A meta-analysis of six controlled studies was performed to evaluate the risk of cytomegalovirus (CMV) infection among pediatric nurses. The pooled risk ratio for CMV infection in pediatric nurses using cumulative incidence data was statistically significant (risk ratio [RR] 2.7; 95% confidence interval [CI] 1.33 - 5.52), but person-year analysis taking account of follow-up periods demonstrated a trend toward increased risk that failed to reach statistical significance (RR 1.8; 95% CI 0.88 - 3.55). Despite pooling, there was low statistical power for comparing person-year rates. The studies included in this analysis failed to provide data on several potential confounding variables. We conclude that studies published prior to the widespread adoption of universal precautions suggest that pediatric nurses may have been at increased risk for CMV infection due to occupational exposure, but inadequate design and sample size of the studies prevent a definitive conclusion. Well-designed, controlled studies are still needed to define the occupational risk of CMV infection.

The postoperative wound infection experience in 11 Israeli hospitals was investigated with two objectives: (1) to utilize the variability among hospitals for a better understanding of the determinants of these infections, and (2) to present surgeons and infection control teams with information upon which they can take action. This article summarizes the methods that were applied to maximize the uniformity of information obtained from hospitals. (1) The same kind of patients were sampled in every hospital. (2) The data collection system was standardized, and analyzed for errors. The overall error rate was small (2%) but there were potential problem areas, such as missing information on underlying diagnoses (12%). Few errors (1%) were found in the nurses' observations of the wounds. (3) All wound infections were diagnosed in a uniform manner by convening a panel of four specialists at the central Israeli Study of Surgical Infections (ISSI) office. (4) The definition of infection that was finally chosen for this multicenter study had to be broadened to include, in addition to pus, “discharge other than pus,” because of the higher reliability among panel members. This definition was also clinically valid in terms of morbidity. (5) The rate of postdischarge infections was estimated and was not found to be related to the discharge policies in the various hospitals.

A cluster of cerebrospinal fluid Gram's stains showing gram-positive bacilli and of cerebrospinal fluid cultures growing Bacillus species in a large community teaching hospital prompted an epidemiologic and microbiologic investigation. Pseudomeningitis was suspected and confirmed when cultures of uninoculated commercial trypticase soy broth with 5% Fildes enrichment grew Bacillus species. Secondary contamination of the pipettes used for inoculation accounted for the positive cerebrospinal fluid Gram's stains. The costs of this pseudo-outbreak included unnecessary antibiotic therapy, lumbar punctures, and hospitalization. Such adverse effects can be minimized by increased physician awareness of pseudoinfections and by prompt investigation of such occurrences.

Plasmid profiling was used to determine the variability of normal flora isolates of Staphylococcus epidermidis in order to evaluate the usefulness of plasmid profiling for identifying pathogens. Fifteen hospital staff members and patients repeatedly had cultures taken from the hands and nares, and multiple isolates were examined for plasmid profiles. S epidermidis isolated from the nares of 15 neonates were also examined. The total number of isolates examined for plasmid profiles was 726. Repetition of profiles was common among the different isolates from a single sampling (one swab). The frequency of re-isolating similar profiles on different days varied from 7% to 13%. Simultaneous isolation of similar profiles from nares and hands on the same individual varied from 0% to 11%, the percentage being lower for personnel. Isolation of the same plasmid profile from different individuals occurred only twice and resulted in an assignment probability of Pa = 0.002 for isolates obtained from different individuals. Significantly more isolates from nares contained plasmids (97%) compared with isolates from hands (89%).Patients who had two or more isolates of coagulase-negative staphylococci with similar profiles were judged, clinically, to have infections in 12 of 13 cases. However, the likelihood of re-isolating an S epidermidis strain with a similar plasmid profile twice from the same person at different times was sufficiently high to prevent plasmid profiling from being used as an absolute criterion for infection.