1,720,968 research outputs found
Prevalence of hepatitis C virus estimates of undiagnosed individuals in different Italian regions. A mathematical modelling approach by route of transmission and fibrosis progression with results up to January 2021
No full textThis study provides an update on hepatitis C virus (HCV) estimates across Italy up to January 2021. A mathematical probabilistic modelling approach, including a Markov chain for liver disease progression, was used to estimate current HCV viraemic burden. Prevalence was defined by geographic area using an estimated annual historical HCV incidence by age, treatment, and migration rate from the Italian National database (ISTAT). Viraemic infection was estimated for the main HCV transmission routes by stages F0-F3 (patients without liver cirrhosis, i.e., potentially asymptomatic liver disease) and F4 (patients with liver cirrhosis, i.e., potentially symptomatic liver disease). By January 2021, we estimated that there were 398,610 individuals in Italy with active HCV infection (prevalence of 0.66%; 95% CI: 0.66-0.67), of which 287,730 (0.48%; 95% CI: 0.46-0.59%) were stage F0-F3. Prevalence values for all individuals with active HCV infection were: North 0.54% (95% CI: 0.53-0.54%), Central 0.88% (95% CI: 0.87-0.89%), South 0.72% (95% CI: 0.71-0.73%), and the Isles 0.67% (95% CI: 0.66-0.68%). The population at risk for previous/current drug injection accounted for 48.6% of all individuals with active HCV infection. A modelling approach such as this to estimate and update the prevalence of active HCV infection could be a useful methodology for the evaluation of healthcare policies related to HCV elimination plans
A mathematical model by route of transmission and fibrosis progression to estimate undiagnosed individuals with HCV in different Italian regions
No full textBackground: Although an increase in hepatitis C virus (HCV) prevalence from Northern to Southern Italy has been reported, the burden of asymptomatic individuals in different Italian regions is currently unknown. Methods: A probabilistic approach, including a Markov chain for liver disease progression, was applied to estimate current HCV viraemic burden. The model defined prevalence by geographic area using an estimated annual historical HCV incidence by age, treatment rate, and migration rate from the Italian National database. Viraemic infection by age group was estimated for each region by main HCV transmission routes of individuals for stage F0–F3 (i.e. patients without liver cirrhosis and thus potentially asymptomatic) and F4 (patients with liver cirrhosis, thus potentially symptomatic). Results: By January 2020, it was estimated that there were 409,184 Italian individuals with HCV (prevalence of 0.68%; 95% CI: 0.54–0.82%), of which 300,171 (0.50%; 95% CI: 0.4–0.6%) were stage F0–F3. Considering all individuals with HCV in stage F0–F3, the geographical distributions (expressed as the proportion of HCV infected individuals by macroarea within the overall estimated number of F0–F3 individuals and prevalence values, expressed as the percentage of individuals with HCV versus the overall number of individuals for each macroarea) were as follows: North 42.1% (0.45%; 95% CI: 0.36–0.55%), Central 24.1% (0.61%; 95% CI: 0.48–0.74%), South 23.2% (0.50%; 95% CI: 0.4–0.61%), and the Isles 10.6% (0.49%; 95% CI: 0.39–0.59%). The population of people who inject drugs accounted for 50.4% of all individuals infected (F0–F3). Undiagnosed individuals (F0–F3) were ~ 15 years younger (⁓ 50 years) compared with patients with stage F4 (⁓ 65 years), with similar age distributions across macroareas. In contrast to what has been reported on HCV epidemiology in Italy, an increasing trend in the proportion of potentially undiagnosed individuals with HCV (absolute number within the F0–F3) from South (23.2%) to North (42.1%) emerged, independent of similar regional prevalence values. Conclusion: This targeted approach, which addresses the specific profile of undiagnosed individuals, is helpful in planning effective elimination strategies by region in Italy and could be a useful methodology for other countries in implementing their elimination plans
Four year incidence of respiratory syncytial virus infection in infants and young children referred to emergency departments for lower respiratory tract diseases in Italy: the "Osservatorio VRS" Study (2000-2004)
No full textRespiratory Syncytial Virus (RSV) is a frequent cause of hospital admission in young children and high risk babies such as premature newborns, or babies with underlying cardiac or pulmonary disease, or immunodeficiency. Outbreaks occur most frequently in the cold season in areas with temperate and Mediterranean climates. Aim of the "Osservatorio VRS" Study was to describe the time-related pattern of RSV epidemics in Italy, across four consecutive epidemics, from 2000 to 2004. Nasal specimens for RSV detection were obtained and tested by an immunoenzymatic test. A total of 2110 children were tested for RSV determination, the rate of children with RSV infection was 21%, and that of children hospitalized for RSV disease was 49%. Considering the whole study period, the RSV epidemics started in October-November and ended in May, showing a peak incidence in February, with a median of 28.1% and a maximum of 48.9%. Analysis of monthly distribution of each year of the study showed a biennial trend for an earlier appearance. A different epidemiological pattern of the infection was observed among the three national areas. In conclusion, even though the mechanism governing RSV infection periodicity remains unknown, its awareness in the absence of an RSV surveillance system as in Italy, may be useful for scheduling RSV prophylaxis and for hospital resource management
Forecasting the long-term impact of COVID-19 on hepatitis c elimination plans in Italy. A mathematical modelling approach
Full text linkBackground: Italy has a high HCV prevalence, and despite the approval of a dedicated fund for 'Experimental screening' for 2 years, screening has not been fully implemented. We aimed to evaluate the long-term impact of the persisting delay in HCV elimination after the Coronavirus disease 2019 (COVID-19) pandemic in Italy. Methods: We used a mathematical, probabilistic modelling approach evaluating three hypothetical 'Inefficient', 'Efficient experimental' and 'WHO Target' screening scenarios differing by treatment rates over time. A Markov chain for liver disease progression evaluated the number of active infections, decompensated cirrhosis (DC), hepatocellular carcinoma (HCC) and HCV liver-related deaths up to the years 2030 and 2050. Results: The 'WHO Target' scenario estimated 3900 patients with DC and 600 with HCC versus 4400 and 600 cases, respectively, similar for both 'Inefficient' and 'Efficient experimental' screening up to 2030. A sharp (10-fold) decrease in DC and HCC was estimated by the 'WHO Target' scenario compared with the other two scenarios in 2050; the forecasted number of DC was 420 cases versus 4200 and 3800 and of HCC <10 versus 600 and 400 HCC cases by 'WHO Target,' 'Inefficient' and 'Efficient experimental' scenarios, respectively. A significant decrease of the cumulative estimated number of liver-related deaths was observed up to 2050 by the 'WHO Target' scenario (52000) versus 'Inefficient' or 'Efficient experimental' scenarios (79 000 and 74 000 liver-related deaths, respectively). Conclusions: Our estimates highlight the need to extensively and efficiently address HCV screening and cure of HCV infection in order to avoid the forecasted long-term HCV adverse outcomes in Italy
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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