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Hepatitis E virus (HEV) is a global health problem, causing an estimated 20 million infections annually. Thus, the management of HEV requires special consideration. In developed countries, hepatitis E is mainly recognized as a foodborne disease (mainly transmitted via undercooked meat consumption) that is generally caused by genotype 3 and 4 circulating in various animals, including pigs and wild boars. The current absence of officially recognized protocols for the analysis of HEV in foods and the lack of awareness of this disease among healthcare workers, together with the high percentage of asymptomatic cases, make HEV infection highly underestimated. Most HEV-3 infections in immunocompetent individuals are self-limited. Nevertheless, the possibility of serious forms of liver disease, especially in patients with co-morbidities, should be considered because it can lead to a fatal outcome. Here, we report a case of fatal hepatitis related to HEV-3 infection in a 67-year-old male patient with underlying chronic liver disease (CLD) and living in a region where a high prevalence and genetic heterogeneity of HEV-3 in wild boar has been recently demonstrated. Our case report describes the interdisciplinary approach used (from the diagnosis to the virus phylogenetic characterization) in order to improve epidemiologic HEV surveillance in central Italy. [ABSTRACT FROM AUTHOR]

The emergence of SARS-CoV-2 and the non-pharmacological interventions adopted to counter its spread appear to have led to changes in the normal circulation and seasonality of respiratory viruses. Our study aims to investigate changes related to the circulation of respiratory viruses, not SARS-CoV-2, among hospitalized patients in Perugia, Central Italy, between 2019 and 2023. The samples were collected from individuals who went to the emergency room (ER) or were hospitalized and analyzed using a molecular multiplex test. The results underline that non-pharmaceutical interventions altered the typical seasonal circulation patterns of different respiratory viruses. Those mostly affected were enveloped viruses like influenza viruses that disappeared in 2021; the least impact was recorded for Rhinovirus, which was detected during the pandemic period, maintaining the same seasonality observed in the pre-pandemic period although with a reduction in the number of positive samples. Our data underline the importance of the continuous monitoring of these viruses, especially to understand the timing with which prevention measures, not only non-pharmacological interventions but also the equipment of vaccine doses and monoclonal antibodies, should be adopted to reduce their circulation, particularly in the population at risk of developing severe forms of lower respiratory tract infection. [ABSTRACT FROM AUTHOR]

Introduction Eggerthia catenaformis, a non-spore-forming anaerobic Gram-positive bacillus component of the human fecal microbiota has rarely been reported in human diseases. In almost every case described in current literature to date, dental diseases (abscesses, periodontitis, or caries), are the most common source of the infection which extends to the brain, cervical spaces, pulmonary parenchyma, the pleural cavity, the abdominal wall, and the abdominal cavity. Case report An 82-year-old male Caucasian patient was admitted to our Emergency Department (ED) with a painless, right submandibular mass, dyspnea, and inspiratory stridor. A CT scan of the head, neck, and chest with intravenous contrast material revealed a retrotonsillar fluid collection. Air bubbles and minimal fluid were present from the right sub-mandibular area to the lower mediastinum between the spine, the descending thoracic aorta, and the trachea. The patient underwent surgical treatment and a broad-spectrum antibiotic. The retropharyngeal fluid collection culture showed the presence of Eggerthia catenaformis. After a first period in the Intensive Care Unit, he was admitted to a Step-Down Unit (SDU) where he underwent respiratory weaning, motor rehabilitation, and gradual oral feeding resumption. At discharge, the patient maintained the tracheal cannula as he still had impaired swallowing of solid foods. Conclusions Here we report the first case of descending necrotizing mediastinitis in a patient with a retropharyngeal abscess, in the absence of dental diseases. [ABSTRACT FROM AUTHOR]

Background/Objectives: Chronic skin wounds are characterized by inflammation, persistent infections, and tissue necrosis. The presence of bacterial biofilms prolongs the inflammatory response and delays healing. Ozone is a potent antimicrobial molecule, and many formulations have been used in the advanced therapeutic treatment of chronic wounds. The aim of this work was to determine the antimicrobial, anti-inflammatory, and regenerative activity of a stable ozone-gel formulation over time. Methods: The antimicrobial property was assessed by measuring the minimal inhibitory concentration and the antibiofilm activity. The anti-inflammatory effect was evaluated by TNF-α determination, and the regenerative effect was measured by scratch assay. Results: The ozone gel demonstrated antimicrobial and antibiofilm activity in all ATCC microorganisms examined and on most clinical isolates. Higher concentrations of the ozone gel were also useful in the dispersion of preformed biofilm. The ozone gel also showed anti-inflammatory activity by reducing the production of TNF-α and regenerative activity in human fibroblasts and keratinocytes. Conclusions: Given all these antimicrobial, anti-inflammatory, and regenerative characteristics, the ozone gel could be, in this formulation, used in the treatment of wounds. The ozone-gel formulation described here retains stability for over 30 months, which facilitates its use compared to formulations that lose efficacy quickly. [ABSTRACT FROM AUTHOR]

Novel Coronavirus disease (COVID-19) has been widely described as the cause for a proinflammatory and hypercoagulable state. The inflammatory process involving the alveolar vascular endothelium in the respiratory system, is a determining factor for the onset of primary Pulmonary Artery Thrombosis (PAT) even in patients with heparin prophylactic treatment. Little is known about the efficacy of the anticoagulant therapy during the course of PAT caused by COVID-19. In this paper we describe the results obtained in patients with moderate COVID-19 disease, previously threated with prophylactic enoxaparin, who then received full Anticoagulant treatment after diagnosis of PAT. After three months Computed Tomography Pulmonary Angiography demonstrated a complete resolution of the vascular obstructive lesions in all patients, while all the coagulation tests were normal. [ABSTRACT FROM AUTHOR]

Idiopathic central diabetes insipidus (CDI) is a disorder characterized by hypotonic polyuria and polydipsia, without any identified etiology. Here we report a case of a 57-year-old woman, with idiopathic CDI, admitted to our department with severe sepsis and acute kidney failure. After clinical and radiological investigations, she was diagnosed with idiopathic CDI. In this case report the findings suggest that severe sepsis could be the trigger for this disease. In addition, we hypothesise that apelin, a diuretic neuropeptide, plays a role in such a process. Apelin levels are known to increase during severe sepsis, which in turn counteracts vasopressin actions through inhibition of vasopressin neuron activity and vasopressin release. [ABSTRACT FROM AUTHOR]

Cataclastic rocks and fault gouge present highly variable properties, from those of soil-like materials to those of competent rock mass. In most cases, the entire rock mass, or internal major shear zones, can be represented as a block-in-matrix rock (bimrock), i.e., rock fragments of different shape and size, embedded in a finer matrix. In this paper, a tectonized metamorphic rock mass at the site of a planned gravity dam is investigated. The dam foundation is crossed by numerous major discontinuities, often grouped to form wider shear zones and characterized by high persistency, waviness, and abundant cataclastic filling. Systematic measurements of local orientation and filling thickness along the discontinuity traces made a detailed morphological analysis possible. The most frequent type of filling is a lightly cemented matrix-supported gouge. Undisturbed sampling of filling materials was successful only in some special cases. Laboratory tests, as well as in-situ mechanical tests, were therefore difficult and not exhaustive. Micromechanical distinct-element method (DEM) modeling was instrumental in obtaining a more comprehensive framework of deformation and failure mechanisms of cataclastic materials. The mechanical properties of the particulate model were first analyzed by numerical simulation of biaxial and direct shear tests. The relationship between the overall constitutive parameters and micromechanical properties, such as interparticle friction, contact stiffness, cement bond strength, volumetric block proportion, and block shape, was determined. The complex interplay between the geometric features of a major discontinuity (joint-wall roughness and waviness) and the properties of the infilling bimrock was then investigated, and finally, the overall strength of the infilled discontinuity was analyzed. [ABSTRACT FROM AUTHOR]

The design of deep tunnels underneath the water-table in clayey soils should carefully take into account the influence of pore pressures and seepage forces on the stability of the excavation and on the loading conditions of the support systems. This paper focuses on the application of analytical solutions and numerical models to the analysis of stress and deformation around deep tunnels, in the short and long term, considering the idealized situation of axisymmetric conditions. General remarks on the influence of hydro-mechanical coupling, artificial boundary conditions and lining permeability are presented. Theoretical predictions are compared with measurements made in tunnels excavated in the Boom clay formation at Mol (Belgium). [ABSTRACT FROM AUTHOR]

Abstract: In a companion paper, basic differences between the hydro-mechanical behaviour of plastic and stiff clay formations were highlighted and some issues, such as the influence of hydro-mechanical coupling and boundary conditions, were pointed out. This paper focuses on the effect of the scaly structure, frequently caused by tectonic shearing, typical of many relatively old and deep-sited argillaceous formations. Different engineering models for the prediction of short- and long-term response to tunnel excavation are compared. The proposed approaches consider some typical features of the hydro-mechanical behaviour of the plastic annulus around the tunnel, focusing on the influence of fissure opening, which may cause loss of saturation, in the short-term, and a general increase in permeability in the long-term. The case of the Raticosa tunnel (Italy), excavated through tectonised argillites, is chosen as an example case to apply the proposed approaches and investigate the aforementioned issues. Laboratory test results and in situ measurements are also discussed. The interpretation of convergence measurements, with the help of empirical correlations and the results of hydro-mechanical analyses, highlights the relevance of time-dependent creep deformation, which could therefore be tentatively distinguished from deformation due to consolidation. The potential of an “observational” approach in which early tunnel convergence measurements are used to predict the total final increment in convergence due to time-dependent deformation is also discussed. [Copyright &y& Elsevier]

Abstract: The paper analyses the response of argillaceous formations to the excavation of deep tunnels, focusing on the role of hydro-mechanical behavior. First, two different types of geologic formations are identified: plastic, soil-like, and stiff, rock-like, argillaceous formations. This paper is specifically concerned with deep tunnels in plastic clays. In particular, the influence of pore pressure changes on the stability of the excavation and on the loading of the support systems is investigated. The state of stress and deformation is analyzed in the short- and long-term, by applying analytical and numerical solutions to the idealized situation of an axisymmetric tunnel. General remarks on the influence of hydro-mechanical coupling, artificial boundary conditions and lining permeability are presented. Theoretical predictions are compared with measurements made in some tunnels excavated in the Boom clay formation at Mol (Belgium). The suggestions provided in the paper may contribute to refining practical design approaches, hence filling the gap between the application of advanced hydro-mechanical models and conventional uncoupled elasto-plastic models. In a companion paper, the behavior of rock-like materials is considered. In particular, the effect of scaly structure, typical of many deep argillaceous formations, and fissure opening around the tunnel walls is examined. Results of conventional and novel models, purposely formulated to analyze such situations, are compared. [Copyright &y& Elsevier]

Splenic infarction (SI) is a rare event occurring when the splenic artery or its branches become occluded by embolus or by in situ thrombosis. Many SI events are a result of embolic sources either cardiac or aortic. Massive splenic infarction (MSI) results from compromised blood flow to more than half of the spleen. In this paper we describe a case of a previously healthy patient who presented with pneumococcal sepsis who, upon investigation, revealed an unknown celiac disease and a MSI. Abdominal ultrasound with contrast agent was a useful tool for a diagnosis and follow up of this patient. [ABSTRACT FROM AUTHOR]

The pathogenesis of coronavirus disease 2019 (COVID-19) is associated with a hyperinflammatory response. The mechanisms of SARS-CoV-2-induced inflammation are scantly known. Methylglyoxal (MG) is a glycolysis-derived byproduct endowed with a potent glycating action, leading to the formation of advanced glycation end products (AGEs), the main one being MG-H1. MG-H1 exerts strong pro-inflammatory effects, frequently mediated by the receptor for AGEs (RAGE). Here, we investigated the involvement of the MG-H1/RAGE axis as a potential novel mechanism in SARS-CoV-2-induced inflammation by resorting to human bronchial BEAS-2B and alveolar A549 epithelial cells, expressing different levels of the ACE2 receptor (R), exposed to SARS-CoV-2 spike protein 1 (S1). Interestingly, we found in BEAS-2B cells that do not express ACE2-R that S1 exerted a pro-inflammatory action through a novel MG-H1/RAGE-based pathway. MG-H1 levels, RAGE and IL-1β expression levels in nasopharyngeal swabs from SARS-CoV-2-positive and -negative individuals, as well as glyoxalase 1 expression, the major scavenging enzyme of MG, seem to support the results obtained in vitro. Altogether, our findings reveal a novel mechanism involved in the inflammation triggered by S1, paving the way for the study of the MG-H1/RAGE inflammatory axis in SARS-CoV-2 infection as a potential therapeutic target to mitigate COVID-19-associated pathogenic inflammation. [ABSTRACT FROM AUTHOR]

Summary: In chronic lymphocytic leukaemia (CLL) the efficacy of SARS‐CoV‐2 vaccination remains unclear as most studies have focused on humoral responses. Here we comprehensively examined humoral and cellular responses to vaccine in CLL patients. Seroconversion was observed in 55.2% of CLL with lower rate and antibody titres in treated patients. T‐cell responses were detected in a significant fraction of patients. CD4+ and CD8+ frequencies were significantly increased independent of serology with higher levels of CD4+ cells in patients under a Bruton tyrosine kinase (BTK) or a B‐cell lymphoma 2 (BCL‐2) inhibitor. Vaccination skewed CD8+ cells towards a highly cytotoxic phenotype, more pronounced in seroconverted patients. A high proportion of patients showed spike‐specific CD4+ and CD8+ cells producing interferon gamma (IFNγ) and tumour necrosis factor alpha (TNFα). Patients under a BTK inhibitor showed increased production of IFNγ and TNFα by CD4+ cells. Vaccination induced a Th1 polarization reverting the Th2 CLL T‐cell profile in the majority of patients with lower IL‐4 production in untreated and BTK‐inhibitor‐treated patients. Such robust T‐cell responses may have contributed to remarkable protection against hospitalization and death in a cohort of 540 patients. Combining T‐cell metrics with seroprevalence may yield a more accurate measure of population immunity in CLL, providing consequential insights for public health. [ABSTRACT FROM AUTHOR]

Generally, off-grid fossil fuel generators provide energy supply to remote regions. The integration of photovoltaic (PV) plants to battery energy storage (BES) systems potentially increases reliability, the system autonomy and lifetime, reducing the generator working hours and the system environmental impact. PV–BES–Diesel generator hybrid energy systems (HESs) offer technical, economic and environmental benefits compared to traditional off-grid systems. This paper proposes a bi-objective design model for off-grid PV–BES–Diesel generator HESs. The aim is to identify the PV plant rated power, the BES system capacity and the technical configuration able to jointly reduce the levelised cost of the electricity ( LCOE ) and the carbon footprint of energy ( CFOE ) . Furthermore, the comparison of the LCOE and CFOE values of the HES against a traditional diesel generator allows determining the economic and environmental advantages coming from the described system. Despite the proposed model is general and suitable for any installation site and HES configuration, this paper exemplifies its application designing a HES to be installed in a remote village in Yakutsk, Russia. The model takes into account the hourly energy demand, the irradiation and temperature profiles of the installation location calculating the hourly PV plant yield, the battery charge–discharge processes and the required generator energy. Results highlight the technical, economic and environmental feasibility of the system for a context with a medium irradiation level, i.e. ∼1400 kW h/(m 2 year), and relatively low fuel cost, i.e. 0.7 €/l. For the best economic scenario LCOE and CFOE reductions are of about 8% and 28%, respectively. Finally, the most effective trade-off between economic and environmental performances leads to a CFOE decrease of about 48% and a slight decrease of the economic performances (−2%). [ABSTRACT FROM AUTHOR]

In the last years, the technological development and the increasing market competitiveness of renewable energy systems, like solar and wind energy power plants, create favorable conditions to the switch of the electricity generation from large centralized facilities to small decentralized energy systems. The distributed electricity generation is a suitable option for a sustainable development thanks to the environmental impact reduction, the load management benefits and the opportunity to provide electricity to remote areas. Despite the current cut off of the national supporting policies to the renewables, the photovoltaic (PV) systems still find profitable conditions for the grid connected users when the produced energy is self-consumed. Due to the intermittent and random nature of the solar source, PV plants require the adoption of an energy storage system to compensate fluctuations and to meet the energy demand during the night hours. This paper presents a technical and economic model for the design of a grid connected PV plant with battery energy storage (BES) system, in which the electricity demand is satisfied through the PV-BES system and the national grid, as the backup source. The aim is to present the PV-BES system design and management strategy and to discuss the analytical model to determine the PV system rated power and the BES system capacity able to minimize the Levelized Cost of the Electricity (LCOE). The proposed model considers the hourly energy demand profile for a reference year relating the analysis to the hourly irradiation and the temperature trend for the installation site. Furthermore, the proposed model is applied to design the grid connected PV-BES system installed at the new buildings of the Engineering and Architecture School of the Bologna University, Italy. A multi-scenario analysis is assessed varying the PV-BES system rated power and capacity. The results highlight the technical feasibility and the economic profitability of such a system for the proposed context. A reduction of 25.5% of the electricity cost respect to the grid electricity price benchmark is among the key outcomes discussed in the present paper. [ABSTRACT FROM AUTHOR]

Abstract: Nowadays, wind energy plays a key role as a sustainable source of energy and wind turbines are a relevant source of power for many countries world-wide. In such a context, this paper investigates the technical and economic feasibility of small wind turbines for five of the main European Union countries (France, Germany, Italy, Spain and The Netherlands). Ten commercial turbines with rated power from 2.5 kW to 200 kW are evaluated considering their installation and operative conditions. Several parameters most affecting wind turbine performances are evaluated and the estimation of the annual cash flows during the expected plant life-time are determined as a function of both the installation location (wind speed probability distribution, national incentive scheme and tax level) and the wind turbine characteristics (rated power curve, maintenance, installation and shipping costs). The obtained data are presented and discussed through a parametric analysis based on the Net Present Value capital budget approach, showing the conditions making these systems profitable or non-profitable and explaining the relative motivations. Moreover, the analysis outcomes are further investigated highlighting the dependence of the turbine profitability from the considered parameters, including a comparative analysis among the five analyzed European countries. [Copyright &y& Elsevier]

Highlights: [•] Performance cost model assesses the feasibility and profitability of PV systems. [•] Multi-country and multi-parameter analysis of PV systems in the European Union area. [•] The impact of key technical, environmental, economic and financial data is assessed. [•] Germany, Italy and Spain present the most effective PV sector support strategies. [•] The rated power and energy self-consumption ratio affect PV plant profitability. [ABSTRACT FROM AUTHOR]

Abstract: Hourly and daily solar radiation data are crucial for the design of energy systems based on the solar source. Global irradiance, measured on the horizontal plane, is, generally, available from weather station databases. The direct and diffuse fractions are measured rarely and should be analytically calculated for many geographical locations. Aim of this paper is to present a multi-location model to estimate the expected profiles of the horizontal daily diffuse component of solar radiation. It focuses on the European (EU) geographical area joining data from 44 weather stations located in 11 countries. Data are collected by the World Radiation Data Centre (WRDC) between 2004 and 2007. Different analytic functions, correlating the daily diffuse fraction of solar radiation to the clearness index, are calculated and compared to outline the analytic expressions of the best fitting curves. The effect of seasonality on solar irradiance is considered developing summer and winter scenarios together with annual models. Similarities among the trends for the 4years are, further, discussed. The most adopted statistical indices are used as key performance factors. Finally, data from three locations not included in the dataset considered for model development allow to test the proposed approach against an independent dataset. Obtained results show the effectiveness of adopting a multi-location approach to estimate solar radiation components on the horizontal surface instead of developing several single location models. This is due to the increase of the geographical range of applicability without a significant decrease of the accuracy. The percentage gap between single and multi-location model performances is lower than 20% for the most of the statistical indices adopted for both the model development and ex-post validation through the three independent datasets. [Copyright &y& Elsevier]

• The Lumipulse® SARS-CoV-2 antigen assay can be safely employed in screening strategies in small and large communities and in the general population. • At a 1.645 pg/mL optimal cutoff, the antigen test and RT-PCR overall agreement was 95.1% (1652/1738) and AUC was 97.4%; sensitivity and NPV were 100%. • The Lumipulse® G SARS-CoV-2 antigen assay is completely automated, faster and less expensive than RT-PCR. To compare the Lumipulse® SARS-CoV-2 antigen test with the gold standard real-time reverse transcription-polymerase chain reaction (RT-PCR) for diagnosis of SARS-CoV-2 infection and to evaluate its role in screening programs. Lumipulse® SARS-CoV-2 antigen assay was compared with the gold standard RT-PCR test in a selected cohort of 226 subjects with suspected SARS-CoV-2 infection, and its accuracy was evaluated. Subsequently, the test was administered to a real-life screening cohort of 1738 cases. ROC analysis was performed to explore test features and cutoffs. All tests were performed in the regional reference laboratory in Umbria, Italy. A 42.0% positive result at RT-PCR was observed in the selected cohort. The Lumipulse® system showed 92.6% sensitivity (95% CI 85.4–97.0%) and 90.8% specificity (95% CI 84.5–95.2%) at 1.24 pg/mL optimal cutoff. In the screening cohort, characterized by 5.2% prevalence of infection, Lumipulse® assay showed 100% sensitivity (95% CI 96.0–100.0%) and 94.8% specificity (95% CI 93.6–95.8%) at 1.645 pg/mL optimal cutoff; the AUC was 97.4%, NPV was 100% (95% CI 99.8–100.0%) and PPV was 51.1% (95% CI 43.5–58.7%). The Lumipulse® SARS-CoV-2 antigen assay can be safely employed in the screening strategies in small and large communities and in the general population. [ABSTRACT FROM AUTHOR]

Abstract The aim of the paper is to provide quantitative elements on the mechanisms that controlled the slope instabilities occurred after two major recent eruptions at Stromboli volcano (i.e. 2002–2003 and 2007). After a brief description of the geological setting and of the largest well documented instability phenomena on volcano flanks, the main objective is pursued using three-dimensional stress-strain analyses for modelling the effects of the magma intrusion on the stability of the volcano flank. Modelling is based on the results of an extensive geotechnical characterization of the volcaniclastic and lava materials. The numerical analyses investigate the influence of different paths and geometry of magma intrusion as well as the spatial variation of mechanical properties. As a result, favourable conditions for specific failure modes are identified. The stress-strain analyses show that magma intrusion can cause both a local failure of a wedge immediately downslope from the dyke or deep-seated movement involving large part of the slope; these two mechanisms were consistent with the deformative patterns observed during the 2007 and 2002–2003 eruptions, respectively. The magma thrust induces shear strains up to levels associated to appreciable grain crushing even below the sea level, where flow liquefaction can be invoked to explain the occurrence of past submarine slides. The submarine landslide is analysed by a combined finite element – limit equilibrium approach that demonstrates that instability conditions can develop if the loading exerted by the upper portion of the slope is sufficiently fast to produce undrained conditions. The analyses also support the hypothesis that at the 2002 subaerial failure occurred, due to combined effects of a magma mild thrust and the removal of the toe support caused by the preceding submarine slide. Highlights • Volcanological evidences were useful for modelling the slope movements of Stromboli. • Subvertical dyke intrusion affects only local stability of the dry subaerial slope. • Larger instabilities can be triggered only by dyke intrusion with relevant horizontal component. • Static liquefaction due to grain crushing can explain the submarine slide. • Submarine sliding can propagate backwards and influence the subaerial sector. [ABSTRACT FROM AUTHOR]

This paper presents an experimental analysis about the retrofitting of two commercial stationary refrigeration systems marketed by an Italian leading company. Such systems operate both at medium temperature (MT), i.e. [−5; 10]°C, and low temperature (LT), i.e. [−25; −15]°C, and they are originally designed to work with hydrofluorocarbon (HFC) R404a, known as a high global warming potential (GWP) fluid (GWP = 3922). The goal is to investigate the performances of HFC R410a (GWP = 2088) and R407f (GWP = 1825), chosen as effective alternatives to HFC R404a. Such fluids are compatible with the refrigeration systems, non-flammable and easy-available. Furthermore, they meet the European Union (EU) restrictions in force in the next future, so that they are suitable to start the transition toward efficient and eco-friendly refrigeration systems. The experimental campaign shows the feasibility of adopting R407f and R410a for the MT refrigeration system and R407f fluid for the system operating at LT. [ABSTRACT FROM AUTHOR]

Background. In SARS-CoV-2 infection, viral RNA may persist in respiratory samples for several weeks after the resolution of symptoms. Criteria to assess the end of infectivity are not unequivocally defined. In some countries, time from diagnosis is the unique criterion used, in addition to symptom cessation. This study evaluates the role of the Lumipulse® Antigen Assay (LAA) for the safe end of isolation of patients ≥21 days after the diagnosis of infection. Methods. A total of 671 nasopharyngeal swabs from patients diagnosed with infection at least 21 days before were assessed by RT-PCR and LAA, and the role of LAA in predicting the absence of infectivity was evaluated by virus cell culture. Results. Viable virus was present in 10/138 cultured samples. Eight out of ten infective patients suffered from a concomitant disease, predisposing them to long-term shedding of infective virus. In particular, infectious virus was isolated from 10/20 RT-PCR+/LAA+ cultured samples, whereas no viable virus was found in all 118 RT-PCR+/LAA– cultured swabs. LLA and RT-PCR agreed in 484/671 (72.1%) samples, with 100% and 26.7% concordance in RT-PCR negative and positive samples, respectively. Conclusions. Viable virus can be found ≥21 days after diagnosis in immunocompromised or severely ill patients. LAA better than RT-PCR predicts non-infectivity of patients and can be safely used to end isolation in cases with long persistence of viral RNA in the respiratory tract. [ABSTRACT FROM AUTHOR]