Some agent characteristics and their coexistence related to occurrence and severity of systemic meningococcal disease in Norway, Winter 1981-1982.

Characteristics of 67 strains of Neisseria meningitidis causing systemic disease in Norway during the winter 1981-82 are reported and related to clinical manifestations. Included in the study were also pharyngeal isolates of meningococci collected in the same period from 35 healthy military recruits. The strains were examined for serogroup, serotype as determined with monoclonal antisera (against antigens 2a, 2b, 12, 15 and 16), and sulfonamide susceptibility. Predominating in the systemic disease material were serogroup B, serotype 15, 16 (or 15), and sulfonamide-resistant strains. This complex of characteristics also appeared to be associated with the severity of manifestations (septicemia and death). The material of meningococci from healthy carriers unassociated with cases of disease was clearly different; these strains were typically non-groupable, non-typable and sulfonamide-sensitive. The full combination of traits usually seen in strains causing systemic disease was rare in carrier isolates. The results are discussed in relation to the epidemiological development of meningococcal disease in Norway.