Meningococcal disease in Italy in 1989.

Meningococcal disease in Italy decreased by 13.4% from 1988 to 1989. The incidence rate was 0.5/100,000 in the general population and 1.3/100,000 in army recruits. The highest proportion of cases (27%) was seen in subjects 5-14 years old. The sex ratio was 1.3. Forty-four percent of the isolates belonged to serogroup B; 37% belonged to group C. Forty-six percent of the strains were resistant to sulphonamides and 10% were resistant to minocycline; only 4% were resistant to rifampicin. None of the four military cases observed could be attributed to vaccine failure. One secondary case and no coprimary cases were observed among civilians. The shift in prevalence from serogroup C to serogroup B isolates is the most important finding of this study.