Phenotypical and genotypical characterization of Neisseria meningitidis carrier strains isolated from Polish recruits in 1998

The aim of this study was to investigate the Neisseria meningitidis carriage rate among two cohorts of Polish recruits upon entry to the military and during the first 2 months of their service, i.e. in the spring and autumn of 1998, and to characterize the meningococcal strains isolated. Pharyngeal swabs were taken four and five times from 151 and 168 men, respectively. Altogether, 81 and 180 meningococcal isolates representing 54 and 102 different strains were recovered. The overall rates of carriage in the spring and in the autumn were 36% and 61%, and, among recruits who submitted to sampling on at least three occasions, 39% and 55%. Eighty-three of 156 (53%) meningococcal carrier strains were nongroupable; among the remaining strains, serogroup B was predominant (32% of all carrier strains). In both surveys the predominant phenotype was Neisseria meningitidis NG:21:P1.7.