Onset of Hemophilus influenzae type-b meningitis during cefaclor therapy for preseptal cellulitis

Second generation cephalosporins are frequently used for the treatment of bacteremic Hemophilus influenzae type b infections. "Breakthrough" meningitis during cefamandole therapy has documented the need for adequate cerebrospinal fluid penetration by these antibiotics if they are to be used in the therapy of Hemophilus infections. A child with H. influenzae type b preseptal cellulitis is reported who initially responded to treatment with intravenous cefuroxime and oral cefaclor. However, while still receiving cefaclor, the child was readmitted with H. influenzae meningitis. Microtiter broth dilution susceptibility testing performed during the second admission showed the isolate to be relatively resistant to cefuroxime (minimum bactericidal concentration [MBC] = 4 micrograms/ml) and resistant to cefaclor (MBC greater than 16 micrograms/ml). This experience documents the need to monitor the clinical response closely during therapy of H. influenzae bacteremic infections with these second generation cephalosporin treatment regimens. In addition, attention should be paid to minimum inhibitory concentrations of these cephalosporins, since variations in H. influenzae type b susceptibility to these agents may limit their efficacy.