (p < 0.001). Of the patients with hospital-acquired influenza, 22 were in shared rooms during their incubation period and 9 were not isolated in single rooms following diagnosis. Treatment was initiated within the recommended 48 h period following symptom onset for 62.5% of hospital-acquired cases compared with 39.8% of community-acquired cases (p = 0.033).

Conclusions

Our results show that clinical presentation differed between patients with hospital-acquired influenza compared with those who acquired influenza in the community. Cases occurred in two clusters suggesting intra-hospital transmission rather than random importation from the community, highlighting the importance of infection control measures to limit influenza spread. Patients with hospital-acquired influenza may present without classical features of an influenza-like illness and this should promote earlier diagnostic testing and isolation to limit spread. Movement of patients after diagnosis is likely to facilitate spread within the hospital.

Intensive Patient Treatment

Intensive care units (ICUs) are treating hospital’s poorest patients that need medical assistance during the most extreme period of their life. Intensive patients are treated with extensive invasive procedures, which may cause a risk of hospital infections in 10–30% of the cases. More than half of these infections can be prevented. The patients are often admitted directly from outside the hospital or from abroad with trauma after accidents, serious heart and lung conditions, sepsis and other life-threatening diseases. Infection or carrier state of microbes is often unknown on arrival and poses a risk of transmission to other patients, personnel and the environment. Patients that are transferred between different healthcare levels and institutions with unknown infection may be a particular risk for other patients. In spite of the serious state of the patients, many ICUs have few resources and are overcrowded and understaffed, with a lack of competent personnel. ICU should have a large enough area and be designed, furnished and staffed for a good, safe and effective infection control. The following chapter is focused on practical measures to reduce the incidence of infections among ICU patients.

Tracing and Preventing Infections

A total of 10–20% of somatic patients experience hospital infections during/after hospitalization. Pneumonia, sepsis, surgical site infections and urinary tract infections are most often associated with patient-related use of medical devices for approximately 65% of cases, while nontechnical equipment may be linked to 35% of cases. It is resource-intensive to detect the cause of infection outbreaks and even more expensive not to take action. Unexplained causes of outbreaks may lead to uncertainty and reduced activity at the hospital. To trace and prevent hospital outbreaks, joint efforts from hospital management, microbiology and infection control are needed. This chapter is focused on practical measures to trace and prevent hospital outbreaks.

Venous Thromboembolism Rates in Transferred Patients: A Cross-Sectional Study

BACKGROUND

Patients undergoing a transfer during a hospitalization may be more likely to be diagnosed with a venous thromboembolism (VTE) than patients who are not transferred.

OBJECTIVE

To determine whether transferred patients have an increased prevalence of VTE diagnosis.

DESIGN

This was a cross-sectional study comparing VTE diagnosis rates between transferred patients and non-transferred patients. For the years 2012-2014, the University HealthSystem Consortium database of multiple community and academic medical centers throughout the United States was parsed using ICD-9 VTE diagnosis codes and patient's point of origin.

PATIENTS

Patients were included in the analysis as transferred patients if their point of origin was a skilled nursing facility, another acute care facility or another facility. Non-transferred patients were those whose point of origin was a clinic or those with a non-facility point of origin.

MAIN MEASURES

The primary comparison of VTE prevalence during hospitalization between transferred and non-transferred patients in the years 2012-2014. Subgroup analysis looked at level I trauma status and case mix index (CMI) to determine whether these had an effect on VTE prevalence.

KEY RESULTS

From 2012 to 2014, a total of 225 unique hospitals and 12,036,029 patients were analyzed, and the prevalence of VTE in transferred patients and non-transferred patients was 3.43% and 1.91% (RR 1.80; 95% CI 1.78-1.81; P <0.001), respectively. VTE prevalence in transferred versus non-transferred patients at level I trauma centers was 3.42% versus 1.88% (RR = 1.82; 95% CI 1.80-1.85; P <0.001). The 3-year average CMI of transferred versus non-transferred patients was 3.53 versus 2.26 (P < 0.001).

CONCLUSIONS

Transferred patients have a higher prevalence of VTE than non-transferred patients, regardless of level I trauma designation. Higher VTE rates in transferred versus non-transferred patients was minimally correlated with CMI.

A hospital-based matched case-control study to identify risk factors for clinical infection with OXA-48-producing Klebsiella pneumoniae in rectal carriers

Asymptomatic colonisation of the gastrointestinal tract by carbapenemase-producing Enterobacteriaceae is an important reservoir for transmission, which may precede infection. This retrospective observational case-control study was designed to identify risk factors for developing clinical infection with OXA-48-producing Klebsiella pneumoniae in rectal carriers during hospitalisation. Case patients (n = 76) had carbapenemase-producing K. pneumoniae (CPKP) infection and positive rectal culture for CPKP. Control patients (n = 174) were those with rectal colonisation with CPKP but without CPKP infection. Multivariate analysis identified the presence of a central venous catheter (OR 4·38; 95% CI 2·27-8·42; P = 0·008), the number of transfers between hospital units (OR 1·27; 95% CI (1·06-1·52); P < 0·001) and time at risk (OR 1·02 95% CI 1·01-1·03; P = 0·01) as independent risk factors for CPKP infection in rectal carriers. Awareness of these risk factors may help to identify patients at higher risk of developing CPKP infection.

Medical Complications of Intra-Hospital Patient Transports: Implications for Architectural Design and Research

Literature on healthcare architecture and evidence-based design has rarely considered explicitly that patient outcomes may be worsened by intra-hospital transport (IHT), which is defined as transport of patients within the hospital. The article focuses on the effects of IHTs on patient complications and outcomes, and the implications of such impacts for designing safer, better hospitals. A review of 22 scientific studies indicates that IHTs are subject to a wide range of complications, many of which occur frequently and have distinctly detrimental effects on patient stability and outcomes. The research suggests that higher patient acuity and longer transport durations are associated with more frequent and serious IHT-related complications and outcome effects. It appears no rigorous research has compared different hospital designs and layouts with respect to having possibly differential effects on transport-related complications and worsened outcomes. Nonetheless, certain design implications can be extracted from the existing research literature, including the importance of minimizing transport delays due to restricted space and congestion, and creating layouts that shorten IHT times for high-acuity patients. Limited evidence raises the possibility that elevator-dependent vertical building layouts may increase susceptibility to transport delays that worsen complications. The strong evidence indicating that IHTs trigger complications and worsen outcomes suggests a powerful justification for adopting acuity-adaptable rooms and care models that substantially reduce transports. A program of studies is outlined to address gaps in knowledge.

Not just a matter of size: a hospital-level risk factor analysis of MRSA bacteraemia in Scotland

Background

Worldwide, there is a wealth of literature examining patient-level risk factors for methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia. At the hospital-level it is generally accepted that MRSA bacteraemia is more common in larger hospitals. In Scotland, size does not fully explain all the observed variation among hospitals. The aim of this study was to identify risk factors for the presence and rate of MRSA bacteraemia cases in Scottish mainland hospitals. Specific hypotheses regarding hospital size, type and connectivity were examined.

Methods

Data from 198 mainland Scottish hospitals (defined as having at least one inpatient per year) were analysed for financial year 2007-08 using logistic regression (Model 1: presence/absence of MRSA bacteraemia) and Poisson regression (Model 2: rate of MRSA bacteraemia). The significance of risk factors representing various measures of hospital size, type and connectivity were investigated.

Results

In Scotland, size was not the only significant risk factor identified for the presence and rate of MRSA bacteraemia. The probability of a hospital having at least one case of MRSA bacteraemia increased with hospital size only if the hospital exceeded a certain level of connectivity. Higher levels of MRSA bacteraemia were associated with the large, highly connected teaching hospitals with high ratios of patients to domestic staff.

Conclusions

A hospital’s level of connectedness within a network may be a better measure of a hospital’s risk of MRSA bacteraemia than size. This result could be used to identify high risk hospitals which would benefit from intensified infection control measures.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1563-6) contains supplementary material, which is available to authorized users.

Efficient national surveillance for health-care-associated infections

Background

Detecting novel healthcare-associated infections (HCAI) as early as possible is an important public health priority. However, there is currently no evidence base to guide the design of efficient and reliable surveillance systems. Here we address this issue in the context of a novel pathogen spreading primarily between hospitals through the movement of patients.

Methods

Using a mathematical modelling approach we compare the current surveillance system for a HCAI that spreads primarily between hospitals due to patient movements as it is implemented in Scotland with a gold standard to determine if the current system is maximally efficient or whether it would be beneficial to alter the number and choice of hospitals in which to concentrate surveillance effort.

Results

We validated our model by demonstrating that it accurately predicts the risk of meticillin-resistant Staphylococcus aureus bacteraemia cases in Scotland.

Using the 29 (out of 182) sentinel hospitals that currently contribute most of the national surveillance effort results in an average detection time of 117 days. A reduction in detection time to 87 days is possible by optimal selection of 29 hospitals. Alternatively, the same detection time (117 days) can be achieved using just 22 optimally selected hospitals. Increasing the number of sentinel hospitals to 38 (teaching and general hospitals) reduces detection time by 43 days; however decreasing the number to seven sentinel hospitals (teaching hospitals) increases detection time substantially to 268 days.

Conclusions

Our results show that the current surveillance system as it is used in Scotland is not optimal in detecting novel pathogens when compared to a gold standard. However, efficiency gains are possible by better choice of sentinel hospitals, or by increasing the number of hospitals involved in surveillance. Similar studies could be used elsewhere to inform the design and implementation of efficient national, hospital-based surveillance systems that achieve rapid detection of novel HCAIs for minimal effort.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2172-9) contains supplementary material, which is available to authorized users.

Outbreak of Carbapenem-Resistant Klebsiella pneumoniae in Puerto Rico Associated with a Novel Carbapenemase Variant

Background.

Carbapenem-resistantKlebsiella pneumoniae(CRKP) is resistant to almost all antimicrobial agents, and CRKP infections are associated with substantial morbidity and mortality.

Objective.

To describe an outbreak of CRKP in Puerto Rico, determine risk factors for CRKP acquisition, and detail the successful measures taken to control the outbreak.

Design.

Two case-control studies.

Setting.

A 328-bed tertiary care teaching hospital.

Patients.

Twenty-six CRKP case patients identified during the outbreak period of February through September 2008, 26 randomly selected uninfected control patients, and 26 randomly selected control patients with carbapenem-susceptibleK. pneumoniae(CSKP) hospitalized during the same period.

Methods.

We performed active case finding, including retrospective review of the hospital's microbiology database and prospective perirectal surveillance culture sampling in high-risk units. Case patients were compared with each control group while controlling for time at risk. We sequenced theblaKPCgene with polymerase chain reaction for 7 outbreak isolates and subtyped these isolates with pulsed-field gel electrophoresis.

Results.

In matched, multivariable analysis, the presence of wounds (hazard ratio, 19.0 [95% confidence interval {CI}, 2.5-142.0]) was associated with CRKP compared with noK. pneumoniae.Transfer between units (adjusted odds ratio [OR], 7.5 [95% CI, 1.8-31.1]), surgery (adjusted OR, 4.0 [95% CI, 1.0-15.7]), and wounds (adjusted OR, 4.9 [95% CI, 1.1-21.8]) were independent risk factors for CRKP compared to CSKP. A novelK. pneumoniaecarbapenemase variant (KPC-8) was present in 5 isolates. Implementation of active surveillance for CRKP colonization and cohorting of CRKP patients rapidly controlled the outbreak.

Conclusions.

Enhanced surveillance for CRKP colonization and intensified infection control measures that include limiting the physical distribution of patients can reduce CRKP transmission during an outbreak.

Efficient surveillance for healthcare-associated infections spreading between hospitals

Early detection of new or novel variants of nosocomial pathogens is a public health priority. We show that, for healthcare-associated infections that spread between hospitals as a result of patient movements, it is possible to design an effective surveillance system based on a relatively small number of sentinel hospitals. We apply recently developed mathematical models to patient admission data from the national healthcare systems of England and The Netherlands. Relatively short detection times are achieved once 10-20% hospitals are recruited as sentinels and only modest reductions are seen as more hospitals are recruited thereafter. Using a heuristic optimization approach to sentinel selection, the same expected time to detection can be achieved by recruiting approximately half as many hospitals. Our study provides a robust evidence base to underpin the design of an efficient sentinel hospital surveillance system for novel nosocomial pathogens, delivering early detection times for reduced expenditure and effort.

Infection prevention in a connected world: the case for a regional approach

Results from microbiological and epidemiological investigations, as well as mathematical modelling, show that the transmission dynamics of nosocomial pathogens, especially of multiple antibiotic-resistant bacteria, is not exclusively amenable to single-hospital infection prevention measures. Crucially, their extent of spread depends on the structure of an underlying "healthcare network", as determined by inter-institutional referrals of patients. The current trend towards centralized healthcare systems favours the spread of hospital-associated pathogens, and must be addressed by coordinated regional or national approaches to infection prevention in order to maintain patient safety. Here we review recent advances that support this hypothesis, and propose a "next-generation" network-approach to hospital infection prevention and control.

Communication interventions to improve adherence to infection control precautions: a randomised crossover trial

Background

Ineffective communication of infection control requirements during transitions of care is a potential cause of non-compliance with infection control precautions by healthcare personnel. In this study, interventions to enhance communication during inpatient transfers between wards and radiology were implemented, in the attempt to improve adherence to precautions during transfers.

Methods

Two interventions were implemented, comprising (i) a pre-transfer checklist used by radiology porters to confirm a patient’s infectious status; (ii) a coloured cue to highlight written infectious status information in the transfer form. The effectiveness of the interventions in promoting adherence to standard precautions by radiology porters when transporting infectious patients was evaluated using a randomised crossover trial at a teaching hospital in Australia.

Results

300 transfers were observed over a period of 4 months. Compliance with infection control precautions in the intervention groups was significantly improved relative to the control group (p < 0.01). Adherence rate in the control group was 38%. Applying the coloured cue resulted in a compliance rate of 73%. The pre-transfer checklist intervention achieved a comparable compliance rate of 71%. When both interventions were applied, a compliance rate of 74% was attained. Acceptability of the coloured cue was high, but adherence to the checklist was low (40%).

Conclusions

Simple measures to enhance communication through the provision of a checklist and the use a coloured cue brought about significant improvement in compliance with infection control precautions by transport personnel during inpatient transfers. The study underscores the importance of effective communication in ensuring compliance with infection control precautions during transitions of care.

Hospital networks and the dispersal of hospital-acquired pathogens by patient transfer

Hospital-acquired infections (HAI) are often seen as preventable incidents that result from unsafe practices or poor hospital hygiene. This however ignores the fact that transmissibility is not only a property of the causative organisms but also of the hosts who can translocate bacteria when moving between hospitals. In an epidemiological sense, hospitals become connected through the patients they share. We here postulate that the degree of hospital connectedness crucially influences the rates of infections caused by hospital-acquired bacteria. To test this hypothesis, we mapped the movement of patients based on the UK-NHS Hospital Episode Statistics and observed that the proportion of patients admitted to a hospital after a recent episode in another hospital correlates with the hospital-specific incidence rate of MRSA bacteraemia as recorded by mandatory reporting. We observed a positive correlation between hospital connectedness and MRSA bacteraemia incidence rate that is significant for all financial years since 2001 except for 2008-09. All years combined, this correlation is positive and significantly different from zero (partial correlation coefficient r = 0.33 (0.28 to 0.38)). When comparing the referral pattern for English hospitals with referral patterns observed in the Netherlands, we predict that English hospitals more likely see a swifter and more sustained spread of HAIs. Our results indicate that hospitals cannot be viewed as individual units but rather should be viewed as connected elements of larger modular networks. Our findings stress the importance of cooperative effects that will have a bearing on the planning of health care systems, patient management and hospital infection control.

Effect of patterns of transferring patients among healthcare institutions on rates of nosocomial methicillin-resistant Staphylococcus aureus transmission: a Monte Carlo simulation

OBJECTIVE

To determine the effect of the rate and pattern of patient transfers among institutions within a single metropolitan area on the rates of methicillin-resistant Staphylococcus aureus (MRSA) transmission among patients in hospitals and nursing homes.

METHODS

A stochastic, discrete-time, Monte Carlo simulation was used to model the rate and spread of MRSA transmission among patients in medical institutions within a single metropolitan area. Admission, discharges, transfers, and nosocomial transmission were simulated with respect to different interinstitutional transfer strategies and various situational scenarios, such as outlier institutions with high transmission rates.

RESULTS

The simulation results indicated that transfer patterns and transfer rate changes do not affect nosocomial MRSA transmission. Outlier institutions with high transmission rates affect the system wide rate of nosocomial infections differently, depending on institution type.

CONCLUSION

It is worth effort to understanding disease-transmission dynamics and interinstitutional transfer patterns for the management of recently introduced diseases or strains. Once endemic in a system, other strategies for transmission control need to be implemented.

Bacterial pathogens in ambulances: results of unannounced sample collection

The concern that the health care environment may harbor a substantial reservoir of infectious agents has been vigorously examined by microbiology and infectious disease experts. Although universal precautions and disposable equipment reduces risks to patients and providers, the ambulance remains vulnerable to bacterial contamination from biological secretions. Additionally, the nature of emergency medical services creates pressures on prehospital care providers.

OBJECTIVE

We hypothesized that a discrepancy exists between the expectation of disinfection of reusable equipment in emergency medical services (EMS) and the cleaning that actually occurs.

METHODS

We chose five areas within the ambulance for specimen collection for their reasoned propensity to yield a large spectrum of bacteria. Four first-due ambulances were selected for culturing. The crews did not have advance knowledge of the study or sample collection. Specific identifications with antibiotic susceptibility were completed, identifying three multidrug resistant organisms.

RESULTS

Specimens from all four ambulances grew moderate-to-large quantities of environmental and skin flora. Newer, automated microbiological techniques and concerns regarding multiple-drug-resistant organism prevalence as well as the potential for biological warfare make complete identification more important.

CONCLUSIONS

This study examined the bacterial pathogens found in EMS vehicles. Four of the seven species isolated were substantial nosocomial pathogens, and three of these four possess formidable antibiotic resistance patterns. All of the organisms detected are susceptible to the disinfectant agents currently in common use by EMS agencies.

The effects of hospitalization on multiple units

Patients are often cared for on multiple units during the course of a hospitalization. This study used general linear modeling and logistic regression analyses to demonstrate the effect of hospitalization on multiple units upon selected nursing treatments, resource use, and clinical outcomes. Primary medical diagnosis, comorbid medical conditions, and severity of illness were controlled for in the analyses. A significant association was found between hospitalizations on multiple units and selected nursing treatments, resource use, and all clinical outcomes except for mortality. Nurses play a central role in coordinating the care that patients receive across inpatient units and are positioned to develop and implement strategies to mediate the negative impacts associated with patients moving across multiple units.

Relationship between immunosuppression and intensive care unit-acquired multidrug-resistant bacteria: a case-control study

OBJECTIVE

To determine the relationship between immunosuppression and intensive care unit (ICU)-acquired multidrug-resistant (MDR) bacteria.

DESIGN

Retrospective case-control study based on prospectively collected data.

SETTING

A 30-bed medical and surgical ICU.

PATIENTS

All patients hospitalized >48 hrs in the ICU were eligible during a 2-yr period.

INTERVENTIONS

Immunosuppression was defined as active solid or hematologic malignancy, leucopenia, or chronic immunosuppressive treatment. MDR bacteria were defined as methicillin-resistant Staphylococcus aureus, ceftazidime- or imipenem-resistant Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia, and extending spectrum beta-lactamase producing Gram-negative bacilli. MDR bacteria screening (nasal, anal, and axilla swabs and tracheal aspirate in intubated patients) was performed at ICU admission and weekly. Only MDR bacteria isolated >48 hrs after ICU admission were taken into account; duplicates were excluded. Isolation measures were applied in all patients at ICU admission, in patients with MDR bacteria, and in patients with immunosuppression. Immunosuppressed patients (cases) were matched (1:1) with immunocompetent patients (controls) according to all the following criteria: age +/-5 yrs, Simplified Acute Physiology Score II +/-5, duration of ICU stay +/-3 days, and category of admission (medical/surgical). Risk factors for ICU-acquired MDR bacteria were determined using univariate and multivariate analyses.

MEASUREMENTS AND MAIN RESULTS

Of 1,065 eligible patients, nine patients were excluded for absence of MDR bacteria screening at ICU admission. One hundred thirty-three (12%) patients were immunosuppressed, and 128 (96%) of them were successfully matched. Mean time between ICU admission and first ICU-acquired MDR bacteria was 12 +/- 9 days. Incidence of MDR bacteria was significantly higher in cases than in controls (22 vs. 12 MDR bacteria/1000 ICU days, p = .004). However, immunosuppression was not independently associated with ICU-acquired MDR bacteria.Multivariate analysis identified prior antibiotic treatment and antibiotic treatment in the ICU as risk factors for ICU-acquired MDR bacteria (odds ratio [95% confidence interval] = 1.9 [1-3.6], p = .003; 11 [1.4-83], p = .02; respectively).

CONCLUSIONS

Immunosuppression is not independently associated with ICU-acquired MDR bacteria. However, infection control measures used in our ICU may have influenced this result.

Impact of Routine Intensive Care Unit Surveillance Cultures and Resultant Barrier Precautions on Hospital‐Wide Methicillin‐ResistantStaphylococcus aureusBacteremia

BACKGROUND

Serial interventions are often used to reduce the risk of health care-associated methicillin-resistant Staphylococcus aureus (MRSA) infections. To our knowledge, the relative impact of these interventions has not previously been ascertained.

METHODS

We conducted a retrospective study of 4 major infection control interventions using an interrupted time series design to evaluate their impact on MRSA bacteremia in an 800-bed hospital with 8 intensive care units (ICUs). Interventions were introduced 1 at a time during a 9-year period and involved the promotion of compliance with maximal sterile barrier precautions during central venous catheter placement, the institution of alcohol-based hand rubs for hand disinfection, the introduction of a hand hygiene campaign, and the institution of routine nares surveillance cultures for MRSA in all ICUs for patients on ICU admission and weekly thereafter while in the ICU. Positive cultures resulted in the initiation of contact isolation precautions. Using segmented regression analyses, we evaluated changes in monthly incidence and prevalence of MRSA bacteremia from their predicted values. Methicillin-susceptible Staphylococcus aureus bacteremia was monitored as a control.

RESULTS

Routine surveillance cultures and subsequent contact isolation precautions resulted in substantial reductions in MRSA bacteremia in both ICUs and non-ICUs. In 16 months, the incidence density of MRSA bacteremia decreased by 75% in ICUs (P=.007) and by 40% in non-ICUs (P=.008), leading to a 67% hospital-wide reduction in the incidence density of MRSA bacteremia (P=.002). Methicillin-susceptible S. aureus bacteremia rates remained stable during this time. The other interventions were not associated with a statistically significant change in MRSA bacteremia.

CONCLUSIONS

Routine surveillance for MRSA in ICUs allowed earlier initiation of contact isolation precautions and was associated with large and statistically significant reductions in the incidence of MRSA bacteremia in the ICUs and hospital wide. In contrast, no similar decrease was attributable to the other infection control interventions.

Enhanced surveillance of meticillin-resistant Staphylococcus aureus bacteraemia in a London teaching hospital

In 2001, the UK Department of Health introduced mandatory surveillance of meticillin-resistant Staphylococcus aureus (MRSA) bacteraemias (blood-culture-positive episodes) in English hospitals. We performed enhanced surveillance in their hospital between April 2001 and March 2003 to determine the epidemiology of MRSA bacteraemia across different specialities. There were 267 MRSA-blood-culture-positive episodes, giving a rate of 0.37 per 1000 occupied bed-days (OBD). Thirty-three (12.4%) episodes were false positives due to contaminants and 15 (5.6%) originated in the community or at another institution. Thirty-one (11.6%) episodes were in outpatients or occurred after recent discharge and were designated 'hospital associated'. The remaining 188 cases were clinically significant hospital-acquired episodes in inpatients, with a rate of 0.26 per 1000 OBDs. The highest rates were in the intensive therapy unit (ITU; 2.74 per 1000 OBDs) and the high-dependency unit (HDU; 1.68 per 1000 OBDs). Fifty-five non-ITU, non-HDU episodes occurred in patients who had been discharged from ITU or HDU prior to the development of bacteraemia but during the same admission. The number of MRSA bacteraemias related to ITU/HDU suggests that these wards may be hubs of MRSA infection. Haematology, oncology and renal (HOR) patients had the greatest number of hospital-associated episodes. The most common source of MRSA bacteraemia was a vascular access device (VAD) (108 episodes, 57%, 64% of which were central lines). The high bacteraemia rates in ITU, HDU and HOR patients were associated with high usage of VADs. The majority of episodes occurred in patients who were newly colonized with MRSA after admission. Thus, in this hospital, VADs and stays in ITU or HDU are important risk factors for bacteraemia, and VAD care and prevention of cross-infection are priorities for intervention. We recommend that the mandatory national surveillance scheme should collect additional data on MRSA bacteraemia to provide information for a national strategy for MRSA control and to allow appropriate comparison between institutions.