Antimicrobial therapy in pneumococcal meningitis: an epidemiological assessment from Turkey

Streptococcus pneumoniae is the singlemost important cause of acute purulent meningitis, occurring in 47% of cases of acute bacterial meningitis. To the authors’ knowledge, there are no published data on the treatment of pneumococcal meningitis based on local epidemiological studies in Turkey. In this letter we refer to recent and current pneumococcal studies carried out in accordance with the National Committee for Clinical Laboratory Standards. Only the susceptibility test results of pathogenic pneumococci are taken into account; resistance patterns of those obtained from carriers are excluded. The epidemiological data from which the therapeutic options for pneumococcal meningitis are derived are presented in Table 1. Approximately 40% of pneumococci are now penicillin resistant and in Turkey 20% of resistant isolates are highlevel penicillin resistant. For this reason penicillin is no longer the best choice for the treatment of pneumococcal meningitis. Third generation cephalosporins (e.g. ceftriaxone or cefotaxime) are another possible therapeutic option when pneumococcus is the probable cause of infection. Ten studies on the susceptibility patterns of pathogenic pneumococci for third generation cephalosporins have been carried out in Turkey. Six of them, completed since 2000, reported ceftriaxone and cefotaxime resistances not exceeding 2.3%. Moreover, in one study over the period 1998— 2000, all of the isolates were susceptible to cefepime. Seventy-six penicillin-resistant pneumococci isolated between 1997 and 2001 were evaluated in a reference laboratory in Ankara. Only four of these isolates (5.3%) were found to be cefotaxime-resistant. Consequently, third generation cephalosporins, ceftriaxone and cefotaxime in particular, are the antibacterial agents of choice in the treatment of pneumococcal meningitis in Turkey. Vancomycin resistance in pneumococci has not been reported in Turkish studies. If a community is known to have significant cephalosporin resistance (minimum inhibitory concentration >0.5 mg/mL) in more than 3% of invasive pneumococci, vancomycin should be added to the thirdgeneration cephalosporin. No recent Turkish studies show resistance rates which exceed the probable threshold of 3%