466 RIFAMPIN IN ERADICATION OF METHICILLIN/GENTAMICINRESISTANT S. AUREUS FROM AN NICU

Abstract

An outbreak of infections caused by methicillin- and gentamicin-resistant Staphylococcus aureus (MGRS) occurred in the Children's Memorial Hospital NICU in 1979-80. MGRS was isolated from 44 patients in a 21-month period. Infections included bacteremia (6), ventriculitis (3), osteomyelitis (3), otitis media (2) and surgical wounds (6). Nasal carriage of MGRS of bacteriophage type 29/52 was present in 4/56 (7%) of personnel and in up to 75% of patients. Traditional infection control measures failed to interrupt MGRS transmission; intranasal bacitracin + oral rifampin eradicated nasal carriage in 4/4 adults. Bacitracin alone or treatment of infections with a single antibiotic to which MGRS was sensitive (vancomycin or chloramphenicol) failed to eradicate carriage in 6/6 and 10/11 trials, respectively. Bacitracin + rifampin terminated nasal carriage in 3/6 infants. Treatment with bacitracin + rifampin + IV vancomycin or oral erythromycin terminated carriage in all of 8 patients. This regimen was superior to bacitracin alone (p< 0.001), vancomycin or chloramphenicol alone (p <0.001), and bacitracin + rifampin (p=0.06). All patients treated with the three-drug regimen have remained MGRS-negative for up to 10 months. We conclude that therapy with bacitracin, rifampin, and another antibiotic to which the organism is sensitive is effective in eradicating neonatal MGRS carriage.