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.

Infection control programs are primarily oriented toward chronicling the incidence of nosocomial infections (NI). Intervention programs oriented toward preventing infection would be facilitated by identifying patients at greatest risk of NI acquisition. We studied the number of comorbidities as a risk predictor for NIs in patients admitted to the medical intensive care unit (ICU) for three or more days. In 148 patients, we found by regression analysis that the number of comorbidities varied directly with the development of nosocomial infections, as well as with the appearance of new complications and length of ICU stay. Diagnosis-related groups did not adequately account for the variance in comorbidities observed.

Although gram-negative meningitis is rare in our hospital, between July, 1982 and July, 1983 clusters of cerebrospinal fluid (CSF) smears were reported positive for gram-negative bacilli. Fourteen specimens were obtained by diagnostic lumbar punctures, and one was obtained during a myelogram. No CSF cultures were positive, and a diagnosis of factitious meningitis was eventually established for each patient. Nonviable gram-negative bacilli were found in 6.7% of manometers, and 23.3% to 90% of the specimen tubes tested from the same lots of commercial lumbar puncture trays. It was estimated that there were between 44 and 333 organisms per specimen tube. Two lots of the commercial myelogram trays yielded nonviable gram-negative bacilli from 50% of the specimen tubes and 33.3% of the manometers tested. Retrospective review of laboratory records for 1982 and 1983 revealed 23 total CSF smears positive for gram-negative bacilli. No CSF grew gram-negative bacilli, and chart reviews confirmed a diagnosis of factitious meningitis in each case. In addition to the clusters of false-positive smears, this had occurred sporadically in both years. The problem did not recur after separate sterile tubes were provided for CSF collection. Physicians and laboratories should be aware that nonviable contaminants in commercial products may be a source of false-positive CSF gram-stained smears.

I read with great interest the article by Kotilainen and Gantz in Infection Control [now Infection Control and Hospital Epidemiology] regarding biological indicators (BIs) for use with flash sterilization processes. Although this study was conducted with greater care than previous investigations in this area, we believe that certain relevant factors regarding the effect of BI design on BI performance may have been overlooked. Because of differences in the design and construction of the BIs evaluated, a significant variation in response to flash sterilization or high temperature processing may result. Such an effect was first noted by Perkins et al and has been commented on by Reich and Fitzpartrick and Joslyn.

The performance of a biological indicator (BI) over a range of sterilization temperatures is known as a z value and, as defined by Roberts, is “the number of degrees change in temperature to achieve a tenfold change in the D value.” A plot of the D values versus exposure temperatures will reveal the z value as the negative reciprocal of the slope of the resulting thermal resistance curve. Historically, paper strip carriers of Bacillus stearothermophilus spores have been found to possess a z value in the range of l7°-2O°F, whereas self-contained BIs tested in our laboratories have exhibited z values as high as 64°F (Figure I), which reflects their excessively high resistance at flash sterilization temperatures. In general, such matters are not of concern to the end user until such time as false positives are encountered during flash sterilization.

In 1986, I wrote of the imminent decline in professional opportunities for the infectious diseases clinician because of unique problems with clinical practice in this specialty.' Although others have disagreed with my prophecy, none were able to refute my basic contention that it soon will be almost impossible for most new physicians with specialty training in infectious diseases to become self-supporting from a purely clinical practice. If a clinician is “an expert clinical [pertaining to or founded on actual observation and treatment of patients] physician and teacher,” then many of us are no longer only clinicians in the strictest sense of the word. The bell does toll for the pure clinician in this field of medicine, and the time of the easy establishment of a clinical practice is coming to a close. Future viability depends on developing beyond the role of clinician and becoming an “infectious diseases practitioner.”

Medical care has come a long way in the last century. People live longer; deadly diseases are prevented, cured, or ameliorated. In short, medical care is more effective than at any previous time. In this sense, effectiveness is a straightforward concept that measures changes in life expectancy, quality of life, and occurrence of disease. Effectiveness is sometimes difficult to quantitate; yet it is an important part of clinical decision making. For example, is the use of universal precautions effective in preventing the spread of the human immunodeficiency virus? Is antibiotic prophylaxis effective in preventing postoperative wound infections? Is chest percussion effective in the therapy of' pneumonia? Is a brain biopsy more effective than empiric therapy in treating encephalitis?