This book offers an insight into the epidemiology of meningococci causing invasive disease in Scotland during 1999 to 2002 using high profile and high impact molecular characterisation tools such as Multi Locus Sequence Typing (MLST) and porA genosubtyping. It provides valuable data highlighting the effect the Meningococcal group C conjugate vaccine (MenC) has on serogroup C disease and its decline over the length of the vaccination campaign. At the same time, the overall number of cases has been monitored including the effect on serogroup B between 1999 and 2002. A decrease in serogroup C disease was observed, but it remains to be seen if this is accompanied by either an increase in serogroup B disease or resurgence of serogroup C disease over a longer period. This body of work show?s that molecular characterisation tools are extremely important for the surveillance of meningococcal disease over a period of years and, and that this evidence, has been effective not only in monitoring the impact of the MenC vaccines, but also providing a detailed genotypic representation of strains commonly associated with disease in Scotland.