H. Influenzae
Recommendations for the treatment of H. influenzae meningitis are affected by the widespread prevalence of β-lactamase–producing strains. These strains accounted for 32 percent of the 1304 isolates tested in the survey published most recently by the CDC.8 Although chloramphenicol is often effective, because resistance to it is rare in the United States (appearing in 0.1 percent of 1025 isolates tested),8 broad-spectrum cephalosporins came into wide use when they were found to be as effective as ampicillin plus chloramphenicol in the treatment of H. influenzae meningitis. We currently recommend cefotaxime or ceftriaxone for patients with H. influenzae meningitis, because of the evidence of superior sterilization of cerebrospinal fluid and the lower incidence of hearing loss as compared with that following treatment with other cephalosporins (such as cefuroxime).37