Genotypic and phenotypic characteristics of Candida parapsilosis bloodstream isolates: Health Care Associated Infections in a teaching Hospital in Italy.

BACKGROUND: Candidemia is the most common healthcare associated invasive fungal infection. Over the last few decades, candidemia caused by Candida species other than Candida albicans, particularly the Candida parapsilosis complex, has emerged worldwide. The aims of this study were: to analyze the genotypic and phenotypic characteristics of C. parapsilosis strains isolated from blood cultures and the environment in a hospital in southern Italy, to study the possible source of infection and to correlate the isolated strains. METHODS: From April to October 2022, cases of candidemia due to C. parapsilosis in patients admitted to a hospital in the Apulia region were investigated. However, 119 environmental samples from the intensive care unit were collected for identification of the likely environmental reservoir of infection. Routine antifungal (amphotericin B, anidulafungin, fluconazole) susceptibility was performed on all isolates. Whole genome sequencing was performed to study the genotypic correlation of the isolates. Biofilm biomass and metabolic activity were also quantified for all isolates. RESULTS: A total of 43 C. parapsilosis isolates were cultured from the bloodstream of each patient in different departments, and seven surface samples were positive for C. parapsilosis. Most of the isolated yeasts (41/50; 85 %) were resistant to fluconazole and were genetically related to each other, suggesting an ongoing clonal outbreak of this pathogen. The fluconazole-susceptible isolates produced significantly more biofilm than did the resistant isolates. Metabolic activity was also higher for fluconazole-susceptible than resistant isolates. CONCLUSION: Cross-transmission of the microorganisms is suggested by the phenotypic similarity and genetic correlation between clinical and environmental strains observed in our study.

Effectiveness of hydrogen peroxide wipes for surface disinfection in healthcare facilities.

Introduction: The correct method of surface disinfection in hospitals is an essential tool in the fight against the spread of healthcare-associated infections caused by multi-resistant microorganisms. Currently, there are many disinfectants on the market that can be used against different microorganisms. However, the effectiveness of different active molecules is controversial in the literature. Study design: The aim of this study was to evaluate the effectiveness of wipes based on hydrogen peroxide (1.0 %) and highly specific plant-based surfactants, contained in H2O2TM (Hi-speed H2O2TM) products, against some hospital-associated microorganisms. Methods: The effectiveness of the wipes was tested against nosocomial and control strains of methicillin-resistant Staphylococcus aureus, carbapenem-resistant Pseudomonas aeruginosa, Klebsiella pneumoniae carbapenemase, Aspergillus fumigatus and Candida parapsilosis. Specifically, in vitro activity was assessed using three different techniques: stainless steel surface testing, surface diffusion testing and well diffusion test. Results: The three different methods tested confirm the wipes' good effectiveness against the most common multi-resistant bacteria and against fungi. Conclusions: These data show that the tested wipes could be a valid adjunct to the disinfection process and could assist in the prevention of healthcare-associated infections.

Rethinking the Healthcare Facilities: The Role of the Buffer Space.

OBJECTIVES: A working group conducted a survey on the use of the principle of buffer space (BS), which in case of emergencies, could benefit healthcare settings. The aim of the preliminary investigation is to define new research lines in hospitals' functional design. BACKGROUND: The global experience of the COVID-19 pandemic highlighted challenges faced by hospitals when responding promptly to emergencies, including spatial reorganization and suspension of ordinary medical activities for ensuring adequate management of the emergency surge of patients. METHODS: The group designed questionnaires to be administered to healthcare staff and healthcare designers aimed at understanding varied conceptions and features of BSs. Content across the two surveys overlapped significantly, allowing for direct comparisons of responses, while also including tailored questions in relation to the respective experience and skills of the two groups of respondents. RESULTS: 102 healthcare professionals and 56 designers took part to the survey. Analysis of the responses permitted for initial recommendations regarding BS typology including (a) proximity to the emergency department (ED), intensive care units (ICUs), and inpatient wards (IWs); (b) location within hospitals but separate from other medical areas; (c) need for independent access; (d) organizational and spatial features similar to ED, ICUs, and IWs; (e) existing as a fully flexible operational space; and (f) BS bed capacity to be approximately 12% of ED beds. CONCLUSIONS: Although the analysis is related to the Italian context, the expansion of this preliminary research to alternate healthcare facilities and geographic areas is necessary for reaching a wide consensus by different professionals on this field. It serves as a starting point for future investigations regarding the implementation of BS in hospital settings.

Case series study of nosocomial Legionnaires' disease in Apulia region (southern Italy): The role of different molecular methods in identifying the infection source

BACKGROUND AND AIM: Legionnaires' disease is a severe form of pneumonia caused by the inhalation or aspiration of water droplets contaminated with Legionella pneumophila and other Legionella species. These bacteria are commonly found in natural habitats and man-made water systems. Legionnaires' disease is a significant public health problem, especially in healthcare settings where patients may be exposed to contaminated environmental sources. Nosocomial outbreaks have been reported worldwide, leading to high morbidity and mortality rates, and increased healthcare costs. This study aimed to compare, the clonal relationship of clinical L. pneumophila strains from two different hospitals with L. pneumophila strains isolated from the water supply. METHODS: In the period from 2019 to 2021, clinical and environmental strains involved in three cases of legionellosis were compared by means of pulsed field gel electrophoresis and sequence based typing techniques. RESULTS: Our findings highlight the persistence of clonally distinct strains within each hospital examined. Furthermore, the L. pneumophila strains detected from hospital environmental sources were related to the clinical strains isolated, demonstrating the nosocomial origin of these cases. CONCLUSIONS: Therefore, it is important to implement more accurate surveillance systems both for epidemiological studies and to check the effectiveness of remediation procedures. (www.actabiomedica.it).

Wastewater-based Epidemiology and SARS-CoV-2: Variant Trends in the Apulia Region (Southern Italy) and Effect of Some Environmental Parameters.

During the COVID-19 pandemic, wastewater monitoring has been used to monitor the levels of SARS-CoV-2 RNA entering the sewerage system. In Italy, the Istituto Superiore di Sanità coordinated the SARI project (Sorveglianza Ambientale Reflue in Italia) to detect SARS-CoV-2 and its variants. In this study, the concentration of SARS-CoV-2 and its variants in raw wastewater against COVID-19 cases was evaluated together with the effect of temperature and precipitation on virus spread. We validated a predictive model, proposed by De Giglio et al., 2021, to establish the number of COVID-19 cases/100,000 inhabitants. A receiver operating characteristic curve model was applied to predict the number of COVID-19 cases and Poisson regression was applied to study the effect of temperature and rainfall on viral load. In Apulia, from October 2021 to December 2022, we analyzed 1041 samples, of which 985 (94.6%) tested positive for SARS-CoV-2. Median atmospheric temperature was inversely proportional to viral load in wastewater; no correlation was found with precipitation. The predictive model confirmed that at least 11 cases/100,000 inhabitants would occur in the 15 days following the detection of the virus in wastewater. Environmental surveillance of SARS-CoV-2 can be used to map the virus and its variants.

Effectiveness of First-Line Therapy with Old and Novel Antibiotics in Ventilator-Associated Pneumonia Caused by Carbapenem-Resistant Acinetobacter baumannii: A Real Life, Prospective, Observational, Single-Center Study.

Evidence-based, standard antibiotic therapy for ventilator-associated pneumonia (VAP) caused by carbapenem-resistant Acinetobacter baumannii (CRAB) is a relevant unmet clinical need in the intensive care unit (ICU). We aimed to evaluate the effectiveness of first-line therapy with old and novel CRAB active antibiotics in monomicrobial VAP caused by CRAB. A prospective, observational study was performed in a mixed non-COVID-19 ICU. The primary outcome measure was clinical failure upon first-line targeted therapy. Features independently influencing failure occurrence were also investigated via Cox proportional multivariable analysis. To account for the imbalance in antibiotic treatment allocation, a propensity score analysis with an inverse probability treatment weighting approach was adopted. Of the 90 enrolled patients, 34 (38%) experienced clinical failure. Compared to patients who experienced a clinical resolution of VAP, those who had clinical failure were of an older age (median age 71 (IQR 64-78) vs. 62 (IQR 52-69) years), and showed greater burden of comorbidities (median Charlson comorbidity index 8 (IQR 6-8) vs. 4 (IQR 2-6)), higher frequency of immunodepression (44% vs. 21%), and greater clinical severity at VAP onset (median SOFA score 10 (IQR 9-11) vs. 9 (IQR 7-11)). Lower rates of use of fast molecular diagnostics for nosocomial pneumonia (8.8% vs. 30.3%) and of timely CRAB active therapy administration (65% vs. 89%), and higher rates of colistin-based targeted therapy (71% vs. 46%) were also observed in patients who failed first-line therapy. Overall, CRAB active iv regimens were colistin-based in 50 patients and cefiderocol-based in 40 patients, both always combined with inhaled colistin. According to the backbone agent of first-line regimens, clinical failure was lower in the cefiderocol group, compared to that in the colistin group (25% vs. 48%, respectively). In multivariable Cox regression analysis, the burden of comorbid conditions independently predicted clinical failure occurrence (Charlson index aHR = 1.21, 95% CI = 1.04-1.42, p = 0.01), while timely targeted antibiotic treatment (aHR = 0.40, 95% CI = 0.19-0.84, p = 0.01) and cefiderocol-based first-line regimens (aHR = 0.38, 95% CI = 0.17-0.85, p = 0.02) strongly reduced failure risk. In patients with VAP caused by CRAB, timely active therapy improves infection outcomes and cefiderocol holds promise as a first-line therapeutic option.

Consumption of Energy Drinks among Italian University students: a cross-sectional multicenter study.

PURPOSE: The aim of the study was to evaluate the caffeinated Energy Drinks (EDs) consumption among a large sample of Italian undergraduates and its association with some of the major lifestyle risk factors. METHODS: Students attending twelve public Italian universities were involved between October 2021 and May 2022. Information on socio-demographic characteristics, ED consumption, and on health-related behaviors of participants was collected by the use of a web-based questionnaire. RESULTS: A total of 2165 students participated in the study and 15.2% of them reported having used caffeinated EDs in the last six months, mainly once a month (41.5%). In comparison with non-users, ED users showed a higher proportion of males (p < 0.001) and a higher father's educational level (p = 0.003), came mainly from Northern universities (p = 0.004) and life sciences degree courses (p < 0.001). Besides, ED users reported higher BMI values (p = 0.003), more particular dietary regimens (p < 0.001), higher levels of weekly moderate-vigorous physical activity (p < 0.001) and participation in sports (p < 0.001) and in team sports (p = 0.003), and higher proportion of smokers (p < 0.001) and alcohol drinkers (p = 0.005). ED use was negatively related with female gender (OR 0.546; 95% CI 0.374-0.798), the Mediterranean diet (OR 0.587; 95% CI 0.362-0.951) and coming from the center of Italy (OR 0.500; 95% CI 0.275-0.909) and positively associated with tobacco smoke (OR 1.712; 95% CI 1.176-2.492) and participation in a team sport (OR 1.686; 95% CI 1.051-2.707). CONCLUSION: These findings could encourage figures engaged in education to increase the students' awareness on this issue in order to prevent the excessive use of EDs and associated unhealthy behaviors, especially in the most interested subgroups.

Preliminary Investigation on Hygienic-Sanitary Quality of Food Vending Machines.

The consumption of hot drinks dispensed from vending machines has become a common practice, both in workplaces and during free time. Every day, millions of bulk drinks are sold, but the quality of the products distributed may not always be guaranteed, as it is related to many factors such as the quality of the water, the raw materials used, and the effectiveness of the equipment's cleaning system. The purpose of this study is to evaluate the hygienic-sanitary requirements of hot drinks and vending machine surfaces. The investigation highlighted the microbial contamination of both coffee and vending machine surfaces. Although the "coffee break" is usually considered a moment of pleasure, apparently not subject to specific jurisdiction, the products dispensed can represent a health risk if the hygienic conditions are not fully respected. Therefore, official controls carried out by the Prevention Department represent a suitable way for evaluating and guaranteeing the hygienic-sanitary requirements, providing for corrective actions, when needed, to protect consumers.

Legionella anisa or Legionella bozemanii? Traditional and molecular techniques as support in the environmental surveillance of a hospital water network.

Understanding the actual distribution of different Legionella species in water networks would help prevent outbreaks. Culture investigations followed by serological agglutination tests, with poly/monovalent antisera, still represent the gold standard for isolation and identification of Legionella strains. However, also MALDI-TOF and mip-gene sequencing are currently used. This study was conducted to genetically correlate strains of Legionella non pneumophila (L-np) isolated during environmental surveillance comparing different molecular techniques. Overall, 346 water samples were collected from the water system of four pavilions located in a hospital of the Apulia Region of Italy. Strains isolated from the samples were then identified by serological tests, MALDI-TOF, and mip-gene sequencing. Overall, 24.9% of water samples were positive for Legionella, among which the majority were Legionella pneumophila (Lpn) 1 (52.3%), followed by Lpn2-15 (20.9%), L-np (17.4%), Lpn1 + Lpn2-15 (7.1%), and L-np + Lpn1 (2.3%). Initially, L-np strains were identified as L. bozemanii by monovalent antiserum, while MALDI-TOF and mip-gene sequencing assigned them to L. anisa. More cold water than hot water samples were contaminated by L. anisa (p < 0.001). PFGE, RAPD, Rep-PCR, and SAU-PCR were performed to correlate L. anisa strains. Eleven out of 14 strains identified in all four pavilions showed 100% of similarity upon PFGE analysis. RAPD, Rep-PCR, and SAU-PCR showed greater discriminative power than PFGE.

Assessment of dietary supplement consumption among Italian university students: The multicenter DiSCo study.

OBJECTIVES: The aim of this study was to analyze the consumption of dietary supplements (DSs) and related sociodemographic characteristics or behaviors in Italian undergraduates. METHODS: A questionnaire-based, cross-sectional study was carried out between October 2021 and May 2022 involving undergraduates from 12 public universities. The use of DSs in the previous 6 mo, the aim and reason for use, the purchasing channel, and related adverse effects were explored and compared by sex. A logistic regression was performed to highlight possible associations between sociodemographic, anthropometric, and behavioral characteristics of participants and supplement consumption. RESULTS: The use of DSs was reported by 71.5% of the 2165 respondents. Supplementation was related to sex (odds ratio [OR] 0.690; 95% confidence interval [CI], 0.516-0.924, for men), vegetarian or vegan (OR 4.814; 95% CI, 1.669-13.887) and other particular diet regimens (OR 1.819; 95% CI, 1.282-2.580), sport (OR 1.688; 95% CI, 1.116-2.553), and type of sport (OR 0.629; 95% CI, 0.423-0.936, for team sports). Women were more likely to use DSs following a doctor's prescription and to buy them in a pharmacy (P < 0.001) but reported more adverse effects (P = 0.018) than men. The main aim pursued was general health; proteins, amino acids, and non-caffeinated energy supplements were consumed to improve physical performance and caffeinated energy supplements for mental performance. CONCLUSIONS: Diet supplementation was common in the sample examined, especially in women, and associated with particular dietary regimens and sports, especially individual sports. Female consumers follow specialists' indications more than males. These results highlight the need for educational interventions about diet supplementation for this category of users.

Application of a Decision Tree Model to Predict the Outcome of Non-Intensive Inpatients Hospitalized for COVID-19.

Many studies have identified predictors of outcomes for inpatients with coronavirus disease 2019 (COVID-19), especially in intensive care units. However, most retrospective studies applied regression methods to evaluate the risk of death or worsening health. Recently, new studies have based their conclusions on retrospective studies by applying machine learning methods. This study applied a machine learning method based on decision tree methods to define predictors of outcomes in an internal medicine unit with a prospective study design. The main result was that the first variable to evaluate prediction was the international normalized ratio, a measure related to prothrombin time, followed by immunoglobulin M response. The model allowed the threshold determination for each continuous blood or haematological parameter and drew a path toward the outcome. The model's performance (accuracy, 75.93%; sensitivity, 99.61%; and specificity, 23.43%) was validated with a k-fold repeated cross-validation. The results suggest that a machine learning approach could help clinicians to obtain information that could be useful as an alert for disease progression in patients with COVID-19. Further research should explore the acceptability of these results to physicians in current practice and analyze the impact of machine learning-guided decisions on patient outcomes.

The Geological Characteristics of the Vadose Zone Influence the Impact of Treated Wastewater on the Groundwater Quality (SCA.Re.S. Project 2019-2020).

This study evaluated whether some chemical and microbial contaminants in treated sewage effluents from two wastewater treatment plants (WWTP) reached the groundwater when they drained through a fractured karst vadose zone (WWTP-K) and a porous vadose zone (WWTP-P). Forty-five samples of sewage water (SW), treated water (TW), and monitoring well (MW), collected from WWTP-P (24) and WWTP-K (21), were analyzed for a range of microbiological and chemical properties. The E. coli and Salmonella counts were below the limits outlined in the Legislative Decree 152/06 in effluents from both types of WWTP. Enteric viruses were found in 37.5% and 12.5% of the SW and TW from WWTP-P, respectively. The percentages of Pepper mild mottle virus isolated were higher in TW (62.5% in WWTP-P, 85.7% in WWTP-K) than in SW and MW. The residual concentrations of contaminants of emerging concern (CEC) of each drug category were higher in the MW downstream of WWTP-K than of WWTP-P. Our results showed that the porous vadose zone was more effective at reducing the contaminant loads than the fractured karst one, especially the CEC, in the effluent. The legislation should include other parameters to minimize the risks from treated effluent that is discharged to soil.

Tendency in Pulmonary Aspergillosis Investigation during the COVID-19 Era: What Is Changing?

Aspergillosis is a disease caused by Aspergillus, and invasive pulmonary aspergillosis (IPA) is the most common invasive fungal infection leading to death in severely immuno-compromised patients. The literature reports Aspergillus co-infections in patients with COVID-19 (CAPA). Diagnosing CAPA clinically is complex since the symptoms are non-specific, and performing a bronchoscopy is difficult. Generally, the microbiological diagnosis of aspergillosis is based on cultural methods and on searching for the circulating antigens galactomannan and 1,3-ß-D-glucan in the bronchoalveolar lavage fluid (bGM) or serum (sGM). In this study, to verify whether the COVID-19 period has stimulated clinicians to pay greater attention to IPA in patients with respiratory tract infections, we evaluated the number of requests for GM-Ag research and the number of positive tests found during the pre-COVID-19 and COVID-19 periods. Our data show a significant upward trend in GM-Ag requests and positivity from the pre-COVID to COVID period, which is attributable in particular to the increase in IPA risk factors as a complication of COVID-19. In the COVID period, parallel to the increase in requests, the number of positive tests for GM-Ag also increased, going from 2.5% in the first period of 2020 to 12.3% in the first period of 2021.

Irrigation of Olives with Reclaimed Wastewaters and Deficit Strategies Affect Pathogenic Bacteria Contamination of Water and Soil.

This study aimed to evaluate pathogenic bacterial contamination of the water-soil-plant system in potted olive trees irrigated with reclaimed wastewater. Desalinated water (DW) obtained by treating municipal wastewater (SW) and reclaimed water (RW) obtained by mixing SW with the brine (BR) produced by DESERT technology (tertiary treatment by ultrafiltration, active carbon and reverse osmosis) were used. Two different irrigation regimes were compared: full irrigation (FI) and regulated deficit irrigation (RDI). During two irrigation seasons the concentrations of Escherichia coli, enterococci, spores of sulfite-reducing Clostridia (SRC) and Salmonella spp. were monitored in water, soil and fruit samples. Microbial concentrations in DW were always below the threshold for reuse in agriculture, while RW showed the highest level of contamination for all observed parameters. RDI management appeared to increase the soil content of SRC spores with respect to FI. Sporadically low SRC spore contamination was recorded in some fruits only in 2018, regardless of the irrigation source, probably because of accidental contamination during sampling or post-harvest handling. This study encourages the creation of a better regulatory framework reference, with specific guidelines for the use of RW as part of integrated environmental systems for the management of sustainable agriculture.

Investigations on the Efficacy of Ozone as an Environmental Sanitizer in Large Supermarkets.

Awareness of the importance of the microbial contamination of air and surfaces has increased significantly during the COVID-19 pandemic. The aim of this study was to evaluate the presence of bacteria and fungi in the air and on surfaces within some critical areas of large supermarkets with and without an ozonation system. Surveys were conducted in four supermarkets belonging to the same commercial chain of an Apulian city in June 2021, of which two (A and B) were equipped with an ozonation system, and two (C and D) did not have any air-diffused remediation treatment. There was a statistically significant difference in the total bacterial count (TBC) and total fungal count (TFC) in the air between A/B and C/D supermarkets (p = 0.0042 and p = 0.0002, respectively). Regarding surfaces, a statistically significant difference in TBC emerged between A/B and C/D supermarkets (p = 0.0101). To the best of our knowledge, this is the first study evaluating the effect of ozone on commercial structures in Italy. Future investigations, supported by a multidisciplinary approach, will make it possible to deepen the knowledge on this method of sanitation, in light of any other epidemic/pandemic waves.

Microbiological and chemical characteristics of beaches along the Taranto Gulf (Ionian Sea, Southern Italy).

Coastal habitats provide important ecosystem services, such as the maintenance of ecological sustainability, water quality regulation, nutrient recycling, and sandy beaches which are important areas for recreation and tourism. The quality of seawater is generally measured by determining the concentrations of Escherichia coli and intestinal Enterococci, which might be affected by the persistent populations of these bacteria in sand. Sand might thus be a significant source of pathogen exposure to beachgoers. The quality of coastal recreational waters can also be affected by eutrophication, water discoloration, and harmful algal blooms, which pose additional human health risks. Here, we conducted a monitoring of the beaches quality along the Taranto Gulf by determining the concentrations of fecal indicator organisms, as well as other parameters that are not traditionally measured (physicochemical parameters, Pseudomonas aeruginosa, and harmful microalgae), in shallow seawater and sand sampled from three beaches. The concentrations of bacteria were determined using both standard microbiological methods and the IDEXX system. Our results demonstrate the utility of measuring a greater number of parameters in addition to those conventionally measured, as well as the importance of assessing the health risks posed by the sand matrix. Additional work is needed to develop rapid analytical techniques that could be used to monitor the microbiological parameters of solid matrices.

No-Touch Automated Disinfection System Based on Hydrogen Peroxide and Ethyl Alcohol Aerosols for Use in Healthcare Environments.

Healthcare-related infections are sustained by various bacteria and fungi. In recent years, various technologies have emerged for the sanitation of healthcare-related environments. This study evaluated the effectiveness of a no-touch disinfection system that aerosolizes 5% hydrogen peroxide and 10% ethyl alcohol. After selecting an environment, the Total Bacterial Count and the Total Fungal Count in the air and on a surface of the room were determined to evaluate the effectiveness of the aerosolization system. In addition, sterile stainless-steel plates inoculated with S. aureus, P. aeruginosa, and Aspergillus spp. isolated from hospitalized patients and reference strains were used to evaluate the effectiveness of the system. For each organism, three plates were used: A (cleaned), B (not cleaned), and C (control). The A plates were treated with non-ionic surfactant and the aerosolization system, the B plates were subjected to the aerosolization system, and the plates C were positioned outside the room that was sanitized. Following sanitization, air and surface sampling was conducted, after which, swabs were processed for bacterial and fungal enumeration. The results showed that the air sanitization system had good efficacy for both bacteria and fungi in the air and on stainless-steel plates, particularly for the A plates.

How do Vaccinators Experience the Pandemic? Lifestyle Behaviors in a Sample of Italian Public Health Workers during the COVID-19 Era.

Public health workers (PHWs) have experienced substantial workload changes because of their role in managing measures to limit the spread of COVID-19. The study's aim was to assess lifestyle changes in Italian PHWs during the pandemic. PHWs attending an annual meeting completed an anonymous questionnaire assessing their sociodemographic and behavioral characteristics and lifestyle changes during the pandemic. A total of 1000 questionnaires were completed. Most participants (63.5% women, mean age 40 ± 13.1 years) were of normal weight (61.5%), non-smokers (81.9%), had a total screen time of ≥5 h/day (83.1%), and slept at least 6 h/night (88.7%). Approximately one-third consumed sweet foods every day (30%) and did not engage in physical activity (34.6%). Current sweet food consumption, physical activity, and sleep were associated with changes in these behaviors in the last 2 years (Tau-b = 0.155; Tau-b = -0.175; Tau-b = -0.276, respectively, p < 0.001). An increase in remote working was associated with worse sleep (odds ratio (OR) 2.065, 95% confidence interval (CI) 1.482-2.877) and diet (OR 1.982, 95% CI 1.385-2.838), and increased tablet/PC use (OR 3.314, 95% CI 2.358-4.656). Health promotion measures are needed to support the adoption of healthy lifestyles in this population during the current pandemic.

Reduced COVID-19 mortality linked with early antibodies against SARS-CoV-2, irrespective of age.

BACKGROUND: COVID-19 pandemic has generated a million deaths worldwide. The efficiency of the immune system can modulate individual vulnerability with variable outcomes. However, the relationships between disease severity and the titer of antibodies produced against SARS-CoV-2 in non-vaccinated, recently infected subjects need to be fully elucidated. METHODS: A total of 99 patients admitted to a COVID-unit underwent clinical assessment and measurement of serum levels of anti-spike protein (S1) IgM, and anti-nucleocapsid protein IgG. Patients were stratified according to the clinical outcome (i.e., discharged at home or in-hospital death). RESULTS: Following hospitalization, 18 died during the hospital stay. They were older, had lymphopenia, a higher co-morbidity rate, and longer hospital stay than 81 patients who were discharged after healing. Patients in this latter group had, at hospital admittance, 7.9-fold higher serum concentration of IgM, and 2.4-fold higher IgG levels. Multivariate Cox regression models indicated age and anti-nucleocapsid protein IgG concentration at admission as independently associated with the risk of in-hospital death. CONCLUSIONS: An efficient immunological response during the early phase of COVID-19 protects from mortality, irrespective of age. Advanced age is a critical risk factor for poor outcome in infected subjects. Further studies must explore potential therapeutic strategies able to restore a valid functional humoral immunity in elderly patients with poor antibody response during the early stage of COVID-19 infection.

Quantitative Microbial Risk Assessment Applied to Legionella Contamination on Long-Distance Public Transport.

The quantitative microbial risk assessment (QMRA) framework is used for assessing health risk coming from pathogens in the environment. In this paper, we used QMRA to evaluate the infection risk of L. pneumophila attributable to sink usage in a toilet cabin on Italian long-distance public transportation (LDT). LDT has water distribution systems with risk points for Legionella proliferation, as well as premise plumbing for drinking water, but they are not considered for risk assessment. Monitoring data revealed that approximately 55% of water samples (217/398) were positive for L. pneumophila, and the most frequently isolated was L. pneumophila sg1 (64%, 139/217); therefore, such data were fitted to the best probability distribution function to be used as a stochastic variable in the QMRA model. Then, a sink-specific aerosolization ratio was applied to calculate the inhaled dose, also considering inhalation rate and exposure time, which were used as stochastic parameters based on literature data. At L. pneumophila sg1 concentration ≤100 CFU/L, health risk was approximately 1 infection per 1 million exposures, with an increase of up to 5 infections per 10,000 exposures when the concentrations were ≥10,000 CFU/L. Our QMRA results showed a low Legionella infection risk from faucets on LDT; however, it deserves consideration since LDT can be used by people highly susceptible for the development of a severe form of the disease, owing to their immunological status or other predisposing factors. Further investigations could also evaluate Legionella-laden aerosols from toilet flushing.