To detect the occurrence of surgical-site infection (SSI) in our study sample, using the traditional variables of the National Nosocomial Infection Surveillance (NNIS) index with a locally modified cut-off point for the “T time” defining length of surgical procedure; to compare the modified and the traditional NNIS index under the hypothesis that a cut-off point discriminating procedures of short and long duration, based upon the actual experience of the study sample, can adequately predict the risk of SSI.

A retrospective chart review of 9,322 patients undergoing surgical procedures in the period January 1993 to December 1998.

A small university hospital (UH) in southern Brazil.

The composite index using the local sample procedure-duration cut-off point (UH-index) performed better than any of the individual components of the composite index (anesthesia risk index and surgical-wound class [SWC]). The UH-index also predicted adequately the risk of SSI when compared to the traditional NNIS index, particularly when stratifying by SWC.

A modified NNIS index, using the sample cut-off point, can adequately predict the risk of SSI in a given population. Further studies are needed to compare and validate the NNIS index of risk for populations other than those of the NNIS-participating hospitals. Larger samples using different hospitals with similar characteristics are needed to investigate the risk of SSI associated with specific operations.

To assess whether hospital work constitutes a risk factor for hepatitis C virus (HCV) infection among employees of a large hospital in Israel.

Seroprevalence survey.

A 1,006-bed, tertiary-care university hospital in Jerusalem.

All 5,444 employees (18-65 years old) were eligible; 4,287 (79%) participated in the survey.

Sera were tested for antibodies to HCV (anti-HCV) using a third-generation enzyme immunoassay. A third-generation strip immunoblot assay was used for confirmation. Participants were interviewed regarding their occupational history, and they completed a self-administered questionnaire covering history of non-occupational exposure to blood and country of birth. Other demographic information was obtained from the personnel department. Rates and odds ratios (ORs) were calculated, and multivariate logistic-regression analyses were performed to adjust for potential confounding variables.

Anti-HCV was found in 0.9% of employees (37/4,287; 95% confidence interval, 0.6-1.1), ranging from 0.1% among those born in Israel to 5.7% among those born in Central Asia. After age, gender, social status, country of birth, and history of blood transfusion were controlled for in a logistic regression, occupational exposure to blood ≥10 years was significantly associated with the presence of antibodies (OR, 2.6; P=.01). Presence of anti-HCV also was associated with country of birth (range: Israel OR, 1; West OR, 3.8 [P=.1]; Central Asia OR, 48.6 [P<.0001]) and history of blood transfusion (OR, 2.7; P=.01). No significant associations were found between anti-HCV and age, gender, social status, history of tattoo, acupuncture, current occupation, department, exposure to blood in current occupation, adherence to safety precautions, or history of percutaneous injury. The association with length of exposure was stronger (OR, 3.6; P=.01) when the same logistic regression was run excluding the outlier ethnic group of Central Asia.

Hospital work does not seem to constitute a major risk factor for HCV infection in Israel today. A higher prevalence of anti-HCV among employees with longer versus shorter lengths of occupational exposure may be due to a cumulative effect of exposure over the years. Infection control efforts in recent years may have contributed to this association.

To determine risk factors for vancomycin-resistant Enterococcus (VRE) colonization during a hospital outbreak and to evaluate Centers for Disease Control and Prevention (CDC)-recommended control measures.

Epidemiological study involving prospective identification of colonization and a case-control study.

A university hospital.

Patients on eight wards involved in outbreak from late 1994 through early 1995.

Cases were matched by ward and culture date with up to two controls. Risk factors were evaluated with four multivariate models using conditional logistic regression. The first evaluated proximity to other VRE patients and isolation status. The second evaluated proximity to unisolated VRE cases and three variables independently predictive after adjustment for proximity. The third evaluated seven significant univariate predictors in addition to proximity to unisolated VRE in backward, stepwise logistic regression. The fourth assessed proximity to VRE with all other variables collected, clustered in a principal components analysis. Pulsed-field gel electrophoresis was performed to assess clonality of two outbreak strains.

The incidence of transmission declined significantly after CDC guidelines were implemented. Proximity to unisolated VRE cases during the prior week was a significant predictor of acquisition in each of four multivariate models. Other significant risk factors in multivariate models included a history of major trauma and treatment with metronidazole. Pulsed-field gel electrophoresis confirmed the clonality of two outbreak strains.

VRE was transmitted between patients during a hospital epidemic, with proximity to previously unisolated VRE patients being an important risk factor. Weekly surveillance cultures and contact isolation of colonized patients significantly reduced spread.

To assess the extent of nosocomial transmission and risk factors associated with tuberculin skin test (TST) conversions among healthcare workers (HCWs) exposed to a patient with genitourinary Mycobacterium tuberculosis.

Retrospective cohort study of exposed HCWs.

A 275-bed community hospital in Middle Tennessee.

A total of 128 exposed HCWs and the index patient, who required drainage of a prostatic abscess and bilateral orchiectomy and expired after a 27-day hospitalization. Disseminated tuberculosis was diagnosed at autopsy.

Contact tracing was performed on exposed HCWs. Logistic regression was used to identify independent risk factors associated with TST conversion.

A total of 128 HCWs were exposed to the index patient. There was no evidence of active pulmonary tuberculosis throughout the patient's hospitalization; TST conversions occurred only among HCWs who were exposed to the patient during or after his surgical procedures. A total of 12 (13%) of 95 exposed HCWs who were previously nonreactive had newly positive TST: 6 of 28 nurses, 3 of 3 autopsy personnel, 2 of 17 respiratory therapists, and 1 of 12 surgical staff. By logistic regression, irrigation or packing of the surgical site was the only independent risk factor associated with TST conversion among nurses (odds ratio, 9; 95% confidence interval, 1.2-67; P=.03).

Manipulation of infected tissues of the genitourinary tract can result in nosocomial transmission of tuberculosis.

To identify risk factors associated with surgical-site infections (SSIs) following cesarean sections.

Prospective cohort study.

High-risk obstetrics and neonatal tertiary-care center in upstate New York.

Population-based sample of 765 patients who underwent cesarean sections at our facility during 6-month periods each year from 1996 through 1998.

Prospective surgical-site surveillance was conducted using methodology of the National Nosocomial Infections Surveillance System. Infections were identified during admission, within 30 days following the cesarean section, by read-mission to the hospital or by a postdischarge survey.

Multiple logistic-regression analysis identified four factors independently associated with an increased risk of SSI following cesarean section: absence of antibiotic prophylaxis (odds ratio [OR], 2.63; 95% confidence interval [CI95], 1.50-4.6; P=.008); surgery time (OR, 1.01; CI95, 1.00-1.02; P=.04); <7 prenatal visits (OR, 3.99; CI95, 1.74-9.15; P=.001); and hours of ruptured membranes (OR, 1.02; CI95,1.01-1.03; P=.04).

Patients given antibiotic prophylaxis had significantly lower infection rates than patients who did not receive antibiotic prophylaxis (F=02), whether or not active labor or ruptured membranes were present.

Among the variables identified as risk factors for SSI, only two have the possibility to be changed through interventions. Antibiotic prophylaxis would benefit all cesarean patients regardless of active labor or ruptured membranes and would decrease morbidity and length of stay. Women's healthcare professionals also must continue to encourage pregnant women to start prenatal visits early in the pregnancy and to maintain scheduled visits throughout the pregnancy to prevent perinatal complications, including postoperative infection.

To investigate and control a nosocomial outbreak of Burkholderia cepacia lower respiratory tract infection.

Outbreak investigation and case-control study.

A 260-bed community hospital.

Participants were mechanically ventilated intensive care patients without cystic fibrosis. A case was defined as a hospitalized patient with a sputum culture positive for B cepacia between January 1 and November 6, 1998.

Respiratory therapy infection control policies and practices were reviewed; laboratory and environmental studies and a retrospective case-control study were conducted. Case-patients were matched with control-patients on age, gender, diagnosis, and type of intensive care unit.

Nine case-patients were identified; B cepacia likely caused pneumonia in seven and colonization in two. Two respiratory therapy practices probably contributed to the transmission of B cepacia: multidose albuterol vials were used among several patients, and nebulizer assemblies often were not dried between uses. B cepacia was grown from cultures of three previously opened multidose vials; pulsed-field gel electrophoresis patterns of B cepacia from seven case-patients and two multidose vials were indistinguishable. Case-patients had longer durations of heated humidified mechanical ventilation (mean, 9.8 days vs 4.4 days; P=.03) and were more likely to have exposure to one particular respiratory therapist than controls (odds ratio, undefined; 95% confidence interval, 4.7-∞ P=.001). The association with the respiratory therapist, a temporary employee, persisted after controlling for duration of heated humidified ventilation. No new B cepacia infections were identified after control measures were implemented.

B cepacia probably was transmitted among patients through use of extrinsically contaminated multidose albuterol vials. Respiratory therapy departments must pay close attention to infection control practices, particularly among new or temporary staff.

To assess the way French hospitals conduct surveillance for, and control infections caused by, methicillin-resis-tant Staphylococcus aureus (MRSA), and to evaluate the incidence of these infections.

Retrospective analysis of sample surveillance data.

Representative sample of French hospitals.

Representative sample of 38 French public hospitals.

Hospitals were selected randomly in 1996, taking into account their location and number of beds. Administrative data, surveillance denominators used, antimicrobial resistance rates, and infection control practices were analyzed for the period 1990 to 1995. The same 38 centers were contacted 3 years later, in 1998, to reassess their surveillance and control activities.

French hospitals were slow to implement MRSA surveillance programs; only 5% had such programs in 1990, when the median incidence per admission (0.37%) and per patient-days (0.04%) of MRSA infections was already high. Despite the implementation of surveillance programs in 66% of French hospitals in 1995 and 87% in 1998, the MRSA infection rates remained stable from 1990 to 1995 and increased from 1995 to 1998. The proportion of French hospitals having a policy for the transfer of MRSA-infected patients to other hospitals increased from 47% in 1995 to 61% in 1998, whereas screening for MRSA colonization (42%-53%) and isolation for colonized or infected patients (87%-89%) remained stable.

This first national survey showed that French hospitals probably were not optimally prepared to control and prevent MRSA infections, since they were slow to respond to the growing problem.

To determine the cause of a coagulase-negative staphylococcal outbreak and to identify risk factors for surgical-site infections among patients following Medtronic Freestyle bioprosthesis implantation.

Retrospective case-control study.

An 800-bed university referral center.

The cohort of 64 patients undergoing Freestyle valve replacement from September 1998 to December 1998.

Seven patients developed infection (10.9% vs 1.1% during the preceding 8 months), including two with mediastinals and five with endocarditis. There were no statistically significant differences between cases and controls with respect to age, gender, weight, underlying illness, preoperative hospital stay, duration of surgery, time on bypass, central venous catheter duration, National Nosocomial Infection Surveillance risk index, New York Heart Association class, albumin, or antibiotic prophylaxis. However, only three cases were documented to have received vancomycin prophylaxis. Of all staff evaluated, only surgical resident A was significantly associated with infection (odds ratio, 7.68; 95% confidence interval, 1.3-44.1; P=.02) Pulsed-field gel electrophoresis patterns on Staphylococcus epidermidis isolates from four of the six cases were identical. These cases were performed on different days. Surgical resident A was the only staff member present in the operating room for all cases caused by the epidemic strain. This S epidermidis strain, however, was not isolated from operating room staff.

A surgical resident was significantly associated with infection. However, the cause of this outbreak was likely multifactorial. Changes occurring during the investigation included institution of vancomycin as routine prophylaxis and modification of surgical technique, which contributed to the resolution of the outbreak.

To investigate an outbreak of scabies in an inner-city teaching hospital, identify pathways of transmission, institute effective control measures to end the outbreak, and prevent future occurrences.

Outbreak investigation, case-control study, and chart review.

Large tertiary acute-care hospital.

A patient with unrecognized Norwegian (crusted) scabies was admitted to the acquired immunodeficiency syndrome (AIDS) service of a 940-bed acute-care hospital. Over 4 months, 773 healthcare workers (HCWs) and 204 patients were exposed to scabies. Of the exposed HCWs, 147 (19%) worked on the AIDS service. Risk factors for being infested with scabies among HCWs included working on the AIDS service (odds ratio [OR], 5.3; 95% confidence interval [CI95], 2.17-13.15) and being a nurse, physical therapist, or HCW with extensive physical contact with infected patients (OR, 4.5; CI95, 1.26-17.45). Aggressive infection control precautions beyond Centers for Disease Control and Prevention barrier and isolation recommendations were instituted, including the following: (1) early identification of infected patients; (2) prophylactic treatment with topical applications for all exposed HCWs; (3) use of two treatments 1 week apart for all cases of Norwegian scabies; (4) maintaining isolation for 8 days and barrier precautions for 24 hours after completing second treatment for a diagnosis of Norwegian scabies; and (5) oral ivermectin for treatment of patients who failed conventional therapy.

HCWs with the most patient contact are at highest risk of acquiring scabies. Because HCWs who used traditionally accepted barriers while caring for patients with Norwegian scabies continued to develop scabies, we found additional measures were required in the acute-care hospital. HCWs with skin exposure to patients with scabies should receive prophylactic treatment. We recommend (1) using heightened barrier precautions for care of patients with scabies and (2) extending the isolation period for 8 days or 24 hours after the second treatment with a scabicide for those patients with Norwegian scabies. Oral ivermectin was well tolerated for treating patients and HCWs who failed conventional treatment. Finally, we developed a surveillance system that provides a “barometric measure” of the infection rate in the community. If scabies increases in the community, a tiered triage system is activated to protect against transmission among HCWs or hospital patients.

To trace the routes of transmission and sources of Staphylococcus aureus found in the surgical wound during cardiothoracic surgery and to investigate the possibility of reducing wound contamination, with regard to total counts of bacteria and S aureus, by wearing special scrub suits.

A total of 65 elective operations for coronary artery bypass graft with or without concomitant valve replacement were investigated. All staff present in the operating room wore conventional scrub suits during 33 operations and special scrub suits during 32 operations. Bacteriological samples were taken from the hands of the scrubbed team after surgical scrub but before putting on sterile gowns and gloves and from the patients' skin (incisional area of sternum and vein harvesting area of legs) after preoperative skin preparation with chlorhexidine gluconate. Air samples were taken during operations. Bacteriological samples also were taken from the subcutaneous walls of the surgical wound just before closing the wound. Total counts of bacteria on sternal skin and wound walls (colony-forming units [CFUs//cm2) were calculated, as well as total counts of bacteria in the air (CFUs/m3). Strains of S aureus recovered from the different sampling sites were compared by pulsed-field gel electrophoresis (PFGE).

Special scrub suits significantly reduced total counts of bacteria in air compared to conventional scrub suits (P=.002). The number of air samples in which S aureus was found was significantly reduced by special scrub suits compared with conventional scrub suits (P=.016; relative risk, 4.4; 95% confidence interval [CI95], 1.3-14.9]). By use of PFGE, it was possible to identify two cases of possible airborne transmission of S aureus when wearing conventional scrub suits, whereas no case was found when wearing special scrub suits. When exposed to airborne S aureus, the concomitant sternal carriage of S aureus was a risk factor for having S aureus in the wound.

Use of tightly woven special scrub suits reduces the dispersal of total counts of bacteria and of S aureus from staff in the operating room, thus possibly reducing the risk of airborne contamination of surgical wounds. The importance of careful preoperative disinfection of the patient's skin should be stressed.

To assess the efficacy of parental education and use of parents as nursing assistants on reducing nosocomial infections.

Prospective study.

Active surveillance for nosocomial infections was performed on two wards. On ward A, parents were educated about infection control practices and assisted nursing staff with routine tasks, so that nursing personnel could focus their efforts on procedures with higher risk of infection. Parental assistance was not sought on ward B, the comparison ward.

From October 1990 through September 1991, 1,081 patients were admitted to wards A (470) or B (611). The overall nosocomial infection rate was 7.1 per 100 admissions; the nosocomial infection rate was significantly higher on ward B than ward A (63/611 vs 14/470; P<.001). Multivariate analysis identified risk factors for nosocomial infection on the two wards as age <2 years (P=.01), malnutrition (P=.005), duration of hospitalization (P<.001), ward B hospitalization (P=.003), and ward cleanliness score (P=.009); the distribution of patients with these factors was similar on the two wards.

Our data suggest that parental infection control education and recruitment to relieve nursing staff of routine low-risk procedures are economical and easily implemented measures to reduce nosocomial infections in hospitals with limited personnel resources in the developing world.

To compare three methods for assessing the excess nurse work load related to recommended procedures for managing nosocomial infections (NI) due to multiresistant bacteria (MRB): two activity scores, the Omega score and the Projet de Recherche en Nursing (PRN) system, and a specific evaluation based on functional analysis of nursing procedures.

10 beds in a medical intensive care unit (MICU).

Patients admitted from November 15,1995, to June 15, 1996, were included and divided in two groups based on presence of MRB colonization or infection (MRB+ and MRB− groups).

Data were collected regarding length of stay (LOS) in days; Omega score for the entire stay; PRN score for the entire stay and per day; and time required to perform correctly four nursing procedures related to MRB NI, as evaluated specifically by the nursing staff, using a detailed functional analysis document that described all elementary nursing tasks in chronological order and all material needed to carry out those tasks.

The LOS and total Omega and PRN scores were higher in the MRB+ group than in the MRB− group: LOS, 23±20.6 versus 12±15.3 days, (P<.001); Omega score, 164±103.4 versus 123±93.7 points (P<.001); PRN score, 3,606±3,187 versus 1,854±2,356 points (P<.001), respectively. The daily PRN score was also higher in MRB+ group (PRN, 160±25 vs 146±34 points in the MRB− group; P<.028). Four nursing procedures made necessary by MRB acquisition were identified: isolation precautions, with two levels according to whether the risk of contamination was mild-moderate or high; bathing the patient with antiseptic solution;, bedpan management; and microbiological screening. The functional analysis indicated that the time needed to carry out these four procedures correctly was 245 minutes per patient per day, as compared to 85 minutes according to the PRN system.

Our data confirm that MRB NIs are responsible for an increase in nurse work load, as estimated by LOS, Omega, and PRN scores. However, the daily excess nurse work load related directly to recommended procedures for managing MRB NIs in MICUs is underestimated by these activity scores, as compared to a specific functional analysis of nursing tasks. This may be of importance in evaluating potential links between nurse work load and MRB NIs and in determining the number of nurse hours needed to comply with infection control recommendations.

To determine the relation of the availability of personal protective equipment (PPE) and engineering controls to infection control (IC) practices in a prison healthcare setting, and to explore the effect on IC practices of a perceived organizational commitment to safety.

Cross-sectional survey.

The study population was drawn from the 28 regional Correctional Health Care Workers Facilities in Maryland.

All full-time Maryland correctional healthcare workers (HCWs) were surveyed, and 225 (64%) of the 350 responded.

A confidential, self-administered questionnaire was mailed to all correctional HCWs employed in the 28 Maryland Correctional Health Care Facilities. The questionnaire was analyzed psychometrically and validated through extensive pilot testing. It included items on three major constructs: IC practices, safety climate (defined as the perception of organizational commitment to safety), and availability of IC equipment and supplies.

A strong correlation was found between the availability of PPE and IC practices. Similarly, a strong correlation was found between IC practices and the presence of engineering controls. In addition, an equally strong association was seen between the adoption of IC practices and employee perception of management commitment to safety. Those employees who perceived a high level of management support for safety were more than twice as likely to adhere to recommended IC practices. IC practices were significantly more likely to be followed if PPE was always readily available. Similarly, IC practices were more likely to be followed if engineering controls were provided.

These findings suggest that ready availability of PPE and the presence of engineering controls are crucial to help ensure their use in this high-risk environment. This is especially important because correctional HCWs are potentially at risk of exposure to bloodborne pathogens such as human immunodeficiency virus and hepatitis B and C viruses. Commitment to safety was found to be highly associated with the adoption of safe work practices. There is an inherent conflict of “custody versus care” in this setting; hence, it is especially important that we understand and appreciate the relation between safety climate and IC practices. Interventions designed to improve safety climate, as well as availability of necessary IC supplies and equipment, will most likely prove effective in improving employee compliance with IC practices in this healthcare setting.

To investigate the persistence of colonization of premature babies by Klebsiella oxytoca, with special emphasis on the mode of transmission of the bacterium and evaluation of Standard Precautions to stop the epidemic.

Retrospective analysis of cases and prospective study of systematic bacteriological samples (stools and throat) from babies, healthcare workers (HCWs), and environment, with genotyping of strains by arbitrarily primed polymerase chain reaction.

A premature baby unit (PBU) and a neonatal intensive care unit in the university hospital of Saint-Etienne, France.

An outbreak of K oxytoca was suspected in two pediatric wards after the occurrence of a fatal bacteremia in a newborn hospitalized in the PBU and the colonization of other babies 2 months later. Retrospective analysis showed that 24 babies' digestive tract had been colonized. No environmental reservoir was recovered in the units nor in enteral feeding. No K oxytoca was isolated from HCW samples. Genotyping confirmed the presence of epidemic strains, although independent clones were responsible for infections or colonizations in each of the two units. The chronology and the site of babies' colonization (isolation of K oxytoca in stools before throat) were determined during a prospective study and suggested that enteral feeding procedures could be the source of contamination. Therefore, use of gloves during this practice by HCWs was recommended and, after readjustment of Standard Precautions, stopped the outbreak.

To prevent cross-contamination among high-risk babies, careful attention must be paid to Standard Precautions. Bacteriological surveillance of the digestive tract of neonates could help to check compliance with these guidelines.