Carriage of penicillin-susceptible and non-susceptible pneumococci in healthy young children in Goteborg, Sweden

Objective: To study carriage of Streptococcus pneumoniae among healthy young children, determine the proportion of strains with decreased susceptibility to penicillin, and study possible risk factors for the carriage of penicillin-resistant strains. Methods: Between February 1996 and February 1997, 620 healthy, 18-month-old children in Goteborg, Sweden were screened for carriage of S, pneumoniae with decreased susceptibility to penicillin, Nasopharyngeal samples were obtained from children visiting child health centres for routine health control. Results: Streptococcus pneumoniae was found in 322 samples and 18 strains (5.6%, CI95 3.4; 8.8) of all pneumococci showed decreased susceptibility to penicillin G with minimum inhibitory concentrations (MICs) ranging from 0.125 to 1.0 mg/l. The proportion of strains with decreased susceptibility was similar to that found in a laboratory-based material (6%) front the same geographical area and time period. A majority of the children with strains with decreased susceptibility to penicillin (n = 1) were not attending day-care centres, Conclusions: The prevalence of S, pneumoniae with reduced susceptibility to penicillin is still low in unselected healthy Swedish children. (C) 2000 The British infection Society.