Tailoring Interventions for Control of Endemic Carbapenem-Resistant Acinetobacter baumannii: An Interrupted Time Series Analysis

Background

We examined temporal trends in carbapenem-resistant Acinetobacter baumannii (CRAB) infections in a hospital with hyperendemic CRAB and assessed the efficacy of varied infection control strategies in different ward types.

Methods

We retrospectively analyzed all CRAB clinical samples from 2006 to 2019 and categorized infections as hospital-onset (HO) or community-onset. We used interrupted time series analysis to assess the impact of interventions on the incidence of all HO-CRAB infections and bloodstream infections (BSIs) at the hospital and ward group levels.

Results

Over 14 years, 4009 CRAB infections were identified (89.7% HO), with 813 CRAB BSI (93.2% HO). The incidence per 100 000 patient-days of CRAB infections peaked in 2008 at 79.1, and that of CRAB BSI peaked in 2010 at 16.2. These rates decreased by two-thirds by 2019. In the general intensive care unit (ICU), hand hygiene and environmental cleaning interventions were followed by a significant reduction in the level of HO-CRAB infections, with an additional decrease in the slope after the introduction of active surveillance and 2% chlorhexidine bathing. In the surgical ICU and surgical department, a reduction in slope or level of CRAB infection was observed after moving ventilated patients to single rooms. In medical wards, a multimodal intervention was followed by a reduction in the slope of HO-CRAB infections and BSIs. In wards where CRAB infections were uncommon, the incidence of HO-CRAB infections decreased throughout the study period.

Conclusions

Ward-specific variables determine the success of interventions in reducing CRAB infections; therefore, interventions should be tailored to each setting.

Active support after natural disasters: a review of a microbiologist's role

In the aftermath of a natural disaster, multispecialty rapid response teams are deployed to support health-related relief work. Microbiologists are often part of such teams, along with public health specialists, clinicians and entomologists, and can contribute to the response in multiple ways. The role of a microbiologist is critical not only for laboratory diagnosis of infectious diseases, but also for situational analysis and evaluation, planning, prevention and control. The task begins with risk assessment, specifically for identification of diseases epidemic and endemic to the area. Evaluation of existing laboratory setups and establishment of services where none exist is a priority, including facilitation of a tiered laboratory system. Training of laboratory staff at short notice in field settings, biosafety and biomedical waste management are niche areas where microbiologists can contribute. Emerging focus areas include establishment of modular laboratories, infection prevention and control in community evacuation centres and considerations for reopening of healthcare facilities closed due to extensive natural damage. A trained and efficient microbiologist will prove a valuable asset to provide timely and useful support for infectious disease diagnosis, prevention, control and management in the wake of natural disasters.

A polymicrobial fungal outbreak in a regional burn center after Hurricane Sandy

OBJECTIVE

To describe a polymicrobial fungal outbreak after Hurricane Sandy.

DESIGN

An observational concurrent outbreak investigation and retrospective descriptive review.

SETTING

A regional burn intensive care unit that serves the greater Baltimore area, admitting 350-450 burn patients annually.

PATIENTS

Patients with burn injuries and significant dermatologic diseases such as toxic epidermal necrolysis who were admitted to the burn intensive care unit.

METHODS

An outbreak investigation and a retrospective review of all patients with non-candida fungal isolates from 2009-2016 were performed.

RESULTS

A polymicrobial fungal outbreak in burn patients was temporally associated with Hurricane Sandy and associated with air and water permeations in the hospital facility. The outbreak abated after changes to facility design.

CONCLUSIONS

Our results suggest a possible association between severe weather events like hurricanes and nosocomial fungal outbreaks. This report adds to the emerging literature on the effect of severe weather on healthcare-associated infections.

Environmental Cleaning in Resource-Limited Settings

Purpose of review

Environmental surfaces in healthcare facilities, particularly in a patient room, are a critical pathway for healthcare-associated pathogen transmission. Despite well-established guides and recommendations regarding environmental surface cleaning and disinfection, there are several challenges in resource-limited settings. This viewpoint article will discuss the practice of environmental cleaning in resource-limited settings including challenges and relationship between environment and healthcare-associated infections in this setting and outlines pre-requisites to overcome these challenges.

Recent findings

Despite several barriers and challenges, environmental cleaning is a crucial component to help reduce transmission of healthcare-associated infections and multi-drug-resistant pathogens as well as emerging infectious disease-associated pathogens in resource-limited settings. However, there is a need to develop a multi-modal strategy together with a mechanism for monitor and feedback to improve the practices of environmental cleaning in resource-limited settings.

Summary

Additional researches on the barriers and implementation gaps and the role of collaborative network as well as how to apply technology would provide significant insights on the practices of environmental cleaning in resource-limited settings.

Extensively drug-resistant Acinetobacter baumannii in a Thai hospital: a molecular epidemiologic analysis and identification of bactericidal Polymyxin B-based combinations

Background

Limited knowledge of the local molecular epidemiology and the paucity of new effective antibiotics has resulted in an immense challenge in the control and treatment of extensively drug-resistant (XDR) Acinetobacter baumannii infections in Thailand. Antimicrobial combination regimens may be the only feasible treatment option in such cases. We sought to characterize the local molecular epidemiology and assess the bactericidal activity of various antibiotics individually and in combination against XDR A. baumannii in a Thai hospital.

Methods

All XDR A. baumannii isolates from Thammasat University Hospital were collected between October 2010 and May 2011. Susceptibility testing was conducted according to reference broth dilution methods. Pulse-field gel electrophoresis was used to genotype the isolates. Carbapenemase genes were detected using polymerase chain reaction. In vitro testing of clinically-relevant concentrations of imipenem, meropenem, doripenem, rifampicin and tigecycline alone and in combination with polymyxin B was conducted using multiple combination bactericidal testing.

Results

Forty-nine polymyxin B-susceptible XDR A. baumannii isolates were identified. bla_OXA-23 and bla_OXA-51 genes were detected in all isolates. Eight clonally related clusters were identified, resulting in the initiation of several infection control measures. Imipenem, meropenem, doripenem, rifampicin, and tigecycline in combination with PB respectively, exhibited bactericidal killing in 100%, 100%, 98.0%, 100% and 87.8% isolates respectively at 24 hours.

Conclusion

Molecular epidemiologic analysis can aid the early detection of infection outbreak within the institution, resulting in the rapid containment of the outbreak. Imipenem/meropenem/rifampicin in combination with polymyxin B demonstrated consistent bactericidal effect against 49 bla_OXA-23-harbouring XDR A. baumannii clinical isolates, suggesting a role of combination therapy in the treatment of these infections.

Effectiveness of infection prevention measures featuring advanced source control and environmental cleaning to limit transmission of extremely-drug resistant Acinetobacter baumannii in a Thai intensive care unit: An analysis before and after extensive flooding

BACKGROUND

Advanced source control (once-daily bathing and 4-times daily oral care with chlorhexidine aqueous solution) and thorough environmental cleaning were implemented in response to an increased incidence of colonization and infection with extremely drug-resistant (XDR) Acinetobacter baumannii in a Thai medical intensive care unit (MICU).

METHODS

During the 12-month baseline period (P1), contact isolation, active surveillance for XDR A baumannii, cohorting of XDR A baumannii patients, twice-daily environmental cleaning with detergent-disinfectant, and antibiotic stewardship were implemented. In the 5.5-month intervention period (P2), additional measures were introduced. Sodium hypochlorite was substituted for detergent-disinfectant, and advanced source control was implemented. All interventions except cleaning with sodium hypochlorite were continued during the 12.5-month follow-up period (P3). Extensive flooding necessitating closure of the hospital for 2 months occurred between P2 and P3.

RESULTS

A total of 1,365 patients were studied. Compared with P1 (11.1 cases/1,000 patient-days), the rate of XDR A baumannii clinical isolates declined in P2 (1.74 cases/1,000 patient-days; P < .001) and further in P3 (0.69 cases/1,000 patient-days; P < .001). Compared with P1 (12.15 cases/1,000 patient-days), the rate of XDR A baumannii surveillance isolates also declined in P2 (2.11 cases/1,000 patient-days; P < .001) and P3 (0.98 cases/1,000 patient-days; P < .001). Incidence of nosocomial infections remained stable. Six patients developed chlorhexidine-induced rash (1.4/1,000 patient-days); 31 patients developed mucositis (17.1/1,000 patient-days).

CONCLUSIONS

These results support advanced source control and thorough environmental cleaning to limit colonization and infection with XDR A baumannii in MICUs in resource-limited settings.

Patterns of nosocomial infections, multidrug-resistant microorganisms, and mold detection after extensive black-water flooding: a survey from central Thailand

Central Thailand was severely affected by black-water flooding between September and November 2011, with resultant closure of 30 regional hospitals. Few data are available for the incidence of nosocomial infections and patterns of preflood versus postflood multidrug-resistant organisms (MDROs) and mold. We therefore conducted a survey of the hospitals in central Thailand in order to evaluate the patterns of nosocomial infections, MDROs, mold, and flood preparedness plans after these floods.

On the basis of a hospital list from the Ministry of Public Health, we identified 104 hospitals in 15 provinces of central Thailand that were affected, but not necessarily closed, by extensive floods. We designed and then conducted a survey, from July 1 through October 31, 2012, that inquired about hospital characteristics, postflood hospital preparedness plans, administrative support, institutional safely culture, incidence of nosocomial infections, and prevalence of MDROs and mold colonization or infection. All 104 secondary care (>100 beds) and tertiary care (>250 beds) hospitals in 15 central Thailand provinces were invited to participate.

The global spread of healthcare-associated multidrug-resistant bacteria: a perspective from Asia

Since antibiotics were first used, each new introduced class has been followed by a global wave of emergent resistance, largely originating in Europe and North America where they were first used. Methicillin-resistant Staphylococcus aureus spread from the United Kingdom and North America across Europe and then Asia over more than a decade. Vancomycin-resistant enterococci and Klebsiella pneumoniae carbapenemase-producing K. pneumoniae followed a similar path some 20 years later. Recently however, metallo-β-lactamases have originated in Asia. New Delhi metallo-β-lactamase-1 was found in almost every continent within a year of its emergence in India. Metallo-β-lactamase enzymes are encoded on highly transmissible plasmids that spread rapidly between bacteria, rather than relying on clonal proliferation. Global air travel may have helped facilitate rapid dissemination. As the antibiotic pipeline offers little in the short term, our most important tools against the spread of antibiotic resistant organisms are intensified infection control, surveillance, and antimicrobial stewardship.

Hospital infection prevention and control issues relevant to extensive floods

The devastating clinical and economic implications of floods exemplify the need for effective global infection prevention and control (IPC) strategies for natural disasters. Reopening of hospitals after excessive flooding requires a balance between meeting the medical needs of the surrounding communities and restoration of a safe hospital environment. Postflood hospital preparedness plans are a key issue for infection control epidemiologists, healthcare providers, patients, and hospital administrators. We provide recent IPC experiences related to reopening of a hospital after extensive black-water floods necessitated hospital closures in Thailand and the United States. These experiences provide a foundation for the future design, execution, and analysis of black-water flood preparedness plans by IPC stakeholders.