To study the relationship between serum high-density lipoprotein cholesterol (HDL-C), total serum cholesterol, and nosocomial infection in patients undergoing general surgery.

Prospective cohort study, with an extended follow-up to 1 month after hospital discharge.

The general surgery service of a tertiary hospital.

Nosocomial infection, mainly surgical-site infection (SSI), urinary tract infection, respiratory tract infection (RTI), and bacteremia.

1,267 surgery patients aged 10 to 92 years.

182 subjects acquired 194 nosocomial infections, a cumulative incidence of 14.5%; most (116, 62.3%) were postoperative wound infections. There was an increase in infection risk at low levels of HDL-C, and both low and high total cholesterol levels. After adjusting simultaneously for several confounders, including total cholesterol, low levels of HDL-C (≤20 mg/dL) yielded an odds ratio (OR) of 2.2 (95% confidence interval [CI95], 0.6-7.9) for SSI and an OR of 10.3 (CI95, 0.7-151.5) for RTI. Otherwise, no trend was observed between HDL-C levels and infection risk, and no increased risk of nosocomial infection was observed for HDL-C values in the range of 21 to 49 mg/dL. Serum cholesterol showed a U-shaped relationship with nosocomial infection risk. Both low levels (below 102 mg/dL) and high levels (above 290 mg/dL) of total cholesterol were associated with a higher risk of SSI (mainly those caused by gram-negative bacteria) and RTI in comparison with the reference group (139-261 mg/dL).

Serum HDL-C and total cholesterol seem to be associated with the risk of nosocomial infection in surgical patients

To compare, in subjects undergoing general surgery, two measures of intrinsic patient risk for nosocomial infection: the Study on the Efficacy of Nosocomial Infection Control (SENIC) index and the National Nosocomial Infection Surveillance (NNIS) System index.

Prospective cohort study, with follow-up for 1 month after hospital discharge.

The general surgery service of a tertiary hospital.

Surgical-site infection.

1,483 subjects aged 10 to 92 years.

During follow-up, 155 patients developed nosocomial infection, yielding a cumulative incidence of 10.5%. The NNIS index showed a linear trend with both crude and adjusted (for SENIC index) rates of surgicalwound infection. The SENIC index did not exhibit any linear trend with adjusted (for NNIS index) rates of surgical-wound infection. To delineate whether the SENIC index added explanatory information to the NNIS index (or vice versa), we regressed each variable on the other. Logistic regression analyses confirmed the results of stratified analysis: residuals of the NNIS index added discriminating ability to the SENIC index, whereas residuals of the SENIC index did not improve the predictive power of the NNIS index.

The NNIS index had a better ability than the SENIC index for discriminating and predicting risk of surgical-wound infection

To determine the annual cost of implementing and maintaining a respiratory personal protective equipment (PPE) program at an urban hospital.

St Clare's Hospital and Health Center, a 250-bed hospital in Manhattan that treats 60 to 100 cases of tuberculosis annually.

Review of Purchasing Department records for all masks acquired by the hospital from 1992 to 1995, and an estimate of administrative time spent developing and implementing the guidelines recommended by various agencies during the study interval.

Respiratory isolation was provided for 6,360 to 10,883 days annually during the 4-year interval. Yearly costs for the PPE program ranged from $86,560 to $175,690. Of note, the daily cost for a respiratory isolation day decreased dramatically between 1994 and 1995 ($25/day to $13/day), when the high-efficiency particulate air-filter (HEPA) respirator was used by all staff. The decrease occurred because of lower administrative costs and a sharp decrease in the numbers of HEPA units purchased. Objective measures of worker compliance with HEPA respirators demonstrated the decrease was not due to less HEPA use but rather that employees were using each HEPA unit for several weeks, as recommended.

We found a significant decrease in cost in the second year of our HEPA program due to increasing employee familiarity with the program. Newly approved, cheaper, but less durable, N-95 masks are unlikely to withstand multiple wearings and may be discarded after a few uses. Thus, cheaper masks may result in a more expensive PPE program.

To determine if compliance with annual tuberculosis skin testing correlated with the number of cases of tuberculosis seen in patients and healthcare workers.

Survey using a written questionnaire.

159 Veterans' Administration facilities.

Hospitals that reported that >80% of their healthcare workers received annual skin tests saw 12.7 patient cases per 10,000 admissions and 4.0 healthcare worker cases per 10,000 personnel. Facilities in which <20% of their healthcare workers were given annual skin tests saw 4.5 cases per 10,000 admissions and 1.6 cases in healthcare workers per 10,000 personnel (P<.001 for patients and P=.31 for healthcare workers). The ratio of the median number of patients placed in acid-fast bacilli (AFB) isolation to the median number of patients with confirmed tuberculosis was 12. There was no correlation of this ratio with the number of cases of tuberculosis in patients or healthcare workers seen in each facility.

Compliance with annual tuberculosis skin testing was related directly to the rate of tuberculosis seen in patients. More standardized policies for placing patients in AFB isolation are needed to control for potentially costly variation among facilities. These measures should have highest priority in the control of tuberculosis in the healthcare setting, before implementing still more expensive interventions.

To evaluate a possible commonsource outbreak of Candida infections in the neonatal intensive-care unit. Systemic Candida infections increased from 6 to 11 cases (0.71 to 1.34 per 1,000 patient-days). In addition, Candida parapsilosis infections increased from 1 in 1992 to 10 in 1993.

Tertiary-care, teaching, pediatric institution with a 40-bed neonatal intensive-care unit (NICU). Clinical characteristics, associated conditions, and antimicrobial therapy were obtained from the medical records of all NICU patients with positive blood cultures for Candida during 1992 and 1993. Nineteen Candida isolates from 15 infants were studied retrospectively using contour-clamped homogeneous electric-field (CHEF) electrophoresis.

CHEF revealed eight karyotypes of C parapsilosis. Five isolates recovered from four patients shared one karyotype. The remaining isolates from seven infants all had distinctly different karyotypes.

The evidence was insufficient to implicate a single source of infection, even though four patients in the same unit had identical strain types. However, identical strains of C parapsilosis were associated geographically, suggesting that nosocomial acquisition of C parapsilosis through indirect patient contact in the NICU was possible. The CHEF technique yields unique patterns that may be used to delineate clinical isolates and to study the molecular epidemiology of candidal infections.

Assess the effect and use of resources associated with implementation of a program for the systematic follow-up of positive blood cultures.

Prospective epidemiologic study.

Tertiary-care military medical center.

All positive blood cultures (BC) were reported via E-mail to an infectious disease specialist as soon as growth was noted. This individual reviewed all Gram stains, clinical data, and antibiotic information on these patients.

From June 26, 1994, through January 25, 1995, there were 3,121 BCs drawn, of which 199 (6.4%) were positive from 145 episodes. Sixty-three episodes involved probable contaminants, and 82 episodes were considered true bacteremias. Six patients with true bacteremia died, two were transferred, and three were discharged within 24 hours of drawing the positive BC. Of the remaining 71 true bacteremias, 9 patients were on inadequate empiric therapy, as judged by the final organism susceptibilities. Changes in empiric therapy were recommended for five of the nine episodes and were implemented by the primary physicians in each case. Each of the changes resulted in improved coverage (as judged by the final identification and susceptibilities).

This program has improved the quality of care at Keesler Medical Center at the cost of one additional hour of consultant time per week.

To describe control of endemic and outbreak-related methicillin-resistant Staphylococcus aureus (MRSA) at two affiliated hospitals.

Prospective surveillance of patients with MRSA. Disposable gloves were used by all staff having direct contact with the affected patient or his immediate environment, and patient isolates were typed by pulsedfield gel electrophoresis (PFGE) of genomic DNA. Surveillance and PFGE typing were used concurrently to identify possible nosocomial outbreaks, confirm or refute cross-infection, and support a need for additional outbreak control interventions.

A university hospital (Hospital A) and a university-affiliated public hospital (Hospital B).

Patients with MRSA colonization or infection over an 18-month interval (June 1993-November 1994).

Proper handwashing and gloving practices were reemphasized with staff following confirmation of outbreaks.

Hospital A had 60 community-acquired and 48 nosocomial cases of MRSA. Two small outbreaks (affecting a total of seven patients) and two pseudo-outbreaks were identified. Hospital B had 36 community-acquired and 22 nosocomial cases of MRSA. Only one outbreak affecting five patients occurred. All outbreaks ended shortly after staff meetings that emphasized ongoing and extremely careful handwashing and gloving when caring for identified patients. The majority of nosocomial cases at both hospitals were not related epidemiologically or had isolates with unique PFGE types. Pseudo-outbreaks were confirmed by demonstrating that isolates from epidemiologically related cases (by time and clinical service or hospital unit) had different PFGE types. Hospital A cases had 39 different PFGE types, and Hospital B cases had 31 different PFGE types.

MRSA in hospitals, including outbreaks identified by prospective surveillance and confirmed by PFGE typing, can be controlled by minimal special precautions and interventions. This is possible despite the continuous admission of patients with MRSA from the community. PFGE typing is useful to confirm outbreaks and pseudo-outbreaks, demonstrate differences among epidemiologically unrelated isolates, and substantiate the efficacy of MRSA control programs within hospitals.