Risk factors and outcome among a large patient cohort with community-acquired acute hepatitis C in Italy

BACKGROUND: The epidemiology of acute hepatitis C has changed during the past decade in Western countries. Acute HCV infection has a high rate of chronicity, but it is unclear when patients with acute infection should be treated. METHODS: To evaluate current sources of hepatitis C virus (HCV) transmission in Italy and to assess the rate of and factors associated with chronic infection, we enrolled 214 consecutive patients with newly acquired hepatitis C during 1999-2004. The patients were from 12 health care centers throughout the country, and they were followed up for a mean (+/- SD) period of 14+/-15.8 months. Biochemical liver tests were performed, and HCV RNA levels were monitored. RESULTS: A total of 146 patients (68%) had symptomatic disease. The most common risk factors for acquiring hepatitis C that were reported were intravenous drug use and medical procedures. The proportion of subjects with spontaneous resolution of infection was 36%. The average timespan from disease onset to HCV RNA clearance was 71 days (range, 27-173 days). In fact, 58 (80%) of 73 patients with self-limiting hepatitis experienced HCV RNA clearance within 3 months of disease onset. Multiple logistic regression analyses showed that none of the variables considered (including asymptomatic disease) were associated with increased risk of developing chronic hepatitis C. CONCLUSIONS: These findings underscore the importance of medical procedures as risk factors in the current spread of HCV infection in Italy. Because nearly all patients with acute, self-limiting hepatitis C - both symptomatic and asymptomatic - have spontaneous viral clearance within 3 months of disease onset, it seems reasonable to start treatment after this time period ends to avoid costly and useless treatment

Clinical, social and relational determinants of paediatric ambulatory drug prescriptions due to respiratory tract infections in Italy.

OBJECTIVES: Collecting information on patterns of drug prescriptions and on factors influencing prescribing decisions is fundamental for supporting the rational use of drugs. This study was aimed at investigating patterns of drug prescription in paediatric outpatients and at evaluating determinants of prescriptions for respiratory tract infections (RTIs). METHODS: We conducted a national cross-sectional survey involving primary care paediatricians and parents. Diagnoses and prescriptions made at each consultation were described. Poisson regression models were used to analyse determinants of drug and antibiotic prescriptions for visits due to RTIs. RESULTS: A total of 4,302 physician and parent questionnaires were analysed. These corresponded to 2,151 visits, 792 of which were due to RTIs. Drugs were prescribed in 83.4% of RTI visits, while antibiotics were prescribed in 40.4%. According to paediatricians' perceptions, 84.2% of parents of children with a RTI expected to receive a drug prescription. Paediatricians' perception of parental expectations was the strongest determinant for prescription of drugs and specifically of antibiotics [adjusted relative risk (RR): 1.7 and 3.6, respectively; P < 0.001]. However, in 77.1% of RTI visits, paediatricians judged themselves as not being influenced at all by parents' expectations in their decision to prescribe. CONCLUSIONS: This study underscores that relational factors, in particular perceived parental expectations, are one of the leading factors of drug prescriptions in paediatric ambulatory care settings, reinforcing the opinion that communication between physicians and parents can affect prescription patterns

Leak behaviour in pressurized PVC pipes.

The correct definition of the leak law, i.e. the relationship between the leak outflow, the total head at the leak and other relevant parameters such as the pipe material, can seriously affect the accuracy of the numerical models used for the management of water distribution systems, either if they are used to forecast the leakage reduction by pressure management or to locate and size the leaks within an inverse analysis. In recent decades the use of the classical Torricelli or orifice equation has been questioned in the sense that some experimental results clearly demonstrated that the assumption of a leak outflow proportional to the square root of the head drop can yield unsatisfactory results. To investigate this behaviour, an experimental activity has been carried out at the Water Engineering Laboratory of the University of Perugia, Italy. Part of the results of the carried out tests are presented in this paper for a leak in a polyvinyl chloride (PVC) pipe. Leak laws based on the assumption of a leak area variation with the pressure are compared and validated by strain measures close to the leak

Transient tests for locating and sizing illegal branches in pipe systems

In pipe systems illegal branches can take away remarkable water resources with negative effects from both the economic and technical points of view. Difficulties in pointing out illegal branches by means of steady-state pressure and discharge measurements are mainly due to the fact that, of course, such systems are not active according to a regular time schedule. In this paper the possibility of using Transient Test-Based Techniques (TTBT) for the location and sizing of branches is shown. Specifically, tests carried out in different branched pipe systems at the Water Engineering Laboratory of the University of Perugia, Italy, show that TTBT allow us to detect branches irrespective of whether they are active or not. To improve the precision of the localization, arrival times of pressure waves are detected by means of wavelet analysis. Finally, a simple relation based on the water hammer theory is proposed to size the branch reliably

Giovanni Sartori e la democrazia della Seconda Repubblica

Il saggio ripercorre e analizza criticamente tutti i passaggi istituzionali della cosiddetta Seconda Repubblica, ossia della peculiare democrazia maggioritaria che si imposta in Italia a partire dal 1994. Tali passaggi sono visti all'interno del pensiero di Giovanni Sartori e in particolare della sua teoria della democrazia. Tale pensiero si è manifestato sia attraverso opere scientifiche sia attraverso una continua attività pubblicistica, in particolare dalle colonne, come editorialista, del Corriere della Sera. Dall'esame di questo pensiero emerge una serrata e continua critica dei caratteri istituzionali della peculiare democrazia maggioritaria all'italiana.The essay traces and critically analyzes all the institutional steps of the so-called Italian Second Republic, that is the peculiar majoritarian democracy that is set in Italy since 1994. These steps are seen within the thoughts of Giovanni Sartori and in particular of his theory of democracy . Such thinking has manifested both through scientific works both through continuous publications, in particular from the columns, as a columnist, of the Corriere della Sera. From an examination of this thinking emerges a close and continuous criticism of the institutional character of the distinctive Italian style majoritarian democracy

Experimental investigation of leak hydraulics

In recent decades the hydraulics of leaks, i.e. the definition of the relationships linking the hydraulic quantities in pipes with leaks, has received increasing attention. On the one hand, the definition of the relationship between the leak outflow and the relevant parameters – e.g. the leak area and shape, the pressure inside the pipe and outside the leak, and the pipe material – is crucial for pressure control and inverse analysis techniques. On the other hand, if the effect of the leakage on the governing equations is not taken into account, i.e. the loss of the flow axial momentum is not considered, significant errors can be introduced in the simulation of water distribution systems. In this paper, the governing equations for a pipe with a leak are derived. The basic equations, obtained within different approaches, are presented in a consistent formulation and then compared with the results of some experimental tests. The leak jet angle and other major features of the results are analysed. The estimated values of the parameters can be used in the water distribution network models when pipes with a diffuse leakage are considered

Equivalent hydraulic resistance to simulate pipes subject to diffuse outflows

In water distribution network simulation models, pipes subject to diffuse outflow, either due to connections or to distributed demand or to leaks along their length, are generally converted into pipe elements only subject to lumped demand at their ending nodes. This approximation, which disregards the flow variation along the pipes, generates a loss of axial momentum, which is not correctly taken into account in the present generation of water distribution network models. In this paper a correction to the lumped demand approximation is provided and this equivalence is analyzed within the framework of the Global Gradient Algorithm. This is obtained through a correction of the pipe hydraulic resistance; this approach has proven to be more effective than the use of an asymmetrical lumped demand of the total distributed outflow at the pipe ending nodes. In order to assess the effect of the introduced correction, an application to a simple water distribution system is finally provided

A Self-Contained and Automated Method for Flood Hazard Maps Prediction in Urban Areas

Water depths and velocities predicted inside urban areas during severe storms are traditionally the final result of a chain of hydrologic and hydraulic models. The use of a single model embedding all the components of the rainfall–runoff transformation, including the flux concentration in the river network, can reduce the subjectivity and, as a consequence, the final uncertainty of the computed water depths and velocities. In the model construction, a crucial issue is the management of the topographic data. The information given by a Digital Elevation Model (DEM) available on a regular grid, as well as all the other elevation data provided by single points or contour lines, allow the creation of a Triangulated Irregular Network (TIN) based unstructured digital terrain model, which provides the spatial discretization for both the hydraulic and the hydrologic models. The procedure is split into four steps: (1) correction of the elevation z* measured in the nodes of a preliminary network connecting the edges with all the DEM cell centers; (2) the selection of a suitable hydrographic network where at least one edge of each node has a strictly descending elevation, (3) the generation of the computational mesh, whose edges include all the edges of the hydrographic network and also other lines following internal boundaries provided by roads or other infrastructures, and (4) the estimation of the elevation of the nodes of the computational mesh. A suitable rainfall–runoff transformation model is finally applied to each cell of the identified computational mesh. The proposed methodology is applied to the Sovara stream basin, in central Italy, for two flood events—one is used for parameter calibration and the other one for validation purpose. The comparison between the simulated and the observed flooded areas for the validation flood event shows a good reconstruction of the urban flooding

Detection and sizing of extended partial blockages in pipelines by means of a stochastic successive linear estimator

Effective water system management depends upon knowledge of the current state of a water pipeline system network. For example, in many cases, partial blockages in a water pipeline system are a source of inefficiencies, and result in an increase of pumping costs. These anomalies must be detected and corrected as early as possible. In this study, an algorithm is developed for detecting blockages by means of pressure transient measurements and estimating the diameter distribution resulting from their formation. The algorithm is a stochastic successive linear estimator that provides statistically the best unbiased estimate of diameter distribution due to partial blockages and quantifies the uncertainty associated with these estimates. We first present the theoretical formulation of the algorithm and then test it with a numerical case study