Although several outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) infections have been reported in recent years, the geographic distribution and frequency of MRSA infections in American hospitals is unknown. We conducted a questionnaire survey to determine the magnitude of the problem. Data from 261 hospitals were included in the survey. MRSA were reported by 145 hospitals located in 36 states. Large hospitals reported these organisms significantly more often than small hospitals (p<.001). University hospitals reported MRSA more often than community or community-teaching hospitals (p<.001 and p<.005, respectively). The number of hospitals reporting MRSA increased from 24 in 1975 to 112 in 1980 (p<.001). Our data suggest that MRSA are widely distributed geographically and that the number of hospitals with these organisms has increased dramatically since 1975.

Forty stock, sink drain and clinical isolates of gram-negative bacilli were tested by broth microdilution against eight aminoglycoside antibiotics. Results show that quantitative antibiograms provide more information as epidemiological tools than qualitative antibiograms.

The sterilizing processes in autoclaves and ethylene oxide sterilizers are challenged on a regular basis with a controlled inoculum of spores from two Bacillus species. Within a two-day period in March 1980, the seven autoclaves at this 550-bed hospital appeared to have failed in their function of killing spores on 18 out of 46 test strips. A shut-down of the autoclaves and a massive investigation failed to identify any mechanical, physical, or human failures. However, after 48 hours, it was found that the broth used as growth medium contained a contaminant, Bacillus coagulans, that resulted in broth turbidity at 55°C. Incubating an uninoculated tube of trypticase soy broth (TSB) for quality control at 55°C in addition to the usual 37°C quality check is a recommended safeguard against such occurrences.

Ninety-six specimens of intravenous fluid solutions (D5/025 NS) were inoculated with S. aureus, E. coli, P. aeruginosa, K. pneumoniae, E. agglomerans, or C. albicans in concentrations of .1, 1, 10, or 102 organisms/ml. They were cultured in tubes containing 5 ml of double enriched broth and after passage through a .45 μ pore membrane filter. After 24 hours of incubation, broth cultures were 68% as sensitive as the filter cultures (p<.001). At the lowest concentration (.1 organism/ml) broth cultures were only 45% as sensitive as the membrane filter technique after 24 hours of growth (p<.001). Membrane filters provide a rapid method to accurately detect and quantitate the presence of microbial contamination even at very low levels of concentration. The simplicity and accuracy of the filtration method offers the clinician a valuable adjunct in managing suspected cases of intravenous fluid related sepsis.

As diagnostic techniques for the identification of Legionella species have become readily available, recognition of the pneumonic form of Legionellosis has increased. In particular, cases of hospital-acquired Legionella pneumophila are being identified and this has led to concern over possible person-to-person transmission. In most epidemiologic investigations where a source has been identified, water has been implicated. Person-to-person transmission has not been convincingly documented. Therefore, we discourage expensive or inconvenient special precautions for patients hospitalized with Legionnaires' Disease. Rather, we recommend that such patients be placed in secretion precautions until effective antimicrobial therapy has eradicated the organism.