Evolution of resistance patterns and identification of risk factors for Streptococcus pneumoniae colonisation in daycare centre attendees in Athens, Greece.

Two cross-sectional surveillance studies were conducted during the winters of 2000 and 2003 in Athens, Greece, to obtain nasopharyngeal swabs from healthy pre-school children attending kindergartens. A total of 460 strains were examined in 2000 and 485 strains in 2003, with carriage rates of 31.7% and 34.6%, respectively. Susceptibility patterns were evaluated for penicillin G, erythromycin, ceftriaxone, moxifloxacin, linezolid and telithromycin. Penicillin non-susceptibility increased from 20% to 34.9%, whereas erythromycin non-susceptibility increased from 23% to 30.5%. Resistance to both agents climbed from 7.5% to 22.3% (P<0.001). No isolates were found to be resistant to any of the other antimicrobial agents. Risk factors for carriage and/or antimicrobial resistance were also assessed.