[Transmission of Sars-Cov-2 and ventilation of indoor environments. Technical notes and preventive measures]. / Trasmissione di Sars-Cov-2 e ventilazione di ambienti confinati. Note tecniche e indicazioni di prevenzione.

Knowledge about the new infectious disease COVID-19, which first spread in the city of Wuhan in China, in December 2019, is based on the evidence retrieved from coronaviruses previously known to humans. The main transmission ways of the new SARS-CoV-2 virus are respiratory droplets and direct and close contact with infected individuals and contaminated surfaces. To date, some scientific publications provide initial evidence that SARS-CoV-2 can be detected in the air, thus assuming a further route of infection, that airborne, although these results are to be considered preliminary and they need careful interpretation. In support of this hypothesis, ventilation systems, aimed to improve indoor air, could represent an easy way to spread and promote the virus infection especially in hospitals and in all health facilities where the presence of infected individuals is potentially high as well as the possibility of infection by air. Indeed, by generating jets of air at different speeds, they can interfere with the mission of respiratory particles and determine an environmental diffusion of the potentially contaminating droplet. Therefore, ventilation systems could provide a potential transmission channel for the viral load able to spread out in indoor air. Nonetheless, good management, technical and operational practices may lead to a low risk of contagion, both in community and health environments.

A management model for Hospital Hygiene Unit: evidence-based proactive surveillance of potential environmental sources of infection in order to prevent patient's risk.

INTRODUCTION: The aim of this study is to describe a proactive surveillance system of food, water and environmental surfaces, in order to avoid Healthcare-Associated Infections (HAIs) from hospital environment. METHODS: It is a retrospective descriptive study. The surveillance system consists of two integrated phases: pre-analytic and post-analytic. The activities are distinguished in ordinary control activities, performed after scheduled and shared surveys, and compliance activities, performed when it is necessary to establish the adequacy of the destination use, for example opening a new ward. RESULTS: A total of 1,470 Samples were collected and 539 Reports were generated across the five-year study period. Water for human consumption procedure: a statistically significant trend was found only in the total number of Samples collected (p < 0.001). Legionella spp. infection water risk procedure: all Samples and Reports, with the exception of Compliance Report Samples, showed a statistically significant trend (p < 0.001). Pseudomonas aeruginosa water risk procedure: only Ordinary Reports and Compliance Report Samples trend were statistically significant (p = 0.002 and p = 0.028 respectively). Effectiveness of surface sanitization procedure: no trend was statistically significant (p < 0.05). Hospital catering and food surfaces procedure: Samples and Reports yearly number was constant, no trend analysis was performed. HAIs prevalence was never over 5% in the hospital under study. CONCLUSIONS: This surveillance system of water, food and environmental surfaces represents an innovative way of approaching hospital safety for patients and personnel because it overcomes the limitations due to a classic approach limited to a laboratory analytic phase only, according to the best available scientific evidence.

[Hospital foodservice through the Cook Chill system: a two-year experience in a University teaching hospital, Italy]. / La ristorazione in ospedale mediante il sistema "Cook and Chill": un'esperienza di 2 anni in un Policlinico Universitario.

The Authors present their two-year experience regarding an evaluation of the hygienic quality of ready-to-eat foods in a hospital foodservice, both for patients' meals and hospital staff, prepared by using the Cook Chill system. According to the microbiological parameters provided by International Guidelines, 23 of 27 food samples that were collected and analyzed were found to be satisfactory, one was acceptable and only three were unsatisfactory (two for aerobic colony count and one both for aerobic colony count and hygienic procedure). Escherchia coli, Staphylococcus aureus, Salmonella, Listeria monocytogenes, and Clostridium perfringens were absent in all of the analyzed products, The study results are encouraging and confirm the need to always verify that the different phases of production of hospital meals are correctly implemented, even when the foodservice is out-sourced. This has always been considered a priority in the study hospital, where the Health Department is at the forefront both in control and verification of food safety practices and in offering training activities, especially in view of the increased susceptibility of hospitalized patients.

Enterobacteriaceae Antibiotic Resistance in Ready-to-Eat Foods Collected from Hospital and Community Canteens: Analysis of Prevalence.

Foodborne diseases and antibiotic resistance are serious widespread health problems in the contemporary world. In this study, we compared the microbiological quality of ready-to-eat (RTE) foods found in community canteens versus hospital canteens in Rome, Italy, focusing on detection and quantification of Enterobacteriaceae and the antibiotic resistance of these bacteria. Our findings show a remarkable difference in Enterobacteriaceae contamination between RTE foods distributed in community canteens (33.5% of samples) and those distributed in hospital canteens (5.3% of samples). This result highlights greater attention to good manufacturing practices and good hygiene practices by the food operators in hospitals compared with food operators in community canteens. As expected, a higher percentage of cold food samples (70.9%) than of hot food samples (10.8%) were positive for these bacteria. Excluding the intrinsic resistance of each bacterial strain, 92.3% of the isolated strains were resistant to at least one antibiotic, and about half of the isolated strains were classified as multidrug resistant. The prevalence of multidrug-resistant strains was 50% in the community samples and 33.3% in hospital canteens. Our results indicate that approximately 38% of RTE foods provided in community canteens is not compliant with microbiological food safety criteria and could be a special risk for consumers through spread of antibiotic-resistant strains. Hygienic processing and handling of foods is necessary for both hospital and community canteens.

[Hygienic suitability of food and food-contact surfaces in a hospital canteen: the experience of a University Hospital in Italy]. / Idoneità igienico-sanitaria di alimenti e superfici in una mensa ospedaliera: un'esperienza in un Policlinico Universitario.

The Authors present the results of a study performed during a time-period of two years, to evaluate the hygienic quality of ready-to-eat foods, prepared and served in a hospital catering service, and the microbiological status of food-contact surfaces. Food hygiene was evaluated using non-pathogenic indicator microorganisms. The study was part of the verification activities that the hospital Health Department considers as a priority in order to guarantee patient safety. Only one of 52 food samples tested was considered unsatisfactory; the examined surfaces were not fully satisfactory in one of four cases. The study results, although encouraging as a whole, especially with respect to the hygienic safety of food prepared and served in the hospital, confirm the need to continuously verify that the appropriate environmental sanitation procedures are applied, even in the case of outsourcing. Considering the increased susceptibility of hospitalized patients, this remains a priority in the hospital where the study was performed.

[Comparison of conventional culture methods and quantitative real-time PCR methods for the detection of Legionella pneumophila in water samples in a large University teaching hospital in Rome, Italy]. / Confronto tra il metodo colturale standard e la real-time PCR per l'identificazione di Legionella pneumophila in campioni di acqua.

The aims of this study were to identify the best threshold value for the real-time PCR method in detecting the presence of Legionella pneumophila in water samples, and to evaluate the prognostic significance of negative results obtained with the molecular method. From 2011 to 2014, 77 water samples were collected from hospital wards of a large University teaching hospital in Rome (Italy) and screened for L.pneumophila by the standard culture method and by real-time PCR. The high sensitivity and negative predictive value of real-time PCR make this method suitable as a quick screening tool to exclude the presence of L. pneumophila in water samples in the hospital setting.

Legionella on board trains: effectiveness of environmental surveillance and decontamination.

BACKGROUND: Legionella pneumophila is increasingly recognised as a significant cause of sporadic and epidemic community-acquired and nosocomial pneumonia. Many studies describe the frequency and severity of Legionella spp. contamination in spa pools, natural pools, hotels and ships, but there is no study analysing the environmental monitoring of Legionella on board trains. The aims of the present study were to conduct periodic and precise environmental surveillance of Legionella spp. in water systems and water tanks that supply the toilet systems on trains, to assess the degree of contamination of such structures and to determine the effectiveness of decontamination. METHODS: A comparative pre-post ecological study was conducted from September 2006 to January 2011. A total of 1,245 water samples were collected from plumbing and toilet water tanks on passenger trains. The prevalence proportion of all positive samples was calculated. The unpaired t-test was performed to evaluate statistically significant differences between the mean load values before and after the decontamination procedures; statistical significance was set at p ≤ 0.05. RESULTS: In the pre-decontamination period, 58% of the water samples were positive for Legionella. Only Legionella pneumophila was identified: 55.84% were serogroup 1, 19.03% were serogroups 2-14 and 25.13% contained both serogroups. The mean bacterial load value was 2.14 × 10(3) CFU/L. During the post-decontamination period, 42.75% of water samples were positive for Legionella spp.; 98.76% were positive for Legionella pneumophila: 74.06% contained serogroup 1, 16.32% contained serogroups 2-14 and 9.62% contained both. The mean bacterial load in the post-decontamination period was 1.72 × 10(3) CFU/L. According to the t-test, there was a statistically significant decrease in total bacterial load until approximately one and a half year after beginning the decontamination programme (p = 0.0097). CONCLUSIONS: This study indicates that systematic environmental surveillance could be a useful approach for assessing the risk of exposure to Legionella bacteria, which still represents a public health threat. According to the study results, an environmental surveillance programme, followed by decontamination procedures where necessary, would decrease the total bacterial count, protecting the health of travellers and workers.