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Poletti P.,Center for Information Technology | Poletti P.,Bocconi University | Melegaro A.,Bocconi University | Ajelli M.,Center for Information Technology | And 8 more authors.
PLoS ONE | Year: 2013

The introduction of mass vaccination against Varicella-Zoster-Virus (VZV) is being delayed in many European countries because of, among other factors, the possibility of a large increase in Herpes Zoster (HZ) incidence in the first decades after the initiation of vaccination, due to the expected decline of the boosting of Cell Mediated Immunity caused by the reduced varicella circulation. A multi-country model of VZV transmission and reactivation, is used to evaluate the possible impact of varicella vaccination on HZ epidemiology in Italy, Finland and the UK. Despite the large uncertainty surrounding HZ and vaccine-related parameters, surprisingly robust medium-term predictions are provided, indicating that an increase in HZ incidence is likely to occur in countries where the incidence rate is lower in absence of immunization, possibly due to a higher force of boosting (e.g. Finland), whereas increases in HZ incidence might be minor where the force of boosting is milder (e.g. the UK). Moreover, a convergence of HZ post vaccination incidence levels in the examined countries is predicted despite different initial degrees of success of immunization policies. Unlike previous model-based evaluations, our investigation shows that after varicella immunization an increase of HZ incidence is not a certain fact, rather depends on the presence or absence of factors promoting a strong boosting intensity and which might or not be heavily affected by changes in varicella circulation due to mass immunization. These findings might explain the opposed empirical evidences observed about the increases of HZ in sites where mass varicella vaccination is ongoing. © 2013 Poletti et al. Source


Alfonsi V.,National Center for Epidemiology Surveillance and Health Promotion
Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin | Year: 2012

In Italy, the 21 regional health authorities are in charge of organising and implementing their own vaccination strategy, based on the national vaccine plan. Immunisation coverage varies greatly among the regions for certain vaccines. Efforts to increase childhood immunisation coverage have included initiatives to develop and implement computerised immunisation registers in as many regions as possible. We undertook a cross-sectional online survey in July 2011 to provide an updated picture of the use, heterogeneity and main functions of different computerised immunisation registers used in the Italian regions and to understand the flow of information from local health units to the regional authorities and to the Ministry of Health. Comparing current data with those obtained in 2007, a substantial improvement is evident. A total of 15 regions are fully computerised (previously nine), with 83% of local health units equipped with a computerised register (previously 70%). Eight of the 15 fully computerised regions use the same software, simplifying data sharing. Only four regions are able to obtain data in real time from local health units. Despite the progress made, the capacity to monitor vaccination coverage and to exchange data appears still limited. Source


Ajelli M.,Predictive Models for Biomedicine and Environment | Merler S.,Predictive Models for Biomedicine and Environment | Pugliese A.,University of Trento | Rizzo C.,National Center for Epidemiology Surveillance and Health Promotion
Epidemiology and Infection | Year: 2011

We describe the real-time modelling analysis conducted in Italy during the early phases of the 2009 A/H1N1v influenza pandemic in order to estimate the impact of the pandemic and of the related mitigation measures implemented. Results are presented along with a comparison with epidemiological surveillance data which subsequently became available. Simulated epidemics were fitted to the estimated number of influenza-like syndromes collected within the Italian sentinel surveillance systems and showed good agreement with the timing of the observed epidemic. On the basis of the model predictions, we estimated the underreporting factor of the influenza surveillance system to be in the range 3.3-3.7 depending on the scenario considered. Model prediction suggested that the epidemic would peak in early November. These predictions have proved to be a valuable support for public health policy-makers in planning interventions for mitigating the spread of the pandemic. © 2010 Cambridge University Press. Source


Poletti P.,Bruno Kessler Foundation | Messeri G.,National Research Council Italy | Messeri G.,Consorzio LaMMa Laboratory of Monitoring and Environmental Modelling for the sustainable | Ajelli M.,Bruno Kessler Foundation | And 4 more authors.
PLoS ONE | Year: 2011

During summer 2007 Italy has experienced an epidemic caused by Chikungunya virus - the first large outbreak documented in a temperate climate country - with approximately 161 laboratory confirmed cases concentrated in two bordering villages in North-Eastern Italy comprising 3,968 inhabitants. The seroprevalence was recently estimated to be 10.2%. In this work we provide estimates of the transmission potential of the virus and we assess the efficacy of the measures undertaken by public health authorities to control the epidemic spread. To such aim, we developed a model describing the temporal dynamics of the competent vector, known as Aedes albopictus, explicitly depending on climatic factors, coupled to an epidemic transmission model describing the spread of the epidemic in both humans and mosquitoes. The cumulative number of notified cases predicted by the model was 185 on average (95% CI 117-278), in good agreement with observed data. The probability of observing a major outbreak after the introduction of an infective human case was estimated to be in the range of 32%-76%. We found that the basic reproduction number was in the range of 1.8-6 but it could have been even larger, depending on the density of mosquitoes, which in turn depends on seasonal meteorological effects, besides other local abiotic factors. These results confirm the increasing risk of tropical vector-borne diseases in temperate climate countries, as a consequence of globalization. However, our results show that an epidemic can be controlled by performing a timely intervention, even if the transmission potential of Chikungunya virus is sensibly high. © 2011 Poletti et al. Source


Olivieri A.,Metabolism and Endocrinology Unit | Corbetta C.,Regional Newborn Screening Laboratory of Lombardia Region | Weber G.,Vita-Salute San Raffaele University | Vigone M.C.,Vita-Salute San Raffaele University | And 2 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2013

Context: Over the years lower TSH cutoffs have been adopted in some screening programs for congenital hypothyroidism (CH) worldwide. This has resulted in a progressive increase in detecting additional mild forms of the disease, essentially with normally located and shaped thyroid. However, the question of whether such additional mildCH casescan benefit from detection by newborn screening and early thyroid hormone treatment is still open. Objective: The aim of this study was to estimate the frequency of cases with mild increase of TSH at screening in the Italian population of babies with permanent CHandto characterize these babies in terms of diagnosis classification and neonatal features. Methods: Data recorded in the Italian National Registry of infants with CH were analyzed. Results: Between 2000 and 2006, 17 of the 25 Italian screening centers adopted a TSH cutoff at screening of <15.0 μU/mL It was found that 21.6% of babies with permanent CH had TSH at screening of 15.0 μU/mL or less, whereas this percentage was 54% in infants with transient hypothyroidism. Among the babies with permanent CH and mild increase of TSH at screening (<15 μU/mL), 19.6% had thyroid dysgenesis with serum TSH levels at confirmation of the diagnosis ranging from 9.9 to 708 μU/mL These babies would have been missed at screening if the cutoff had been higher. Conclusions: Lowering TSH cutoff in our country has enabled us to detect additional cases of permanent CH, a number of which had defects of thyroid development and severe hypothyroidism at confirmation of the diagnosis. Copyright © 2013 by The Endocrine Society. Source

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