An epidemiological study assessing the relative importance of airborne and direct contact transmission of microorganisms in a medical intensive care unit

Influence of making beds on loads of airborne and surface-associated drug-resistant bacteria in patient rooms

INTRODUCTION

Limited information is available on the kinetics of airborne multidrug-resistant bacteria after making of patient beds. Previous experience of bed making on MRSA-loads was re-evaluated with a substantial sample size and, for the first time, simultaneous examination for the environmental load of multidrug-resistant Gram-negative bacteria (MDRGN).

METHODS

Airborne pathogen measurement was carried out in 26 rooms with MRSA patients and 25 rooms with MDRGN patients before (-1 min) and after (1 min, 15 min, 60 min) bed making at 0 m and 3 m distance. Surface sampling was performed from the patients' surroundings. Factors of potential influence were recorded.

RESULTS

Gram-positive non-pathogenic species dominated the air samples, while Gram-negative organisms constituted only 1.4%. Bed making shifted the proportions towards coagulase-negative staphylococci and S. aureus. A transient increase in MRSA in the room air was detected in most samples 1 minute and 15 minutes after bed making, MDRGN were detected in the air of two patient rooms. In the surface samples, MRSA but not MDRGN were regularly isolated from the patient environment. A correlation between the airborne and surface pathogen loads after bed making was demonstrated.

CONCLUSIONS

The study results indicate the importance of wearing a face mask in combination with cautious handling techniques when making beds of patients carrying multidrug-resistant bacteria. If the carrier status of a patient is unknown, consideration should be given to protection measures during and shortly after bed making for staff and for other patients also present. Surface disinfection should be started not earlier than 30 minutes after the making of the bed.

Supplementing hand washing with proper use of alcoholic hand rub in a special neonatal care unit in a large academic public health institute at Jabalpur, Madhya Pradesh, India

Objective

The purpose was to increase use of alcoholic hand rub (AHR) in specialised newborn care unit (SNCU) to improve hand hygiene in order to reduce neonatal sepsis and mortality at Netaji Subhash Chandra Bose Medical College and Hospital, Jabalpur.

Design

A prospective interventional and observational study.

Methodology

We formed a quality improvement (QI) team in our SNCU consisting of doctors, nurses, auxiliary staff and parents (a floating member) to improve proper use of AHR. To identify the barriers to the problem, we used fishbone analysis tool. The barriers which were not allowing the health providers to use AHR properly identified were amount of AHR in millilitres to be used per day per baby, how much and when the amount of AHR to be indented from the main store and what is the proper site to place the bottle. We used plan–do–study–act cycles to test and adapt solutions to these problems. Within 5–6 weeks of starting our project, AHR use increased from 44 mL to 92 mL per baby per day and this is sustained around 100 mL per baby per day for over 2 years now.

Results

Significant decrease in neonatal mortality was observed (reduced from median of 41.0 between August 2016 and April 2018 to 24.0 between May 2018 and December 2019). The neonates discharged alive improved from 41.2 to 52.3 as a median percentage value. The percentage of babies who were referred out and went Left Against Medical Advice (LAMA) deceased too.

Conclusion

Multiple factors can lead to neonatal deaths, but the important factors are always contextual to facilities. QI methodology provides health workers with the skills to identify the major factors contributing to mortality and develop strategies to deal with them. Improving processes of care can lead to improved hand hygiene and saves lives.

Hand hygiene during facility-based childbirth in Cambodia: a theory-driven, mixed-methods observational study

Background

Despite current efforts to improve hand hygiene in health care facilities, compliance among birth attendants remains low. Current improvement strategies are inadequate, largely focusing on a limited set of known behavioural determinants or addressing hand hygiene as part of a generalized set of hygiene behaviours. To inform the design of a facility –based hand hygiene behaviour change intervention in Kampong Chhnang, Cambodia, a theory-driven formative research study was conducted to investigate the context specific behaviours and determinants of handwashing during labour and delivery among birth attendants.

Methods

This formative mixed-methods research followed a sequential explanatory design and was conducted across eight healthcare facilities. The hand hygiene practices of all birth attendants present during the labour and delivery of 45 women were directly observed and compliance with hand hygiene protocols assessed in analysis. Semi-structured, interactive interviews were subsequently conducted with 20 key healthcare workers to explore the corresponding cognitive, emotional, and environmental drivers of hand hygiene behaviours.

Results

Birth attendants’ compliance with hand hygiene protocol was 18% prior to performing labour, delivery and newborn aftercare procedures. Hand hygiene compliance did not differ by facility type or attendants’ qualification, but differed by shift with adequate hand hygiene less likely to be observed during the night shift (p = 0.03). The midwives’ hand hygiene practices were influenced by cognitive, psychological, environmental and contextual factors including habits, gloving norms, time, workload, inadequate knowledge and infection risk perception.

Conclusion

The resulting insights from formative research suggest a multi-component improvement intervention that addresses the different key behaviour determinants to be designed for the labour and delivery room. A combination of disruption of the physical environment via nudges and cues, participatory education to the midwives and the promotion of new norms using social influence and affiliation may increase the birth attendants’ hand hygiene compliance in our study settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03901-7.

Microbial analyses of blood spot surfaces collected from a laboratory and the bathroom of a female single-person household under different environmental conditions

Many people spend most of their time indoors, thereby exposing themselves to indoor environmental microbial communities that might interact with the human microbiota. These potential interactions have only been considered for personal identification; however, accumulating evidence indicates that these microbial interactions are potentially implicated with the identification of human interactions and location-specific factors including time and seasonal variations in the microbial community. To augment the potential of metagenomics-based forensic tools, we compared the composition of microbial communities in blood spot surfaces from healthy adults placed in different environments, such as in the bathroom of a female single-person household and on a laboratory, which were sampled across seasons and time points. The laboratory samples showed more changes in the bacterial community over time owing to the higher number of individuals using the laboratory, whereas the microbial communities in the bathroom samples remained relatively stable over time. Moreover, the two locations could be distinguished according to their specific bacterial community compositions. Variations were also observed related to changes in temperature and humidity, allowing for prediction of season-based microbial community. These findings offer a new perspective regarding the use of microbial community analysis in forensic science.

In vitro investigation of the Flusso™ Bypass adapter efficiency upon ventilator circuit disconnect in a clinical simulated environment

Rationale

Mechanically ventilated patients must be disconnected from the ventilator during intra-facility transfers. Intentional and accidental circuit disconnections represent a potential hazard to patients (sudden collapse and re-expansion of the alveoli) as well as to clinical staff (exposure to patient’s unfiltered exhalation). Therefore, avoiding abrupt circuit disconnections could better protect the patient’s health and reduce or eliminate contamination risks around clinical staff.

Objective

The purpose of this in-vitro work was to investigate and evaluate the potential for environmental exposure of Nitric Oxide (NO, as an indicator of any contamination exposure) before and after implementing the novel Flusso™ Bypass adapter during the disconnect procedure of a mechanical ventilator system.

Methods

A mechanical ventilator delivering NO was connected to a breathing simulator with and without the Flusso™ Bypass adapter. The ambient NO concentration was measured when the circuit was briefly disconnected (3 s) during inhalation and exhalation. Both volume and pressure ventilation modes were used.

Measurements and main results

Disconnecting the standard ventilator circuit (pressure-controlled mode) without the Flusso™ Bypass adapter produced higher NO escape to the surroundings (compared with the volume-controlled mode), leading to a longer NO dissipation time. No ambient NO traces were detected when the Flusso™ adapter was used.

Conclusion

The usage of the Flusso™ adapter drastically decreases the unwanted exposure among clinical staff dealing with potentially hazardous airborne biological aerosols emanating from the circuit. Avoiding abrupt disconnection in the ventilator circuit could reduce lung injuries and alveolar over distension and collapse.

Close contact behavior in indoor environment and transmission of respiratory infection

Close contact was first identified as the primary route of transmission for most respiratory infections in the early 20th century. In this review, we synthesize the existing understanding of the mechanisms of close contact transmission. We focus on two issues: the mechanism of transmission in close contact, namely the transmission of the expired particles between two people, and the physical parameters of close contact that affect the exposure of particles from one individual to another, or how the nature of close contact plays a role in transmission. We propose the existence of three sub-routes of transmission: short-range airborne, large droplets, and immediate body-surface contact. We also distinguish a "body contact," which is defined with an interpersonal distance of zero, from a close contact. We demonstrate herein that the short-range airborne sub-route may be most common. The timescales over which data should be collected to assess the transmission risk during close contact events are much shorter than those required for the distant airborne or fomite routes. The current paucity of high-resolution data over short distances and timescales makes it very difficult to assess the risk of infection in these circumstances.

Effect of Frequency of Changing Point-of-Use Reminder Signs on Health Care Worker Hand Hygiene Adherence: A Cluster Randomized Clinical Trial

IMPORTANCE

Although hand hygiene (HH) is considered the most effective strategy for preventing hospital-acquired infections, HH adherence rates remain poor.

OBJECTIVE

To examine whether the frequency of changing reminder signs affects HH adherence among health care workers.

DESIGN, SETTING, AND PARTICIPANTS

This cluster randomized clinical trial in 9 US Department of Veterans Affairs acute care hospitals randomly assigned 58 inpatient units to 1 of 3 schedules for changing signs designed to promote HH adherence among health care workers: (1) no change; (2) weekly; and (3) monthly. Hand hygiene rates among health care workers were documented at entry and exit to patient rooms during the baseline period from October 1, 2014, to March 31, 2015, of normal signage and throughout the intervention period of June 8, 2015, to December 28, 2015. Data analyses were conducted in April 2018.

INTERVENTIONS

Hospital units were randomly assigned into 3 groups: (1) no sign changes throughout the intervention period, (2) signs changed weekly, and (3) signs changed monthly.

MAIN OUTCOMES AND MEASURES

Hand hygiene adherence as measured by covert observation. Interrupted time series analysis was used to examine changes in HH adherence from baseline through the intervention period by group.

RESULTS

Among 58 inpatient units, 19 units were assigned to the no change group, 19 units were assigned to the weekly change group, and 20 units were assigned to the monthly change group. During the baseline period, 9755 HH opportunities were observed at room entry and 10 095 HH opportunities were observed at room exit. During the intervention period, a total of 15 855 HH opportunities were observed at room entry, and 16 360 HH opportunities were observed at room exit. Overall HH adherence did not change from baseline compared with the intervention period at either room entry (4770 HH events [48.9%] vs 3057 HH events [50.1%]; P = .14) or exit (6439 HH events [63.8%] vs 4087 HH events [65.2%]; P = .06). In units that changed signs weekly, HH adherence declined from baseline at room entry (-1.9% [95% CI, -2.7% to -0.8%] per week; P < .001) and exit (-0.8% [95% CI, -1.5% to 0.1%] per week; P = .02). No significant changes in HH adherence were observed in other groups.

CONCLUSIONS AND RELEVANCE

The frequency of changing reminder signs had no effect on HH rates overall. Units assigned to change signs most frequently demonstrated worsening adherence. Considering the abundance of signs in the acute care environment, the frequency of changing signs did not appear to provide a strong enough cue by itself to promote behavioral change.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02223455.

Continuous monitoring of aerial bioburden within intensive care isolation rooms and identification of high-risk activities

Background

The spread of pathogens via the airborne route is often underestimated, and little is known about the extent to which airborne microbial contamination levels vary throughout the day and night in hospital facilities.

Aims

To evaluate airborne contamination levels within intensive care unit (ICU) isolation rooms over 10–24-h periods in order to improve understanding of the variability of environmental aerial bioburden, and the extent to which ward activities may contribute.

Methods

Environmental air monitoring was conducted within occupied and vacant inpatient isolation rooms. A sieve impactor sampler was used to collect 500-L air samples every 15 min over 10-h (08:00–18:00 h) and 24-h (08:00–08:00 h) periods. Samples were collected, room activity was logged, and bacterial contamination levels were recorded as colony-forming units (cfu)/m³ air.

Findings

A high degree of variability in levels of airborne contamination was observed across all scenarios in the studied isolation rooms. Air bioburden increased as room occupancy increased, with air contamination levels highest in rooms occupied for the longest time during the study (10 days) (mean 104.4 cfu/m³, range 12–510 cfu/m³). Counts were lowest in unoccupied rooms (mean 20 cfu/m³) and during the night.

Conclusion

Peaks in airborne contamination were directly associated with an increase in activity levels. This study provides the first clear evidence of the extent of variability in microbial airborne levels over 24-h periods in ICU isolation rooms, and found direct correlation between microbial load and ward activity.

The Correlation between Airborne Methicillin-resistant Staphylococcus aureus with the Presence of MRSA Colonized Patients in a General Intensive Care Unit

Air sampling directly onto a methicillin-resistant Staphylococcus aureus (MRSA) selective agar was performed at six locations three times weekly over a period of 32 weeks in a new, initially MRSA-free Intensive Care Unit to examine if MRSA is present in air sample cultures and, if so, whether it is affected by the number of MRSA colonized patients present. A total of 480 air samples were collected on 80 days. A total of 39/480 (8.1%) samples were found to be MRSA positive of which 24/160 (15%) positive air samples were from the single rooms, where MRSA colonised patients were isolated, and 15/320 (4.7%) were from the open bed areas. A significant correlation was found between the daily number of MRSA colonized or infected patients in the Unit and the daily number of MRSA positive air samples cultures obtained (r2=0.128; P<0.005). The frequency of positive cultures was significantly higher in the single rooms than in the open bed areas (relative risk=3.2; P<0.001). The results from one of the single rooms showed a strong correlation between the presence of MRSA patients and MRSA positive air samples (relative risk=11.4; P<0.005). Our findings demonstrate that the presence of airborne MRSA in our unit is strongly related to the presence and number of MRSA colonized or infected patients in the Unit.

Building conditions and the risk of nosocomial infection from microbial contamination of hospital appliances in a health care facility

Nosocomial infections (NIs) remain a global health burden with higher incidence in Africa. We assessed building conditions and risk of NIs from microbial contamination of appliances and surfaces in a Specialist hospital in Southwest Nigeria. The study sampled 120 surfaces in 12 wards during normal occupational activities. Moulds on ceilings and dusty surfaces were observed in the wards. Microbial burden (1038.0 × 10⁵ cfu) peaked in the ICU but was lowest (446.9 × 10⁵ cfu) in the male ward. Bacteria counts ( × 10⁵ cfu) of 234.7, 199.7 and 67.0 were measured on ICU tap, doorknob and ECG, respectively. Theatre diatomy machine, anaesthetic machine and operating lamp had bacteria counts ( × 10⁵ cfu) of 40.0, 85.0 and 109.0, respectively. Highest total fungal count (58.2 × 10⁵ cfu) was recorded on ICU trolley handle, switch and suturing tube. Our study established surfaces as major environmental routes for NI transmission in this health care facility.

Longitudinal nosocomial outbreak of Pseudomonas fluorescens bloodstream infection of 2 years' duration in a coronary care unit

BACKGROUND

Outbreaks of bloodstream infections (BSI) of nonfermenting bacteria are a critical issue and often associated with hospital environments. We experienced a long-lasting outbreak of Pseudomonas fluorescens BSI limited to a coronary care unit (CCU).

METHODS

We conducted a retrospective epidemiologic investigation and a case-control study for Pseudomonas fluorescens BSI from April 2011-July 2014. Environmental sample culture was conducted to detect the specific environmental source of transmission.

RESULTS

Hospital-wide microbiology data from the term identified 13 case patients with P fluorescens BSI and 32 control patients with BSI due to organisms other than P fluorescens in the CCU. The case-control study revealed that the case group had significantly higher odds of exposure to only cardiac output (CO) measurement with thermodilution method (odds ratio, 22.0; 95% confidence interval, 2.4-202.3). The organism was identified only from an ice bath used for CO measurement. The susceptibility patterns were identical among all strains derived from the cases and the environment.

CONCLUSIONS

The nosocomial outbreak of P fluorescens BSI in our CCU over 2 years was associated with a contaminated ice bath used for CO measurement within the unit. Detection and elimination of the specific source was essential to stop the outbreak.

A Network Model of Hand Hygiene: How Good Is Good Enough to Stop the Spread of MRSA?

BACKGROUND Simulation models have been used to investigate the impact of hand hygiene on methicillin-resistant Staphylococcus aureus (MRSA) transmission within the healthcare setting, but they have been limited by their ability to accurately model complex patient-provider interactions. METHODS Using a network-based modeling approach, we created a simulated neonatal intensive care unit (NICU) representing the potential for per-hour infant-infant MRSA transmission via the healthcare worker resulting in subsequent colonization. The starting prevalence of MRSA colonized infants varied from 2% to 8%. Hand hygiene ranged from 0% (none) to 100% (theoretical maximum), with an expected effectiveness of 88% inferred from literature. RESULTS Based on empiric care provided within a 1-hour period, the mean number of infant-infant MRSA transmissible opportunities per hour was 1.3. Compared to no hand hygiene and averaged across all initial colonization states, colonization was reduced by approximately 29%, 51%, 67%, 80%, and 86% for the respective levels of hygiene: 24%, 48%, 68%, 88%, and 100%. Preterm infants had a 61% increase in MRSA colonization, and mechanically ventilated infants had a 27% increase. CONCLUSIONS Even under optimal hygiene conditions, horizontal transmission of MRSA is possible. Additional prevention paradigms should focus on the most acute patients because they are at greatest risk. Infect Control Hosp Epidemiol 2017;38:945-952.

Respiratory syncytial virus is present in the neonatal intensive care unit

Nosocomial transmission of respiratory syncytial virus (RSV) occurs in children within the neonatal intensive care unit (NICU). During peak community RSV transmission, three swabs were collected from the nose, hand and personal clothing of visitors and health care workers (HCW) in NICU once every week for eight weeks. Nasal swabs were collected from every third neonate and from any neonate clinically suspected of having a respiratory infection. Environmental sampling of high touch areas was done once during the study period. All swabs were tested for RSV using real time RT-PCR. There were 173 (519 total) and 109 (327 total) swabs, each of nose, hand and dress from 84 HCWs and 80 visitors respectively and 81 nasal swabs from 55 neonates collected. Thirty five environmental swabs from surfaces of the beds, side tables, counter tops, chairs, tables and computers were collected. Overall 1% of nasal swabs from each of HCWs, visitors and neonates, 4% of dress specimens from visitors and 9% of environmental swabs were positive for RSV-RNA. The results suggest that though the risk for RSV in the NICU remains low, personnel clothing are contaminated with RSV-RNA and may have a role in transmission.

Comparative efficacy of interventions to promote hand hygiene in hospital: systematic review and network meta-analysis

OBJECTIVE

To evaluate the relative efficacy of the World Health Organization 2005 campaign (WHO-5) and other interventions to promote hand hygiene among healthcare workers in hospital settings and to summarize associated information on use of resources.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Medline, Embase, CINAHL, NHS Economic Evaluation Database, NHS Centre for Reviews and Dissemination, Cochrane Library, and the EPOC register (December 2009 to February 2014); studies selected by the same search terms in previous systematic reviews (1980-2009).

REVIEW METHODS

Included studies were randomised controlled trials, non-randomised trials, controlled before-after trials, and interrupted time series studies implementing an intervention to improve compliance with hand hygiene among healthcare workers in hospital settings and measuring compliance or appropriate proxies that met predefined quality inclusion criteria. When studies had not used appropriate analytical methods, primary data were re-analysed. Random effects and network meta-analyses were performed on studies reporting directly observed compliance with hand hygiene when they were considered sufficiently homogeneous with regard to interventions and participants. Information on resources required for interventions was extracted and graded into three levels.

RESULTS

Of 3639 studies retrieved, 41 met the inclusion criteria (six randomised controlled trials, 32 interrupted time series, one non-randomised trial, and two controlled before-after studies). Meta-analysis of two randomised controlled trials showed the addition of goal setting to WHO-5 was associated with improved compliance (pooled odds ratio 1.35, 95% confidence interval 1.04 to 1.76; I(2)=81%). Of 22 pairwise comparisons from interrupted time series, 18 showed stepwise increases in compliance with hand hygiene, and all but four showed a trend for increasing compliance after the intervention. Network meta-analysis indicated considerable uncertainty in the relative effectiveness of interventions, but nonetheless provided evidence that WHO-5 is effective and that compliance can be further improved by adding interventions including goal setting, reward incentives, and accountability. Nineteen studies reported clinical outcomes; data from these were consistent with clinically important reductions in rates of infection resulting from improved hand hygiene for some but not all important hospital pathogens. Reported costs of interventions ranged from $225 to $4669 (£146-£3035; €204-€4229) per 1000 bed days.

CONCLUSION

Promotion of hand hygiene with WHO-5 is effective at increasing compliance in healthcare workers. Addition of goal setting, reward incentives, and accountability strategies can lead to further improvements. Reporting of resources required for such interventions remains inadequate.

Characteristics of airborne micro-organisms in a neurological intensive care unit: Results from China

OBJECTIVE

To describe the characteristics of airborne micro-organisms in the environment in a Chinese neurological intensive care unit (NICU).

METHODS

This prospective study monitored the air environment in two wards (large and small) of an NICU in a tertiary hospital in China for 12 months, using an LWC-1 centrifugal air sampler. Airborne micro-organisms were identified using standard microbiology techniques.

RESULTS

The mean ± SD number of airborne bacteria was significantly higher in the large ward than in the small ward (200 ± 51 colony-forming units [CFU]/m(3) versus 110 ± 40 CFU/m(3), respectively). In the large ward only, the mean number of airborne bacteria in the autumn was significantly higher than in any of the other three seasons. A total of 279 airborne micro-organisms were identified (large ward: 195; small ward: 84). There was no significant difference in the type and distribution of airborne micro-organisms between the large and small wards. The majority of airborne micro-organisms were Gram-positive cocci in both wards.

CONCLUSION

These findings suggest that the number of airborne micro-organisms was related to the number of patients on the NICU ward.

Nasal and Hand Carriage ofStaphylococcus aureusin Staff at a Department for Thoracic and Cardiovascular Surgery: Endogenous or Exogenous Source?

Objective:

To investigate the rates ofStaphylococcus aureuscarriage on the hands and in the noses of healthcare workers (HCWs) and the relatedness ofS. aureusisolates found in the two sites.

Design:

Point-prevalence study.

Setting:

Department for Thoracic and Cardiovascular Surgery at the University Hospital of Uppsala, Uppsala, Sweden.

Subjects and Methods:

Samples were obtained from 133 individuals, 18 men and 115 women, using imprints of each hand on blood agar and a swab from the nose.S. aureusisolates were identified by standard methods and typed by pulsed-field gel electrophoresis.

Results:

S. aureuswas found on the hands of 16.7% of the men and 9.6% of the women, and in the noses of 33.3% of the men and 17.4% of the women. The risk ratio forS. aureuscarriage on the hands with nasal carriage was 7.4 (95% confidence interval, 2.7 to 20.2;P< .001). Among the 14 HCWs carryingS. aureuson their hands, strain likeness to the nasal isolate was documented for 7 (50%).

Conclusions:

Half of the HCWs acquiredS. aureuson the hands from patients or the environment and half did so by apparent self-inoculation from the nose. Regardless of the source of contamination, good compliance with hand hygiene is needed from all HCWs to protect patients from nosocomial infections. The moderate rate ofS. aureuscarriage on hands in this setting could be the result of the routine use of alcoholic hand antisepsis.

Review of technologies available to improve hand hygiene compliance - are they fit for purpose?

Hand hygiene has been empirically proven to prevent cross-transmission of infection, which has led to the development of global guidelines such as the World Health Organization's 'My 5 Moments for Hand Hygiene.' Because of the relatively recent launch of these guidelines (2009) technology designed to assist in measuring hand hygiene compliance appears not to fully acknowledge the influence of the WHO 5 Moments for hand hygiene Consequently, they may not be fit for purpose (FFP). This paper uses a review of the literature on current hand hygiene technology to assess the extent to which these are FFP based on these global guidelines. The results show that there are a variety of technologies available to assist with the monitoring and measurement of hand hygiene levels. However, none appear to explicitly achieve detection of all WHO 5 Moments for hand hygiene, limiting their effectiveness. The authors conclude that a systems approach offers a potential aid for developers aspiring to meet domain specific FFP requirements. Human factors may help guide such developments to meet user and context specific needs.

Technology and the future of intensive care unit design

Changing market demand, aging population, severity of illnesses, hospital acquired infection, clinical staff shortage, technological innovations, and environmental concerns-all are shaping the critical care practice in the United States today. However, how these will shape intensive care unit (ICU) design in the coming decade is anybody's guess. In a graduate architecture studio of a research university, students were asked to envision the ICU of the future while responding to the changing needs of the critical care practice through innovative technological means. This article reports the ICU design solutions proposed by these students.

Influence of tracheal suctioning systems on health care workers' gloves and equipment contamination: a comparison of closed and open systems

The impact of tracheal suctioning with an open or a closed system on equipment and health care workers contamination with multidrug-resistant pathogens was compared. Only the closed system reduced hand and equipment contamination during tracheal suctioning. This equipment could be systematically used to reduce risk of cross contamination in the intensive care unit.

Hospital Room Design and Health Outcomes of the Aging Adult

Objective:

To determine differences in the rate of falls, healthcare-acquired infections (HAIs), and the degree of social isolation in hospitalized older adults admitted to private versus semiprivate rooms.

Background:

The American Institute of Architects recommends that private rooms become the industry standard for all new construction of acute care hospitals. Healthcare design researchers contend that private rooms decrease infection, facilitate healthcare workers' efficiency, provide space for families, and afford greater access to privacy. Although links between room type and health outcomes have been described in the literature, the actual relationship between these two variables has not been determined, nor is it clear whether a one-size-fits-all approach to hospital design is appropriate for all patient populations, particularly older adults.

Methods:

This retrospective case comparative design utilized a sample of patients admitted to the University Medical Center of Princeton in 2006 and received full internal review board approval. Patient records were randomly selected through the admission/discharge/transfer system of the hospital and then divided into two groups based on room type. Data collected included demographics, incidence of falls, HAIs, and risk of social isolation.

Results:

All patients were more than 65 years old and had been admitted to the hospital for a variety of diagnoses. Length of stay was between 3 and 10 days. There was no significant difference between the type of room and the likelihood of falling ( p = .37), however the relative risk of falling in a private room was 4.01. There was no significant difference in the occurrence of HAIs based on room type ( p = 1.0). The risk-of-social-isolation variable was unable to significantly affect which hospitalized older adults would suffer a negative outcome, fall, or HAI ( p = .52).

Conclusion:

Room type may play a role in the occurrence of falls in hospitalized older adults, but room type alone does not increase the chance of acquiring an infection in the hospital. Nor does the risk of social isolation affect the likelihood of an adverse outcome.

Evaluation of the bactericidal efficacy of three different alcohol hand rubs against 57 clinical isolates of S. aureus

We tested the efficacy of three alcohol hand rubs (AHRs) used in two local Welsh intensive therapy units (ITUs) against Staphylococcus aureus. The test protocol was based on a carrier test and parameters (concentration, contact time) were chosen following observation of hand-sanitising practices in the ITUs. Following AHR exposure, surviving bacteria were enumerated using a standard plate count method plus a Bioscreen C Microbial Growth Analyser. The AHRs demonstrated variable efficacy against the clinical isolates: the mean log(10) reduction after 10 s exposure to Soft Care Med H5, Cutan and Guest Medical AHRs was 2.67, 0.696 and 1.96, respectively, and after 30 s exposure was 4.58, 1.74 and 3.60, respectively. Since the average time taken by healthcare workers (HCWs) to rub AHR onto their hands was 11 s and 15 s at the two hospitals, the efficacy of these AHRs may be significantly limited against the S. aureus isolates under the conditions observed in practice. In addition, differences observed in log(10) reduction in bacterial number post-exposure using the Bioscreen compared to the plate count method provided evidence that S. aureus may be able to recover following Guest Medical AHR treatment within 2 min exposure, whereas after 5 min exposure bacterial damage caused by the AHR was irreversible. Although the introduction of AHRs improved hand hygiene compliance among HCWs, our observations highlighted that contact time is an important factor to ensure the efficacy of these products.

[Hand hygiene: scientific evidence and common sense]

Hand washing was rightly considered a measure of personal hygiene for centuries. Today there is enough scientific evidence showing that a simple and inexpensive measure can help significantly reduce clinical infections. In spite of this, published studies show that hand hygiene only takes place between 15% and 50% of the instances in which it should be done. In order to support countries in setting priorities to deal with infections related to health care, the World Health Organization has developed a campaign to improve compliance with hand hygiene. Fundamental elements of the campaign include staff training, change of habits, motivating health professionals, and enabling access to effective products at the point of patient care. At institutional level, healthcare managers need to make a firm commitment, and make hand hygiene one of the quality assurance objectives of their organisations.

Antimicrobial efficacy in vivo of a new formulation of 2-butanone peroxide in n-propanol: comparison with commercial products in a cross-over trial

The use of hand rub to obtain maximum decrease in bacterial load is important because the reduction needed to avoid transmission is unknown. The monomer of 2-butanone peroxide is a peroxygen derivative with potential biocidal use in hospitals. The aim of this study was to compare the efficacy of hand rub with an alcoholic solution of peroxide 2-butanone versus five antiseptic products, against E. coli K12 (CECT 433) transient flora acquired by hand immersion in a broth culture following the UNE-EN-1500 standard. Isopropanol 60% (control) obtained 99.99% reductions, driving down the bacterial load from 10(6) cfu/mL in the initial inocula to <100 cfu/mL. Products A, B and C (different alcoholic solutions ranging from 65% to 75% with low amounts of biguanidines and/or quaternary ammonium compounds) resulted in significantly lower amounts, reducing initial inocula to approximately 500 cfu/mL. Products D and E (70-75% alcohol solutions containing higher amounts of different quaternary ammonium compounds and triclosan in the case of product E) produced reductions similar to that of isopropanol, with significantly larger reductions than products A, B and C. The product with the solution of 2-butanone peroxide produced the same effect as products D and E with mean reductions of approximately 4log(10) (99.99%), driving the initial inocula down to < or = 100 cfu/mL, despite the low concentration (35%) of propanol in the solution. This novel peroxygen biocide offers high in-vivo cidal activity against acquired E. coli transient flora, offering an alternative to products with higher alcohol concentrations.

A Multidimensional Framework for Assessing Patient Room Configurations

Purpose:

A framework for multidimensional assessment of patient room configurations is presented. Twenty-three issues are considered and categorized under six domains of assessment: (1) patient safety, (2) staff efficiency, (3) circulation, (4) infection control, (5) patient considerations, and (6) family amenities. Use of the framework to rank issues by importance and assess six alternative patient room configurations by a diverse group of experts in a symposium is described.

Background:

One of the key questions posed during inpatient room design is the location of the bathroom. What issues are affected by the variations in room configuration that arise from bathroom location? A complete articulation of the issues that potentially are affected by room configuration is not available in the literature.

Framework:

The list of issues was developed by the authors in preparation for a symposium. The symposium was organized in May 2007 and attended by 14 experts from four institutions. Six alternative room configurations were used. Variations in the configurations included: (1) three same-handed and three mirror-image rooms; (2) three outboard, two inboard, and one nested bathroom; and (3) three rooms with footwall bathrooms and three with headwall bathrooms. In a four-step process, the attendees ranked the issues, discussed them in detail, rated each room configuration against each issue on a seven-point suitability scale, and conducted an overall assessment of the six configurations.

Conclusions:

Based on the ratings and rankings provided by the symposium participants, outboard bathroom locations were found to be most suitable, followed by nested and inboard configurations. Furthermore, configurations with patient bathrooms located on the footwall were rated as more suitable than headwall locations. The authors recommend, however, that the framework be used to determine a suitable room configuration in a specific context, rather than to identify configurations that will perform well universally.

Compliance with hand hygiene in a genitourinary medicine department

The ability to control hospital-acquired infections is highly dependent upon control of cross-contamination from health-care workers to patients, and from one anatomical area of the patient to another anatomical area. Hand hygiene has been demonstrated to be an essential prerequisite in preventing cross-contamination. Wearing gloves does not afford complete protection against cross-contamination. Hand hygiene includes handwashing between patients, the use of alcohol-based skin cleansers and changing or removing gloves between examining different anatomical sites. There are no previously published audits regarding compliance to hand hygiene in genitourinary (GU) medicine clinics. A validated observation tool was employed in this audit. Doctors and nurses were observed in clinical practice. The adherence to hand hygiene protocols was overall poor. Doctors were more likely to adhere to protocols than nurses (83.3% vs. 66%). However, techniques of glove removal were universally satisfactory. Strategies for improvement in hand hygiene are suggested. These include performance feedback and use of posters.

A Review of the Research Literature on Evidence-Based Healthcare Design

Objective:

This report surveys and evaluates the scientific research on evidence-based healthcare design and extracts its implications for designing better and safer hospitals.

Background:

It builds on a literature review conducted by researchers in 2004.

Methods:

Research teams conducted a new and more exhaustive search for rigorous empirical studies that link the design of hospital physical environments with healthcare outcomes. The review followed a two-step process, including an extensive search for existing literature and a screening of each identified study for the relevance and quality of evidence.

Results:

This review found a growing body of rigorous studies to guide healthcare design, especially with respect to reducing the frequency of hospital-acquired infections. Results are organized according to three general types of outcomes: patient safety, other patient outcomes, and staff outcomes. The findings further support the importance of improving outcomes for a range of design characteristics or interventions, including single-bed rooms rather than multibed rooms, effective ventilation systems, a good acoustic environment, nature distractions and daylight, appropriate lighting, better ergonomic design, acuity-adaptable rooms, and improved floor layouts and work settings. Directions for future research are also identified.

Conclusions:

The state of knowledge of evidence-based healthcare design has grown rapidly in recent years. The evidence indicates that well-designed physical settings play an important role in making hospitals safer and more healing for patients, and better places for staff to work.

Fungal Infections

The incidence of invasive fungal infections has increased dramatically over the past two decades, mostly due to an increase in the number of immunocompromised patients.1–4 Patients who undergo chemotherapy for a variety of diseases, patients with organ transplants, and patients with the acquired immune deficiency syndrome have contributed most to the increase in fungal infections.5 The actual incidence of invasive fungal infections in transplant patients ranges from 15% to 25% in bone marrow transplant recipients to 5% to 42% in solid organ transplant recipients.6,7 The most frequently encountered are Aspergillus species, followed by Cryptococcus and Candida species. Fungal infections are also associated with a higher mortality than either bacterial or viral infections in these patient populations. This is because of the limited number of available therapies, dose-limiting toxicities of the antifungal drugs, fewer symptoms due to lack of inflammatory response, and the lack of sensitive tests to aid in the diagnosis of invasive fungal infections.1 A study of patients with fungal infections admitted to a university-affiliated hospital indicated that community-acquired infections are becoming a serious problem; 67% of the 140 patients had community-acquired fungal pneumonia.8

An outbreak of Pseudomonas aeruginosa infection caused by contaminated mouth swabs

BACKGROUND

Pseudomonas aeruginosa is an opportunistic bacterium that can cause severe infection in susceptible patients. During the winter of 2001-2002, we investigated an outbreak of P. aeruginosa infection among patients in several hospitals across Norway.

METHODS

A nationwide outbreak investigation was performed with case finding, questionnaires, and product sampling. All available clinical and environmental P. aeruginosa strains were genotyped. Detailed information was collected from patients with the outbreak strain or with any P. aeruginosa in blood or cerebrospinal fluid samples. To identify risk factors, we conducted a case-control study among patients with P. aeruginosa isolated from blood or cerebrospinal fluid samples during October 2001-December 2002. Case patients were patients infected with the outbreak genotype, and control subjects were patients infected with other genotypes.

RESULTS

A total of 231 patients from 24 hospitals were identified as having the outbreak strain; 39 of these patients had positive blood culture results. Seventy-one patients (31%) died while hospitalized; all of the patients who died had severe underlying disease. Among 39 case patients and 159 control subjects, use of the moist mouth swab (adjusted odds ratio, 5.3; 95% confidence interval, 2.0-13.6) and receipt of mechanical ventilation (adjusted odds ratio, 6.4; 95% confidence interval, 2.3-17.2) were associated with infection due to the outbreak strain. Genotypically identical strains of P. aeruginosa were identified in 76 mouth swabs from 12 different batches and from the production line.

CONCLUSIONS

Contamination of mouth swabs during production caused the largest-ever outbreak of P. aeruginosa infection in Norway. Susceptible patient groups should use only documented quality-controlled, high-level-disinfected products and items in the oropharynx.

Analysis of sites of bacterial contamination in an enteral feeding system

BACKGROUND

Contamination of enteral feedings is an often overlooked source for bacterial infection in the intensive care unit. A new 1-L enteral feeding system with minimal chances of touching critical areas (Nutrison Pack) was compared with routinely used 0.5-L glass bottle systems.

METHODS

Patients admitted to intensive care were randomized to Pack or glass bottle feeding systems. Cultures were taken from the delivery sets 5 times during the day and from feeding containers and different sites of the system after 24 hours.

RESULTS

Bacteria were present in 3 of 112 glass bottles and in 2 of 95 Pack bags. True bacterial contamination (defined as >10(2) colony-forming units/mL, with same bacteria also present in the delivery set) was found in none of the Packs with a 12-h (69 Packs) or a 24-h (26 Packs) hanging time and in only 1 of the glass bottles with a hanging time of 24 hours, which exceeded the advised hanging time of 8 hours. In contrast, the contamination rate of delivery sets was 48%, with increasing bacterial counts over the day and 4 subsequent days. Bacteria mainly belonged to the group of potentially pathogenic bacteria (Enterobacteriaceae and Pseudomonaceae). They likely originated from throat, lungs, and stomach and grew into and along feeding tubes upwards until they reached the delivery set.

CONCLUSIONS

Prolonged hanging times of Pack bags were safe with respect to bacterial contamination. However, the bacterial safety of enteral feedings is more likely to be endangered by the endogenous route of contamination rather than exogenous contamination, as high bacterial counts were found in feeding tubes and delivery sets as a result of retrograde growth.

The evolution and maintenance of virulence in Staphylococcus aureus: a role for host-to-host transmission?

Despite progress in our understanding of infectious disease biology and prevention, the conditions that select for the establishment and maintenance of microbial virulence remain enigmatic. To address this aspect of pathogen biology, we focus on two members of the Staphylococcus genus - Staphylococcus aureus and Staphylococcus epidermidis - and consider why S. aureus has evolved to become more virulent than S. epidermidis. Several hypotheses to explain this phenomenon are discussed and a mathematical model is used to argue that a complex transmission pathway is the key factor in explaining the evolution and maintenance of virulence in S. aureus. In the case of S. epidermidis, where skin contact affords easier transmission between hosts, high levels of virulence do not offer an advantage to this pathogen.

Factors involved in the aerosol transmission of infection and control of ventilation in healthcare premises

The epidemics of severe acute respiratory syndrome (SARS) in 2003 highlighted both short- and long-range transmission routes, i.e. between infected patients and healthcare workers, and between distant locations. With other infections such as tuberculosis, measles and chickenpox, the concept of aerosol transmission is so well accepted that isolation of such patients is the norm. With current concerns about a possible approaching influenza pandemic, the control of transmission via infectious air has become more important. Therefore, the aim of this review is to describe the factors involved in: (1) the generation of an infectious aerosol, (2) the transmission of infectious droplets or droplet nuclei from this aerosol, and (3) the potential for inhalation of such droplets or droplet nuclei by a susceptible host. On this basis, recommendations are made to improve the control of aerosol-transmitted infections in hospitals as well as in the design and construction of future isolation facilities.

Evidence-based model for hand transmission during patient care and the role of improved practices

Hand cleansing is the primary action to reduce health-care-associated infection and cross-transmission of antimicrobial-resistant pathogens. Patient-to-patient transmission of pathogens via health-care workers' hands requires five sequential steps: (1) organisms are present on the patient's skin or have been shed onto fomites in the patient's immediate environment; (2) organisms must be transferred to health-care workers' hands; (3) organisms must be capable of surviving on health-care workers' hands for at least several minutes; (4) handwashing or hand antisepsis by the health-care worker must be inadequate or omitted entirely, or the agent used for hand hygiene inappropriate; and (5) the caregiver's contaminated hand(s) must come into direct contact with another patient or with a fomite in direct contact with the patient. We review the evidence supporting each of these steps and propose a dynamic model for hand hygiene research and education strategies, together with corresponding indications for hand hygiene during patient care.

MRSA acquisition in an intensive care unit

BACKGROUND

This paper describes a retrospective investigation of methicillin-resistant Staphylococcus aureus (MRSA) acquisition in an 8-bed intensive care unit (ICU) over a 5-month period.

METHODS

Clinical and microbiologic data were collected from the ICU, including MRSA detection dates, patient dependency scores, standardized environmental screening data, weekly bed occupancies, number of admissions, and nurse staffing levels. MRSA acquisition weeks were defined as weeks during which initial delivery of MRSA occurred before sampling and laboratory confirmation. Weekly workloads were plotted against staffing levels and modelled against MRSA acquisition weeks and hygiene failures.

RESULTS

Of 174 patients admitted into the ICU, 28 (16%) were found to have MRSA; 12 of these (7%) acquired MRSA on the ICU within 7 of the 23 weeks studied. Six of these 7 weeks were associated with a deficit of trained nurses during the day and 5 with hygiene failures (data unavailable for 2). Pulsed-field gel electrophoresis (PFGE) profiles demonstrated relationships between staphylococci from staff hands, hand-touch sites, and patients' blood.

CONCLUSION

MRSA acquisition in the ICU was temporally associated with reduced numbers of trained nurses and hygiene failures predominantly involving hand-touch sites. Epidemiologic analysis suggested that patient acquisitions were 7 times more likely to occur during periods of nurse understaffing.

Use of strain typing data to estimate bacterial transmission rates in healthcare settings

OBJECTIVE

To create an affordable and accurate method for continuously monitoring bacterial transmission rates in healthcare settings.

DESIGN

We present a discrete simulation model that relies on the relationship between in-hospital transmission rates and strain diversity. We also present a proof of concept application of this model to a prospective molecular epidemiology data set to estimate transmission rates for Pseudomonas aeruginosa and Staphylococcus aureus.

SETTING

Inpatient units of an academic referral center.

PATIENTS

All inpatients with nosocomial infections.

INTERVENTION

Mathematical model to estimate transmission rates.

RESULTS

Maximum likelihood estimates for transmission rates of these two species on different hospital units ranged from 0 to 0.36 transmission event per colonized patient per day.

CONCLUSIONS

This approach is feasible, although estimates of transmission rates based solely on strain typed clinical cultures may be too imprecise for routine use in infection control. A modest level of surveillance sampling substantially improves the estimation accuracy.

Hand hygiene: an evidence-based review for surgeons

This review of the literature discusses the scientific evidence behind using different hand hygiene agents on the surgical ward, and in theatre for preoperative disinfection. It considers the mechanism of action of the agents and their effectiveness against different pathogens, as well as possible future agents, and how they are tested. It addresses problems such as the poor compliance with hand hygiene guidelines by healthcare workers (especially doctors) and investigates what can be done to improve compliance. Finally, it demonstrates the reduction in hospital acquired infection (HAI) rate that can be achieved by improving hand hygiene compliance, and shows that the savings associated with this easily outweigh the cost.

Hand hygiene practices in a neonatal intensive care unit: a multimodal intervention and impact on nosocomial infection

OBJECTIVE

Health care-associated infections persist as a major problem in most neonatal intensive care units. Hand hygiene has been singled out as the most important measure in preventing hospital-acquired infection. However, hand hygiene compliance among health care workers (HCWs) remains low. The objective of this study was to assess the frequency and nature of patient contacts in neonatal intensive care units and observe the compliance and technique of hand hygiene among HCWs before and after the implementation of a multimodal intervention program.

METHODS

The nature and frequency of patient contacts, the hand hygiene compliance, and hand-washing techniques of HCWs were observed unobtrusively to reflect the baseline compliance and to investigate factors for noncompliance. The intervention consisted of problem-based and task-orientated hand hygiene education, enhancement of minimal handling protocol and clustering of nursing care, liberal provision of alcohol-based hand antiseptic, improvement in hand hygiene facilities, ongoing regular hand hygiene audit, and implementation of health care-associated infection surveillance. The observational study was repeated 6 months after the completion of the intervention program, which extended over 1-year period.

RESULTS

Overall hand hygiene compliance increased from 40% to 53% before patient contact and 39% to 59% after patient contact. More marked improvement was observed for high-risk procedures (35%-60%). The average number of patient contacts also decreased from 2.8 to 1.8 per patient per hour. There was improvement in most aspects of hand-washing technique in the postintervention stage. The health care-associated infection rate decreased from 11.3 to 6.2 per 1000 patient-days.

CONCLUSION

A problem-based and task-orientated education program can improve hand hygiene compliance. Enhancement of minimal handling and clustering of nursing procedures reduced the total patient contact episodes, which could help to overcome the major barrier of time constraints. A concurrent decrease in health care-associated infection rate and increase in hand hygiene compliance was observed in this study. The observational study could form part of an ongoing audit to provide regular feedback to HCWs to sustain the compliance.

Clearing the cervical spine in unconscious polytrauma victims, balancing risks and effective screening

Cervical spine injury occurs in 5-10% of cases of blunt polytrauma. A missed or delayed diagnosis of cervical spine injury may be associated with permanent neurological sequelae. However, there is no consensus about the ideal evaluation and management of the potentially injured cervical spine and, despite the publication of numerous clinical guidelines, this issue remains controversial. In addition, many studies are limited in their application to the obtunded or unconscious trauma victim. This review will provide the clinician managing unconscious trauma victims with an assessment of the actual performance of clinical examination and imaging modalities in detecting cervical spine and isolated ligamentous injury, a review of existing guidelines in light of the available evidence, relative risk estimates and a proposed management scheme.

Hand hygiene: promoting compliance among nurses and health workers

Around 10% of hospital patients acquire a healthcare-associated infection and it has been estimated that around one-third of these could be prevented. This article discusses the causal link between hand hygiene and infection and the reasons why healthcare workers (HCW) fail to comply with hand-hygiene policies. The action of hand hygiene is discussed in terms of the removal of transient micro-organisms and the agents used. Reasons for non-compliance and some measures for achieving compliance, such as education and patient empowerment, are discussed alongside the difficulties that these present. In order to move forward, it is suggested that the problem has to be managed through cultural change, making it easier for HCWs to comply by improving hand-cleansing facilities and materials and providing feedback to personnel on local infection rates so that high-priority areas can be targeted. This may be facilitated by locally based action research.

Methicillin resistant Staphylococcus aureus in the critically ill

Methicillin resistant Staphylococcus aureus (MRSA) is endemic within many hospitals worldwide. Critically ill patients on intensive care units have increased risk factors making them especially prone to nosocomially acquired infections. This review addresses the current situation regarding the evolution of MRSA and the techniques for identifying and epidemiologically typing it. It discusses specific risk factors, the morbidity and mortality associated with critically ill patients, and possibilities for future antibiotic treatments.

Introduction of a waterless alcohol-based hand rub in a long-term-care facility

OBJECTIVE

To examine the impact of introduction of an alcohol-based hand rub on hand hygiene knowledge and compliance and hand colonization of healthcare workers (HCWs) in a long-term-care facility (LTCF).

METHODS

Two floors of an LTCF participated. Ward A used the hand rub as an adjunct to soap and water; ward B was the control. HCWs' hands were cultured using the bag-broth technique for Staphylococcus aureus, gram-negative bacilli (GNB), Candida, and vancomycin-resistant enterococci (VRE). HCWs completed a questionnaire at baseline and after an educational intervention and introduction of rub.

RESULTS

Hand hygiene practices, knowledge, and opinions did not change after the educational or rub intervention. Ward A HCWs thought that the rub was faster (P = .002) and less drying (P = .04) than soap. Hand hygiene frequency did not differ at baseline between the two floors, but increased on ward A by the end of the study (P = .04). HCWs were colonized frequently with GNB (66%), Candida (41%), S. aureus (20%), and VRE (9%). Although colonization did not change from baseline on either ward, the rub was more effective in clearing GNB P =.03) and S. aureus (P = .003). Nosocomial infection rates did not change.

CONCLUSION

The alcohol-based hand rub was a faster, more convenient, less drying method of hand hygiene for HCWs in an LTCF, and it improved compliance. Although microbial colonization did not change, the rub was more efficacious in removing pathogens already present on the hands of HCWs.