Coagulase-negative staphylococci are frequently isolated from blood cultures. As these organisms may occasionally cause serious disease, differentiating bacteremia from contamination is very important but often difficult. Over a 26-month period, of 29,542 blood cultures processed at the University of Michigan Medical Center, 2,875 (9.7%) were positive, and of those, 694 (from 527 patients) grew coagulase-negative staphylococci. Isolates from the 439 patients with only one blood culture positive for coagulase-negative staphy-lococci and those from the 18 patients with two positive cultures 10 days or more apart were deemed contaminants. Review of the records of the remaining 70 patients with multiple isolates indicated that 33 had had an episode of true bacteremia, 29 (87.9%) of which were associated with intravascular catheters or prosthetic valves. Overall, 85% of all coagulase-negative staphylococci isolated during the study period were judged to be contaminants. Seventy-one percent of the blood cultures drawn during the episodes of bacteremia were positive for coagulase-negative staphylococci as opposed to only 34% in the patients with contaminated cultures (p < 0.01). Moreover, coagulase-negative staphylococci grew in both aerobic and anaerobic bottles in 85% of blood culture sets drawn during episodes of bacteremia, but in only 30% of the cultures thought to be contaminated (p < 0.001). Growth of coagulase-negative staphylococci in less than 48 hours was also significantly associated with bacteremia (p < 0.01). Antibiotic sensitivity patterns were not useful in differentiating bacteremia from contamination. Thus, clinicians should consider coagulase-negative staphylococci as true blood pathogens in patients with intravascular devices who have a high proportion of blood cultures positive for this organism over a short period of time, and whose cultures became positive in less than 48 hours, with a high percent positive in both bottles. Microbiology laboratories can conserve considerable resources by limiting sensitivity studies to isolates from such patients.

During a 4-month period, 693 patients undergoing surgical procedures were prospectively studied to investigate the etiology of postoperative fever (≥38°C during 48 hours or more). The overall rate of fever was similar for the three categories of surgical procedures studied (14%, 13.4% and 13.1% respectively after clean, clean contaminated and contaminated surgical procedures). No cause of fever was found in 5%, 2.7% and 1.7% of patients who underwent clean, clean contaminated and contaminated surgical procedures. Several episodes of fever were observed for 12 patients after clean surgery; for 11 of them this was due to infection. The mean interval between febrile episodes was 4.7 days. After clean wound surgery, fever documented as infectious began significantly later (2.7 vs 1.6 days) and lasted significantly longer (5.4 vs 3.5 days) than fever for which no source was determined. Only half of the infections were associated with fever.

Diabetic patients frequently use their insulin vials for prolonged periods, even though antibacterial preservatives used in multidose insulin vials are not required to be effective beyond 28 days. For this reason, we evaluated the antibacterial activity present in multidose insulin vials for up to 50 days. Multidose lente insulin vials were inoculated with S. aureus and P. aeruginosa. Vials incubated at room temperature (21°C) were sterile by 48 hours, whereas when they were incubated at refrigerator temperatures (4°C), S. aureus contamination persisted up to the 17th day and P. aeruginosa were killed after 10 days. The same vials were serially contaminated on days 17, 30, and 50, and a similar antibacterial effect was maintained. Sixty-nine multidose insulin vials used for an average of 53 days were cultured. Eight vials demonstrated bacterial contamination with 1 cfu/ml of S. epidermidis or Propionibacterium acnes. No endotoxin was detected in the multidose vials used for more than 28 days. Insulin assays on 40 multidose insulin vials used for more than 28 days showed an average insulin content of 101.6±1.9 units/ml. This study did not demonstrate significant bacterial contamination, endotoxin activity, or insulin degradation of multidose insulin in vials used for periods longer than 28 days. In addition, antibacterial preservatives were more effective at room temperature than at refrigerator temperature; thus, the practice of patients not refrigerating insulin vials is sensible.

Hospital employees are at risk for numerous possible complications of accidental needlesticks. The mechanisms of such accidents suggest that many are preventable. This article presents a simple but novel revision of the needlecap which facilitates resheathing of a used needle. With routine use the hospital environment could be made safer for virtually all employees at almost no additional cost. Ultimate hospital savings could be significant through prevention of injury.

Unusual infections, many of which are easily preventable, may occur during the summer months as a result of travel and recreational activities. Infection Control Practitioners may be consulted for isolation recommendations, but more importantly may have opportunities to educate patients and personnel about preventive measures.

During the summer months, Americans of all ages travel extensively and participate in a variety of outdoor recreational activities such as swimming, boating, camping, hiking, and gardening, which may result in exposure to unusual pathogens. Climatic factors, poor immunity to these pathogens, and lack of attention to hygiene may increase the risk for infections caused by these organisms. They may be transmitted by ingestion of contaminated food or water, contact with contaminated water, soil, or vegetation, or by insect bites. Basic preventive measures are effective against many infections related to recreational activities. Persons traveling to underdeveloped areas should consult a physician about the need for immunization or prophylactic medication.