Neisseria meningitidis serogroups A and W-135: carriage and immunity in Burkina Faso, 2003.
OBJECTIVE
We 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.


METHODS
We 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 <1%) but not from serogroups A, B, or C. At baseline, the prevalence of putatively protective specific IgG concentrations (> or =2 microg/mL) and bactericidal titers (> or =8) was 85% and 54%, respectively, against serogroup A, and 6% and 22%, respectively, against serogroup W-135. Putatively protective anti-W-135 IgG concentrations and bactericidal titers were of short duration and were not associated with carriage.


CONCLUSIONS
N. meningitidis serogroup W-135 strains did not induce immunity, despite their circulation. Carriage of serogroup A strains was rare despite the hyperendemic incidence of serogroup A meningitis during 2003 in Bobo-Dioulasso. A vaccine that includes serogroup W-135 antigen and eliminates serogroup A carriage is needed for sub-Saharan Africa.
Agence de Medecine Preventive, Paris, France. jmueller@aamp.org
Judith E
JE
Mueller
Seydou
S
Yaro
Yves
Y
Traore
Lassana
L
Sangare
Zekiba
Z
Tarnagda
Berthe-Marie
BM
Njanpop-Lafourcade
Raymond
R
Borrow
Bradford D
BD
Gessner
D000293:Adolescent; D000328:Adult; D002050:Burkina Faso; D002353:Carrier State / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D006801:Humans; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000276:immunology* / Q000382:microbiology; D008589:Meningococcal Infections / Q000453:epidemiology / Q000276:immunology* / Q000382:microbiology; D038381:Neisseria meningitidis, Serogroup A / Q000276:immunology*; D038582:Neisseria meningitidis, Serogroup W-135 / Q000276:immunology*; D009960:Oropharynx