Outbreak of invasive Aspergillus infection in surgical patients, associated with a contaminated air-handling system

Odour and indoor air quality hazards in railway cars: an Australian mixed methods case study

Purpose

This case study aimed to diagnose the cause(s) of a seasonal, and objectionable odour reported by travellers and drivers in the railway cars of Australian passenger trains. The research questions were to: (1) identify whether significant microbial colonisation was present within the air handling system of trains and causing the odours; to (2) identify other potential sources and; (3) remedial options for addressing the issue.

Methods

A mixed-methods, action research design was used adopted. Sections of the heating, ventilation, and air conditioning (HVAC) systems from odour-affected trains were swabbed for bacteria and fungi and examined for evidence of wear, fatigue and damage on-site and off-site. Insulation foam material extracted from the walls of affected trains was also subjected to a chemical assessment following exposure to varying humidity and temperature conditions in a climate simulator. This was accompanied by a qualitative sensory characterisation.

Results

Upon exposure to a variety of simulated temperature and humidity combinations to recreate the odour, volatile chemical compounds released from the insulation foam by water were identified as its likely cause. In addition, a range of potentially serious pathogenic and odour-causing microbes were cultured from the HVAC systems, although it is considered unlikely that bacterial colonies were the odour source.

Conclusion

The research has implications for the sanitising and maintenance policies for HVAC systems on public transport, especially when operating in humid environments. The sanitary imposition, especially in the wake of COVID-19 may be required to ensure the safety of the travelling public and drivers.

Interventions Implemented to Remediate Mold Identified in Neonatal Intensive Care Unit (NICU) Incubators, 2022-2023

INTRODUCTION

Neonatal Intensive Care Units (NICUs) utilize incubators to sustain core temperatures associated with transepidermial water loss. High relative humidity in incubators provide an environment for fungi to grow. In August 2022, mold was identified growing in eleven (85%) NICU incubators.

METHODS

A team assembled to address mold in incubators. The environment was addressed as a possible source of contamination by consulting an environmental specialist. The air handler, ducts, and environment were terminally cleaned. Specimens were collected from the contaminated incubators and the manufacturer reviewed cleaning practices. Experimental trials were conducted using the incubators to replicate mold growth after interventions.

RESULTS

The environmental consultant approved when the space could be reoccupied. Incubators introduced to the clean environment did not grow mold. Various fungi and/or yeast were identified in the contaminated incubators. Opportunities to improve cleaning and replacement of parts were identified by the manufacturer. September 2022-February 2023, seven experimental trials were completed after cleaning the incubators. Four (36%) of the eleven contaminated incubators were placed back in use due to no fungal growth. No patient illnesses occurred.

CONCLUSION

The interventions implemented stopped ongoing contamination of incubators and use of previously contaminated incubators.

Molecular Analysis for Potential Hospital-Acquired Infection Caused by Aspergillus Tubingensis Through the Environment

The identification of Aspergillus species has been performed mainly by morphological classification. In recent years, however, the revelation of the existence of cryptic species has required genetic analysis for accurate identification. The purpose of this study was to investigate five Aspergillus section Nigri strains isolated from a patient and the environment in a university hospital. Species identification by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry identified all five black Aspergillus strains as Aspergillus niger. However, calmodulin gene sequence analysis revealed that all five strains were cryptic species, four of which, including the clinical strain, were Aspergillus tubingensis. Hospital-acquired infection of the patient with the A. tubingensis strain introduced from the environment was suspected, but sequencing of six genes from four A. tubingensis strains revealed no environmental strain that completely matched the patient strain. The amount of in vitro biofilm formation of the four examples of the A. tubingensis strain was comparable to that of Aspergillus fumigatus. An extracellular matrix was observed by electron microscopy of the biofilm of the clinical strain. This study suggests that various types of biofilm-forming A. tubingensis exist in the hospital environment and that appropriate environmental management is required.

Relationship Between Airborne Fungi Presence and the Position of the High Efficiency Particulate Air Filter in the Heating, Ventilation, and Air Conditioning System

AIM

Establish the influence of the terminal or nonterminal position of High Efficiency Particulate Air (HEPA) filters in the Heating, Ventilation, and Air Conditioning (HVAC) system on the presence of airborne fungi in controlled environment rooms.

BACKGROUND

Fungal infections are an important cause of morbidity and mortality in hospitalized patients.

METHODS

This study was realized from 2010 to 2017, in rooms with terminal and nonterminal HEPA filters, in eight Spanish hospitals. In rooms with terminal HEPA filters, 2,053 and 2,049 samples were recollected, and in rooms with nonterminal HEPA filters, 430 and 428 samples were recollected in the air discharge outlet (Point 1) and in the center of the room (Point 2), respectively. Temperature, relative humidity, air changes per hour, and differential pressure were recollected.

RESULTS

Multivariable analysis showed higher odds ratio (OR) of airborne fungi presence when HEPA filters were in nonterminal position (OR: 6.78; 95% CI [3.77, 12.20]) in Point 1 and (OR: 4.43; 95% CI [2.65, 7.40]) in Point 2. Other parameters influenced airborne fungi presence, such as temperature (OR: 1.23; 95% CI [1.06, 1.41]) in Point 2 differential pressure (OR: 0.86; 95% CI [0.84, 0.90]) and (OR: 0.88; 95% CI [0.86, 0.91]) in Points 1 and 2, respectively.

CONCLUSIONS

HEPA filter in terminal position of the HVAC system reduces the presence of airborne fungi. To decrease the presence of airborne fungi, adequate maintenance of the environmental and design parameters is necessary in addition to the terminal position of the HEPA filter.

Mycoviruses in Fungi: Carcinogenesis of Fungal Agents May Not Always Be Mycotoxin Related

Certain viruses have been found to induce diverse biological pathways to carcinogenesis, evidenced by the presence of viral gene products in some tumors. Despite the fact that many fungal agents contain mycoviruses, until recently, their possible direct effects on human health, including carcinogenesis and leukemogenesis, had not been explored. In this regard, most studies of fungal agents have rightly concentrated on their mycotoxin formation and effects. Recently, the direct role of yeasts and fungi in the etiology of cancers, including leukemia, have been investigated. While greater attention has been placed on the carcinogenic effects of Candida, the role of filamentous fungi in carcinogenesis has also been explored. Recent findings from studies using the enzyme-linked immunosorbent assay (ELISA) technique indicate that the plasma of patients with acute lymphoblastic leukemia (ALL) uniformly contains antibodies for a certain mycovirus-containing Aspergillus flavus, while controls are negative. The exposure of mononuclear leukocytes from patients with ALL in full remission, and long-term survivors, to the product of this organism was reported to result in the re-development of typical genetics and cell surface phenotypes characteristic of active ALL. Mycoviruses are known to be able to significantly alter the biological characteristics and functions of their host. The possible carcinogenic and leukemogenic role of mycoviruses, with and without their host, needs to be further investigated.

Characterization of Aspergillus spp. isolated from patients with coronavirus disease 2019

INTRODUCTION

Invasive pulmonary aspergillosis (IPA) is an important complication of coronavirus disease 2019 (COVID-19), and while there are case reports and epidemiological studies, few studies have isolated Aspergillus strains from patients. Therefore, we analyzed the strains, sensitivities, and genetic homology of Aspergillus spp. Isolated from patients with COVID-19.

METHODS

We investigated the Aspergillus strains detected from patients with COVID-19 hospitalized in Osaka Metropolitan University Hospital from December 2020 to June 2021. A molecular epidemiological analysis of Aspergillus fumigatus was performed using drug susceptibility tests and TRESPERG typing, and data on patient characteristics were collected from electronic medical records.

RESULTS

Twelve strains of Aspergillus were detected in 11 of the 122 patients (9%) with COVID-19. A. fumigatus was the most common species detected, followed by one strain each of Aspergillus aureolus, Aspergillus nidulans, Aspergillus niger, and Aspergillus terreus. A. aureolus was resistant to voriconazole, and no resistance was found in other strains. All A. fumigatus strains were genetically distinct strains. Six of the 11 patients that harbored Aspergillus received antifungal drug treatment and tested positive for β-D-glucan and/or Aspergillus galactomannan antigen. The results indicated that Aspergillus infections were acquired from outside the hospital and not from nosocomial infections.

CONCLUSION

Strict surveillance of Aspergillus spp. is beneficial in patients at high-risk for IPA. When Aspergillus is detected, it is important to monitor the onset of IPA carefully and identify the strain, perform drug sensitivity tests, and facilitate early administration of therapeutic agents to patients with IPA.

Aspergillus fumigatus sternal osteomyelitis following cardiac surgery: Case report and literature review

BACKGROUND

Sternal osteomyelitis caused by Aspergillus spp is uncommon in cardiac surgery patients requiring sternotomy.

CASE PRESENTATION

We report a 77-year-old male with a history of poorly controlled diabetes who was diagnosed with Aspergillus sternal osteomyelitis, three months following an uneventful coronary artery bypass surgery. He underwent multiple debridement surgeries and was treated with voriconazole. Despite a complicated post-operative course, the patient responded well to voriconazole with clinical and biochemical evidence of remission. Unfortunately, he died of an unrelated cause due to decompensated heart failure.

DISCUSSION

Though uncommon, Aspergillus sternal osteomyelitis should be considered in the differential diagnosis of immunocompetent patients with post-operative sternal wound infections and negative bacterial tissue cultures. Management should include a combination of medical and surgical therapy.

Identification of SARS-CoV-2 RNA in healthcare heating, ventilation, and air conditioning units

Evidence continues to grow supporting the aerosol transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To assess the potential role of heating, ventilation, and air conditioning (HVAC) systems in airborne viral transmission, this study sought to determine the viral presence, if any, on air handling units in a healthcare setting where coronavirus disease 2019 (COVID-19) patients were being treated. The presence of SARS-CoV-2 RNA was detected in approximately 25% of samples taken from ten different locations in multiple air handlers. While samples were not evaluated for viral infectivity, the presence of viral RNA in air handlers raises the possibility that viral particles can enter and travel within the air handling system of a hospital, from room return air through high-efficiency MERV-15 filters and into supply air ducts. Although no known transmission events were determined to be associated with these specimens, the findings suggest the potential for HVAC systems to facilitate transfer of virions to locations remote from areas where infected persons reside. These results are important within and outside of healthcare settings and may present necessary guidance for building operators of facilities that are not equipped with high-efficiency filtration. Furthermore, the identification of SARS-CoV-2 in HVAC components indicates the potential utility as an indoor environmental surveillance location.

Identification of SARS-CoV-2 RNA in healthcare heating, ventilation, and air conditioning units

Evidence continues to grow supporting the aerosol transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To assess the potential role of heating, ventilation, and air conditioning (HVAC) systems in airborne viral transmission, this study sought to determine the viral presence, if any, on air handling units in a healthcare setting where coronavirus disease 2019 (COVID-19) patients were being treated. The presence of SARS-CoV-2 RNA was detected in approximately 25% of samples taken from ten different locations in multiple air handlers. While samples were not evaluated for viral infectivity, the presence of viral RNA in air handlers raises the possibility that viral particles can enter and travel within the air handling system of a hospital, from room return air through high-efficiency MERV-15 filters and into supply air ducts. Although no known transmission events were determined to be associated with these specimens, the findings suggest the potential for HVAC systems to facilitate transfer of virions to locations remote from areas where infected persons reside. These results are important within and outside of healthcare settings and may present necessary guidance for building operators of facilities that are not equipped with high-efficiency filtration. Furthermore, the identification of SARS-CoV-2 in HVAC components indicates the potential utility as an indoor environmental surveillance location.

Addressing COVID-19 contagion through the HVAC systems by reviewing indoor airborne nature of infectious microbes: Will an innovative air recirculation concept provide a practical solution?

As the world continues to grapple with the reality of coronavirus disease, global research communities are racing to develop practical solutions to adjust to the new challenges. One such challenge is the control of indoor air quality in the COVID-19 era and beyond. Since COVID-19 became a global pandemic, the "super spread" of the virus has continued to amaze policymakers despite measures put in place by public health officials to sensitize the general public on the need for social distancing, personal hygiene, etc. In this work, we have reviewed the literature to demonstrate, by investigating the historical and present circumstances, that indoor spread of infectious diseases may be assisted by the conditions of the HVAC systems. While little consideration has been given to the possibility of indoor airborne transmission of the virus, the available reports have demonstrated that the virus, with average aerodynamic diameter up to 80-120 nm, is viable as aerosol in indoor atmosphere for more than 3 h, and its spread may be assisted by the HVAC systems. Having reviewed the vulnerability of the conventional ventilation systems, we recommend innovative air circulation concept supported by the use of UVGI in combination with nanoporous air filter to combat the spread of SARS-CoV-2 and other harmful microbes in enclosed spaces.

The Role of HVAC Design and Windows on the Indoor Airflow Pattern and ACH

The purpose of heating, ventilation, and air conditioning (HVAC) systems are to create optimum thermal comfort and appropriate indoor air quality (IAQ) for occupants. Air ventilation systems can significantly affect the health risk in indoor environments, especially those by contaminated aerosols. Therefore, the main goal of the study is to analyze the indoor airflow patterns in the heating, ventilation, and air conditioning (HVAC) systems and the impact of outlets/windows. The other goal of this study is to simulate the trajectory of the aerosols from a human sneeze, investigate the impact of opening windows on the number of air changes per hour (ACH) and exhibit the role of dead zones with poor ventilation. The final goal is to show the application of computational fluid dynamics (CFD) simulation in improving the HVAC design, such as outlet locations or airflow rate, in addition to the placement of occupants. In this regard, an extensive literature review has been combined with the CFD method to analyze the indoor airflow patterns, ACH, and the role of windows. The airflow pattern analysis shows the critical impact of inflow/outflow and windows. The results show that the CFD model simulation could exhibit optimal placement and safer locations for the occupants to decrease the health risk. The results of the discrete phase simulation determined that the actual ACH could be different from the theoretical ACH as the short circuit and dead zones affect the ACH.

CFD Investigation of Vehicle’s Ventilation Systems and Analysis of ACH in Typical Airplanes, Cars, and Buses

The simulation of the ventilation and the heating, ventilation, and air conditioning (HVAC) systems of vehicles could be used in the energy demand management of vehicles besides improving the air quality inside their cabins. Moreover, traveling by public transport during a pandemic is a concerning factor, and analysis of the vehicle’s cabin environments could demonstrate how to decrease the risk and create a safer journey for passengers. Therefore, this article presents airflow analysis, air changes per hour (ACH), and respiration aerosols’ trajectory inside three vehicles, including a typical car, bus, and airplane. In this regard, three vehicles’ cabin environment boundary conditions and the HVAC systems of the selected vehicles were determined, and three-dimensional numerical simulations were performed using computational fluid dynamic (CFD) modeling. The analysis of the airflow patterns and aerosol trajectories in the selected vehicles demonstrate the critical impact of inflow, outflow, and passenger’s locations in the cabins. The CFD model results exhibited that the lowest risk could be in the airplane and the highest in the bus because of the location of airflows and outflows. The discrete CFD model analysis determined the ACH for a typical car of about 4.3, a typical bus of about 7.5, and in a typical airplane of about 8.5, which were all less than the standard protocol of infection prevention, 12 ACH. According to the results, opening windows in the cars could decrease the aerosol loads and improve the low ACH by the HVAC systems. However, for the buses, a new design for the outflow location or an increase in the number of outflows appeared necessary. In the case of airplanes, the airflow paths were suitable, and by increasing the airflow speed, the required ACH might be achieved. Finally, in the closed (recirculating) systems, the role of filters in decreasing the risk appeared critical.

Fungi in the indoor air of critical hospital areas: a review

Invasive fungal infection is an important cause of mortality and morbidity in neonates, especially in low-birthweight neonates. The contribution of fungi in the indoor air to the incidence of mucocutaneous colonization and to the risk of invasive fungal infection in this population is uncertain. This review aimed to identify and to summarize the best available evidence on the fungal contamination in the indoor air of critical hospital areas with an emphasis on pediatric/neonatal ICUs. Publications from 2005 to 2019 were searched in the databases Scientific Electronic Library Online (SciELO), US National Library of Medicine National Institutes of Health Search (PubMed), and Latin American Caribbean Health Sciences (LILACS). Descriptors in Health Sciences (DeCS) were used. Research papers published in Portuguese, English, and Spanish were included. Twenty-nine papers on all continents except Australia were selected. The results showed that the air mycobiota contained several fungal species, notably Aspergillus, Penicillium, Cladosporium, Fusarium, and yeast (Candida) species. The selected papers point out the risks that fungi pose to neonates, who have immature immune system, and describe simultaneous external factors (air humidity, seasonality, air and people flow, use of particulate filters, and health professionals' hand hygiene) that contribute to indoor air contamination with fungi. Improving communication among health professionals is a great concern because this can prevent major health complications in neonates, especially in low-birthweight neonates. The results reinforced the need to monitor environmental fungi more frequently and efficiently in hospitals, especially in neonatal ICUs.

COVID-19 Outbreak and Hospital Air Quality: A Systematic Review of Evidence on Air Filtration and Recirculation

The outbreak of SARS-CoV-2 has made us all think critically about hospital indoor air quality and the approaches to remove, dilute, and disinfect pathogenic organisms from the hospital environment. While specific aspects of the coronavirus infectivity, spread, and routes of transmission are still under rigorous investigation, it seems that a recollection of knowledge from the literature can provide useful lessons to cope with this new situation. As a result, a systematic literature review was conducted on the safety of air filtration and air recirculation in healthcare premises. This review targeted a wide range of evidence from codes and regulations, to peer-reviewed publications, and best practice standards. The literature search resulted in 394 publications, of which 109 documents were included in the final review. Overall, even though solid evidence to support current practice is very scarce, proper filtration remains one important approach to maintain the cleanliness of indoor air in hospitals. Given the rather large physical footprint of the filtration system, a range of short-term and long-term solutions from the literature are collected. Nonetheless, there is a need for a rigorous and feasible line of research in the area of air filtration and recirculation in healthcare facilities. Such efforts can enhance the performance of healthcare facilities under normal conditions or during a pandemic. Past innovations can be adopted for the new outbreak at low-to-minimal cost.

Molecular Epidemiology of Aspergillus fumigatus in Chronic Pulmonary Aspergillosis Patients

Molecular fungal genotyping techniques developed and employed for epidemiological studies have understandably concentrated on establishing the genetic diversity of Aspergillus fumigatus in invasive aspergillosis due to its severity, the urgency for treatment, and the need to demonstrate possible sources. Some early studies suggested that these strains were phenotypically, if not genotypically, different from others. However, with improved discrimination and evaluations, incorporating environmental as well as clinical isolates from other Aspergillus conditions (e.g., chronic pulmonary aspergillosis and cystic fibrosis), this premise is no longer upheld. Moreover, with the onset of increased global triazole resistance, there has been a concerted effort to incorporate resistance profiling into genotyping studies and the realisation that the wider population of non-immunocompromised aspergillosis patients are at risk. This review summarises the developments in molecular genotyping studies that incorporate resistance profiling with attention to chronic pulmonary aspergillosis and an example of our UK experience.

Microbial Monitoring as a Tool for Preventing Infectious Risk in the Operating Room: Results of 10 Years of Activity

Environmental microbial contamination in the operating room (OR) can favour contamination of the surgical wound, posing the risk of infection of the surgical site. Thus, environmental monitoring is a useful tool for assessing environmental health and the effectiveness and efficiency of the measures adopted to control the risk of infection in the OR. This work aimed to analyse the long term environmental quality of 18 ORs throughout Sardinia, Italy, through the quantitative and qualitative characterisation of the microbial flora present in the air and on surfaces, in order to evaluate the trend over time, including in relation to any control measures adopted. The results of the sampling carried out in the period from January 2010 to December 2019 have been extrapolated from the archive-database of the Laboratory of the Hygiene and Control of Hospital Infections Unit of the University Hospital in Sassari. During the period in question, 188 air evaluations were carried out, both in empty rooms and during surgery, and 872 surface samples were taken. When the air was monitored, it emerged that significant contamination was detectable in a reduced number of examinations and a limited number of rooms. Microbial load values higher than the reference values may have been mainly determined by sub-optimal operation/maintenance of the air conditioning system. Surface testing showed a good level of sanitisation, given the low percentage of non-compliant values detected. The possibility of having data available on environmental quality is a useful educational and training tool both for those responsible for sanitisation procedures and the surgical team, in order to increase awareness of the effects of a lack of compliance with behavioural standards.

Heating, ventilation and air conditioning (HVAC) in intensive care unit

The aim of this review is to describe variation in standards and guidelines on ‘heating, ventilation and air-conditioning (HVAC)’ system maintenance in the intensive care units, across the world, which is required to maintain good ‘indoor air quality’ as an important non-pharmacological strategy in preventing hospital-acquired infections. An online search and review of standards and guidelines published by various societies including American Institute of Architects (AIA), American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), Centers for Disease Control and Prevention (CDC), Department of Health Estates and Facilities Division, Health Technical Memorandum 2025 (HTM) and Healthcare Infection Control Practices Advisory Committee (HICPAC) along with various national expert committee consensus statements, regional and hospital-based protocols available in a public domain were retrieved. Selected publications and textbooks describing HVAC structural aspects were also reviewed, and we described the basic structural details of HVAC system as well as variations in the practised standards of HVAC system in the ICU, worldwide. In summary, there is a need of universal standards for HVAC system with a specific mention on the type of ICU, which should be incorporated into existing infection control practice guidelines.

Relocating to a New OR Suite: Practical Observations

Operating room renovation projects usually involve updated technology and processes that can create challenges for administrative leaders (eg, maintaining a surgery schedule during a move) and require staff member adjustments. The perioperative team of a large tertiary care and trauma center relocated from a 35-year-old suite to a new suite, which required years of planning, months of training, and weeks of organizing. This article discusses the processes and observations that helped ensure a smooth transition to the new space. Early planning allowed time for leaders to make equipment decisions, develop and test new processes, and train staff members. The actual move required detailed planning, thorough execution, patience, and flexibility to ensure a safe transition. Perioperative leaders balanced operational needs with relocation plans to maintain patient and staff member safety. Open, multidisciplinary communication combined with staff member participation and buy-in contributed to an efficient, safe move at this facility.

Sternal osteomyelitis secondary to Aspergillus fumigatus after cardiothoracic surgery

Sternal Osteomyelitis from Aspergillus fumigatus in immunocompetent patients is extremely rare with limited number of cases reported so far. Here we discuss the case of a 65-year-old female with osteomyelitis of the sternum caused by Aspergillus fumigatus after undergoing coronary artery bypass graft surgery. Patient was treated with surgical debridement and prolonged antifungal therapy; however, the course was complicated due to poor adherence to antifungal therapy.

Effects of indoor environmental parameters related to building heating, ventilation, and air conditioning systems on patients' medical outcomes: A review of scientific research on hospital buildings

The indoor environment of a mechanically ventilated hospital building controls infection rates as well as influences patients' healing processes and overall medical outcomes. This review covers the scientific research that has assessed patients' medical outcomes concerning at least one indoor environmental parameter related to building heating, ventilation, and air conditioning (HVAC) systems, such as indoor air temperature, relative humidity, and indoor air ventilation parameters. Research related to the naturally ventilated hospital buildings was outside the scope of this review article. After 1998, a total of 899 papers were identified that fit the inclusion criteria of this study. Of these, 176 papers have been included in this review to understand the relationship between the health outcomes of a patient and the indoor environment of a mechanically ventilated hospital building. The purpose of this literature review was to summarize how indoor environmental parameters related to mechanical ventilation systems of a hospital building are impacting patients. This review suggests that there is a need for future interdisciplinary collaborative research to quantify the optimum range for HVAC parameters considering airborne exposures and patients' positive medical outcomes.

Microbiological Air Quality in Heating, Ventilation and Air Conditioning Systems of Surgical and Intensive Care Areas: The Application of a Disinfection Procedure for Dehumidification Devices

International literature data report that the increase of infectious risk may be due to heating, ventilation and air conditioning (HVAC) systems contaminated by airborne pathogens. Moreover, the presence of complex rotating dehumidification wheels (RDWs) may complicate the cleaning and disinfection procedures of the HVAC systems. We evaluated the efficacy of a disinfection strategy applied to the RDW of two hospitals’ HVAC systems. Hospitals have four RDW systems related to the surgical areas (SA1 and SA2) and to the intensive and sub-intensive care (IC and sIC) units. Microbiological air and surface analyses were performed in HVAC systems, before and after the disinfection treatment. Hydrogen peroxide (12%) with silver ions (10 mg/L) was aerosolized in all the air sampling points, located close to the RDW device. After the air disinfection procedure, reductions of total microbial counts at 22 °C and molds were achieved in SA2 and IC HVAC systems. An Aspergillus fumigatus contamination (6 CFU/500 L), detected in one air sample collected in the IC HVAC system, was eradicated after the disinfection. The surface samples proved to be of good microbiological quality. The results suggest the need for a disinfection procedure to improve the microbiological quality of the complex HVAC systems, mostly in surgical and intensive care areas.

Door openings in the operating room are associated with increased environmental contamination

Door openings in the operating room (OR) have been hypothesized to increase OR environmental contamination. This study measured average colony-forming units (CFU) in the OR as a function of door openings and other potentially important variables. Bacterial settle plates were placed inside and outside of laminar airflow (LAF) by both exit doors, on the instrument table, and on the back instrument table (if applicable) for 48 orthopedic and general surgery procedures. CFU data were paired to Staphylococcus aureus colonization status, door openings, surgery duration, time of day, OR location, number of staff, use of warming devices, temperature, and humidity. The number of door openings in the OR and surgery duration were significantly associated with increased CFU in the OR overall and outside of LAF. However, under LAF conditions, only the number of OR personnel was significantly associated with increased CFU.

Postsurgical mediastinal aspergilloma masquerading as malignancy

A 70-year-old man with non-ischaemic dilated cardiomyopathy presented with symptoms of fatigue, chills and unintentional weight loss over the past 2 months. Initial evaluation revealed anaemia, peripheral leucocytosis and elevated inflammatory markers. Results of an oesophagogastroduodenoscopy, colonoscopy, blood bacterial and fungal cultures and bone marrow biopsy were negative. An ¹⁸F-FDG positron-emission tomography-CT demonstrated an indeterminate, intensely FDG-avid 5 cm × 2 cm × 5.6 cm × 6.7 cm mass centred within the junction of the superior vena cava and right atrium, suggestive of probable malignancy versus an inflammatory thrombus. After multidisciplinary consideration, patient underwent a diagnostic minithoracotomy and a thick fibrotic mediastinal mass was visualised and evacuated. The encapsulated mass contained thick, white creamy liquid that appeared to be purulent/necrotic material. The biopsies of the capsule wall on frozen section demonstrated fungal elements consistent with Aspergillosis species. Fungal culture confirmed diagnosis of Aspergillus fumigatus.

Spatial Patterns and Impacts of Environmental and Climatic Factors on Canine Sinonasal Aspergillosis in Northern California

Sinonasal aspergillosis (SNA) causes chronic nasal discharge in dogs and has a worldwide distribution, although most reports of SNA in North America originate from the western USA. SNA is mainly caused by Aspergillus fumigatus, a ubiquitous saprophytic filamentous fungus. Infection is thought to follow inhalation of spores. SNA is a disease of the nasal cavity and/or sinuses with variable degrees of local invasion and destruction. While some host factors appear to predispose to SNA (such as belonging to a dolichocephalic breed), environmental risk factors have been scarcely studied. Because A. fumigatus is also the main cause of invasive aspergillosis in humans, unraveling the distribution and the environmental and climatic risk factors for this agent in dogs would be of great benefit for public health studies, advancing understanding of both distribution and risk factors in humans. In this study, we reviewed electronic medical records of 250 dogs diagnosed with SNA between 1990 and 2014 at the University of California Davis Veterinary Medical Teaching Hospital (VMTH). A 145-mile radius catchment area around the VMTH was selected. Data were aggregated by zip code and incorporated into a multivariate logistic regression model. The logistic regression model was compared to an autologistic regression model to evaluate the effect of spatial autocorrelation. Traffic density, active composting sites, and environmental and climatic factors related with wind and temperature were significantly associated with increase in disease occurrence in dogs. Results provide valuable information about the risk factors and spatial distribution of SNA in dogs in Northern California. Our ultimate goal is to utilize the results to investigate risk-based interventions, promote awareness, and serve as a model for further studies of aspergillosis in humans.

Role of Human Factors Engineering in Infection Prevention: Gaps and Opportunities

Human factors engineering (HFE), with its focus on studying how humans interact with systems, including their physical and organizational environment, the tools and technologies they use, and the tasks they perform, provides principles, tools, and techniques for systematically identifying important factors, for analyzing and evaluating how these factors interact to increase or decrease the risk of Healthcare-associated infections (HAI), and for identifying and implementing effective preventive measures. We reviewed the literature on HFE and infection prevention and control and identified major themes to document how researchers and infection prevention staff have used HFE methods to prevent HAIs and to identify gaps in our knowledge about the role of HFE in HAI prevention and control. Our literature review found that most studies in the healthcare domain explicitly applying (HFE) principles and methods addressed patient safety issues not infection prevention and control issues. In addition, most investigators who applied human factors principles and methods to infection prevention issues assessed only one human factors element such as training, technology evaluations, or physical environment design. The most significant gap pertains to the limited use and application of formal HFE tools and methods. Every infection prevention study need not assess all components in a system, but investigators must assess the interaction of critical system components if they want to address latent and deep-rooted human factors problems.

A Pseudo-outbreak of Aspergillosis at a Tertiary Care Hospital: Thinking Beyond the Infection Control Risk Assessment

In the modern era of carefully monitored renovations, construction-relatedAspergillusoutbreaks have decreased. We investigated an increase in clinical cultures growingAspergillusspecies, determining that contamination of the mycology lab caused a pseudo-outbreak. A major construction site was appropriately sealed, but unrecognized staff traffic may have facilitated laboratory contamination.

Infect Control Hosp Epidemiol2016;1–4

Aspergillus mediastinitis after cardiac surgery

BACKGROUND

Mediastinitis is a serious complication after cardiac surgery. While bacteria are the more common pathogens, fungal infections are rare. In particular, several cases of postoperative Aspergillus mediastinitis have been reported, the majority of which had an extremely poor outcome.

METHODS

A case of mediastinitis in a 42-year-old patient due to Aspergillus fumigatus after cardiac surgery is described. Two main risk factors were found: cardiogenic shock requiring veno-arterial extracorporeal life support and failure of primary closure of the sternum. A full recovery was attained after surgical drainage and antifungal therapy with liposomal amphotericin B, followed by a combination of voriconazole and caspofungin. The patient was followed for 18 months without relapse.

RESULTS

This is an extremely rare case of postoperative Aspergillus mediastinitis exhibiting a favourable outcome. Based on a systematic review of the literature, previous cases were examined with a focus on risk factors, antifungal therapies, and outcomes.

CONCLUSION

The clinical features of postoperative Aspergillus mediastinitis may be paucisymptomatic, emphasizing the need for a low index of suspicion in cases of culture-negative mediastinitis or in indolent wound infections. In addition to surgical debridement, the central component of antifungal therapy should include amphotericin B or voriconazole.

Surface contamination in operating rooms: a risk for transmission of pathogens?

BACKGROUND

The role of surface contamination in the transmission of nosocomial pathogens is recognized increasingly. For more than 100 years, the inanimate environment in operating rooms (e.g., walls, tables, floors, and equipment surfaces) has been considered a potential source of pathogens that may cause surgical site infections (SSIs). However, the role of contaminated surfaces in pathogen acquisition in this setting generally is considered negligible, as most SSIs are believed to originate from patients' or healthcare workers' flora.

METHODS

A search of relevant medical literature was performed using PubMed to identify studies that investigated surface contamination of operating rooms and its possible role in infection transmission.

RESULTS

Despite a limited number of studies evaluating the role of surface contamination in operating rooms, there is accumulating evidence that the inanimate environment of the operating room can become contaminated with pathogens despite standard environmental cleaning. These pathogens can then be transmitted to the hands of personnel and then to patients and may result in SSIs and infection outbreaks.

CONCLUSION

Contaminated surfaces can be responsible for the transmission of pathogens in the operating room setting. Further studies are necessary to quantify the role of contaminated surfaces in the transmission of pathogens and to inform the most effective environmental interventions. Given the serious consequences of SSIs, special attention should be given to the proper cleaning and disinfection of the inanimate environment in operating rooms in addition to the other established infection control measures to reduce the burden of SSIs.

Environmental contamination and hospital-acquired infection: factors that are easily overlooked

There is an ongoing debate about the reasons for and factors contributing to healthcare-associated infection (HAI). Different solutions have been proposed over time to control the spread of HAI, with more focus on hand hygiene than on other aspects such as preventing the aerial dissemination of bacteria. Yet, it emerges that there is a need for a more pluralistic approach to infection control; one that reflects the complexity of the systems associated with HAI and involves multidisciplinary teams including hospital doctors, infection control nurses, microbiologists, architects, and engineers with expertise in building design and facilities management. This study reviews the knowledge base on the role that environmental contamination plays in the transmission of HAI, with the aim of raising awareness regarding infection control issues that are frequently overlooked. From the discussion presented in the study, it is clear that many unknowns persist regarding aerial dissemination of bacteria, and its control via cleaning and disinfection of the clinical environment. There is a paucity of good-quality epidemiological data, making it difficult for healthcare authorities to develop evidence-based policies. Consequently, there is a strong need for carefully designed studies to determine the impact of environmental contamination on the spread of HAI.

Spatial and temporal analyses to investigate infectious disease transmission within healthcare settings

Background

Healthcare-associated infections (HCAIs) cause significant morbidity and mortality worldwide, and outbreaks are often only identified after they reach high levels. A wide range of data is collected within healthcare settings; however, the extent to which this information is used to understand HCAI dynamics has not been quantified.

Aim

To examine the use of spatiotemporal analyses to identify and prevent HCAI transmission in healthcare settings, and to provide recommendations for expanding the use of these techniques.

Methods

A systematic review of the literature was undertaken, focusing on spatiotemporal examination of infectious diseases in healthcare settings. Abstracts and full-text articles were reviewed independently by two authors to determine inclusion.

Findings

In total, 146 studies met the inclusion criteria. There was considerable variation in the use of data, with surprisingly few studies (N = 22) using spatiotemporal-specific analyses to extend knowledge of HCAI transmission dynamics. The remaining 124 studies were descriptive. A modest increase in the application of statistical analyses has occurred in recent years.

Conclusion

The incorporation of spatiotemporal analysis has been limited in healthcare settings, with only 15% of studies including any such analysis. Analytical studies provided greater data on transmission dynamics and effective control interventions than studies without spatiotemporal analyses. This indicates the need for greater integration of spatiotemporal techniques into HCAI investigations, as even simple analyses provide significant improvements in the understanding of prevention over simple descriptive summaries.

Aspergillus osteomyelitis: epidemiology, clinical manifestations, management, and outcome

BACKGROUND

The epidemiology, pathogenesis, diagnosis, and management of Aspergillus osteomyelitis are not well understood.

METHODS

Protocol-defined cases of Aspergillus osteomyelitis published in the English literature were reviewed for comorbidities, microbiology, mechanisms of infection, clinical manifestations, radiological findings, inflammatory biomarkers, antifungal therapy, and outcome.

RESULTS

Among 180 evaluable patients, 127 (71%) were males. Possible predisposing medical conditions in 103 (57%) included pharmacological immunosuppression, primary immunodeficiency, and neutropenia. Seventy-three others (41%) had prior open fracture, trauma or surgery. Eighty (44%) followed a hematogenous mechanism, 58 (32%) contiguous infections, and 42 (23%) direct inoculation. Aspergillus osteomyelitis was the first manifestation of aspergillosis in 77%. Pain and tenderness were present in 80%. The most frequently infected sites were vertebrae (46%), cranium (23%), ribs (16%), and long bones (13%). Patients with vertebral Aspergillus osteomyelitis had more previous orthopedic surgery (19% vs 0%; P = 0.02), while those with cranial osteomyelitis had more diabetes mellitus (32% vs 8%; P = 0.002) and prior head/neck surgery (12% vs 0%; P = 0.02). Radiologic findings included osteolysis, soft-tissue extension, and uptake on T2-weighted images. Vertebral body Aspergillus osteomyelitis was complicated by spinal-cord compression in 47% and neurological deficits in 41%. Forty-four patients (24%) received only antifungal therapy, while 121 (67%) were managed with surgery and antifungal therapy. Overall mortality was 25%. Median duration of therapy was 90 days (range, 10-772 days). There were fewer relapses in patients managed with surgery plus antifungal therapy in comparison to those managed with antifungal therapy alone (8% vs 30%; P = 0.006).

CONCLUSIONS

Aspergillus osteomyelitis is a debilitating infection affecting both immunocompromised and immunocompetent patients. The most common sites are vertebrae, ribs, and cranium. Based upon this comprehensive review, management of Aspergillus osteomyelitis optimally includes antifungal therapy and selective surgery to avoid relapse and to achieve a complete response.

Roles of sunlight and natural ventilation for controlling infection: historical and current perspectives

BACKGROUND

Infections caught in buildings are a major global cause of sickness and mortality. Understanding how infections spread is pivotal to public health yet current knowledge of indoor transmission remains poor.

AIM

To review the roles of natural ventilation and sunlight for controlling infection within healthcare environments.

METHODS

Comprehensive literature search was performed, using electronic and library databases to retrieve English language papers combining infection; risk; pathogen; and mention of ventilation; fresh air; and sunlight. Foreign language articles with English translation were included, with no limit imposed on publication date.

FINDINGS

In the past, hospitals were designed with south-facing glazing, cross-ventilation and high ceilings because fresh air and sunlight were thought to reduce infection risk. Historical and recent studies suggest that natural ventilation offers protection from transmission of airborne pathogens. Particle size, dispersal characteristics and transmission risk require more work to justify infection control practices concerning airborne pathogens. Sunlight boosts resistance to infection, with older studies suggesting potential roles for surface decontamination.

CONCLUSIONS

Current knowledge of indoor transmission of pathogens is inadequate, partly due to lack of agreed definitions for particle types and mechanisms of spread. There is recent evidence to support historical data on the effects of natural ventilation but virtually none for sunlight. Modern practice of designing healthcare buildings for comfort favours pathogen persistence. As the number of effective antimicrobial agents declines, further work is required to clarify absolute risks from airborne pathogens along with any potential benefits from additional fresh air and sunlight.

An outbreak of acute post-cataract surgery Pseudomonas sp. endophthalmitis caused by contaminated hydrophilic intraocular lens solution

OBJECTIVE

To report the investigation for the source of infection and the clinical course and treatment response of 11 cases of acute post-cataract surgery endophthalmitis that developed during an outbreak.

DESIGN

Retrospective, consecutive, interventional case series.

PARTICIPANTS

Eleven patients who developed acute postoperative endophthalmitis after an uneventful cataract surgery with intraocular lens implantation from September 6 to 29, 2010, at a tertiary eye care center in South India.

METHODS

Aqueous aspirates, vitreous aspirates, and environmental surveillance specimens were sampled. All specimens were subjected to smear and culture. Positive cultures were subjected to antibiotic susceptibility. Genotypic diversity was determined by polymerase chain reaction (PCR) with enterobacterial repetitive intergenic consensus (ERIC) primers of each strain and was used to establish the clonal relationship between clinical and environmental isolates. The clinical patterns were analyzed.

MAIN OUTCOME MEASURES

Positive microbiology, molecular diagnostic similarity among the culture positive endophthalmitis cases, and surveillance specimens.

RESULTS

Aqueous and vitreous samples showed gram-negative bacilli in the smears of 8 of 11 eyes, and cultures grew Pseudomonas aeruginosa in 5 of 11 eyes. Among the samples from various surveillance specimens cultured, only the hydrophilic acrylic intraocular lenses and their solution grew P. aeruginosa, with antibiotic susceptibility pattern identical to the clinical isolates. The isolates from the patients and the intraocular lens solution revealed matching patterns similar to an American Type Culture Collection (ATCC) strain of P. aeruginosa on ERIC-PCR. The intraocular lenses of the same make were discontinued at our hospital, and the endophthalmitis did not recur. The final visual acuity improved to ≥ 20/50 in 8 of 11 patients (72.7%). One patient developed retinal detachment, but was treated successfully, and 2 other patients progressed to phthisis bulbi.

CONCLUSIONS

Positive microbiology and the ERIC-PCR results proved that contamination of hydrophilic intraocular lenses and the preservative solution was the source of infection in this outbreak. Early detection and a planned approach during the outbreak helped us to achieve good visual and anatomic outcomes, even though the offending organism was identified as P. aeruginosa.

Dynamics of fungal colonization in a new medical mycology laboratory

OBJECTIVE OF THE STUDY

Study of the spatio-temporal fungal colonization in a new medical mycology laboratory.

METHODS

A 17-month survey of airborne fungal contamination was conducted in a new medical mycology laboratory at a tertiary care university hospital. This survey was implemented at three different periods: before the new premises were occupied (period A), during the move into the new laboratory (period B) and after resumption of the mycological activities in these new premises (period C).

RESULTS

During period A, the airborne fungal load ranged from 2.3 to 6 cfu/m(3). The most frequently recovered airborne fungi were Penicillium spp. (75 to 100%). During period B, a dramatic increase in Penicillium chrysogenum conidia was observed in the air of the new laboratory (40 to 160 cfu/m(3)). During period C, the fungal load ranged from 4.5 to 8.4 cfu/m(3). Penicillium was the most common genus identified in rooms of the laboratory where no filamentous fungi were handled, while Aspergillus was clearly the predominant genus (78%) in the room dedicated to the culture of filamentous fungi.

CONCLUSIONS

We suggest that the specific fungal ecology in air of the room dedicated to the culture of filamentous fungi is due to the handling of a large number of medical strains of A. fumigatus.

Isolation and characterization of Acanthamoeba spp. from air-conditioners in Kuala Lumpur, Malaysia

During a study on the quality of the indoor environment, Acanthamoeba spp. were detected in 20 out of 87 dust samples collected from air-conditioners installed in a four-story campus building located in Kuala Lumpur, Malaysia. Twenty-one cloned Acanthamoeba isolates designated as IMU1 to IMU21 were established from the positive primary cultures. Five species were identified from the 16 isolates according to the morphological criteria of Pussard and Pons; i.e. A. castellanii, A. culbertsoni, A. griffini, A. hatchetti and A. polyphaga. Species identities for the remaining five isolates (IMU4, IMU5, IMU15, IMU20 and IMU21), however, could not be determined morphologically. At genotypic characterization, these isolates were placed into T3 (IMU14); T5 (IMU16 and IMU17) and T4 (all the remaining isolates). To predict the potential pathogenicity of these Acanthamoeba isolates, thermo- and osmotolerance tests were employed; many isolates were predicted as potential human pathogens based on the outcome of these tests. This is the first time potentially pathogenic Acanthamoeba have been isolated from air-conditioners in Malaysia.

Mediastinitis in pediatric cardiac surgery: Prevention, diagnosis and treatment

In spite of advances in the management of mediastinitis following sternotomy, mediastinitis is still associated with significant morbidity. The prognosis is much better in pediatric surgery compared to adult surgery, but the prolonged hospital stays with intravenous therapy and frequent required dressing changes that occur with several therapeutic approaches are poorly tolerated. Prevention includes nasal decontamination, skin preparation, antibioprophylaxis and air filtration in the operating theater. The expertise of the surgical team is an additional factor that is difficult to assess precisely. Diagnosis is often very simple, being made on the basis of a septic state with wound modification, while retrosternal puncture and CT scan are rarely useful. Treatment of mediastinitis following sternotomy is always a combination of surgical debridement and antibiotic therapy. Continued use of numerous surgical techniques demonstrates that there is no consensus and the best treatment has yet to be determined. However, we suggest that a primary sternal closure is the best surgical option for pediatric patients. We propose a simple technique with high-vacuum Redon's catheter drainage that allows early mobilization and short term antibiotherapy, which thus decreases physiological and psychological trauma for patients and families. We have demonstrated the efficiency of this technique, which is also cost-effective by decreasing intensive care and hospital stay durations, in a large group of patients.

Mold remediation in a hospital

As occupants in a hospital, patients are susceptible to air contaminants that can include biological agents dispersed throughout the premise. An exposed patient can become ill and require medical intervention. A consideration for patients is that they may have become environmentally sensitive and require placement in an environment that does not compromise their health. Unfortunately, the hospital environment often contains more biological substances than can be expected in an office or home environment. When a hospital also experiences water intrusion such as flooding or water leaks, resulting mold growth can seriously compromise the health of patients and others such as nursing staff and physicians (Burge, Indoor Air and Infectious Disease. Occupational Medicine: State of the Art Reviews, 1980; Lutz et al., Clinical Infectious Diseases 37: 786—793, 2003). Micro-organism growth can propagate if the water is not addressed quickly and effectively. Immunocompromised patients are particularly at risk when subjected to fungal infection such that the US Center for Disease Control issued guideline for building mold in health care facilities (Centers for Disease and Control [CDC], Centers for Disease and Control: Questions and Answers on Stachybotrys chartarum and Other Molds, 2000). This paper is based on mold remediation of one portion of a hospital unit due to water from construction activity and inadequate maintenance, resulting in mold growth. A large proportion of the hospital staff, primarily nurses in the dialysis unit, exhibited health symptoms consistent with mold exposure. Unfortunately, the hospital administrators did not consider the mold risk to be serious and refused an independent consultant retained by the nurse’s union to examine the premise (Canadian Broadcasting Corporation [CBC], Nurses file complaints over mold at Foothills. Canadian Broadcasting Corporation, 2003). The nurse’s union managed to have the premise examined by submitting a court order of detention and inspection and for an interlocutory injunction to allow their consultants to undertake air quality testing. Mold remediation procedures are readily available and are not to be discussed here (Silicato, http://www.nibs.org/BETEC/M6/ 13-Silicato_Mold-Remediation.pdf, 2004). However, the difficulty of determining the qualifications of consultants, contactors and project managers are discussed. It also describes the need and importance of a buffer zone between the occupied areas and the mold abatement containment area.

The first documented case of Aspergillus cardiac surgical site infection in Sweden: an epidemiology study using arbitrarily primed PCR

Here we report two rare cases of severe thoracic Aspergillus fumigatus infections after lung and heart surgery at the same thoracic intensive care unit at the same time. The main objective was to identify a possible source of transmission. With arbitrarily primed polymerase chain reaction a patient-to-patient transmission could rapidly be ruled out as the cause of the first documented case of aspergillosis after open-heart surgery in Sweden. Although no definitive source was identified, a genetically similar strain was found in a contaminated supply room.