Types and subtypes of group B meningococci isolated in Finland from 1976 through April 1986

Abstract

In the ten year period 1976–1986 the incidence of group B meningococcal infections in Finland has been stable at appr. 1.5/100000/year. Group B strains have accounted for over 70% of all bacteremic meningococcal infections since 1979 after the group A epidemic (whose peak was in 1974) waned. At the same time as the group B epidemic spread in Norway, the incidence of group B infections increased in Northern Finland.

Group B meningococcal strains from 291 patients with bacterenic infection seen in 1976–86 were typed and subtyped by coagglutination and/or enzyme immuno assay methods using monoclonal antibodies against the 2a, 2b, 15, P1.2, P1.9, P1.15 and P1.16 determinants. No single type was predominant. Except the type B:?:P1.16 (15.8% of all isolates) all other types accounted each for less than 10% of all straints. The Norwegian type B:15:P1.16 was seen infrequently during the whole period, but is was more prevalent in the 1980’ in Northern (which has close contacts with Norway) than in Southern Finland (13.5 vs. 2.9%).