The incidence of penicillin-resistant pneumococci in the Slovak Republic. Pneumococcus Study Group.

The prevalence of penicillin-resistant Streptococcus pneumoniae and multiresistant strains isolated in Europe from the early 1970s has continued to rise. Twenty-four microbiology laboratories in the Slovak Republic analyzed 4,018 S. pneumoniae strains isolated from September 1, 1993, to December 31, 1993. The overall resistance rate to penicillin was 3.4% in strains isolated from outpatients and 8.5% from inpatients with considerable variation between regions. The highest regional resistance rate to penicillin was 21% from outpatients in Levice, in the western Slovakia, and ranged between 13 and 52% in strains collected from hospitalized patients in 6 regions. Rates of penicillin-resistant pneumococci were significantly higher (p < or = 0.01) in children aged < or = 3 years. Two thirds of penicillin-resistant strains had intermediate levels of resistance (MICs 0.1-1 microgram/ml) and one third was resistant (MICs 2-8 micrograms/ml). Resistance to multiple classes of agents was found in 75.9% of penicillin-resistant strains. These data support continued surveillance of antimicrobial resistance in pneumococcal infections. Standardization of susceptibility testing methods and monitoring of clinical outcomes is of critical importance to this complex problem.