Survey of N. Meningitidis Carriers in the Gran Canaria Health Jurisdiction

Abstract

BACKGROUND: A) To ascertain the rate of carriers and the Types of Neisseria Meningitidis circulating in the population resident in the health jurisdiction of Gran Canaria. B) to ascertain the pattern of distribution of such carriers. METHODS: A descriptive transversal design was made, with a random sampling in multiple stages and by conglomerates. A minimum sample size was determined at 707 individuals for an expected prevalence of 8.6 %, with a rate of reliability of 95.6 % and a precision of 0.02. Assuming that 15 % if the individuals would not be willing to co-operate, the sample size was increased to 831 individuals, distributed in each conglomerate in proportion to the existing population. RESULTS: A total of 828 samples were obtained, that is, 99.6% of the number foreseen. With the exception of three, all of the individuals selected participated voluntarily in the study, a circumstance rendering it highly representative. All of the strains obtained corresponded to N. Meningitidis Serogroup B, except for one identified as N. Meningitidis Serogroup C Sero/Subtype 4:P1.2,5. The strains of N. Meningitidis serogroup B identified corresponded to 25 different sero-subtypes. CONCLUSIONS: A clear predominance of N. Meningitidis serogroup B strains among carriers has been verified. There are no statistically significant differences in the prevalence observed among the different age groups nor between sexes.