EFFECTS OF 4 ANTIMICROBIAL DRUG REGIMENS ON SPUTUM SUPERINFECTION IN HOSPITALIZED PATIENTS

Abstract

The frequency of bacteriologic superinfection was analyzed by quantitative analyses of microbial populations in the sputum of 154 patients treated with antimicrobials following hospitalization for acute pulmonary inflammatory disease. The superinfection rate was 0% on penicillin alone (up to 2.4 million units daily), 5.4% in patients receiving tetracycline or chloramphenicol, 19.4% in those given penicillin plus streptomycin, and 47% in those treated with penicillin plus either tetracycline or chloramphenicol. Twenty-nine per cent of the patients superinfected with coagulase-positive staphylococci or gram-negative enteric bacteria developed clinical disease attributable to the hospital-acquired bacteria. Superinfection was not related to age, sex, severity of illness, the presence of underlying disease, or any combination of these factors. It usually occurred within 72 hours and frequently disappeared spontaneously when antimicrobials were discontinued or were reduced in amount.