Carriage and antibiotic susceptibility of Haemophilus influenzae type b and non b in Danish day-care attendees.

A study of carriage of Haemophilus influenzae type b (Hib) and non b in Danish day-care facilities, employing a highly selective medium supplemented with three antibiotics and direct detection of the type b capsular antigen by latex-agglutination and coagglutination, was carried out. Of 329 children, 217 (66%) were found to be carriers of Haemophilus influenzae. Among 64 children from day-care centers in which a case of invasive Hib infection had occurred, four carriers of type b were found, whereas no type b carriers were identified among 265 children from unexposed day-care centers (p less than 0.003). Of 217 isolated strains, seven (3.2%) were found to have lowered susceptibility to ampicillin, two (0.9%) to chloramphenicol, two (0.9%) to cefuroxim, and one (0.5%) to cefotaxim.