Isolation of Neisseria meningitidis from Healthy Persons in Japan

Abstract

Between September 2000 and March 2003 healthy subjects in 10 prefectures of Japan were investigated to identify carriers of Neisseria meningitidis. Twenty-five N. meningitidis strains were isolated from 5886 throat swab specimens collected from healthy persons, such as students, elderly, and foreigners. Of the 25 carriers, 9 were teenagers, 15 were in their twenties, and only one was in the fifties. The male-female ratio of the carriers was 17 to 8, showing male dominance. The serogroups of the 25 strains were B (9 strains), Y (4 strains) and non-groupable (12 strains). One of the strains was found to be deficient in gamma-glutamyl aminopeptidase activity, which is an identification marker for N. meningitidis.