Vaccine strategies of meningococcal disease: results of a 10-year population-based study.

Invasive meningococcal disease (IMD) is an important cause of morbidity and mortality in children and adults. This study was conducted to determine a possible increase in IMD in recent years with special interest focused on serogroup C disease. From January 1st 1993 to December 31st 2002, IMD was studied in one million residents of Austria. We used active, population-based surveillance data from the Office of Public Health. A total of 126 patients with positive blood and/or cerebrospinal fluid culture or positive swabs for Neisseria meningitidis were studied. The median age of all patients was 9.5 years (range 1 month to 63 years). The average incidence of all IMD subgroups was 1.05 cases per 100,000 person years and was highest in children 0–4 years old (7.08 cases per 100,000 person years) followed by young adults aged 15 to 19 years (4.35 cases per 100,000 person years). Serogroup C IMD occurred in 1.30 cases/100,000 person years in patients aged 0 to 4 years and in 1.92 cases/100,000 person years in patients aged 15 to 19 years. Overall mortality was 11.1%. There was a significant increase ( P =0.001) in IMD due to serogroup B disease within the last 10 years. In contrast, serogroup C disease did not increase during the last decade. Conclusion:Currently, we do not recommend mass vaccination against serogroup C disease in Austria, but young adults aged 15 to 19 years display a high incidence of meningococcal C disease. In this age group, vaccination against serogroup C disease should be considered.