Influence of child care on nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae

Background. Children cared for by a child minder (CM) should be less exposed to upper respiratory tract infections than those in group day care (GDC) and therefore to antibiotic treatment. Thus fewer CM children should carry resistant bacteria. To test this hypothesis nasopharyngeal carriage of Streptococcus pneumoniae (SP) and Haemophilus influenzae (HI) and exposure to recent antibiotic treatment were investigated among children in both types of care settings in the Alpes Maritimes (France) between November 1999 and March 2000. Methods and population. A two stage cluster sample of children attending group day care or cared for by a child minder was selected. Nasopharyngeal samples were cultured for SP and HI. Penicillin susceptibility was tested by disk diffusion and E-test and beta-lactamase production. Results. We sampled 235 children in the CM group and 298 in the GDC group who were ages 6 to 36 months. Age and sex distribution were similar in both groups. S. pneumoniae was isolated in 80 children in the CM group (34.0%) and in 163 (54.7%) children in GDC (P < 10(-6)). Proportions of non-penicillin susceptible (NPSP) were 52.5 and 55.8%, respectively (P = 0.6). H. influenzae was present in 37.2% of children in GDC vs. 23.8% in the CM group (P < 0.001). Proportions of beta-lactamase-positive HI (HIBL+) were 40.2% vs. 46.4%, respectively (P = 0.4). Antibiotic exposure during the previous 3 months occurred in 41.3% of children in GDC and in 47.4% in the CM group (P = 0.16). There was no association between antibiotic use and carriage of NPSP or HIBL+ strains. Conclusion. SP and HI carriage rates were significantly lower among children in the CM group than in GDC. The proportion of NPSP and HIBL+ was similar in both groups, and comparable patterns of antibiotic use were observed. Continued efforts must concentrate on parental education and enforcement of recommendations for management of pediatric upper respiratory tract infections.