The epidemiology of penicillin resistance in Streptococcus pneumoniae.

Pneumococci are not intrinsically resistant penicillin or other commonly used antibiotics. Penicillin-resistant strains were not encountered until 1965 when two strains were identified in Boston. At that time, the resistance was of a minor degree and its significance was not recognized by the authors. In 1971, resistant strains were encountered in New Guinea and, by the late 1970s, penicillin-resistant pneumococci had spread worldwide. By the early 1980s, areas where more than 10% of isolates were found to be penicillin resistant included Israel, Poland, Spain, South Africa, New Guinea, and the United States from New Mexico to Alaska. In this decade a number of countries including South Korea, Hungary, and Spain have reported dramatic increases in penicillin resistance. Penicillin resistance, once acquired by a virulent pneumococcal clone, has the ability to spread from country to country and to other continents in a relatively short time. Coincident with the increasing penicillin resistance has been the development of resistance to a wide variety of other antibiotics, including other cephalosporins, macrolides, trimethoprim-sulfamethoxazole, tetracycline, and chloramphenicol. Some strains are so highly resistant as to significantly impair our ability to treat patients with meningitis and to choose an appropriate oral agent for the treatment of pneumococcal otitis media.