Prevention of nosocomial fungal infection: the French approach

Fungal contamination of the water distribution system of a tertiary hospital water supply system in a resource-limited setting

Background

Fungal contamination of hospital water distribution systems has been implicated in outbreaks of healthcare-associated infections.

Objectives

To evaluate the prevalence of fungi in the water distribution system of a tertiary hospital in Nigeria.

Design

This was a descriptive cross-sectional study.

Methods

Swabs and water samples were collected from taps and faucets in the hospital categorized into low (Accidents and Emergency Unit, Children Emergency Unit, Acute Stroke Unit and the 24 in-patient hospital wards) and high-risk (Renal Dialysis Unit, Central Sterile Services Department, Theatres and Intensive Care Units (ICUs)) units based on the vulnerability of patients being managed there. The membrane filtration method for water analysis was used. Where possible, isolates cultured were identified to species level. In total, 105 water and 49 swab samples were collected for analysis.

Results

All analysed water samples grew fungi. A total of 289 (high-risk; n = 178; low-risk; n = 111) and 76 fungi isolates were recorded from water and swab samples, respectively, with 31 different species identified. Aspergillus was the most predominant genus with five different species: Aspergillus niger (9.9%), terreus (4.4%), flavus (3.3%), fumigatus (8.8%) and versicolor (2.20%) isolated. Twenty-five and 18 species of fungi were identified in the low and high-risk units, respectively. The labour ward (n = 46; 25.8%) and modular theatre (n = 47; 42.3%) were the most contaminated units. Cladosporium spp. and Paecilomyces spp. were the most frequently isolated fungi in the low and high-risk units, respectively. The dialysis centre (n = 9; 8.1%) and renal transplant theatre (n = 7; 6.31%) had the lowest contamination rates in the high-risk units. Aspergillus niger, Cephalosporium curtipes, Penicillium chrysogenum and Penicillium glabrum were each identified in 4/6 units from which swabs were taken. The facility had no documented protocol for its water safety and quality.

Conclusion

Our data reveal a high rate of contamination of hospital water sources by fungi, some of which are known to cause life-threatening infections. For better water treatment and water tank cleaning and disinfection, a standard protocol is advised. Ensuring that the water distribution systems in hospital settings are free of fungal contaminants is important to prevent the possibility of waterborne mycosis outbreaks.

COVID-19 Associated Pulmonary Aspergillosis (CAPA): Hospital or Home Environment as a Source of Life-Threatening Aspergillus fumigatus Infection?

Most cases of invasive aspergillosis are caused by Aspergillus fumigatus, whose conidia are ubiquitous in the environment. Additionally, in indoor environments, such as houses or hospitals, conidia are frequently detected too. Hospital-acquired aspergillosis is usually associated with airborne fungal contamination of the hospital air, especially after building construction events. A. fumigatus strain typing can fulfill many needs both in clinical settings and otherwise. The high incidence of aspergillosis in COVID patients from our hospital, made us wonder if they were hospital-acquired aspergillosis. The purpose of this study was to evaluate whether the hospital environment was the source of aspergillosis infection in CAPA patients, admitted to the Hospital Universitario Central de Asturias, during the first and second wave of the COVID-19 pandemic, or whether it was community-acquired aspergillosis before admission. During 2020, sixty-nine A. fumigatus strains were collected for this study: 59 were clinical isolates from 28 COVID-19 patients, and 10 strains were environmentally isolated from seven hospital rooms and intensive care units. A diagnosis of pulmonary aspergillosis was based on the ECCM/ISHAM criteria. Strains were genotyped by PCR amplification and sequencing of a panel of four hypervariable tandem repeats within exons of surface protein coding genes (TRESPERG). A total of seven genotypes among the 10 environmental strains and 28 genotypes among the 59 clinical strains were identified. Genotyping revealed that only one environmental A. fumigatus from UCI 5 (box 54) isolated in October (30 October 2020) and one A. fumigatus isolated from a COVID-19 patient admitted in Pneumology (Room 532-B) in November (24 November 2020) had the same genotype, but there was a significant difference in time and location. There was also no relationship in time and location between similar A. fumigatus genotypes of patients. The global A. fumigatus, environmental and clinical isolates, showed a wide diversity of genotypes. To our knowledge, this is the first study monitoring and genotyping A. fumigatus isolates obtained from hospital air and COVID-19 patients, admitted with aspergillosis, during one year. Our work shows that patients do not acquire A. fumigatus in the hospital. This proves that COVID-associated aspergillosis in our hospital is not a nosocomial infection, but supports the hypothesis of “community aspergillosis” acquisition outside the hospital, having the home environment (pandemic period at home) as the main suspected focus of infection.

Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

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.

Preliminary study of the fungal ecology at the haematology and medical-oncology ward in Bamako, Mali

Data on fungal epidemiology in sub-Saharan African countries are scarce. This exploratory study aimed to characterize the fungal flora at the Onco-Haematology ward of the National Teaching Hospital of Point G in Bamako, Mali. A cross-sectional survey was conducted in the dry and in the rainy seasons. Nasal swab and sputum samples were collected from the hospitalized patients while airborne fungal spores were collected using electrostatic dust-fall collectors. Fungi were identified by their morphological characteristics and MALDI-TOF mass spectrometry. Candida albicans was the most frequent yeast species colonizing patients; Aspergillus species were isolated in 86 % of the patients and were the main airborne environmental contaminants. Overall, airborne fungal contamination rates increased from 33.8 % in the dry to 66.2 % in the rainy season (p < 0.001). The most frequent Aspergillus species were Aspergillus niger (36.6 %) and Aspergillus flavus (32.92 %). In contrast, Aspergillus fumigatus (5.43 %) was relatively rare. This high level of fungal exposure raises concern regarding the management of at-risk patients in this Onco-Haematology ward and stresses the need for strengthening the mycological diagnostic capacities to accompany the implementation of adapted fungal infection prevention and management policies.

Evaluation of fungal contamination in operating rooms using a dusting cloth pad: comparison among different sampling methods

To evaluate microbial contamination in hospitals environments, several methods are available, each one having its limitations. Therefore, the choice of system to use is open. This study compares the ability of a dusting cloth pad (DC pad) with 2 other methods (Rodac contact plate and air sampling) to detect contamination because of filamentous fungi in operating rooms, performing 110 sampling campaigns in hospitals of 3 Italian cities. Overall, 96% of the DC pad samples were positive compared with 51% of Rodac plates (P < .0001) and 35% of air samples (P < .0001). Authors conclude that the DC pad improves the ability to detect an environmental contamination of filamentous fungi.

Indoor fungal contamination: health risks and measurement methods in hospitals, homes and workplaces

Indoor fungal contamination has been associated with a wide range of adverse health effects, including infectious diseases, toxic effects and allergies. The diversity of fungi contributes to the complex role that they play in indoor environments and human diseases. Molds have a major impact on public health, and can cause different consequences in hospitals, homes and workplaces. This review presents the methods used to assess fungal contamination in these various environments, and discusses advantages and disadvantages for each method in consideration with different health risks. Air, dust and surface sampling strategies are compared, as well as the limits of various methods are used to detect and quantify fungal particles and fungal compounds. In addition to conventional microscopic and culture approaches, more recent chemical, immunoassay and polymerase chain reaction (PCR)-based methods are described. This article also identifies common needs for future multidisciplinary research and development projects in this field, with specific interests on viable fungi and fungal fragment detections. The determination of fungal load and the detection of species in environmental samples greatly depend on the strategy of sampling and analysis. Quantitative PCR was found useful to identify associations between specific fungi and common diseases. The next-generation sequencing methods may afford new perspectives in this area.

Invasive aspergillosis: drug-dispensing systems as a source of filamentous fungal contamination in high-risk units?

High-risk units with air-control measures at Grenoble University Hospital are equipped with automated dispensing systems that are filled daily using drug trolleys routed from the pharmacy to the ward. The aim of this study was to evaluate the level of filamentous fungi (FF) contamination present in trolleys under usual conditions and after cleaning with Aniosurf(®) (fungicidal disinfectant). FF were detected in all samples, and 83.3% of samples were contaminated with Aspergillus fumigatus. Cleaning trolleys with Aniosurf(®) decreased the level of FF significantly, but contamination re-appeared within 24 h due to storage in a non-controlled environment.

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.

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.

[Prevention of fungal infections related to the water supply in French hospitals: proposal for standardization of methods]

OBJECTIVES

The aims of this study were to assess the risk of fungal infections related to the water supply in several hospitals and to clarify the appropriate methodology in order to standardize the technical conditions of the controls and develop guidelines. It was conducted in 10 university hospital centers across the country from February 2004 through March 2005.

METHOD

A preliminary study allowed us to optimize the mycological analysis. The study was conducted under the same conditions as for bacteriological controls: water filtration through a cellulose acetate membrane cultured on agar. Departments with the highest patient risk were selected, including hematology, organ transplantation, and burn units. We selected 98 sites and sampled both water and water-related surfaces at each: three one-liter water samples (the first flow, cold and hot water) and two or three surface samples (inside the tap, pommel of the shower and siphon). At each site, a form was filled to specify its location in the unit, any water treatment (chlorine or other), filtering, and temperature. Water from taps equipped with sterilized filtration was sampled without the filter.

RESULTS

There was a significant difference (p=0.039) in the number of positive cultures between the three types of water sampled: hot water (>50 degrees C) was colonized less often than first flow or cold water. Only 4% of the hot-water samples had positive cultures, compared to the 52% of the cold-water samples. Except in two hospitals with generalized contamination of the water pipes (one with Exophiala spp and the other with Fusarium spp), colonization was usually slight. Cold water was more colonized than hot water, but 79% of the samples yielded fewer than 5CFU/L. Dematiaceous hyphomycetes were isolated; Aspergillus spp were rare. The number of CFU in surface samples (that is, biofilms) was higher (mean=15 CFU per sample) but surfaces were positive less often than water (13% compared with 43% of all water samples). Sampling from siphons was productive more often than from taps (23%), but the molds isolated differed from those in the related water. Relations to bacterial flora and P. aeruginosa were also studied, together with the effects of chemical treatment.

CONCLUSION

Current regulations require only bacteriological survey. The absence of knowledge about the threshold of contamination at which there is a risk of nosocomial invasive fungal infections makes it difficult to impose routine monitoring. Mycological surveys of water are required during hospital renovation, plumbing work, pipe maintenance and when air samples are negative during nosocomial infection investigations.

Evaluation of a new mobile system for protecting immune-suppressed patients against airborne contamination

BACKGROUND

Invasive aspergillosis is one of the most lethal airborne dangers for immune-suppressed subjects. Providing patient protection from such airborne threats requires costly and high-maintenance facilities. We herein evaluate a new self-contained mobile unit as an alternative for creating a patient protective environment.

METHODS

Airborne contamination levels were monitored for different simulated scenarios and under actual clinical conditions. Functional tests were used to challenge the unit under adverse conditions, and a preliminary clinical study with patients and staff present was performed at 2 different French hospitals.

RESULTS

Functional tests demonstrated that the unit can rapidly decontaminate air in the protected zone created by the unit and in the surrounding room. In addition, the protected zone is not sensitive to large disturbances that occur in the room. The clinical study included 4 patients with 150 accumulated days of testing. The protected zone created by the unit systematically provided an environment with undetectable airborne fungal levels (ie, <1 CFU/m(3)) regardless of the levels in the room or corridor (P < .01).

CONCLUSIONS

These tests show that the unit can be used to create a mobile protective environment for immune-suppressed patients in a standard hospital setting.

High risk factors for pulmonary fungous infection in intensive care units of neurosurgery

By analyzing the high risk factors for pulmonary fungous infection in intensive care units of neurosurgery, the strategy of early diagnosis and treatment was explored. According to the domestic diagnostic standard on pulmonary fungous infection, clinical data on 58 patients with the infection in our department were analyzed. One hundred and seventeen strains of fungi were separated from the 58 cases. Candidiasis was the most frequent type, accounting for 92.3% of the cases. Conditions such as the severity of primary diseases, long-time coma, long-term use of broad-spectrum antibiotic, abuse of glucocorticoid, the open airway, and some invasive intubations, may be regarded as high risk factors for pulmonary fungous infection. Fluconazole showed good clinical effects on the treatment of fungous infection. To eliminate these high risk factors, early diagnosis and the use of prophylactic antifungal agents can help reduce the incidence of pulmonary fungous infection.

Filamentous fungi in a tertiary care hospital: environmental surveillance and susceptibility to antifungal drugs

OBJECTIVE

To evaluate filamentous fungi with respect to environmental load and potential drug resistance in a tertiary care teaching hospital.

DESIGN

Monthly survey in 2 buildings of the hospital during a 12-month period.

SETTING

Hippokration Hospital in Thessaloniki, Greece.

METHODS

Air, surface, and tap water sampling was performed in 4 departments with high-risk patients. As sampling sites, the solid-organ transplantation department and the hematology department (in the older building) and the pediatric oncology department and the pediatric intensive care unit (in the newer building) were selected.

RESULTS

From January to May of 2000, the fungal load in air (FLA) was low, ranging from 0 to 12 colony-forming units (cfu) per m(3) in both buildings. During the summer months, when high temperature and humidity predominate, the FLA increased to 4-56 cfu/m(3). The fungi commonly recovered from culture of air specimens were Aspergillus niger (25.9%), Aspergillus flavus (17.7%), and Aspergillus fumigatus (12.4%). Non-Aspergillus filamentous fungi, such as Zygomycetes and Dematiaceous species, were also recovered. The pediatric intensive care unit had the lowest mean FLA (7.7 cfu/m(3)), compared with the pediatric oncology department (8.7 cfu/m(3)), the solid-organ transplantation department (16.1 cfu/m(3)), and the hematology department (22.6 cfu/m(3)). Environmental surfaces were swabbed, and 62.7% of the swab samples cultured yielded filamentous fungi similar to the fungi recovered from air but with low numbers of colony-forming units. Despite vigorous sampling, culture of tap water yielded no fungi. The increase in FLA observed during the summer coincided with renovation in the building that housed the solid-organ transplantation and hematology departments. All 54 Aspergillus air isolates randomly selected exhibited relatively low minimum inhibitory or effective concentrations for amphotericin B, itraconazole, voriconazole, posaconazole, micafungin, and anidulafungin.

CONCLUSION

Air and surface fungal loads may vary in different departments of the same hospital, especially during months when the temperature and humidity are high. Environmental Aspergillus isolates are characterized by lack of resistance to clinically important antifungal agents.

Ten-year surveillance of fungal contamination of food within a protected haematological unit

Since 1992, we have established a protocol of food management (restrictive diet, food distribution protocol and fungal surveillance) for allogeneic stem-cell transplant (SCT) recipients hospitalised in protected ward. This study analyses the results of 10-year surveillance of fungal contamination of this diet. Among the 456 types of foods tested filamentous fungi were isolated in 37 of them (8.1%). Aspergillus fumigatus was isolated in one type of food only, while the majority of the food was contaminated to a lower extent.

Bacterial and fungal counts in hospital air: comparative yields for 4 sieve impactor air samplers with 2 culture media

We compared the yields of 4 recently developed sieve impactor air samplers that meet international standard ISO 14698-1, using 2 growth media (tryptic soy agar and malt extract agar) in real conditions of use. Several hospital sites expected to have different densities of airborne microflora were selected in 2 hospitals. The Samplair MK2, Air Ideal, and Mas-100 samplers yielded higher bacterial counts than did the SAS Super-100 device (P<.05). No significant differences in fungal counts were noted between the 4 devices. The use of malt extract agar in addition to tryptic soy agar significantly improved the fungal yield.

Prevention of systemic mycoses by reducing exposure to fungal pathogens in hospitalized and ambulatory neutropenic patients

PURPOSE/OBJECTIVES

To describe sources of fungal contamination that can incite invasive mycoses in hospitalized and ambulatory neutropenic patients and to discuss approaches to reduce exposure to pathogens.

DATA SOURCES

Published articles, books, and brochures.

DATA SYNTHESIS

Modifications of patient environments and lifestyles include hand hygiene for patients and healthcare workers, air filtration in hospitals, and reduction in exposure to plants, soil, standing water, and dusty environments. The effectiveness of dietary restrictions is controversial, although avoidance of pepper is recommended. These restrictions should be implemented prior to, during, and following neutropenia.

CONCLUSIONS

Mycoses can be hospital or community acquired; however, although guidelines for environmental and lifestyle modifications are well documented for the institutional setting, they are more limited for ambulatory patients.

IMPLICATIONS FOR NURSING

Nurses have a key role in the early identification of outbreaks of fungal infections, evaluation of hospital and home environments for sources of pathogens, education of patients on preventive measures, and research on neutropenic diets and improved technology to reduce exposure to fungal pathogens.

Les aspergilloses cérébrales

INTRODUCTION

The brain is almost always a localization of invasive aspergillosis, after hematogenous spread from pulmonary aspergillosis. Brain aspergilosis is not rare and is one of the worst prognosis factors of invasive aspergillosis.

STATE OF ART

The incidence of this severe mycosis is currently on the rise due to the development of major immunosuppressive treatments. Brain aspergillosis is noteworthy for its vascular tropism, leading to infectious cerebral vasculitis, mainly involving thalamoperforating and lenticulostriate arteries, with a high frequency of thalamic or basal nuclei lesions. Extra-neurologic features that suggest this diagnosis are: i) risk factors for invasive aspergillosis (major or prolonged neutropenia, hematologic malignancies, prolonged corticosteroid treatment, bone marrow or solid organ transplant, AIDS); ii) persistent fever not responding to presumptive antibacterial treatment; iii) respiratory signs (brain aspergillosis is associated with pulmonary aspergillosis in 80 to 95 p. 100 of cases). Perspectives. Two recent major improvements in brain aspergillosis management must be outlined: i) for diagnostic purposes, the development of testing for Aspergillus antigenemia (a non-invasive procedure with good diagnostic value for invasive aspergillosis); ii) for therapeutic purposes, the demonstration that voriconazole is better than amphotericin B in terms of clinical response, tolerance and survival, for all types of invasive aspergillosis, the benefit being probably even greater in case of brain aspergillosis because of the good diffusion of voriconazole into the central nervous system.

CONCLUSIONS

Brain aspergillosis is a severe emerging opportunistic infection for which diagnostic and therapeutic tools have recently improved. Thus, this diagnostic must be suspected early, especially in the immunocompromised patient, in the event of respiratory symptoms and when the brain lesions are localized in the central nuclei and the thalamus.

Positive-pressure isolation and the prevention of invasive aspergillosis. What is the evidence?

Positive-pressure ventilation implies a sealed room, usually with an anteroom to facilitate the donning of protective clothing, airflows of at least 12 air changes per hour and high-efficiency particulate air (HEPA) to prevent infection in susceptible patients. Laminar airflow (LAF) involves much greater air changes, expense and inconvenience to the patient due to noise and draughts. There are few, if any, truly controlled trials on the impact of positive-pressure ventilation and the prevention of invasive aspergillosis (IA); most are observational studies conducted during an outbreak or retrospective analyses of the incidence of IA over periods of time when a variety of preventative interventions were introduced. Therefore, it is often difficult to determine the specific impact of positive-pressure ventilation with HEPA in leading to a reduction in IA. During periods of hospital demolition or construction, HEPA significantly reduces the aspergillus spore counts and in many studies, the incidence of IA, but other measures such as enhanced cleaning, the sealing of windows and the use of prophylactic anti-fungal agents are also important. On balance, the additional expense and inconvenience of LAF does not appear to be justified. Where positive-pressure ventilation is installed, it is imperative that the system be monitored to ensure that the pressure differentials and air changes are appropriate. Whilst there is a role for positive-pressure ventilation in reducing the incidence of IA, we need a better definition of the importance of hospital-acquired IA compared with community-acquired infection and of the relationship between strains of Aspergillus species isolated from the environment and those strains causing infection.