An Outbreak ofPseudomonas aeruginosaPneumonia and Bloodstream Infection Associated With Intermittent Otitis Externa in a Healthcare Worker

Hand and environmental hygiene: respective roles for MRSA, multi-resistant gram negatives, Clostridioides difficile, and Candida spp

Healthcare-associated infections (HAIs) caused by multidrug-resistant organisms (MDROs) represent a global threat to human health and well-being. Because transmission of MDROs to patients often occurs via transiently contaminated hands of healthcare personnel (HCP), hand hygiene is considered the most important measure for preventing HAIs. Environmental surfaces contaminated with MDROs from colonized or infected patients represent an important source of HCP hand contamination and contribute to transmission of pathogens. Accordingly, facilities are encouraged to adopt and implement recommendations included in the World Health Organization hand hygiene guidelines and those from the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America/Association for Professionals in Infection Control and Epidemiology. Alcohol-based hand rubs are efficacious against MDROs with the exception of Clostridiodes difficile, for which soap and water handwashing is indicated. Monitoring hand hygiene adherence and providing HCP with feedback are of paramount importance. Environmental hygiene measures to curtail MDROs include disinfecting high-touch surfaces in rooms of patients with C. difficile infection daily with a sporicidal agent such as sodium hypochlorite. Some experts recommend also using a sporicidal agent in rooms of patients colonized with C. difficile, and for patients with multidrug-resistant Gram-negative bacteria. Sodium hypochlorite, hydrogen peroxide, or peracetic acid solutions are often used for daily and/or terminal disinfection of rooms housing patients with Candida auris or other MDROs. Products containing only a quaternary ammonium agent are not as effective as other agents against C. auris. Portable medical equipment should be cleaned and disinfected between use on different patients. Detergents are not recommended for cleaning high-touch surfaces in MDRO patient rooms, unless their use is followed by using a disinfectant. Facilities should consider using a disinfectant instead of detergents for terminal cleaning of floors in MDRO patient rooms. Education and training of environmental services employees is essential in assuring effective disinfection practices. Monitoring disinfection practices and providing personnel with performance feedback using fluorescent markers, adenosine triphosphate assays, or less commonly cultures of surfaces, can help reduce MDRO transmission. No-touch disinfection methods such as electrostatic spraying, hydrogen peroxide vapor, or ultraviolet light devices should be considered for terminal disinfection of MDRO patient rooms. Bundles with additional measures are usually necessary to reduce MDRO transmission.

Pseudomonas aeruginosa: Infections and novel approaches to treatment "Knowing the enemy" the threat of Pseudomonas aeruginosa and exploring novel approaches to treatment

Pseudomonas aeruginosa is an aerobic Gram-negative rod-shaped bacterium with a comparatively large genome and an impressive genetic capability allowing it to grow in a variety of environments and tolerate a wide range of physical conditions. This biological flexibility enables the P. aeruginosa to cause a broad range of infections in patients with serious underlying medical conditions, and to be a principal cause of health care associated infection worldwide. The clinical manifestations of P. aeruginosa include mostly health care associated infections and community-acquired infections. P. aeruginosa possesses an array of virulence factors that counteract host defence mechanisms. It can directly damage host tissue while utilizing high levels of intrinsic and acquired antimicrobial resistance mechanisms to counter most classes of antibiotics. P. aeruginosa co-regulates multiple resistance mechanisms by perpetually moving targets poses a significant therapeutic challenge. Thus, there is an urgent need for novel approaches in the development of anti-Pseudomonas agents. Here we review the principal infections caused by P. aeruginosa and we discuss novel therapeutic options to tackle antibiotic resistance and treatment of P. aeruginosa infections that may be further developed for clinical practice.

Nebulized Antibiotics for Healthcare- and Ventilator-Associated Pneumonia

Global emergence of multidrug-resistant and extensive drug-resistant gram-negative bacteria has increased the risk of treatment failure, especially for healthcare- or ventilator-associated pneumonia (HAP/VAP). Nebulization of antibiotics, by providing high intrapulmonary antibiotic concentrations, represents a promising approach to optimize the treatment of HAP/VAP due to multidrug-resistant and extensive drug-resistant gram-negative bacteria, while limiting systemic antibiotic exposure. Aminoglycosides and colistin methanesulfonate are the most common nebulized antibiotics. Although optimal nebulized drug dosing regimen is not clearly established, high antibiotic doses should be administered using vibrating-mesh nebulizer with optimized ventilator settings to ensure safe and effective intrapulmonary concentrations. When used preventively, nebulized antibiotics reduced the incidence of VAP without any effect on mortality. This approach is not yet recommended and large randomized controlled trials should be conducted to confirm its benefit and explore the impact on antibiotic selection pressure. Compared with high-dose intravenous administration, high-dose nebulized colistin methanesulfonate seems to be more effective and safer in the treatment of ventilator-associated tracheobronchitis and VAP caused by multidrug resistant and extensive-drug resistant gram-negative bacteria. Adjunctive nebulized aminoglycosides could increase the clinical cure rate and bacteriological eradication in patients suffering from HAP/VAP due to multidrug-resistant and extensive drug-resistant gram-negative bacteria. As nebulized aminoglycosides broadly diffuse in the systemic circulation of patients with extensive bronchopneumonia, monitoring of plasma trough concentrations is recommended during the period of nebulization. Large randomized controlled trials comparing high dose of nebulized colistin methanesulfonate to high dose of intravenous colistin methanesulfonate or to intravenous new β-lactams in HAP/VAP due to multidrug-resistant and extensive drug-resistant gram-negative bacteria are urgently needed.

Outbreak of Pseudomonas aeruginosa producing VIM carbapenemase in an intensive care unit and its termination by implementation of waterless patient care

BACKGROUND

Long-term outbreaks of multidrug-resistant Gram-negative bacilli related to hospital-building water systems have been described. However, successful mitigation strategies have rarely been reported. In particular, environmental disinfection or replacement of contaminated equipment usually failed to eradicate environmental sources of Pseudomonas aeruginosa.

METHODS

We report the investigation and termination of an outbreak of P. aeruginosa producing VIM carbapenemase (PA-VIM) in the adult intensive care unit (ICU) of a Swiss tertiary care hospital with active case finding, environmental sampling and whole genome sequencing (WGS) of patient and environmental strains. We also describe the implemented control strategies and their effectiveness on eradication of the environmental reservoir.

RESULTS

Between April 2018 and September 2020, 21 patients became either infected or colonized with a PA-VIM strain. For 16 of them, an acquisition in the ICU was suspected. Among 131 environmental samples collected in the ICU, 13 grew PA-VIM in sink traps and drains. WGS confirmed the epidemiological link between clinical and environmental strains and the monoclonal pattern of the outbreak. After removing sinks from patient rooms and implementation of waterless patient care, no new acquisition was detected in the ICU within 8 months after the intervention.

DISCUSSION

Implementation of waterless patient care with removal of the sinks in patient rooms was successful for termination of a PA-VIM ICU outbreak linked to multiple environmental water sources. WGS provides highly discriminatory accuracy to investigate environment-related outbreaks.

Comparative Efficacy of Hand Disinfection Potential of Hand Sanitizer and Liquid Soap among Dental Students: A Randomized Controlled Trial

Background

Hands are the most common medium for initiation and spread of infection in clinics. Hand hygiene is the simplest and most economic method for reducing the healthcare-associated infections (HCAIs).

Aim

The aim of the present study was to compare the efficacy of hand sanitizer, liquid soap, and their combination for reducing the microbial colonies on hands.

Materials and methods

The study was a single-blinded randomized controlled trial executed in a dental college on 90 participants, which were randomly assigned into three intervention groups of 30 each. The participants were instructed to contaminate their hands followed by a hand hygiene protocol for the liquid hand-wash group, the alcohol-based hand sanitizer (ABHS) group, and the combination group according to WHO guidelines. The swabs were collected pre- and post-intervention and mean colony-forming units were determined for each group.

Results

Median percentage reduction was highest for the combination group (100%), followed by the ABHS group (94.29%) and lowest for the liquid soap (92.31%). This difference in the amount of colony-forming units (CFU) among all the groups was nonsignificant (p = 0.114).

Conclusion

The results of the study show that there was no significant difference in hand disinfection potential among hand sanitizer, liquid soap, or their combination. All the three interventions were equally effective with the reduction of total bacterial contamination from participants' hands.

How to cite this article

Khairnar MR, Anitha G, Dalvi TM, Kalghatgi S, Datar UV, Wadgave U, et al. Comparative Efficacy of Hand Disinfection Potential of Hand Sanitizer and Liquid Soap among Dental Students: A Randomized Controlled Trial. Indian J Crit Care Med 2020;24(5):336-339.

A multimodal regional intervention strategy framed as friendly competition to improve hand hygiene compliance

OBJECTIVE

To investigate the effects of friendly competition on hand hygiene compliance as part of a multimodal intervention program.

DESIGN

Prospective observational study in which the primary outcome was hand hygiene compliance. Differences were analyzed using the Pearson χ2 test. Odds ratios (ORs) with 95% confidence interval were calculated using multilevel logistic regression.

SETTING

Observations were performed in 9 public hospitals and 1 rehabilitation center in Rotterdam, Netherlands.ParticipantsFrom 2014 to 2016, at 5 time points (at 6-month intervals) in 120 hospital wards, 20,286 hand hygiene opportunities were observed among physicians, nurses, and other healthcare workers (HCWs).InterventionThe multimodal, friendly competition intervention consisted of mandatory interventions: monitoring and feedback of hand hygiene compliance and optional interventions (ie, e-learning, kick-off workshop, observer training, and team training). Hand hygiene opportunities, as formulated by the World Health Organization (WHO), were unobtrusively observed at 5 time points by trained observers. Compliance data were presented to the healthcare organizations as a ranking.

RESULTS

The overall mean hand hygiene compliance at time point 1 was 42.9% (95% confidence interval [CI], 41.4-44.4), which increased to 51.4% (95% CI, 49.8-53.0) at time point 5 (P<.001). Nurses showed a significant improvement between time points 1 and 5 (P<.001), whereas the compliance of physicians and other HCWs remained unchanged. In the multilevel logistic regressions, time points, type of ward, and type of HCW showed a significant association with compliance.

CONCLUSION

Between the start and the end of the multimodal intervention program in a friendly competition setting, overall hand hygiene compliance increased significantly.

Effectiveness of healthcare worker screening in hospital outbreaks with gram-negative pathogens: a systematic review

Background

Identifying the source of an outbreak is the most crucial aspect of any outbreak investigation. In this review, we address the frequently discussed question of whether (rectal) screening of health care workers (HCWs) should be carried out when dealing with outbreaks caused by gram negative bacteria (GNB).

A systematic search of the medical literature was performed, including the Worldwide Outbreak Database and PubMed. Outbreaks got included if a HCW was the source of the outbreak and the causative pathogen was an Escherichia coli, Klebsiella spp., Enterobacter spp., Serratia spp., Pseudomonas aeruginosa, or Acinetobacter baumannii.

This was true for 25 articles in which there were 1196 (2.1%) outbreaks due to GNB, thereof 14 HCWs who were permanently colonized by the outbreak strain. Rectal screening of HCWs was helpful in only 2 of the 1196 (0.2%) outbreaks. Instead, the hands of HCWs served as a reservoir for the outbreak strain in at least 7 articles – especially when they suffered from onychomycosis or used artificial fingernails or rings.

Conclusion

Due to very weak evidence, we do not recommend rectal screening of HCWs in an outbreak situation with GNB. However, besides a critical review of hand hygiene habits, it might be useful to examine the hands of staff carefully. This measure is cheap, quick to perform, and seems to be quite effective.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0330-4) contains supplementary material, which is available to authorized users.

Provider Role in Transmission of Carbapenem-Resistant Enterobacteriaceae

OBJECTIVE We sought to evaluate the role healthcare providers play in carbapenem-resistant Enterobacteriaceae (CRE) acquisition among hospitalized patients. DESIGN A 1:4 case-control study with incidence density sampling. SETTING Academic healthcare center with regular CRE perirectal screening in high-risk units. PATIENTS We included case patients with ≥1 negative CRE test followed by positive culture with a length of stay (LOS) >9 days. For controls, we included patients with ≥2 negative CRE tests and assignment to the same unit set as case patients with a LOS >9 days. METHODS Controls were time-matched to each case patient. Case exposure was evaluated between days 2 and 9 before positive culture and control evaluation was based on maximizing overlap with the case window. Exposure sources were all CRE-colonized or -infected patients. Nonphysician providers were compared between study patients and sources during their evaluation windows. Dichotomous and continuous exposures were developed from the number of source-shared providers and were used in univariate and multivariate regression. RESULTS In total, 121 cases and 484 controls were included. Multivariate analysis showed odds of dichotomous exposure (≥1 source-shared provider) of 2.27 (95% confidence interval [CI], 1.25-4.15; P=.006) for case patients compared to controls. Multivariate continuous exposure showed odds of 1.02 (95% CI, 1.01-1.03; P=.009) for case patients compared to controls. CONCLUSIONS Patients who acquire CRE during hospitalization are more likely to receive care from a provider caring for a patient with CRE than those patients who do not acquire CRE. These data support the importance of hand hygiene and cohorting measures for CRE patients to reduce transmission risk. Infect Control Hosp Epidemiol 2017;38:1329-1334.

Pseudomonas aeruginosa Outbreak in a Neonatal Intensive Care Unit Attributed to Hospital Tap Water

OBJECTIVE To investigate an outbreak of Pseudomonas aeruginosa infections and colonization in a neonatal intensive care unit. DESIGN Infection control assessment, environmental evaluation, and case-control study. SETTING Newly built community-based hospital, 28-bed neonatal intensive care unit. PATIENTS Neonatal intensive care unit patients receiving care between June 1, 2013, and September 30, 2014. METHODS Case finding was performed through microbiology record review. Infection control observations, interviews, and environmental assessment were performed. A matched case-control study was conducted to identify risk factors for P. aeruginosa infection. Patient and environmental isolates were collected for pulsed-field gel electrophoresis to determine strain relatedness. RESULTS In total, 31 cases were identified. Case clusters were temporally associated with absence of point-of-use filters on faucets in patient rooms. After adjusting for gestational age, case patients were more likely to have been in a room without a point-of-use filter (odds ratio [OR], 37.55; 95% confidence interval [CI], 7.16-∞). Case patients had higher odds of exposure to peripherally inserted central catheters (OR, 7.20; 95% CI, 1.75-37.30) and invasive ventilation (OR, 5.79; 95% CI, 1.39-30.62). Of 42 environmental samples, 28 (67%) grew P. aeruginosa. Isolates from the 2 most recent case patients were indistinguishable by pulsed-field gel electrophoresis from water-related samples obtained from these case-patient rooms. CONCLUSIONS This outbreak was attributed to contaminated water. Interruption of the outbreak with point-of-use filters provided a short-term solution; however, eradication of P. aeruginosa in water and fixtures was necessary to protect patients. This outbreak highlights the importance of understanding the risks of stagnant water in healthcare facilities. Infect Control Hosp Epidemiol 2017;38:801-808.

Molecular epidemiology of Pseudomonas aeruginosa bloodstream infection isolates in a non-outbreak setting

PURPOSE

The molecular epidemiology of Pseudomonas aeruginosa bloodstream infection (BSI) isolates has received limited attention. This study aims to characterize the molecular relationship of P. aeruginosa BSI isolates in the non-outbreak setting at a single tertiary healthcare facility.

METHODOLOGY

  P. aeruginosa BSI isolates from patients who were admitted to the Royal Brisbane and Women's Hospital over a 13 month period from November 2009 were identified retrospectively from the Pathology Queensland Clinical and Scientific Information System. The isolates were typed by the iPLEX MassARRAY matrix assisted lazer desorption/isonisation time of flight (MALDI-TOF) MS genotyping. The DiversiLab automated rapid strain typing platform (bioMérieux) was used to assess the genotypic relationships between study isolates that showed indistinguishable iPLEX20SNP profiles. Clinical data was also collected retrospectively from patient notes.

RESULTS

Fifty-three P. aeruginosa BSI episodes were available for study. Thirty-five different clones or clonal complexes were identified by the iPLEX MassARRAY MALDI-TOF MS genotyping. Seventeen BSI isolates with indistinguishable iPLEX20SNP profiles underwent further DiversiLab genotyping and were found to belong to a further 13 different genotypes. There was no relationship between clonality and acquisition type, source of infection or length of stay in the setting of hospital-acquired infection.

CONCLUSION

The non-clonal population structure suggests that there is ongoing environmental exposure of inpatients to P. aeruginosa. In clinical areas dealing with at-risk patients, routine attention to mechanism of environmental colonization is important and should be addressed even in the non-outbreak setting.

Outbreak of Methicillin-Resistant Staphylococcus aureus Colonization and Infection in a Neonatal Intensive Care Unit Epidemiologically Linked to a Healthcare Worker With Chronic Otitis

Objective.

To describe the investigation and interventions necessary to contain an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection in a neonatal intensive care unit (NICU).

Design.

Retrospective case finding that involved prospective performance of surveillance cultures for detection of MRSA and molecular typing of MRSA by repetitive-sequence polymerase chain reaction (rep-PCR).

Setting.

Level III NICU in a tertiary care center.

Participants.

Three neonates in a NICU were identified with MRSA bloodstream infection on April 16, 2004. A point prevalence survey identified 6 additional colonized neonates (attack rate, 75% [9 of 12 neonates]). The outbreak strain was phenotypically unusual.

Interventions.

Cohorting and mupirocin therapy were initiated for neonates who had acquired MRSA during the outbreak. Contact precautions were introduced in the NICU, and healthcare workers (HCWs) were retrained in cleaning and disinfection procedures and hand hygiene. Noncolonized neonates and newly admitted patients had surveillance cultures performed 3 times per week.

Results.

Two new colonized neonates were identified 1 month later. HCW X, who had worked in the NICU since June 2003, was identified as having chronic otitis. MRSA was isolated from cultures of swab specimens from HCW X's ear canal and nares. HCW X was epidemiologically linked to the outbreak. Molecular typing (by rep-PCR) confirmed that the isolates from HCW X and from the neonates were more than 90% similar. Retrospective review of NICU isolates revealed that the outbreak strain was initially cultured from a neonate 2 months after HCW X began working on the unit. The epidemic strain was eradicated after removing HCW X from patient care in the NICU.

Conclusion.

An outbreak of MRSA colonization and infection in a NICU was epidemiologically linked to a HCW with chronic otitis externa and nasal colonization with MRSA. Eradication was not achieved until removal of HCW X from the NICU. Routine surveillance for MRSA may have allowed earlier recognition of the outbreak and is now standard practice in our NICU.

Effectiveness of hand hygiene depends on the patient's health condition and care environment

AIM

The present authors examined how patient hand contamination was associated with underlying disease and treatment environment in order to determine effective hand hygiene methods.

METHODS

Samples were collected from inpatients (45 with hematological malignancies, 48 postoperative), outpatients (48 undergoing hemodialysis, 55 on chemotherapy), and 44 individuals living in nursing homes. All participants provided informed consent for study participation. All subjects performed hand hygiene. Before and after hand hygiene, samples of bacteria were collected from the palm of the hand onto agar media. Bacteria were counted and bacterial strains were identified. The authors then collected smear samples from the contralateral palm and measured adenosine triphosphate (ATP) levels.

RESULTS

Patient hand contamination was the highest in hemodialysis patients, followed by residents of nursing homes, postoperative patients, patients with cancer receiving chemotherapy, and patients of hematological malignancies. Regardless of the underlying disease and treatment environment, patients were able to reduce the number of bacterial colonies and ATP by proper hand hygiene. Compared with wet wipes, hand washing seemed to remove bacteria more effectively. Methicillin-resistant Staphylococcus aureus (MRSA) was detected in 30 subjects, none of whom were patients of hematological malignancies. Of these, 19 tested negative for MRSA after performing proper hand hygiene.

CONCLUSION

Patient hand contamination is affected by underlying disease and care environment, but can be reduced by encouraging proper hand washing. Proper patient hand hygiene can reduce MRSA on patients' hands, and thus may serve as an effective tool for prevention of healthcare-associated infections.

Use of ward closure to control outbreaks among hospitalized patients in acute care settings: a systematic review

BACKGROUND

Though often used to control outbreaks, the efficacy of ward closure is unclear. This systematic review sought to identify studies defining and describing ward closure in outbreak control and to determine impact of ward closure as an intervention on outbreak containment.

METHODS

We searched these databases with no language restrictions: MEDLINE, 1946 to 7 July 2014; EMBASE, 1974 to 7 July 2014; CINAHL, 1937 to 8 July 2014; and Cochrane Database of Systematic Reviews, 2005 to May 2014. We also searched the following: IndMED; LILACS; reference lists from retrieved articles; conference proceedings; and websites of the CDCP, the ICID, and the WHO. We included studies of patients hospitalized in acute care facilities; used ward closure as a control measure; used other control measures; and discussed control of the outbreak(s) under investigation. A component approach was used to assess study quality.

RESULTS

We included 97 English and non-English observational studies. None included a controlled comparison between ward closure and other interventions. We found that ward closure was often used as part of a bundle of interventions but could not determine its direct impact separate from all the other interventions whether used in parallel or in sequence with other interventions. We also found no universal definition of ward closure which was widely accepted.

CONCLUSIONS

With no published controlled studies identified, ward closure for control of outbreaks remains an intervention that is not evidence based and healthcare personnel will need to continue to balance the competing risks associated with its use, taking into consideration the nature of the outbreak, the type of pathogen and its virulence, mode of transmission, and the setting in which it occurs. Our review has identified a major research gap in this area.

Institutional Control Measures to Curtail the Epidemic Spread of Carbapenem-Resistant Klebsiella pneumoniae: A 4-Year Perspective

Objective.

To describe the implementation of an institution-wide, multiple-step intervention to curtail the epidemic spread of carbapenem-resistant Klebsiella pneumoniae (CRKP).

Design.

Consecutive intervention analyses.

Patients and Setting.

All patients admitted to a 775-bed tertiary care medical center in Jerusalem, Israel, from 2006 through 2010.

Interventions.

The effects of 4 interventions were assessed: (1) a policy of isolation for patients colonized or infected with CRKP in single rooms, which was started in March 2006; (2) cohorting of CRKP patients with dedicated nursing staff and screening of patients neighboring a patient newly identified as a carrier of CRKP, which was started in March 2007; (3) weekly active surveillance of intensive care unit patients, which was started during August 2008; and (4) selective surveillance of patients admitted to the emergency department, which was started in March 2009. Interrupted regression analysis and change-point analysis were used to assess the effect of each intervention on the CRKP epidemic.

Results.

Patient isolation alone failed to control the spread of CRKP, with incidence increasing to a peak of 30 new cases per 1,000 hospital beds per month. Institution of patient cohorting led to a steep decline in the incidence of CRKP acquisition (P< .001). Introduction of active surveillance interventions was followed by a decrease in the incidence of CRKP-positive clinical cultures but an increase in the incidence of CRKP-positive screening cultures. The mean prevalence of CRKP positivity for the period after cohorting began showed a statistically significant change from the mean prevalence in the preceding period (P< .001).

Conclusions.

The cohorting of patients with dedicated staff, combined with implementation of focused active surveillance, effectively terminated the epidemic spread of CRKP. Cohorting reduced cross-infection within the hospital, and active surveillance allowed for earlier detection of carrier status. Both interventions should be considered in attempts to contain a hospital epidemic.

Prompt control of an outbreak caused by extended-spectrum β-lactamase-producing Klebsiella pneumoniae in a neonatal intensive care unit

OBJECTIVES

To assess the effectiveness of a set of multidisciplinary interventions aimed at limiting patient-to-patient transmission of extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) during a neonatal intensive care unit (NICU) outbreak, and to identify risk factors associated with ESBL-KP colonization and disease in this setting.

STUDY DESIGN

A 61-infant cohort present in the NICU during an outbreak of ESBL-KP from April 26, 2011, to May 16, 2011, was studied. Clinical characteristics were compared in infected/colonized infants and unaffected infants. A multidisciplinary team formulated an outbreak control plan that included (1) staff reeducation on recommended infection prevention measures; (2) auditing of hand hygiene and environmental services practices; (3) contact precautions; (4) cohorting of infants and staff; (5) alleviation of overcrowding; and (6) frequent NICU-wide screening cultures. Neither closure of the NICU nor culturing of health care personnel was instituted.

RESULTS

Eleven infants in this level III NICU were infected/colonized with ESBL-KP. The index case was an 18-day-old infant born at 25 weeks' gestation who developed septicemia from ESBL-KP. Two other infants in the same room developed sepsis from ESBL-KP within 48 hours; both expired. Implementation of various infection prevention strategies resulted in prompt control of the outbreak within 3 weeks. The ESBL-KP isolates presented a single clone that was distinct from ESBL-KP identified previously in other units. Being housed in the same room as the index infant was the only risk factor identified by logistic regression analysis (P = .002).

CONCLUSION

This outbreak of ESBL-KP affected 11 infants and was associated with 2 deaths. Prompt control with eradication of the infecting strain from the NICU was achieved with multidisciplinary interventions based on standard infection prevention practices.

Pseudomonas in augmented care: should we worry?

The problem of Pseudomonas as a nosocomial pathogen is not new, with some authors dating its onset to the start of the antimicrobial era, although other factors, such as the growth of intensive or augmented care, have a part to play. This paper outlines the historical and environmental issues that may be associated with a potential increase in the incidence of this difficult-to-treat pathogen.

Hand hygiene perception among health care workers in Hungarian hospitals: prior to a nationwide microbiological survey

Transmission of pathogens via healthcare workers' (HCWs) hands is one of the most frequent means of spreading multi-resistant organisms and occurring healthcare-associated infections (HAIs) in hospitals. The role of contaminated hands in pathogen transmission was recognized by Hungarian physician, Ignác Semmelweis. Hand hygiene prevents cross-infections in hospitals, but numerous epidemiological and microbiology-based studies have documented low compliance of HCWs with this simple procedure. Furthermore, hand hygiene perception of HCWs plays an important role in determining hand hygiene compliance. Our aim was to describe the opinion of HCWs about their perception regarding hand hygiene practice. Our further goal was to strengthen a laboratory basis for bacterial backup control of nosocomial pathogens. A cross-sectional descriptive study was conducted between December 2010 and February 2011 in 13 participating hospitals in Hungary. HCWs know that there is correlation between contaminated hands and HAIs (83%), but neither the frequency (62%) nor the implementation (73%) of their hand hygiene performance are satisfying.We recommend that multimodal interventions - highlighted active microbiological surveillance of HCWs' hands - are the most suitable strategies to reduce the occurrence of HAIs and to determine their impact on cross-transmission of microorganisms and to overcome barriers of HCWs.

Quarantine, isolation, and cohorting: from cholera to Klebsiella

BACKGROUND

Isolation is defined as the separation of persons with communicable diseases from those who are healthy. This public health practice, along with quarantine, is used to limit the transmission of infectious diseases and provides the foundation of current-day cohorting.

METHODS

Review of the pertinent English-language literature.

RESULTS

Mass isolation developed during the medieval Black Death outbreaks in order to protect ports from the transmission of epidemics. In the mid-1800s, infectious disease hospitals were opened. It now is clear that isolation and cohorting of patients and staff interrupts the transmission of disease. Over the next century, with the discovery of penicillin and vaccines against many infectious agents, the contagious disease hospitals began to close. Today, we find smaller outbreaks of microorganisms that have acquired substantial resistance to antimicrobial agents. In the resource-limited hospital, a dedicated area or region of a unit may suffice to separate affected from unaffected patients.

CONCLUSION

Quarantine, or cohorting when patients are infected with the same pathogen, interrupts the spread of infections, just as the contagious disease hospitals did during the epidemics of the 18th and 19th centuries.

Pseudomonas aeruginosa and the host pulmonary immune response

Pseudomonas aeruginosa is a highly adaptable, opportunistic pathogen that is commonly found in the environment. It can infect a number of sites in the body and disseminate. It can cause both acute and chronic pulmonary infection and the acuity of infection and accompanying inflammatory phenotype is determined, for the most part, by the host. Although P. aeruginosa has been a successful opportunist in the context of a number of different disease states, it has been best studied in the context of cystic fibrosis (CF). The adaptability of P. aeruginosa has enabled it to adjust quickly to the CF airway, transitioning from initial colonization to chronic infection. The organism quickly expresses virulence factors that allow it to circumvent some elements of the host immune response and, even more importantly, quickly develops antimicrobial resistance. In the case of CF, chronic infection resulting in progressive lung damage, coupled with antimicrobial resistance, becomes an increasingly important issue as individuals with CF live longer. It is for these reasons that both organism- and host-targeted immunotherapies are being increasingly explored.

Pseudomonas aeruginosa outbreak in a pediatric intensive care unit linked to a humanitarian organization residential center

BACKGROUND

Pseudomonas aeruginosa commonly colonizes the hospital environment. Between April 2006 and September 2008, we investigated an outbreak of P. aeruginosa infection occurring in a pediatric intensive care unit. We conducted epidemiologic and molecular investigations to identify the source of the outbreak.

METHODS

Retrospective case finding; surveillance cultures of patients and environmental sites; admission screening; case-control study; and molecular typing.

PATIENT AND SETTING

Infants and children in a pediatric intensive care unit of a tertiary-care institution.

RESULTS

Thirty-seven cases of P. aeruginosa infection or colonization were detected between April 2006 and September 2008, including 3 fatal bloodstream infections. A closely-related strain was detected in 4 residents of a humanitarian nongovernmental organization (NGO) center who developed an infection, from 4 additional residents upon their hospital admission, and from a sink drain at the NGO residential center. NGO recipients represented 65% (24/37) of the total number of cases of P. aeruginosa colonization or infection during the outbreak period. Investigation at the residential center showed widespread contamination of the sewage system (10/14 sinks and shower drains, 70%) and a high prevalence (38%) of P. aeruginosa carriage among children.

CONCLUSIONS

These findings suggest that the probable cause of the outbreak was the contamination of the NGO residential center with further nosocomial transmission after admission, and highlight the importance of considering external sources when investigating hospital outbreaks.

Pseudomonas aeruginosa in a neonatal intensive care unit: molecular epidemiology and infection control measures

BACKGROUND

Pseudomonas aeruginosa, a non-fermentative, gram-negative rod, is responsible for a wide variety of clinical syndromes in NICU patients, including sepsis, pneumonia, meningitis, diarrhea, conjunctivitis and skin infections. An increased number of infections and colonisations by P. aeruginosa has been observed in the neonatal intensive care unit (NICU) of our university hospital between 2005 and 2007.

METHODS

Hand disinfection compliance before and after an educational programme on hand hygiene was evaluated. Identification of microrganisms was performed using conventional methods. Antibiotic susceptibility was evaluated by MIC microdilution. Genotyping was performed by PFGE analysis.

RESULTS

The molecular epidemiology of Pseudomonas aeruginosa in the NICU of the Federico II University hospital (Naples, Italy) and the infection control measures adopted to stop the spreading of P. aeruginosa in the ward were described. From July 2005 to June 2007, P. aeruginosa was isolated from 135 neonates and caused severe infections in 11 of them. Macrorestriction analysis of clinical isolates from 90 neonates identified 20 distinct genotypes, one major PFGE type (A) being isolated from 48 patients and responsible for 4 infections in 4 of them, four other distinct recurrent genotypes being isolated in 6 to 4 patients. Seven environmental strains were isolated from the hand of a nurse and from three sinks on two occasions, two of these showing PFGE profiles A and G identical to two clinical isolates responsible for infection. The successful control of the outbreak was achieved through implementation of active surveillance of healthcare-associated infections in the ward together with environmental microbiological sampling and an intense educational programme on hand disinfection among the staff members.

CONCLUSION

P. aeruginosa infections in the NICU were caused by the cross-transmission of an epidemic clone in 4 neonates, and by the selection of sporadic clones in 7 others. An infection control programme that included active surveillance and strict adherence to hand disinfection policies was effective in controlling NICU-acquired infections and colonisations caused by P. aeruginosa.

Contaminated feeding bottles: the source of an outbreak of Pseudomonas aeruginosa infections in a neonatal intensive care unit

BACKGROUND

Outbreaks of Pseudomonas aeruginosa have been reported in relationship with contamination of staff fingernails, hands, water baths, hand lotions and others. To our knowledge, contamination of milk and feeding bottles as a source of an outbreak of P aeruginosa infections has not been reported. The incidence of P aeruginosa infection/colonization in our neonatal intensive care unit increased from 1.9 per 1000 patient-days in August 2004 to 8.8 per 1000 patient-days in September 2004.

METHODS

Samples were collected including hand and body lotions, water from the incubator humidifying system, the health care worker hands, and the feeding bottle preparation room. Strains were epidemiologically characterized by pulsed-field gel electrophoresis of SpeI-digested genomic DNA. P aeruginosa was isolated from a total of 30 neonates during the period September 2004 to December 2004.

RESULTS

All cultures (139) of hand and body lotions, water from the incubator humidifying system, and hands of health care personnel were negative. Nine out of 48 samples collected from the feeding bottle preparation room were positive for P aeruginosa (6 samples of in-house prepared milk and 3 samples of water from dishwashers). Pulsed-field gel electrophoresis with SpeI showed that the strains isolated from neonates and from environmental samples were identical. Discontinuation of in-house preparation of feeding bottles and incorporation of unidose milk bottles stopped the outbreak.

CONCLUSION

The preparation and solution of milk from multidose powder preparation may be a source of P aeruginosa infections in a neonatal intensive care unit. The use of manufactured, nonmanipulated, unidose feeding bottles should be considered more adequate.

An outbreak of Pseudomonas aeruginosa because of inadequate disinfection procedures in a urology unit: a pulsed-field gel electrophoresis-based epidemiologic study

BACKGROUND

Pseudomonas aeruginosa is an opportunistic pathogen causing nosocomial infections in many hospitals. We aimed to investigate the source of urinary tract infections by determining clonal relationship of Pseudomonas aeruginosa strains with pulsed-field gel electrophoresis (PFGE).

METHODS

During a 2-month period, all postoperative infections because of P aeruginosa were investigated in the Urology Department. Patient data were collected from medical records. Surveillance samples were obtained from various places in urological operating rooms. PFGE typing was performed for all P aeruginosa isolates.

RESULTS

A total of 14 P aeruginosa strains (12 from patients and 2 from environmental samples) were isolated. PFGE typing of these 14 strains yielded 2 possibly related clones, which differed from each other by 4 major bands. Ten of the patient isolates were clonally identical with the strains of 2 forceps.

CONCLUSION

Typing results confirmed that inadequately disinfected surgical devices can be the source of outbreak. After institution of infection control measures and education, no further clusters of P aeruginosa infection were detected in the Urology Department.

Prolonged use of carbapenems and colistin predisposes to ventilator-associated pneumonia by pandrug-resistant Pseudomonas aeruginosa

OBJECTIVE

We present our experience with five cases of pandrug-resistant Pseudomonas aeruginosa ventilator-associated pneumonia (VAP) and analysis of risk factors.

DESIGN AND SETTING

Case-control study in a 15-bed intensive care unit (ICU).

PATIENTS AND PARTICIPANTS

The study included 5 cases and 20 controls. Each case patient was matched to four contemporary controls according to gender, prior hospital admissions, hospitalization duration, ICU admission cause, Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Function Assessment (SOFA) scores on ICU admission, and length of ICU stay, and mechanical ventilation duration until first VAP episode by a multidrug-resistant bacterium.

MEASUREMENTS AND RESULTS

Recorded variables included age, gender, daily APACHE II and SOFA scores, patient medication, treatment interventions, positive cultures and corresponding antibiograms, occurrence of infection, sepsis, and septic shock, other ICU-associated morbidity, length of ICU stay and mechanical ventilation, and patient outcome. Healthcare worker and environmental cultures, and a hand-disinfection survey were performed. Pandrug-resistant P. aeruginosa isolates belonged to the same genotype and were bla (VIM-1)-like gene positive. The outbreak resolved following reinforcement of infection-control measures (September 27). The sole independent predictor for pandrug-resistant P. aeruginosa VAP was combined use of carbapenem for more than 20 days and colistin use for and more than 13 days (odds ratio 76.0; 95% confidence interval 3.7-1487.6). An additional risk factor was more than 78 open suctioning procedures during 6-26 September (odds ratio 16.0; 95% confidence interval 1.4-185.4).

CONCLUSIONS

Prolonged carbapenem-colistin use predisposes to VAP by pandrug-resistant P. aeruginosa. Cross-transmission may be facilitated by open suctioning.

The epidemiology, pathogenesis and treatment of Pseudomonas aeruginosa infections

Pseudomonas aeruginosa is an important bacterial pathogen, particularly as a cause of infections in hospitalised patients, immunocompromised hosts and patients with cystic fibrosis. Surveillance of nosocomial P. aeruginosa infections has revealed trends of increasing antimicrobial resistance, including carbapenem resistance and multidrug resistance. Mechanisms of antimicrobial resistance include multidrug efflux pumps, ss-lactamases and downregulation of outer membrane porins. Mechanisms of virulence include secreted toxins and the ability to form biofilms. The effective treatment of infections caused by P. aeruginosa includes prevention when possible, source control measures as necessary and prompt administration of appropriate antibacterial agents. Antibacterial de-escalation should be pursued in patients with an appropriate clinical response, especially when antibacterial susceptibilities are known. Multidrug-resistant P. aeruginosa may require treatment with less commonly used antibacterials (e.g. colistin), but newer anti-pseudomonal antibacterials are expected to be available in the near future.

A neonatal specialist with recurrent methicillin-resistant Staphylococcus aureus (MRSA) carriage implicated in the transmission of MRSA to newborns

This study reports an investigation of outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) infection and colonization involving 17 newborns in the neonatal unit of a teaching hospital. A neonatal specialist colonized with MRSA that eventually became mupirocin-resistant was implicated as a recurrent source of transmission of MRSA to newborns.

[Pseudomonas aeruginosa infections in a neonatal care unit at Reunion Island]

OBJECTIVE

To investigate an outbreak of Pseudomonas aeruginosa (PA) hospital-acquired infections in neonates.

METHODS

Incidences were assessed retrospectively in the neonatal care units of the Groupe Hospitalier Sud-Réunion, from January 2003 to September 2005. Environmental survey, audit of health care workers and case-control study were performed to reinforce staff training and to determine risk factors.

RESULTS

Of 1432 neonates, 40 were infected (median gestational age: 29 weeks, median birth weight: 1195 g), accounting for an attack rate of 2.8%. Between January 2003 and January 2004, incidence rates were less than 2 infections per 1000 hospitalisation days. In the last trimester of year 2004, the incidence rose to 5.6 infections per 1000 hospitalisation days and PA was found in all ocular swabs, leading to diagnose an epidemic. However, it was only 3 months later, after 3 new deaths of very preterm neonates, that the implementation of control measures and an audit of health care practices focused on water utilisation ruled out the outbreak. The overall fatality rate was 25%, and of 71% in severe diseases (septicemia or pneumonia). The epidemic pattern argued for a common unique source. Two risk factors were identified by logistic regression: exposure to mechanical ventilation beyond 4 days (OR 3.3; CI 95%: 1.3-8.4) and very preterm birth (OR 2.7; CI 95%: 1.0-7.7).

CONCLUSION

Our findings highlight the need for a close collaboration between neonatologists and hygienists to improve health care practices and surveillance.

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.

Nosocomial outbreak of Pseudomonas aeruginosa infections related to a flexible bronchoscope

An outbreak of Pseudomonas aeruginosa infections affecting 17 patients was detected in the 27-bed intensive care unit (ICU) of a community hospital from 1 July to 30 September 2003. An ambidirectional cohort study was conducted to identify the risk factors for infection. Nosocomial infections were defined using the criteria of the Centers for Disease Control and Prevention. Random arbitrary polymorphic DNA-polymerase chain reaction was used for genotypic characterization. Logistic regression analyses demonstrated that case patients were more likely than non-cases to have had a longer stay in the ICU, and to have undergone mechanical ventilation and antimicrobial treatment. The multi-variate analysis identified recent bronchoscopy [risk ratio (RR) 3.8, 95% confidence interval (CI) 2.5-3.9] and exposure to an infected patient (RR 2.9, 95% CI 1.1-3.7) as independent risk factors. Molecular analysis showed that of the nine isolates available, four patients had a similar strain. The factor with the strongest influence on the risk of death was infection with P. aeruginosa (RR 2.1, 95% CI 1.0-2.4, P=0.04). A combined infection control strategy was implemented, including strict compliance with isolation precautions and recommendations for cleaning and disinfecting bronchoscopes, and a sharp reduction in the incidence of P. aeruginosa infection followed. It is thought that this outbreak was caused by patient-to-patient transmission and infection from a common source, i.e. the flexible bronchoscope.