Detection of Neisseria meningitidis in asymptomatic carriers in a university hospital from Brazil.

Asymptomatic meningococcus carriers in hospitals is a risk factor for acquiring meningococcal disease. Meningococcal carrier (MC) frequency was investigated in oropharyngeal swab samples collected from 200 staff members at a teaching hospital from Brazil. MC prevalence was 9% (95% CI 5-13%). Risk factors associated with MC were: mean age of 26.5 years, male gender, bar attendance frequency and number of persons/house. Of 18 isolated meningococcal strains, 14 were non-group able (NG), 3 corresponded to serogroup B and 1 to serogroup 29E. The frequency of serotypes and serosubtypes was heterogenous, with a slight predominance of serotypes 4 and 7 and serosubtypes P1.7 and P1.5. Most strains (n=13) were susceptible to the antimicrobials tested. The ctrA gene (PCR) was identified in 9 (64.3%) of the 14 NG strains, suggesting virulence in most of the NG isolated strains. Therefore, a constant surveillance of these asymptomatic carriers is required.