Reduction of Invasive Aspergillosis Incidence among Immunocompromised Patients after Control of Environmental Exposure

A practical approach to investigating nosocomial acquisition of Aspergillus

Invasive mould disease (IMD) has a high mortality in immunosuppressed patients. Invasive aspergillosis (IA) is the most common IMD. A guideline for preventing IA has been published jointly by the Centers for Disease Control and Prevention, the Infectious Disease Society of America, and the American Society of Blood and Marrow Transplantation. Use of high-efficiency particulate air filters, adequate air exchange rates, sealing of patient rooms, and preventing exposure to moulds by nursing patients in areas away from construction sites are recommended by the guideline. However, there is limited information in relation to the actions to be undertaken by infection prevention and control teams in the event of one or more cases of nosocomial aspergillosis. In this review, we describe a systematic approach to aspergillosis by defining possible and probable nosocomial acquisition based on the number of days since hospital admission. We advocate an incremental response to the investigation of nosocomial aspergillosis in patients in protective isolation taking into account the number of cases and the likelihood of nosocomial origin. For single cases of nosocomial IA, we suggest that infection control investigations should focus on case surveillance and walk-through inspection escalating in a stepwise manner to enhanced case surveillance, verification of environmental controls, environmental monitoring, genotyping of clinical and environmental isolates, and review of antifungal prophylaxis for multiple cases and outbreaks. Where applicable, the construction site should be inspected with the aim to reduce the dispersal of conidia. Surveillance systems need to be strengthened to better understand the epidemiology of IA.

Association between negative-pressure room utilization and hospital-acquired Aspergillus rates in patients with coronavirus disease 2019 (COVID-19) in two academic hospitals

Hospital-acquired Aspergillus rates among coronavirus disease 2019 (COVID-19) patients were initially higher at a hospital with high negative-pressure room utilization compared to a similar hospital with low utilization but with otherwise identical infection control policies. After the index hospital decreased negative-pressure utilization, hospital-acquired Aspergillus case rates at the 2 hospitals converged.

Neutropenia-related aspergillosis in non-transplant haematological patients hospitalised under ambient air versus purified air conditions

BACKGROUND

To reduce the risk of invasive aspergillosis (IA), air purification by high-efficiency particulate air filtration and laminar air flow (HEPA/LAF) is standard of care in allogeneic blood stem cell transplantation. Its use in non-transplant haematological patients is inconsistent.

OBJECTIVES

We sought to assess the incidence and outcome of pulmonary IA in non-transplant patients with life-threatening neutropenia by comparing an ambient air hospitalisation period (2008-2011) with a subsequent HEPA/LAF hospitalisation period (2012-2014).

PATIENTS AND METHODS

We compared 204 consecutive patients with acute myeloid leukaemia, acute lymphoblastic leukaemia or aplastic anaemia completing 534 neutropenia-related hospitalisations under ambient air conditions with 126 such patients completing 437 neutropenia-related hospitalisations under HEPA/LAF conditions. IA was defined using the 2008 EORTC/MSG criteria.

RESULTS

Within a 7-year study period, we observed one 'proven', three 'probable' and 73 'possible' IAs, most often during acute leukaemia remission induction. Their frequency rose with increasing duration of life-threatening neutropenia (1-10 days, 1.8%; >40 days, 35.2%) and concomitant severe anaemia (0 days, 3.2%; >20 days, 31.0%). Multiple logistic regression revealed a strong correlation between IA incidence and hospitalisation under HEPA/LAF conditions (odds ratio [OR], 0.368 [95% confidence interval, 0.207-0.654]; p < .001) and duration of neutropenia (OR, 1.043 [1.023-1.062] per day; p < .001) and anaemia (OR, 1.044 [1.008-1.081] per day; p = .016). IA-associated fatal outcomes were non-significantly reduced under HEPA/LAF (OR, 0.077 [0.005-1.151]; p = .063). The protective effect of HEPA/LAF was not seen under posaconazole prophylaxis (OR, 0.856 [0.376-1.950]; p = .711).

CONCLUSIONS

Implementation of HEPA/LAF was associated with a significant reduction in neutropenia-related IA in non-transplant haematological patients.

Airborne fungal spores and invasive aspergillosis in hematologic units in a tertiary hospital during construction: a prospective cohort study

Background

Invasive aspergillosis (IA) is an opportunistic fungal infection that mostly occurs in immunocompromised patients, such as those having hematologic malignancy or receiving hematopoietic stem cell transplantation. Inhalation of Aspergillus spores is the main transmission route of IA in immunocompromised patients. Construction work in hospitals is a risk factor for environmental fungal contamination. We measured airborne fungal contamination and the incidence of IA among immunocompromised patients, and evaluated their correlation with different types of construction works.

Methods

Our tertiary hospital in Seoul, Korea underwent facility construction from September 2017 to February 2018. We divided the entire construction period into period 1 (heavier works: demolition and excavation) and period 2 (lighter works: framing, interior designing, plumbing, and finishing). We conducted monthly air sampling for environmental spore surveillance in three hematologic wards. We evaluated the incidence of IA among all immunocompromised patients hospitalized in the three hematologic wards (2 adult wards and 1 pediatric ward) during this period. IA was categorized into proven, probable, and possible aspergillosis based on the revised European Organization for Research and Treatment of Cancer/Mycosis Study Group (EORTC/MSG) criteria.

Results

A total of 15 patients was diagnosed with proven (1 case), probable (8 cases), or possible (6 cases) hospital-acquired IA during period 1. In period 2, 14 patients were diagnosed with either proven (1 case), probable (10 cases), or possible (3 cases) hospital-acquired IA. Total mold and Aspergillus spp. spore levels in the air tended to be higher in period 1 (p = 0.06 and 0.48, respectively). The incidence rate of all IA by the EORTC/MSG criteria was significantly higher in period 1 than in period 2 (1.891 vs. 0.930 per 1000 person-days, p = 0.05).

Conclusions

Airborne fungal spore levels tended to be higher during the period with heavier construction works involving demolition and excavation, during which the incidence of IA was significantly higher as well. We recommend monitoring airborne fungal spore levels during construction periods in hospitals with immunocompromised patients. Subsequently, the effect of airborne fungal spore level monitoring in reducing hospital-acquired IA should be evaluated.

Electronic supplementary material

The online version of this article (10.1186/s13756-019-0543-1) contains supplementary material, which is available to authorized users.

Outcome of non-mold effective anti-fungal prophylaxis in patients at high-risk for invasive fungal infections after allogenic stem cell transplantation

Patients who develop severe graft-versus-host disease (GvHD) after allogeneic stem cell transplantation (alloSCT) have a higher risk for invasive fungal infection (IFI). At our center, fluconazole prophylaxis is standard and upfront mold-effective prophylaxis performed only in patients with specific risk constellations. A total of 290 patients undergoing alloSCT between May 2002 and August 2011 were analyzed. Patients were regarded as high-risk if they suffered from acute GvHD II-IV° or extensive chronic GvHD. The 2-year incidence of an IFI after alloSCT was 8.97% (26/290) in the entire cohort and 7.78% (7/90) in the high-risk group. Mortality due to IFI was 3.85% (1/26) without including a high-risk patient. In the multivariate analysis a pre-transplant fungal infection was the only significant risk factor for developing an IFI after alloSCT (HR = 5.298; p = .001). A fluconazole prophylaxis in patients with GvHD after alloSCT is feasible in facilities with HEPA filtration and high awareness of clinical signs for IFI.

Update on infection control practices in cancer hospitals

Therapies in oncology have evolved rapidly over the last years. At the same pace, supportive care for patients receiving cancer therapy has also evolved, allowing patients to safely receive the newest advances in treatment in both an inpatient and outpatient basis. The recognition of the role of infection control and prevention (ICP) in the outcomes of patients living with cancer has been such that it is now a requirement for hospitals and involves multidisciplinary groups. Some unique aspects of ICP for patients with cancer that have gained momentum over the past few decades include catheter-related infections, multidrug-resistant organisms, community-acquired viral infections, and the impact of the health care environment on the horizontal transmission of organisms. Furthermore, as the potential for infections to cross international borders has increased, alertness for outbreaks or new infections that occur outside the area have become constant. As the future approaches, ICP in immunocompromised hosts will continue to integrate emerging disciplines, such as antibiotic stewardship and the microbiome, and new techniques for environmental cleaning and for controlling the spread of infections, such as whole-genome sequencing. CA Cancer J Clin 2018;000:000-000. © 2018 American Cancer Society.

Monitoring of clinical strains and environmental fungal aerocontamination to prevent invasive aspergillosis infections in hospital during large deconstruction work: a protocol study

INTRODUCTION

Monitoring fungal aerocontamination is an essential measure to prevent severe invasive aspergillosis (IA) infections in hospitals. One central block among 32 blocks of Edouard Herriot Hospital (EHH) was entirely demolished in 2015, while care activities continued in surrounding blocks. The main objective was to undertake broad environmental monitoring and clinical surveillance of IA cases to document fungal dispersion during major deconstruction work and to assess clinical risk.

METHODS AND ANALYSIS

A daily environmental survey of fungal loads was conducted in eight wards located near the demolition site. Air was collected inside and outside selected wards by agar impact samplers. Daily spore concentrations were monitored continuously by volumetric samplers at a flow rate of 10 L.min^-1. Daily temperature, wind direction and speed as well as relative humidity were recorded by the French meteorological station Meteociel. Aspergillus fumigatus strains stored will be genotyped by multiple-locus, variable-number, tandem-repeat analysis. Antifungal susceptibility will be assessed by E-test strips on Roswell Park Memorial Institute medium supplemented with agar. Ascertaining the adequacy of current environmental monitoring techniques in hospital is of growing importance, considering the rising impact of fungal infections and of curative antifungal costs. The present study could improve the daily management of IA risk during major deconstruction work and generate new data to ameliorate and redefine current guidelines.

ETHICS AND DISSEMINATION

This study was approved by the clinical research and ethics committees of EHH.

Hospital-Associated Infections

Hospital-associated infection (HAI) in immunocompromised patients can result in high rates of morbidity and mortality. Infections caused by multidrug-resistant organisms (MDROs) are especially worrisome because of the limited choice of remaining antibiotics available when a patient becomes colonized or infected with an MDRO. It is therefore important that immunocompromised patients be cared for in an environment that limits the risk for acquiring infections. However, with healthcare being increasingly delivered in settings other than the traditional inpatient hospital wards, a bigger effort will need to be set forth to prevent or rapidly diagnose HAI. The last few years have seen a significant increase in the number of singleplex and multiplex molecular assays for the detection of many of the organisms responsible for HAI, but more is needed as infections caused by organisms like Legionella pneumophila and Aspergillus species are still diagnosed with methods that have relatively low yield and are slow to provide actionable results. Finally, the use of novel techniques for outbreak investigations will provide new information on transmission of infectious agents in healthcare settings and allow stronger, evidence-based recommendations to be developed for prevention of HAIs in the immunocompromised host.

Recommendations for Risk Categorization and Prophylaxis of Invasive Fungal Diseases in Hematological Malignancies: A Critical Review of Evidence and Expert Opinion (TEO-4)

This is the last of a series of articles on invasive fungal infections prepared by opinion leaders in Turkey. The aim of these articles is to guide clinicians in managing invasive fungal diseases in hematological malignancies and stem cell transplantation based on the available best evidence in this field. The previous articles summarized the diagnosis and treatment of invasive fungal disease and this article aims to explain the risk categorization and guide the antifungal prophylaxis in invasive fungal disease.

Risk factors and prophylaxis against invasive fungal disease for haematology and stem cell transplant recipients: an evolving field

INTRODUCTION

Due to increasing intensity and complexity of therapies and longer survivorship, many patients with haematologic malignancy (HM) are at risk of invasive fungal disease (IFD). Mortality from IFD is high and treatment of an episode of IFD results in an excess length of hospital stay and costs and delays delivery of curative therapy of the underlying haematologic condition. Therefore, prevention and early recognition and treatment of IFD are crucial. Areas covered: Risk factors particular to certain HMs and haematopoietic stem cell transplantation, as well as those risk factors universal to all HM groups are examined. Expert commentary: Risk stratification identifies those patients who would benefit most from mould active versus yeast active prophylaxis and those who can be safely managed with monitoring and clinically driven interventions for IFD. This approach aids in antifungal stewardship.

The Plasmair Decontamination System Is Protective Against Invasive Aspergillosis in Neutropenic Patients

OBJECTIVE Invasive aspergillosis (IA) is a rare but severe infection caused by Aspergillus spp. that often develops in immunocompromised patients. Lethality remains high in this population. Therefore, preventive strategies are of key importance. The impact of a mobile air decontamination system (Plasmair, AirInSpace, Montigny-le-Bretonneux, France) on the incidence of IA in neutropenic patients was evaluated in this study. DESIGN Retrospective cohort study METHODS Patients with chemotherapy-induced neutropenia lasting 7 days or more were included over a 2-year period. Cases of IA were confirmed using the revised European Organization for Research and Treatment of Cancer (EORTC) criteria. We took advantage of a partial installation of Plasmair systems in the hematology intensive care unit during this period to compare patients treated in Plasmair-equipped versus non-equipped rooms. Patients were assigned to Plasmair-equipped or non-equipped rooms depending only on bed availability. Differences in IA incidence in both groups were compared using Fisher's exact test, and a multivariate analysis was performed to take into account potential confounding factors. RESULTS Data from 156 evaluable patients were available. Both groups were homogenous in terms of age, gender, hematological diagnosis, duration of neutropenia, and prophylaxis. A total of 11 cases of probable IA were diagnosed: 10 in patients in non-equipped rooms and only 1 patient in a Plasmair-equipped room. The odds of developing IA were much lower for patients hospitalized in Plasmair-equipped rooms than for patients in non-equipped rooms (P=.02; odds ratio [OR] =0.11; 95% confidence interval [CI], 0.00-0.84). CONCLUSION In this study, Plasmair demonstrated a major impact in reducing the incidence of IA in neutropenic patients with hematologic malignancies. Infect Control Hosp Epidemiol 2016;37:845-851.

A Quasi-Experimental Study Analyzing the Effectiveness of Portable High-Efficiency Particulate Absorption Filters in Preventing Infections in Hematology Patients during Construction

OBJECTIVE

The increased risk of infection for patients caused by construction and renovation near hematology inpatient clinics is a major concern. The use of high-efficiency particulate absorption (HEPA) filters can reduce the risk of infection. However, there is no standard protocol indicating the use of HEPA filters for patients with hematological malignancies, except for those who have undergone allogeneic hematopoietic stem cell transplantation. This quasi-experimental study was designed to measure the efficacy of HEPA filters in preventing infections during construction.

MATERIALS AND METHODS

Portable HEPA filters were placed in the rooms of patients undergoing treatment for hematological malignancies because of large-scale construction taking place near the hematology clinic. The rates of infection during the 6 months before and after the installation of the portable HEPA filters were compared. A total of 413 patients were treated during this 1-year period.

RESULTS

There were no significant differences in the antifungal prophylaxis and treatment regimens between the groups. The rates of infections, clinically documented infections, and invasive fungal infections decreased in all of the patients following the installation of the HEPA filters. When analyzed separately, the rates of invasive fungal infections were similar before and after the installation of HEPA filters in patients who had no neutropenia or long neutropenia duration. HEPA filters were significantly protective against infection when installed in the rooms of patients with acute lymphocytic leukemia, patients who were undergoing consolidation treatment, and patients who were neutropenic for 1-14 days.

CONCLUSION

Despite the advent of construction and the summer season, during which environmental Aspergillus contamination is more prevalent, no patient or patient subgroup experienced an increase in fungal infections following the installation of HEPA filters. The protective effect of HEPA filters against infection was more pronounced in patients with acute lymphocytic leukemia, patients undergoing consolidation therapy, and patients with moderate neutropenia.

Monitoring of Microscopic Filamentous Fungi in Indoor Air of Transplant Unit

AIM

The aim of the study was to control the microbial contamination of indoor air monitored monthly at the Transplant Unit of the University Hospital Olomouc from August 2010 to July 2011.

METHODS

The unit is equipped with a three-stage air filtration system with HEPA filters. The MAS-100 air sampler (Merck, GER) was used. Twenty locations were singled out for the purposes of collecting a total of 720 samplings of the indoor air. Swabs of the HVAC diffusers at the sampling locations were always carried out after the sampling of the indoor air.

RESULTS

In total, 480 samples of the indoor air were taken for Sabouraud chloramphenicol agar. In 11 cases (2.29%) the cultivation verified the presence of microscopic filamentous fungi. Only two cases involved the sanitary facilities of a patient isolation box; the other positive findings were from the facilities. The most frequent established genus was Aspergillus spp. (4x), followed by Trichoderma spp. (2x) and Penicillium spp. (2x), Paecilomyces spp., Eurotium spp., and Chrysonilia spp. (1x each). In 2 cases the cultivation established sterile aerial mycelium, unfortunately no further identification was possible. A total of 726 swabs of HVAC diffusers were collected (2 positive-0.28%). The study results demonstrated the efficacy of the HVAC equipment.

CONCLUSIONS

With the continuing increase in the number of severely immunocompromised patients, hospitals are faced with the growing problem of invasive aspergillosis and other opportunistic infections. Preventive monitoring of microbial air contaminants is of major importance for the control of invasive aspergillosis.

In-hospital transfer is a risk factor for invasive filamentous fungal infection among hospitalized patients with hematological malignancies: a matched case-control study

OBJECTIVE

Immunocompromised patients now benefit from a longer life expectancy due to advanced medical techniques, but they are also weakened by aggressive treatment approaches and are at high risk for invasive fungal disease. We determined risk factors associated with an outbreak of invasive filamentous fungal infection (IFFI) among hospitalized hemato-oncological patients.

METHODS

A retrospective, matched, case-control study was conducted between January 1, 2009, and April 31, 2011, including 29 cases (6 proven, 8 probable, and 15 possible) of IFFI and 102 matched control patients hospitalized during the same time period. Control patients were identified from the hospital electronic database. Conditional logistic regression was performed to identify independent risk factors for IFFI.

RESULTS

Overall mortality associated with IFFI was 20.7% (8.0%-39.7%). Myelodysplastic syndrome was associated with a higher risk for IFFI compared to chronic hematological malignancies. After adjustment for major risk factors and confounders, >5 patient transfers outside the protected environment of the hematology ward increased the IFFI risk by 6.1-fold. The risk increased by 6.7-fold when transfers were performed during neutropenia.

CONCLUSION

This IFFI outbreak was characterized by a strong association with exposure to the unprotected environment outside the hematology ward during patient transfer. The independent associations of a high number of transfers with the presence of neutropenia suggest that affected patients were probably not sufficiently protected during transport in the corridors. Our study highlights that a heightened awareness of the need for preventive measures during the entire care process of at-risk patients should be promoted among healthcare workers.

En-suite bathrooms in protected haematology wards: a source of filamentous fungal contamination?

BACKGROUND

In spite of 25 recently built high-risk haematology rooms with a protected environment and fitted with en-suite bathrooms in our university hospital centre in 2008, sporadic cases of hospital-acquired invasive aspergillosis remained in these wards.

AIM

This study aimed to identify unsuspected environmental sources of filamentous fungal contamination in these rooms.

METHODS

Over two months, environmental fungal flora in the air (150 samples) as well as air particle counting and physical environmental parameters (airspeed, temperature, humidity, pressure) were prospectively monitored twice on the sampling day in all 25 protected rooms and en-suite bathrooms in use, and on bathroom surfaces (150 samples).

FINDINGS

In rooms under laminar airflow, in the presence of patients during sampling sessions, fungi were isolated in two samples (4%, 2/50) with a maximum value of 2cfu/500L (none was Aspergillus sp.). However, 88% of the air samples (44/50) in the bathroom were contaminated with a median range and maximum value of 2 and 16cfu/500L. Aspergillus spp. were involved in 24% of contaminated samples (12/44) and A. fumigatus in 6% (3/44). Bathroom surfaces were contaminated by filamentous fungi in 5% of samples (8/150).

CONCLUSION

This study highlighted that en-suite bathrooms in protected wards are likely to be a source of fungi. Before considering specific treatment of air in bathrooms, technicians have first corrected the identified deficiencies: replacement of high-efficiency particulate air filters, improvement of air control automation, and restoration of initial technical specifications. Assessment of measure effectiveness is planned.

Invasive aspergillosis in neutropenic patients during hospital renovation: effectiveness of mechanical preventive measures in a prospective cohort of 438 patients

BACKGROUND

Aspergillus species are the main cause of invasive fungal disease for patients with severe and prolonged neutropenia. Building or renovation works have been shown as one of the major causes of outbreaks of aspergillosis.

OBJECTIVES

This study aimed to assess the effectiveness of introduction and adaptation by air sampling of mechanical preventive measures on the incidence of invasive pulmonary aspergillosis in neutropenic patients during hospital renovation.

PATIENTS

All of the patients admitted for prolonged and severe neutropenia during a renovation period from 2003 to 2008 were prospectively enrolled. Invasive pulmonary aspergillosis (IPA) cases were classified as possible, probable, and proven, according to the 2008 European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group criteria. The effectiveness of preventive measures was determined by air sampling.

RESULTS

We recorded 705 hospitalizations for neutropenia concerning 438 patients. The majority of hospitalized neutropenic patients was treated for acute leukemia (38.3 %), followed by patients suffering from non-Hodgkin and Hodgkin lymphomas (33 %). The total cumulative incidence of probable and proven IPA was 4.1 %. Risk factors for developing IPA were underlying disease, treatment course at the time of hospitalization, and the mean duration of hospitalization and of neutropenia.

CONCLUSIONS

In this prospective study, the incidence of invasive pulmonary aspergillosis did not increase in neutropenic patients during a renovation period because of efficient mechanical preventive measures systematically adjusted using the results of air sampling.

Evaluation of invasive aspergillosis risk of immunocompromised patients alternatively hospitalized in hematology intensive care unit and at home

Contrary to hospital exposure, little is known about the indoor fungal exposure of hematology patients at home. The aim of our study was to investigate the mold exposure of hematology patients both at home and at hospital to assess their invasive aspergillosis (IA) risk. Fungal exposure was assessed by quantifying opportunistic molds at hospital during hospitalization and in homes of 53 hematology patients. IA was diagnosed in 13 of 53 patients and invasive fungal infection (IFI) in one patient. In hospital, no opportunistic species, or low levels of opportunistic species, were found in 98% of weekly controls. Only 2% of hematology intensive care unit (ICU) controls showed a high level of Aspergillus fumigatus spores in corridor air. Five patients IA were hospitalized during these periods. Seven dwellings of 53 (5/14 dwellings of patients with IA/IFI and 2/39 dwellings of non-IA patients) had a percentage of A. fumigatus and Aspergillus flavus to total mold (significant predictor variable of IA/IFI in our study, general linear model, P-value = 0.02) as high as 15%. Maintaining a 'zero Aspergillus' goal at hospital is essential, and establishing specific and individually opportunistic mold monitoring at home could help to further reduce the IA risk through continuous surveillance.

PRACTICAL IMPLICATIONS

This study emphasizes the fact that preventive measures should not be aimed only at the hospital setting: among patients diagnosed with invasive aspergillosis/invasive fungal infection (IA/IFI), 5 of 14 (36%) were exposed to opportunistic fungal species at home exclusively. Moreover, four of these five patients were living in homes having the highest percentage of Aspergillus fumigatus and Aspergillus flavus (>15%), one of which had 48% of A. fumigatus. Therefore, our work supports the need for a counselor to carry out an environmental survey in patients’ homes.

Testing an innovative device against airborne Aspergillus contamination

Aspergillus fumigatus is a major airborne nosocomial pathogen that is responsible for severe mycosis in immunocompromised patients. We studied the efficacy of an innovative mobile air-treatment device in eliminating A. fumigatus from the air following experimental massive contamination in a high-security room. Viable mycological particles were isolated from sequential air samples in order to evaluate the device's effectiveness in removing the fungus. The concentration of airborne conidia was reduced by 95% in 18 min. Contamination was reduced below the detection threshold in 29 min, even when the machine was at the lowest airflow setting. In contrast, during spontaneous settling with no air treatment, conidia remained airborne for more than 1 h. This indoor air contamination model provided consistent and reproducible results. Because the air purifier proved to be effective at eliminating a major contaminant, it may prove useful in preventing air-transmitted disease agents. In an experimental space mimicking a hospital room, the AirLyse air purifier, which uses a combination of germicidal ultraviolet C irradiation and titanium photocatalysis, effectively eliminated Aspergillus conidia. Such a mobile device may be useful in routine practice for lowering microbiological air contamination in the rooms of patients at risk.

Preventing invasive fungal disease in patients with haematological malignancies and the recipients of haematopoietic stem cell transplantation: practical aspects

Invasive fungal disease (IFD), predominantly aspergillosis, is associated with significant morbidity and mortality in immunocompromised patients, especially those with haematological malignancies and recipients of allogeneic haematopoietic stem cell transplantation. There has been a great deal of scientific debate as to the effectiveness of antifungal prophylaxis in preventing infection in different patient groups and in which patients it is an appropriate management option. Deciding on an appropriate prophylaxis regimen for IFD is challenging as the incidence varies among different patient groups, due to the varied nature of their underlying haematological disease, and in different regions and centres. Attempts have been made to define risk factors and include them in treatment protocols. Impaired immune status of the patient, especially neutropenia, is a key risk factor for IFD and can sometimes be related to specific polymorphisms of genes controlling innate immunity. Risk factors also vary according to the type of fungal pathogen. Consequently, prophylaxis needs to be tailored to individual patient groups. Furthermore, the choice of antifungal agent for prophylaxis depends on the potential for drug-drug interactions with the patients' concomitant medications. Additional challenges are optimal timing of antifungal prophylaxis, when to change from prophylaxis to antifungal treatment and how to prevent recurrence of IFD. This article considers the use of antifungal prophylaxis for patients at risk of IFD in daily clinical practice, with clinical profiles that may be distinct from those covered by guidelines, and aims to provide practical advice for treatment of these patient groups.

Assessment of microbiological air quality in hemato-oncology units and its relationship with the occurrence of invasive fungal infections: an integrative review

Worldwide aging of the human population has promoted an increase in the incidence of neoplasia, including hematological cancers, which render patients particularly vulnerable to invasive fungal infections. For this reason, air filtration in hematooncology units has been recommended. However, scarce literature has assessed the impact of microbiological air quality on the occurrence of fungal infections in this population. We performed an integrative review of studies in the MEDLINE database that were published between January 1980 and October 2012, using the following combinations of keywords: air × quality × HEPA, air × quality × hematology, and airborne fungal infections. The search yielded only 13 articles, suggesting that high-efficiency filtering of the ambient air in hemato-oncology units can prevent the incidence of invasive fungal infections. However, no randomized clinical trial was found to confirm this suggestion. Currently, there is no consensus about the maximum allowable count of fungi in the air, which complicates filtration monitoring, including filter maintenance and replacement, and needs to be addressed in future studies.

Clinical and economic burden of invasive fungal diseases in Europe: focus on pre-emptive and empirical treatment of Aspergillus and Candida species

Invasive fungal diseases (IFDs) have been widely studied in recent years, largely because of the increasing population at risk. Aspergillus and Candida species remain the most common causes of IFDs, but other fungi are emerging. The early and accurate diagnosis of IFD is critical to outcome and the optimisation of treatment. Rapid diagnostic methods and new antifungal therapies have advanced disease management in recent years. Strategies for the prevention and treatment of IFDs include prophylaxis, and empirical and pre-emptive therapy. Here, we review the available primary literature on the clinical and economic burden of IFDs in Europe from 2000 to early 2011, with a focus on the value and outcomes of different approaches.

Bayesian development of a dose-response model for Aspergillus fumigatus and invasive aspergillosis

Invasive aspergillosis (IA) is a major cause of mortality in immunocompromized hosts, most often consecutive to the inhalation of spores of Aspergillus. However, the relationship between Aspergillus concentration in the air and probability of IA is not quantitatively known. In this study, this relationship was examined in a murine model of IA. Immunosuppressed Balb/c mice were exposed for 60 minutes at day 0 to an aerosol of A. fumigatus spores (Af293 strain). At day 10, IA was assessed in mice by quantitative culture of the lungs and galactomannan dosage. Fifteen separate nebulizations with varying spore concentrations were performed. Rates of IA ranged from 0% to 100% according to spore concentrations. The dose-response relationship between probability of infection and spore exposure was approximated using the exponential model and the more flexible beta-Poisson model. Prior distributions of the parameters of the models were proposed then updated with data in a Bayesian framework. Both models yielded close median dose-responses of the posterior distributions for the main parameter of the model, but with different dispersions, either when the exposure dose was the concentration in the nebulized suspension or was the estimated quantity of spores inhaled by a mouse during the experiment. The median quantity of inhaled spores that infected 50% of mice was estimated at 1.8 × 10(4) and 3.2 × 10(4) viable spores in the exponential and beta-Poisson models, respectively. This study provides dose-response parameters for quantitative assessment of the relationship between airborne exposure to the reference A. fumigatus strain and probability of IA in immunocompromized hosts.

Fungal spore concentrations in two haematopoietic stem cell transplantation (HSCT) units containing distinct air control systems

Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments.

Incidence of hospital-acquired pneumonia, bacteraemia and urinary tract infections in patients with haematological malignancies, 2004-2010: a surveillance-based study

Objective

This study charted incidence trends of hospital-acquired (HA) pneumonia, bacteraemia and urinary tract infections (UTI) in a haematology department.

Methods

Prospective surveillance of hospital-acquired infections (HAI) was undertaken in a 42-bed haematology department of a university hospital. All patients hospitalized ≥48 hours between 1^st January 2004 and 31^st December 2010 were included. Definitions of HAI were based on a standardized protocol. The incidence was the number of events per 1000 patient-days at risk; only the first HAI was counted. Multivariate Poisson regression was fitted to assess temporal trends.

Results

Among 3 355 patients (58 063 patient-days at risk) included, 1 055 (31%) had HAI. The incidence of HA pneumonia, HA bacteraemia and HA UTI was respectively 3.3, 12.0 and 2.9 per 1000 patient-days at risk. HA bacteraemia incidence increased by 11% (95% confidence interval: +6%, +15%, P<0.001) per year, independently of neutropenia, central venous catheterization (CVC) and haematological disease. The incidences of HA pneumonia and HA UTI were stable. The most frequently isolated pathogens were Aspergillus spp. (59.2%) for pneumonia, coagulase-negative Staphylococcus (44.2%) for bacteraemia and enterobacteria (60%) for UTI.

Conclusion

The incidence of bacteraemia increased, indicating that factors other than CVC exposure, including chemotherapy with its impact on the immune system, could explain this trend. Further analytic studies are needed to explore the factors that could explain this trend.

Reanimación y prevención de las infecciones nosocomiales

Los servicios de reanimación deben organizar de forma minuciosa la prevención de infecciones en sus enfermos, ya que éstos suelen estar inmunodeprimidos, están sometidos a múltiples procedimientos invasivos realizados por un personal sanitario variado, a menudo en situaciones de urgencia y a cualquier hora del día o de la noche. Las principales infecciones que hay que tratar de prevenir son las neumonías bacterianas adquiridas asociadas a ventilación mecánica (NAVM), las infecciones relacionadas con catéteres intravasculares y las infecciones urinarias asociadas al sondeo vesical. La incidencia de estas infecciones ha disminuido en la mayoría de los servicios que realizan un control cifrado, sobre todo gracias a la implantación de programas de mejora de la calidad. Las técnicas de prevención son múltiples y deben aplicarse simultáneamente. Incluyen medidas globales, como las modalidades de prevención de la transmisión cruzada (higiene de las manos, sobre todo) o de uso de antibióticos, concebidas para reducir la presión de selección de bacterias resistentes a éstos, así como medidas específicas relativas a la colocación y uso de cada uno de los dispositivos invasivos. Numerosas técnicas han demostrado su eficacia en estudios de buen nivel metodológico (higiene de las manos, apósitos para catéteres, etc.), mientras que otras siguen siendo objeto de controversias, por lo que las recomendaciones nacionales e internacionales se actualizan regularmente de acuerdo con los nuevos datos científicos. Estas medidas, implantadas de manera razonada en el marco de programas de mejora de la calidad, permiten obtener tasas muy bajas de infecciones relacionadas con el uso de catéteres vasculares y resultados menos satisfactorios con las NAVM, que justifican la necesidad de proseguir la investigación en este campo.

Rianimazione e prevenzione delle infezioni nosocomiali

I servizi di rianimazione devono organizzare la prevenzione delle infezioni nei loro pazienti in modo minuzioso, in quanto i pazienti sono spesso immunodepressi e subiscono gesti invasivi molteplici, realizzati da personale differente, spesso in situazioni di urgenza e a qualsiasi ora del giorno o della notte. Le principali infezioni che bisogna tentare di prevenire sono le polmoniti batteriche acquisite sotto ventilazione meccanica (PAVM), le infezioni su cateteri intravascolari e le infezioni urinarie su catetere vescicale. L’incidenza di queste infezioni è diminuita nella maggior parte dei servizi che ne effettuano un monitoraggio su base numerica, in particolare nel quadro di programmi di miglioramento della qualità. Le tecniche di prevenzione sono molteplici e devono essere applicate simultaneamente. Esse riguardano delle misure globali, come le modalità di prevenzione della trasmissione crociata (igiene delle mani, in particolare) o di utilizzo degli antibiotici nella prospettiva di ridurre la pressione di selezione di batteri resistenti agli antibiotici, così come delle misure specifiche relative al posizionamento e all’utilizzo di ciascuno dei dispositivi invasivi. Numerose tecniche si sono dimostrate efficaci in studi di buon livello metodologico (igiene delle mani, medicazioni dei cateteri, ecc.) mentre altre sono ancora oggetto di controversie, portando a raccomandazioni nazionali e internazionali regolarmente aggiornate in funzione dei nuovi dati scientifici. Queste misure, implementate in modo ragionato nel quadro di programmi di miglioramento della qualità, consentono di ottenere dei tassi molto bassi per quanto riguarda le infezioni dei cateteri vascolari e dei risultati meno buoni per le PAVM, illustrando la necessità di proseguire la ricerca in questo settore.

Chemosensitization as a means to augment commercial antifungal agents

Antimycotic chemosensitization and its mode of action are of growing interest. Currently, use of antifungal agents in agriculture and medicine has a number of obstacles. Foremost of these is development of resistance or cross-resistance to one or more antifungal agents. The generally high expense and negative impact, or side effects, associated with antifungal agents are two further issues of concern. Collectively, these problems are exacerbated by efforts to control resistant strains, which can evolve into a treadmill of higher dosages for longer periods. This cycle in turn, inflates cost of treatment, dramatically. A further problem is stagnation in development of new and effective antifungal agents, especially for treatment of human mycoses. Efforts to overcome some of these issues have involved using combinations of available antimycotics (e.g., combination therapy for invasive mycoses). However, this approach has had inconsistent success and is often associated with a marked increase in negative side effects. Chemosensitization by natural compounds to increase effectiveness of commercial antimycotics is a somewhat new approach to dealing with the aforementioned problems. The potential for safe natural products to improve antifungal activity has been observed for over three decades. Chemosensitizing agents possess antifungal activity, but at insufficient levels to serve as antimycotics, alone. Their main function is to disrupt fungal stress response, destabilize the structural integrity of cellular and vacuolar membranes or stimulate production of reactive oxygen species, augmenting oxidative stress and apoptosis. Use of safe chemosensitizing agents has potential benefit to both agriculture and medicine. When co-applied with a commercial antifungal agent, an additive or synergistic interaction may occur, augmenting antifungal efficacy. This augmentation, in turn, lowers effective dosages, costs, negative side effects and, in some cases, countermands resistance.

[Quantitative assessment of fungal risk in the case of construction works in healthcare establishments: Proposed indicators for the determination of the impact of management precautions on the risk of fungal infection]

Construction works in healthcare establishments produce airborne fungal spores and considerably increase the risk of exposure of immunosuppressed patients. It is necessary to reinforce protective measures, or even to implement specific precautions, during this critical phase. The aim of these precautions is to protect both those areas, which are susceptible to dust, and patients at risk of a fungal infection particularly invasive aspergillosis. When construction works are planned in healthcare establishments, the first step consists in the characterisation of the environmental fungal risk and the second one in proposing risk management methods. It is then essential to establish impact indicators in order to evaluate the risk management precautions applied. The working group promoted by the French societies of medical mycology and hospital hygiene (SFMM & SF2H) details here both environmental and epidemiological impact indicators that can be used.

Molecular epidemiology of Aspergillus fumigatus: an in-depth genotypic analysis of isolates involved in an outbreak of invasive aspergillosis

We recently reported an outbreak of invasive aspergillosis in the major heart surgery unit of Hospital Gregorio Marañón, Madrid, Spain (T. Peláez, P. Muñoz, J. Guinea, M. Valerio, M. Giannella, C. H. W. Klaassen, and E. Bouza, Clin. Infect. Dis., in press). Aspergillus fumigatus was isolated from clinical samples from 10 patients admitted to the unit during the outbreak period (surgical wound invasive aspergillosis, n = 2; probable pulmonary invasive aspergillosis, n = 4; colonization, n = 4). In the study described here, we have studied the genotypic diversity of the A. fumigatus isolates found in the air and clinical samples. We used short tandem repeats of A. fumigatus (STRAf) typing to analyze the genotypes found in the 168 available A. fumigatus isolates collected from the clinical samples (n = 109) from the patients and from the environmental samples taken from the air of the unit (n = 59). The genotypic variability of A. fumigatus was higher in environmental than in clinical samples. Intrasample variability was also higher in environmental than in clinical samples: 2 or more different genotypes were found in 26% and 89% of clinical and environmental samples, respectively. We found matches between environmental and clinical isolates in 3 of the 10 patients: 1 patient with postsurgical invasive aspergillosis and 2 patients with probable pulmonary invasive aspergillosis. A total of 7 genotypes from 3 different patients and the air grouped together in 2 clusters. Clonally related genotypes and microvariants were detected in both clinical and environmental samples. STRAf typing proved to be a valuable tool for identifying the source of invasive aspergillosis outbreaks and for studying the genotypic diversity of clinical and environmental A. fumigatus isolates.

Invasive aspergillosis in patients with hematologic malignancies: incidence and description of 127 cases enrolled in a single institution prospective survey from 2004 to 2009

BACKGROUND

The study objectives were: 1) to report on invasive aspergillosis patients in a hematology department; and 2) to estimate its incidence according to the hematologic diagnosis.

DESIGN AND METHODS

A prospective survey of invasive aspergillosis cases was undertaken between January 2004 and December 2009 in the hematology department of a university hospital. Meetings with clinicians, mycologists and infection control practitioners were organized monthly to confirm suspected aspergillosis cases. Demographic characteristics, clinical and complementary examination results were recorded prospectively. Information on hospitalization was extracted from administrative databases. Invasive aspergillosis diagnosis followed the European Organization for Research and Treatment of Cancer criteria, and proven and probable IA cases were retained. A descriptive analysis was conducted with temporal trends of invasive aspergillosis incidence assessed by adjusted Poisson regression.

RESULTS

Overall, 4,073 hospitalized patients (78,360 patient-days) were included in the study. In total, 127 (3.1%) patients presented invasive aspergillosis. The overall incidence was 1.6 per 1,000 patient-days (95% confidence interval: 1.4, 1.9) with a decrease of 16% per year (-1%, -28%). The incidence was 1.9 per 1,000 patient-days (1.5, 2.3) in acute myeloid leukemia patients with a decrease of 20% per year (-6%, -36%). Serum Aspergillus antigen was detected in 89 (71%) patients; 29 (23%) had positive cultures, and 118 (93%), abnormal lung CT scans. One-month mortality was 13%; 3-month mortality was 42%. Mortality tended to decrease between 2004 and 2009.

CONCLUSIONS

Invasive aspergillosis incidence and mortality declined between 2004 and 2009. Knowledge of invasive aspergillosis characteristics and its clinical course should help to improve the management of these patients with severe disease.

Fungal aero-decontamination efficacy of mobile air-treatment systems

Immunosuppressed patients are at high risk of acquiring airborne fungal infections, mainly caused by Aspergillus species. Although HEPA filters are recommended to prevent environmental exposure, mobile air-treatment units can be an alternative. However, many different models of mobile units are available but there are few data on their fungal aero-decontamination efficacy and usefulness in the prevention of Aspergillus infections. Thus, we developed a challenge test, based on the aerosolization of 10(6) Aspergillus niger conidia, in order to compare the particle and fungal decontamination efficacy of the following four mobile air-treatment systems; Plasmair T2006, Mobil'Air 1200 (MA1200), Mobil'Air 600 (MA600) combined with Compact AirPur Mobile C250 (C250), and the prototype unit Compact AirPur Mobile 1800 (C1800). The use of all these air-treatment systems was able to significantly decrease the concentration of particles or fungal viable conidia. ISO7 was the maximum particle class reached within 20 min with the Plasmair T2006 and MA1200, 1 h by the combined MA600/C250, and 1 h and 30 min with the C1800. After 2 h, fungal counts were significantly lower with Plasmair T2006, MA1200 and the combined MA600/C250 (2.2 ± 1.9 to 5.0 ± 3.7 CFU/m(3)) than achieved with the C1800 (23.8 ± 12.8 CFU/m(3); P ≤ 6.0E-3). All the air-treatment systems were able to decrease aerial particle and fungal counts, but their efficacy was variable, depending on the units' air-treatment modalities and rates of air volume that was processed. This comparative study could be helpful in making an informed choice of mobile units, and in improving the prevention of air-transmitted fungal infections in non-protected areas.

Field validation of a dusting cloth for mycological surveillance of surfaces

Efficient monitoring of surfaces for spores of filamentous fungi is essential for detecting minor contamination even when air samples test negative for fungi. This study evaluates and compares a pad prepared using a dusting cloth with Rodac contact plates and humidified swabs for detecting mycological contamination, and concludes that the new method is superior and cheaper.

Aspergillosis: nosocomial or community-acquired?

Discrimination between nosocomial and community infections is important for investigation and prevention. Nosocomial and hospital-acquired infections require appropriate hospital control measures to avert additional cases. Nosocomial infections (NI) occur during hospitalization or are caused by microorganisms acquired during hospital stay. Such infections should not be evident when patients are admitted to the hospital. Furthermore, the definition of NI is based on epidemiological criteria, such as the time lapse between admission and onset, or microbiological criteria. This definition might be difficult to apply to invasive aspergillosis (IA) which often afflicts patients with severe immunosuppression or transplantation. Identification of the source may be difficult which could arise outside or inside the hospital. Another significant issue is the lack of valid and reproducible data on the incubation period. The incubation duration of IA is influenced by different individual or environmental determinants, including the severity of immunosuppression and air quality. The criteria of causality are also a means of discussing the contribution of hospital vs. community determinants of IA. The definition of nosocomial IA remains difficult. A better understanding of early events related to IA onset will help to prevent this disease for which the prognosis remains negative.

Influence of internal and outdoor factors on filamentous fungal flora in hematology wards

BACKGROUND

Nosocomial invasive filamentous fungi infections could result from inhalation of filamentous fungi conidia present in hospital environment.

METHODS

The environmental fungal flora in 3 different hospital wards with similar air conditioning was prospectively studied during 30 months and compared to internal (presence of agranulocytosis patient, behavioral practices, activity, cleaning work) and outdoor factors (meteorologic data, outdoor fungi). The general preventive measures differed from one unit to another.

RESULTS

The hematology wards with filamentous fungi preventive measures were significantly less contaminated than a conventional ward without specific measures. Internal and outdoor factors influenced the level of fungal flora. However, the influence of internal factors was greater in the conventional ward than in hematology wards. The variation of flora in the hospital environment was seasonal, and the level of this contamination in each ward was influenced by the meteorology. However, outdoor factors more readily explain the variations of fungal load in hematology than in the conventional ward.

CONCLUSION

This study highlights that specific preventive measures participate significantly in the control of the filamentous fungal flora intensity due to internal factors but not those due to outdoor factors, stressing the importance of high-efficiency particulate air filtration in high-risk units.