Neisseria meningitidis Serogroups A and W-135: Carriage and Immunity in Burkina Faso, 2003

ObjectivesWe sought to describe Neisseria meningitidis immunity and its association with pharyngeal carriage in Burkina Faso, where N. meningitidis serogroup W-135 and serogroup A disease are hyperendemic and most of the population received polysaccharide A/C vaccine during 2002 MethodsWe collected oropharyngeal swab samples from healthy residents of Bobo-Dioulasso (4–14 years old, n=238; 15–29 years old, n=250) monthly during February–June 2003; N. meningitidis isolates were analyzed using polymerase chain reaction and serogrouped using immune sera. Serum samples were collected at the first and last clinic visit and analyzed for anti-A, anti-C, anti–W-135, and anti-Y immunoglobulin G (IgG) concentrations and anti-A and anti–W-135 bactericidal titers Results N. meningitidis was carried at least once by 18% of participants; this carriage included strains from serogroups W-135 (5%) and Y and X (both