hhh4: Endemic-epidemic modeling of areal count time series

The availability of geocoded health data and the inherent temporal structure of communicable diseases have led to an increased interest in statistical models and software for spatio-temporal data with epidemic features. The R package surveillance can handle various levels of aggregation at which infective events have been recorded. This vignette illustrates the analysis of area-level time series of counts using the endemic-epidemic multivariate time-series model “hhh4” described in, e.g., Meyer and Held (2014, Section 3). See vignette("hhh4") for a more general introduction to hhh4 models, including the univariate and non-spatial bivariate case. We first describe the general modeling approach and then exemplify data handling, model fitting, visualization, and simulation methods for weekly counts of measles infections by district in the Weser-Ems region of Lower Saxony, Germany, 2001–2002.