Understanding the dynamics of seasonal influenza in Italy: incidence, transmissibility and population susceptibility in a 9-year period.

Objectives: Influenza surveillance systems have been established in many countries in the world, yielding timely information about the intensity and features of seasonal outbreaks. Such data have also been used to estimate epidemiological parameters and to evaluate the effect of factors on infection dynamics. However, little is known about the extent of under-reporting in surveillance data, and thus of the true influenza incidence in the population.

An SEI model for sarcoptic mange among chamois.

We consider a simple model to study the dynamics of sarcoptic mange in a population of chamois. The epidemiological patterns observed during an epidemic in Italy are reconstructed and key parameters of the model are estimated from field data. In particular, we calculate the basic reproductive ratio R (0), a threshold value for chamois density for the occurrence of an epidemic and the speed of propagation of the epidemic wave.

Epidemic patch models applied to pandemic influenza: contact matrix, stochasticity, robustness of predictions.

Due to the recent emergence of H5N1 virus, the modelling of pandemic influenza has become a relevant issue. Here we present an SEIR model formulated to simulate a possible outbreak in Italy, analysing its structure and, more generally, the effect of including specific details into a model. These details regard population heterogeneities, such as age and spatial distribution, as well as stochasticity, that regulates the epidemic dynamics when the number of infectives is low.

Evaluating the effectiveness of antiviral treatment in models for influenza pandemic.

We study the effectiveness of antiviral treatment in simple susceptible-exposed-infectious-removed models that are at the base of models used for influenza pandemic. The strategy is assessed in terms of the value of the reproductive ratio R(0). We consider a general framework and analyse six different specific cases.

Scenarios of diffusion and control of an influenza pandemic in Italy.

To predict the spread of a pandemic strain of influenza virus in Italy and the impact of control measures, we developed a susceptible-exposed, but not yet infectious-infectious-recovered, and no longer susceptible (SEIR) deterministic model with a stochastic simulation component. We modelled the impact of control measures such as vaccination, antiviral prophylaxis and social distancing measures. In the absence of control measures, the epidemic peak would be reached about 4 months after the importation of the first cases in Italy, and the epidemic would last about 7 months.