NASOPHARYNGEAL CARRIAGE OF PNEUMOCOCCI IN GAMBIAN CHILDREN AND IN THEIR FAMILIES

Background. Nasopharyngeal carriage of pneumococci is prevalent among children in developing countries but little is known about the relatio nship of nasopharyngeal carriage to invasive disease or about the way in which pneumococci spread within households. Objectives. To determin e the prevalence of nasopharyngeal carriage in healthy and sick. Gambi an children and to investigate transmission within households. Methods . Nasopharyngeal swabs were obtained by the per nasal route and cultur ed for pneumococci on selective media. Pneumococci were serotyped with the use of latex particles coated with type-specific antisera. Result s. Pneumococci mere isolated from the nasopharynx of 73 (90.1%) of 81 children with invasive pneumococcal disease, 86 (76.1%) of 113 healthy , age-matched control children and 911 (85.1%) of 1071 sick children. Pneumococci belonging to serotypes 1, 14 and 12 were isolated signific antly more frequently from cases than from matched controls. In 43 (76 .8%) of 56 children with invasive disease, pneumococci isolated from t he nasopharynx and from the blood or other sterile site belonged to th e same serotype. Pneumococci of the same serotype as the bacterium res ponsible for invasive disease in a child mere obtained from 72 (8.5%) of 843 family members, most frequently from young siblings of the case patient; Conclusion. Nasopharyngeal carriage of pneumococci is more p revalent among young Gambian children than among adults and invasive i nfections are probably acquired more frequently from siblings than fro m parents. However, further studies are needed to confirm this hypothe sis with more discriminating markers than polysaccharide serotyping.