Basic mathematical models for the temporal dynamics of HAV in medium-endemicity Italian areas

In some Southern Italy areas Hepatitis A still represents a serious public health issue. In 1996 a big epidemics in Puglia led that region to adopt a mass vaccination programme. In this paper a basic mathematical model for the temporal trends of Hepatitis A Virus (HAV) in Southern Italy is proposed and investigated. The model includes the main distinctive features of HAV in Southern Italy, i.e. multiplicity of exposure factors, and periodic forcing caused by yearly patterns of seafood consumption. The analysis illustrates the role played by the risk factors on equilibria, stability, and the period of HAV oscillations, both natural and in presence of vaccination. The model also fits well temporal trends of HAV in Southern Italy, suggesting that it is a good starting point for more structured modelling.