ABSTRACT
Infectious disease underreporting and reporting delays are phenomenon in which surveillance data suffer from incompleteness or delays. They impede the timely detection of important disease incidences and should be controlled in order to obtain a clearer picture on disease prevalence. Numerous factors contribute to missing data and these happen at the various stages of the surveillance chain. Studies for understanding such processes date back more than half a century. The main aim of this chapter is to provide a general view on these processes including methods used and results obtained. Section 1 is concerned with underreporting and the various methods for estimating the magnitude of incompleteness. Section 2 demonstrates different approaches for modelling reporting delays with a close look at two recent studies that incorporate reporting delays in outbreak detection. Section 3 includes a brief discussion.
