Factors influencing host susceptibility to meningococcal disease.

Host-parasite interactions influencing the development of the protective humoral immune response to Neisseria meningitidis are briefly reviewed. Possible consequences of the observed decreased titres of bactericidal activity specific for meningococcal serogroups A, B and C among patients with gonorrhoea are discussed with reference to: the epidemiology of the two diseases, the protective role of "natural" antibodies to the Neisseria species and the carriage rate of serogroupable strains of N. meningitidis among patients with gonorrhoea and a control population.