Implementation of community health care services to counter the SARS-CoV2 pandemic.

BACKGROUND: The COVID-19 pandemic has ravaged many countries worldwide since December 2019. The high infection rates, and the need for health care assistance for individuals with comorbidities, strained the national health care systems around the world. Outbreak peaks increased the burden on hospitals that where perceived as high-risk places by people, who often decided to cancel or defer hospital visits. Thus, Italian Local Health Authorities had to develop new organizational models to meet the increased health care needs of the population. The aim of this study is to assess the impact of strengthened community health services on the hospital burden. METHODS: We analysed the number of Emergency Department access at the Hospital De Lellis covered by the Local Health Authority in Rieti, from March 2020 to November 2021. We then assessed the effects of community health services: the Special District Continuing Care Units (SDCUs) and the the COVID hub, on the COVID-19-related ED access, admission and mortality rates. A Chi-squared test for trend and three multivariable logistic regression models were used to investigate the trends and the possible predictors of COVID ED access, COVID hospital admissions, and deaths. RESULTS: Being male (OR = 1.41, CI95% 1.05-1.90; p = 0.022) and older age (OR = 1.03, CI95% 1.02-1.04; p < 0.0001) increase the likelihood of hospitalisation for Sars-CoV-2. The implementation of the nursing and medical SDCUs contributed to reducing COVID-19-related deaths (OR = 0.09, CI95% 0.03-0.29; p < 0.0001). The simultaneous implementation of the COVID hub and of the nursing SDCUs had a synergistic effect in reducing the likelihood of hospitalisation (OR = 0.24, CI95% 0.09-0.65; p = 0.005). The subsequent implementation of the medical SDCUS has further contributed to lowering the admission rates. These protective effects persisted also after potential cofounders, such as age, sex, clinical condition on admission, and the immunisation status, were adjusted. CONCLUSIONS: These measures have helped in the management of patients in a complex context such as that of a pandemic by reducing the hospital load and playing an important role in the management of the pandemic. Further studies could assess the transferability of this model in a non-pandemic context.

A Machine Learning Approach Unveils the Relationships between Sickness Behavior and Interoception after Vaccination: Suggestions for Psychometric Indices of Higher Vulnerability.

OBJECTIVE: Prior research has suggested a possible connection between vaccination and manifestations of Sickness Behavior; however, a need remains to first delve deeper into this association and second examine how Interoceptive Awareness and emotional factors may modulate individuals' perceptions of their health status post vaccination. METHOD: An online retrospective cross-sectional survey of 647 individuals who received a COVID-19 vaccination was conducted. Together with vaccination side effects, socio-demographic characteristics, health status, level of concern about vaccination, and Interoceptive Awareness were collected at the baseline level. Mood, sleep, and Sickness Behavior were assessed at baseline and after vaccination. Data were analyzed using inferential statistics and machine learning techniques. RESULTS: After vaccination, there was a significant increase in Sickness Behavior levels (mean (±SD) SicknessQ T0 = 1.57 (±2.72), mean (±SD) SicknessQ T1 = 5.54 (±5.51); p-value = 0.001; ES = 0.77). A Machine Learning analysis revealed specific patterns of individual dispositions (sex and age), baseline emotional characteristics (levels of depression, anxiety, stress, and concern about adverse reactions), as well as some components of Interoceptive Awareness (Noticing, Body Listening, and Attention Regulation), as predictors of high levels of Sickness Behavior, both in terms of overall scores (JRIP: 72.65% accuracy, AUC = 0.692, d = 0.709; F1 = 0.726) and individual items (JRIP: 75.77% accuracy, AUC = 0.694; d = 0.717; F1 = 0.754). CONCLUSIONS: Our results provide new insight into post-immune reactions by highlighting the contribution of Interoceptive Awareness in modulating the severity of Sickness Behavior. This sheds light on the role of awareness of bodily sensations in modulating perceptions of health status, helping to identify the characteristics that make individuals more prone to feeling sick.

Renovation and creation of a Biocontainment Unit: the experience of Azienda Ospedaliero-Universitaria Pisana (Pisa, Italy).

Infectious diseases are a major public health concern. In recent decades, there has been a succession of bacterial and viral diseases, which when added to the endemic diseases found in certain areas of the world, can become a global health problem. In emergency medicine we talk a lot about Mass Casualty Incident (MCI) preparedness, but the main focus today is bio-preparedness. Therefore, especially after the Ebola experience, much investment has been made in the development of Biocontainment Units (BCUs). At present, in Italy there are no national realities that have experimented the construction of a completely new biocontainment units detached from the Emergency Department (ED) RNPP-funded. Given this, the project of the Azienda Ospedaliero-Universitaria Pisana (AOUP) is to make renovations on existing ED structure and build an entire new facility for biocontainment.

Evaluation, Description and Magnitude of Readmission Phenomenon in Azienda Ospedaliero Universitaria Pisana (AOUP) for Chronic-Degenerative Diseases in the Period 2018-2021.

BACKGROUND: Readmissions are hospitalizations following a previous hospitalization (called index hospitalization) of the same patient that occurred in the same facility or nursing home. They may be a consequence of the progression of the natural history of a disease, but they may also reveal a previous suboptimal stay, or ineffective management of the underlying clinical condition. Preventing avoidable readmissions has the potential to improve both a patient's quality of life, by avoiding exposure to the risks of re-hospitalization, and the financial well-being of health care systems. METHODS: We investigated the magnitude of 30 day repeat hospitalizations for the same Major Diagnostic Category (MDC) in the Azienda Ospedaliero Universitaria Pisana (AOUP) over the period from 2018 to 2021. Records were divided into only admissions, index admissions and repeated admission. The length of the stay of all groups was compared using analysis of variance and subsequent multi-comparison tests. RESULTS: Results showed a reduction in readmissions over the period examined (from 5.36% in 2018 to 4.46% in 2021), likely due to reduced access to care during the COVID-19 pandemic. We also observed that readmissions predominantly affect the male sex, older age groups, and patients with medical Diagnosis Related Groups (DRGs). The length of stay of readmissions was longer than that of index hospitalization (difference of 1.57 days, 95% CI 1.36-1.78 days, p < 0.001). The length of stay of index hospitalization is longer than that of single hospitalization (difference of 0.62 days, 95% CI 0.52-0.72 days, p < 0.001). CONCLUSIONS: A patient who goes for readmission thus has an overall hospitalization duration of almost two and a half times the length of the stay of a patient with single hospitalization, considering both index hospitalization and readmission. This represents a heavy use of hospital resources, about 10,200 more inpatient days than single hospitalizations, corresponding to a 30-bed ward working with an occupancy rate of 95%. Knowledge of readmissions is an important piece of information in health planning and a useful tool for monitoring the quality of models of patient care.

Implementation of an Environmental Cleaning Protocol in Hospital Critical Areas Using a UV-C Disinfection Robot.

Improving the cleaning and disinfection of high-touch surfaces is one of the core components of reducing healthcare-associated infections. The effectiveness of an enhanced protocol applying UV-C irradiation for terminal room disinfection between two successive patients was evaluated. Twenty high-touch surfaces in different critical areas were sampled according to ISO 14698-1, both immediately pre- and post-cleaning and disinfection standard operating protocol (SOP) and after UV-C disinfection (160 sampling sites in each condition, 480 in total). Dosimeters were applied at the sites to assess the dose emitted. A total of 64.3% (103/160) of the sampling sites tested after SOP were positive, whereas only 17.5% (28/160) were positive after UV-C. According to the national hygienic standards for health-care setting, 9.3% (15/160) resulted in being non-compliant after SOP and only 1.2% (2/160) were non-compliant after UV-C disinfection. Operation theaters was the setting that resulted in being less compliant with the standard limit (≤15 colony-forming unit/24 cm2) after SOP (12%, 14/120 sampling sites) and where the UV-C treatment showed the highest effectiveness (1.6%, 2/120). The addition of UV-C disinfection to the standard cleaning and disinfection procedure had effective results in reducing hygiene failures.

Role of environmental sanitization in health clinics: evaluation of potassium peroxymonosulfate (KMPS) efficacy at two different concentrations.

BACKGROUND: Healthcare-associated infections (HAI) are closely related to several factors, such as prolonged hospital stay in high-risk areas and intensive care units, potentially predisposing underlying conditions. It has also been demonstrated that HAI incidence may be related to non-respected standards of assistance, such as not adequately cleaned structures or medical devices contaminated by environmental bacteria and multidrug resistant enterobacteria. OBJECTIVE: In this case it has been carried on an efficacy evaluation of a microionization system using potassium peroxymonosulfate (KMPS) for outpatient clinics indoor air disinfection. MATERIAL AND METHODS: Two outpatient clinics (AMB-1 and AMB-2) were treated with KMPS (1% and 2% concentration), at the end of routinary clinic activities. Microbial sampling of air (settle plates) and surfaces (contact plates) were submitted before and after sanitizing, checking total microbial load at 37°C, possible opportunistic pathogens and moulds. RESULTS: Sanitizing system at 1% concentration was efficient in mesophilic bacteria reduction (max 83%). Moreover, total abatement of Klebsiella pneumoniae in AMB1 and Acinetobacter lwoffi in AMB2 has been seen, both on surfaces. Regarding air samplings, 89% moulds reduction has been seen, as observed on surfaces. Scaling up concentration to 2%, mesophilic bacteria reduction was ≥ 94%, both in air and on surfaces of the outpatient clinics. Same results have also been seen on moulds, whose maximum reduction was 97%. DISCUSSION: Comparing results at different concentrations it has been observed that 2% KMPS induces an higher average reduction of mesophilic bacteria and moulds than 1%. BACKGROUND: In this regard, microbial reduction percentage, either on surfaces or in the air, can be considered positive for outpatient clinics and healthcare settings indoor decontamination.

Adoption of Improved Reprocessing Decreased Microbiological Non-Compliance for Bronchoscopes.

BACKGROUND: In the past few decades, the inadequate reprocessing of bronchoscopes has been associated with several serious outbreaks caused by multidrug-resistant microorganisms. In this study we evaluated the improvement in the quality of reprocessing in a Bronchoscopy Unit (BU), after the introduction of a new procedure. METHODS: In 2019, observational and clinical audits were conducted in the BU. After the introduction of an improved procedure in 2020, a microbiological surveillance plan was implemented in 2021. RESULTS: In 2019, 13 of 22 bronchoscopes (59%) resulted as non-compliant, 18% as high concern organisms (HCO) and 36.4% as high microbial count (≥100 CFU/all channels) and HCO. The most frequent microorganisms were Staphylococcus aureus (38.5%) and NDM-producing Klebsiella pneumoniae (15.4%). The bronchoscopes were stored inside their transport cases, which in some cases were found to be contaminated by the same strains isolated on the bronchoscopes (Enterobacter gergoviae and Vibrio alginolyticus). In 2021, all 31 bronchoscopes were sampled at least three times and 13/99 (13.1%) resulted as non-compliant, mostly K. pneumoniae (4.04%). Contamination level increases weakly in bronchoscopes in use for more than 14 years (R = 0.32). CONCLUSIONS: The adoption of an improved reprocessing procedure decreased the non-compliance of bronchoscopes, increasing the quality of the process and patient safety.

Effectiveness of a Water Disinfection Method Based on Osmosis and Chlorine Dioxide for the Prevention of Microbial Contamination in Dental Practices.

In dental clinics, the infections may be acquired through contaminated devices, air, and water. Aerosolized water may contain bacteria, grown into the biofilm of dental unit waterlines (DUWLs). We evaluated a disinfection method based on water osmosis and chlorination with chlorine dioxide (O-CD), applied to DUWL of five dental clinics. Municipal water was chlorinated with O-CD device before feeding all DUWLs. Samplings were performed on water/air samples in order to research total microbial counts at 22-37 °C, Pseudomonas aeruginosa, Legionella spp., and chlorine values. Water was collected from the taps, spittoons, and air/water syringes. Air was sampled before, during, and after 15 min of aerosolizing procedure. Legionella and P. aeruginosa resulted as absent in all water samples, which presented total microbial counts almost always at 0 CFU/mL. Mean values of total chlorine ranged from 0.18-0.23 mg/L. Air samples resulted as free from Legionella spp. and Pseudomonas aeruginosa. Total microbial counts decreased from the pre-aerosolizing (mean 2.1 × 102 CFU/m3) to the post-aerosolizing samples (mean 1.5 × 10 CFU/m3), while chlorine values increased from 0 to 0.06 mg/L. O-CD resulted as effective against the biofilm formation in DUWLs. The presence of residual activity of chlorine dioxide also allowed the bacteria reduction from air, at least at one meter from the aerosolizing source.

Efficacy of Plant Sterol-Enriched Food for Primary Prevention and Treatment of Hypercholesterolemia: A Systematic Literature Review.

Plant sterols/phytosterols (PSs) are molecules with a similar structure to cholesterol that have a recognized effect on elevated LDL concentrations (LDL-c). PSs are used as a natural therapy against elevated LDL-c in combination with a healthy diet and exercise. A systematic review was performed to evaluate the efficacy of PS-enriched foods in the treatment of hypercholesterolemia. Randomized controlled clinical studies reporting the use of PS-enriched foods to reduce LDL-c among adult individuals were retrieved and assessed for risk of bias. Meta-analyses were performed to assess changes in LDL-c by treatment, food matrix, LDL-c range, sterols dosage and risk of bias (RoB). In the 13 studies analyzed, LDL-c in PS-treated participants decreased by an average of 12.14 (8.98; 15.29) mg/dL. PS administration was statistically more effective in patients with LDL-c ≥ 140 mg/dL and for PS dosages > 2 g/day. It can be concluded that PSs can be used as an important primary prevention measure for hypercholesterolemia and as tertiary prevention for cardiovascular events in patients who already have mild to moderate LDL-c. However, in severe hypercholesterolemia and in cases of familial hypercholesterolemia, it is necessary to combine dietary treatment with the use of statins.

Covid-19 vaccine management (Comirnaty and mrna-1273 Moderna) in a teaching hospital in Italy: a short report on the vaccination campaign.

OBJECTIVES: In this article, we aim to share our experience in the hospital reorganization made to conduct the SARS-CoV-2 vaccination campaign, based on the principles of flexibility and adaptability. STUDY DESIGN: A descriptive study. METHODS: The data concerning the organization of the vaccination campaign were taken from the operative protocol developed by the hospital dedicated task force, composed by experts in hygiene, public health, occupational medicine, pharmacists, nurses, hospital quality, and disaster managers. Data about the numbers of vaccine administered daily were collected by the Innovation and Development Operative Unit database. RESULTS: Vaccinations against COVID-19 started across the EU on the 27th of December 2020. The first phase of the vaccination campaign carried out in our hospital was directed to healthcare workers immunization including medical residents, social care operators, administrative staff and technicians, students of medicine, and health professions trainees. The second phase was enlarged to the coverage of extremely fragile subjects. Thanks to the massive employment of healthcare workers and the establishment of dynamic pathways, it was possible to achieve short turnaround times and a large number of doses administered daily, with peaks of 870 vaccines per day. From the 27th of December up to the 14th of March a total of 26,341 doses of Pfizer have been administered. 13,584 were first doses and 12,757 were second doses. From the 4th to the 14th of March, 296 first doses of Moderna were dispensed. It was necessary to implement adequate spaces and areas adopting anti-contagion safety measures: waiting area for subjects to be vaccinated, working rooms for the dilution of the vaccine and the storage of the material, vaccination rooms, post-vaccination observation areas, room for observation, and treatment of any adverse reactions, with an emergency cart available in each working area. CONCLUSIONS: The teaching hospital of Pisa faced the beginning of the immunization campaign readjusting its spaces, planning an adequate hospital vaccination area and providing an organization plan to ensure the achievement of the targets of the campaign. This represented a challenge due to limited vaccine doses supplied and the multisectoral teams of professionals to coordinate in the shortest time and the safest way possible. The organizational model adopted proved to be adequate and therefore exploited also for the second phase aimed to extremely fragile subjects.

Effectiveness of Disinfection with Chlorine Dioxide on Respiratory Transmitted, Enteric, and Bloodborne Viruses: A Narrative Synthesis.

A viral spread occurrence such as the SARS-CoV-2 pandemic has prompted the evaluation of different disinfectants suitable for a wide range of environmental matrices. Chlorine dioxide (ClO2) represents one of the most-used virucidal agents in different settings effective against both enveloped and nonenveloped viruses. This narrative synthesis is focused on the effectiveness of ClO2 applied in healthcare and community settings in order to eliminate respiratory transmitted, enteric, and bloodborne viruses. Influenza viruses were reduced by 99.9% by 0.5-1.0 mg/L of ClO2 in less than 5 min. Higher concentration (20 mg/L) eliminated SARS-CoV-2 from sewage. ClO2 concentrations from 0.2 to 1.0 mg/L ensured at least a 99% viral reduction of AD40, HAV, Coxsackie B5 virus, and other enteric viruses in less than 30 min. Considering bloodborne viruses, 30 mg/L of ClO2 can eliminate them in 5 min. Bloodborne viruses (HIV-1, HCV, and HBV) may be completely eliminated from medical devices and human fluids after a treatment with 30 mg/L of ClO2 for 30 min. In conclusion, ClO2 is a versatile virucidal agent suitable for different environmental matrices.

Improving the Reprocessing Quality of Flexible Thermolabile Endoscopes: How to Learn from Mistakes.

Background: Failure in the reprocessing of thermolabile flexible endoscopes has been reported as one of the most important threats to patient health. Method: A case report and observational study was conducted, from August 2014 to December 2019, in the Digestive Endoscopy Unit of a University Hospital in Italy, where two cases of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae infections in patients undergoing endoscopic retrograde cholangio-pancreatography were observed. Following the risk/safety management practices, an epidemiological investigation was started, duodenoscopes were removed from use and the reprocessing practices reviewed. Moreover, microbiological surveillance of endoscopes was carried out according to the CDC guidelines. Results: In the first phase of sampling, 10/10 (100%) endoscopes were found to be non-compliant, of which 7 showed results for high-concern organisms (HCOs), such as KPC-K. pneumoniae, P. aeruginosa and E. coli. After implementing corrective actions, 12 out of 17 endoscopes were found to be non-compliant (70.5%), of which 8 showed results for HCOs, such as KPC-K. oxytoca and P. aeruginosa. During the last year of regular microbiological surveillance, only 23% of endoscopes (35/152) were found to be non-compliant, of which 7 showed results for HCOs, such as NDM-K. pneumoniae, P. aeruginosa and A. baumannii. The crucial issues were related to samples collected from the internal channels of duodenoscopes. Conclusion: Managing the risk associated with the reprocessing of digestive endoscopes, through risk assessment at every stage of the process, is important for the prevention of infections associated with the use of these device.

Experimental Evaluation of Aerosol Production after Dental Ultrasonic Instrumentation: An Analysis on Fine Particulate Matter Perturbation.

Aerosol production represents a major concern during the majority of dental procedures. The aim of the present study is to investigate the dynamics of aerosol particles after 15 min of continuous supragingival ultrasonic instrumentation with no attempt of containment through particle count analysis. Eight volunteers were treated with supragingival ultrasonic instrumentation of the anterior buccal region. A gravimetric impactor was positioned 1 m away and at the same height of the head of the patient. Particles of different sizes (0.3-10 µm) were measured at the beginning of instrumentation, at the end of instrumentation (EI), and then every 15 min up to 105 min. The 0.3-µm particles showed non-significant increases at 15/30 min. The 0.5-1-µm particles increased at EI (p < 0.05), and 0.5 µm remained high for another 15 min. Overall, all submicron aerosol particles showed a slow decrease to normal values. Particles measuring 3-5 µm showed non-significant increases at EI. Particles measuring 10 µm did not show any increases but a continuous reduction (p < 0.001 versus 0.3 µm, p < 0.01 versus 0.5 µm, and p < 0.05 versus 1-3 µm). Aerosol particles behaved differently according to their dimensions. Submicron aerosols peaked after instrumentation and slowly decreased after the end of instrumentation, whilst larger particles did not show any significant increases. This experimental study produces a benchmark for the measurement of aerosol particles during dental procedures and raises some relevant concerns about indoor air quality after instrumentation.

COVID-19 Emergency Management: From the Reorganization of the Endoscopy Service to the Verification of the Reprocessing Efficacy.

Microbiological surveillance carried out in order to verify the effectiveness of endoscope reprocessing does not include the research of viruses, although endoscopes may be associated with the transmission of viral infections. This paper reports the experience of the University Hospital of Pisa in managing the risk from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during an endoscopy. A review of the reprocessing procedure was conducted to assess whether improvement actions were needed. To verify the reprocessing efficacy, a virological analysis was conducted both before and after the procedure. Five bronchoscopes and 11 digestive endoscopes (6 gastroscopes and 5 colonoscopes) were sampled. The liquid samples were subjected to concentration through the use of the Macrosep Advance Centrifugal Devices (PALL Life Sciences, Port Washington, NY, USA) and subsequently analyzed using the cobas® SARS-CoV-2 Test (Roche Diagnostics, Basel, Switzerland), together with eSwab 490 CE COPAN swabs (COPAN, Brescia, Italy), which were used to sample surfaces. In accordance with the first ordinance regarding the coronavirus disease 2019 (COVID-19) emergency issued by the Tuscany Region in March 2020, a procedure dedicated to the management of the COVID-19 emergency in endoscopic practices was prepared, including the reprocessing of endoscopes. The virological analysis carried out on samples collected from endoscopes after reprocessing gave negative results, as well as on samples collected on the endoscopy column surfaces and the two washer-disinfectors that were dedicated to COVID-19 patients. The improvement in endoscope reprocessing implemented during the COVID-19 emergency was effective in ensuring the absence of SARS-CoV-2, thus reducing the risk of infections after an endoscopy on COVID-19 patients.

Preparedness and Response to the COVID-19 Emergency: Experience from the Teaching Hospital of Pisa, Italy.

In Italy, the coronavirus disease 2019 (COVID-19) emergency took hold in Lombardy and Veneto at the end of February 2020 and spread unevenly among the other regions in the following weeks. In Tuscany, the progressive increase of hospitalized COVID-19 patients required the set-up of a regional task force to prepare for and effectively respond to the emergency. In this case report, we aim to describe the key elements that have been identified and implemented in our center, a 1082-bed hospital located in the Pisa district, to rapidly respond to the COVID-19 outbreak in order to guarantee safety of patients and healthcare workers.

Evaluation of Legionella spp. Colonization in Residential Buildings Having Solar Thermal System for Hot Water Production.

Despite an increase of literature data on Legionella spp. presence in private water systems, epidemiological reports assert a continuing high incidence of Legionnaires' disease infection in Italy. In this study, we report a survey on Legionella spp. colonization in 58 buildings with solar thermal systems for hot water production (TB). In all buildings, Legionella spp. presence was enumerated in hot and cold water samples. Microbiological potability standards of cold water were also evaluated. Legionella spp. was detected in 40% of the buildings. Moreover, we detected correlations between the count of Legionella spp. and the presence of the optimal temperature for the microorganism growth (less than 40 °C). Our results showed that cold water was free from microbiological hazards, but Legionella spp., was detected when the mean cold water temperature was 19.1 ± 2.2 °C. This may considered close to the suboptimal value for the Legionella growth (more then 20 °C). In conclusion, we observed the presence of a Legionnaires' disease risk and the need of some strategies aimed to reduce it, such as the application of training programs for all the workers involved in water systems maintenance.

Increased Risk of Acquisition of New Delhi Metallo-Beta-Lactamase-Producing Carbapenem-Resistant Enterobacterales (NDM-CRE) among a Cohort of COVID-19 Patients in a Teaching Hospital in Tuscany, Italy.

We describe the epidemiology of New Delhi Metallo-Beta-Lactamase-Producing Carbapenem-Resistant Enterobacterales (NDM-CRE) colonization/infection in a cohort of COVID-19 patients in an Italian teaching hospital. These patients had an increased risk of NDM-CRE acquisition versus the usual patients (75.9 vs. 25.3 cases/10,000 patient days). The co-infection significantly increased the duration of hospital stay (32.9 vs. 15.8 days).

Role of Hydrogen Peroxide Vapor (HPV) for the Disinfection of Hospital Surfaces Contaminated by Multiresistant Bacteria.

The emergence of multiresistant bacterial strains as agents of healthcare-related infection in hospitals has prompted a review of the control techniques, with an added emphasis on preventive measures, namely good clinical practices, antimicrobial stewardship, and appropriate environmental cleaning. The latter item is about the choice of an appropriate disinfectant as a critical role due to the difficulties often encountered in obtaining a complete eradication of environmental contaminations and reservoirs of pathogens. The present review is focused on the effectiveness of hydrogen peroxide vapor, among the new environmental disinfectants that have been adopted. The method is based on a critical review of the available literature on this topic.

Prevention and Control of Legionella and Pseudomonas spp. Colonization in Dental Units.

Introduction: Dental Unit Waterlines (DUWLs) have shown to be a source of Legionella infection. We report the experience of different dental healthcare settings where a risk management plan was implemented. Materials and methods: In a Hospital Odontostomatology Clinic (HOC) and three Private Dental Clinics (PDCs) housing 13 and six dental units (DUs), respectively, an assessment checklist was applied to evaluate staff compliance with guideline recommendations. DUWLs microbial parameters were investigated before and after the application of corrective actions. Results: In the HOC a poor adherence to good practices was demonstrated, whereas protocols were carefully applied in PDCs. L. pneumophila sg 2-15 was isolated in 31% (4/13) and 33% (2/6) of DUs in HOC and PDCs, respectively, mainly from handpieces (32%, 6/19) with counts >102 colony-forming units per milliliter (CFU/L), often associated with P. aeruginosa (68%, 13/19). The shock disinfection with 3% v/v hydrogen peroxide (HP) showed a limited effect, with a recolonization period of about 4 weeks. Legionella was eradicated only after 6% v/v HP shock disinfection and filters-installation, whilst P. aeruginosa after the third shock disinfection with a solution of 4% v/v HP and biodegradable surfactants. Conclusions: Our data demonstrate the presence and persistence of microbial contamination within the DUWLs, which required strict adherence to control measures and the choice of effective disinfectants.