title: Meningococcal carriage, meningococcal disease and vaccination.
abstract: Group A meningococcal carriage rates were determined 6 months before and 6 and 18 months after a mass vaccination campaign with a combined group A and group C meningococcal polysaccharide vaccine in a rural area of The Gambia. During the first pre-vaccination survey, performed during an outbreak of meningococcal disease, the carriage rate was high (16%). The carriage rate remained high during a second survey made 6 months after a vaccination campaign that covered approximately 90% of the study population. A year later very few group A meningococcal carriers were found. Membrane protein patterns of isolates obtained before and after vaccination were similar. We conclude that vaccination had little influence on the carriage rate of group A meningococci but that this was influenced by changes in herd immunity or by other unidentified factors.
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D002353:Carrier State / Q000175:diagnosis* / Q000382:microbiology; D004196:Disease Outbreaks; D004591:Electrophoresis, Polyacrylamide Gel; D005714:Gambia; D006801:Humans; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D009345:Neisseria meningitidis / Q000032:analysis; D011135:Polysaccharides, Bacterial / Q000008:administration & dosage; D014611:Vaccination
chemical_list: D001425:Bacterial Outer Membrane Proteins; D011135:Polysaccharides, Bacterial