Resistant pneumococci and use of antibiotics

Sammanfattning: Pneumococcal resistance to antibiotics has become a worldwide problem. The rapid increase in frequency seems to be caused by intercontinental spread of a few resistant clones. Resistance to antibiotics in pneumococci has reduced the therapeutic arsenal for common respiratory tract infections as well as for invasive infections. Problems of specific clinical concern are meningitis due to penicillin-resistant strains, and otitis media due to multiply resistant strains, often resistant to all currently available classes of oral antimicrobial drugs. Sweden has for years reported low frequencies of penicillin non-susceptible pneumococci (PNSP), but in the southernmost county, Malmöhus, the rates increased during the late 1980s, to about 10% in 1992. This county has also for long had the highest utilisation of antibiotics among the Swedish counties, especially of macrolides and broadspectrum antibiotics. · A continuous spread of serogroup 9 PNSP from municipality to municipality within Malmöhus county was found, and DNA fingerprinting with PCR strongly suggested that these strains belonged to the same clone, 9V. · The main factor influencing the duration of nasopharyngeal carriage of PNSP seems to be the age at which the pneumococcal strain is acquired; the younger the age at acquisition, the longer the carriage. · In a day care centre study, the PNSP carriers had higher antibiotic consumption, were younger and more often boys than the non-carriers. When adjusting for age, gender, and day care centre attended, recent consumption of co-trimoxazole emerged as an independent risk factor for PNSP carriage. · The utilisation of antibiotics at the community level is highly correlated to the frequency of PNSP in the community. The utilisation of macrolides, cephalosporins, amoxicillin and co-trimoxazole also correlated to the frequency of PNSP. Utilisation of penicillin V seems to have the least ecological impact. · The Audit Project Odense Model of medical audit appears to be a valuable method for influencing physicians' prescribing of antibiotics for respiratory tract infections in general practice. A continuum of the emergence and spread of antibiotic-resistant pneumococci would lead not only to increased morbidity and mortality but also to increased costs of medical care, as has already been seen. To maintain the favourable situation with low rates of PNSP still current in Sweden, the aim must be to restrict the utilisation of antibiotics (without compromising patient care), especially for pre-school children, as they are the most frequent PNSP carriers. It seems important to influence both physicians and the public to reach a general understanding of the problem of antibiotic resistance.