Septal course of left anterior descending artery from the right aortic sinus in tetralogy of Fallot: a benign anomaly and important lessons learned.

The proximal course of an anomalously arising coronary artery is a decisive factor in the surgical approach for tetralogy of Fallot (TOF). Studies have shown that echocardiography provides a good anatomic definition of the ostium and proximal epicardial course of coronary arteries [1, 2]. This report describes a case of TOF with an atrioventricular canal defect whose preoperative echocardiography showed abnormal origin of the left anterior descending artery (LAD) from right aortic sinus, which was interpreted as crossing the right ventricular outflow tract. Perioperative inspection did not show any abnormal vessel crossing the outflow, and corrective surgery was performed. At the echocardiographic evaluation after surgery, it was noted that the abnormal LAD arising from right aortic sinus was taking a septal course in relation to the posterior aspect of the pulmonary annulus. It is important to recognize this anomalous course because it is benign with no surgical implications.

Surveillance of extended-spectrum-beta-lactamase-producing Enterobacteriaceae in a Swiss Tertiary Care Hospital.

BACKGROUND: Extended spectrum beta-lactamase producing enterobacteriaceae (ESBL-E) are increasing worldwide, but there is sparse data on patient-to-patient transmission and the prevalence among risk groups in Switzerland. A prospective, observational cohort study was performed to: 1) assess the prevalence of ESBL-E at admission among at-risk groups; 2) evaluate nosocomial cross-transmission in acute care (ACF) versus long-term care facilities (LTCF); and 3) evaluate prevalent mutations of the detected beta-lactamase genes. METHODS: Predefined risk groups were screened either on admission or after having been in contact with index patients diagnosed with ESBL-E by clinical cultures. Three patient categories were distinguished: patients previously known to be ESBL-E carrier (category I); patients transferred from countries with known high ESBL-E prevalence and thus at risk for ESBL-E carriage (category II); and roommates of index patients (category III). RESULTS: A total of 93 patients with ESBL-E were identified: Sixty-two percent (31/50) of category I patients were positive when screened upon rehospitalisation (category I); eighteen percent (22/124) of category II patients; and eight out of 177 category III patients (4.5%) of which five showed identical ESBL-E strains or shared the same beta-lactamase gene as their index cases. The incidence density of transmission was 0.9/1000 exposure-days, with more transmissions in ACF than in LTCF (4.2 vs 0.4/1000 exposure days). CTX-M-15 was the predominant beta-lactamase gene (60%) among the index patients. CONCLUSIONS: The prevalence of ESBL-E carriage among patients coming from regions with endemic rates or those previously identified as carriers is high; on-admission screening should be considered for these high risk populations. Documented nosocomial ESBL-E transmission was low.

Methods to evaluate the microbicidal activities of hand-rub and hand-wash agents.

In vitro carrier tests, suspension tests, time-kill curves, and determinations of minimum inhibitory concentrations to evaluate the microbicidal activities of hand antiseptics provide only a preliminary indication of the antimicrobial spectrum and speed of action of a given formulation. Ex vivo testing with human or animal skin at human skin temperature and at contact times reflecting field conditions may give a better indication of a formulation's ability to tackle hand-transmitted pathogens. Field testing of hands for levels of skin microbiota before and after antisepsis may be easier to perform, but it is subject to many uncontrollable factors. Whereas randomised clinical trials may be the ultimate approach to assess the effectiveness of hand hygiene protocols and products in preventing microbial cross-transmission and, ultimately, infections, they can be prohibitively expensive, time-consuming, difficult to design, and therefore impractical. Hence, the primary emphasis should be on in vivo testing on human hands, using a well-designed protocol that closely simulates the recommended field use of the formulation, and possibly followed by clinical studies. The use of these method is the most likely to yield useful data on the potential of a formulation to interrupt the spread of pathogens transmitted by hands in healthcare settings. This review provides a critical assessment of the methods currently used to meet regulatory requirements for hand antiseptics in Europe and North America.

Control of a cluster of community-associated, methicillin-resistant Staphylococcus aureus in neonatology.

To control an outbreak of community-associated MRSA (CA-MRSA) in a neonatology unit, an investigation was conducted that involved screening neonates and parents, molecular analysis of MRSA isolates and long-term follow-up of cases. During a two-month period in the summer of 2000, Panton-Valentine leukocidin (PVL)-producing CA-MRSA (strain ST5-MRSA-IV) was detected in five neonates. The mother of the index caseshowed signs of mastitis and wound infection and consequently tested positive for CA-MRSA. A small cluster of endemic, PVL-negative MRSA strains (ST228-MRSA-I) occurred in parallel. Enhanced hygiene measures, barrier precautions, topical decolonization of carriers, and cohorting of new admissions terminated the outbreak. Four months after the outbreak, the mother of another neonate developed furunculosis with the epidemic CA-MRSA strain. One infant had persistent CA-MRSA carriage resulting in skin infection in a sibling four years after the outbreak. In conclusion, an epidemic CA-MRSA strain was introduced by the mother of the index case. This spread among neonates and was subsequently transmitted to another mother and a sibling. This is the first report of a successfully controlled neonatology outbreak of genetically distinct PVL-producing CA-MRSA in Europe.

Environmental controls in operating theatres.

Surgical-site infection is the leading complication of surgery. Normal skin flora of patients or healthcare workers causes more than half all infections following clean surgery, but the importance of airborne bacteria in this setting remains controversial. Modern operating theatres have conventional plenum ventilation with filtered air where particles >/=5 microm are removed. For orthopaedic and other implant surgery, laminar-flow systems are used with high-efficiency particulate air (HEPA) filters where particles >/=0.3 microm are removed. The use of ultra-clean air has been shown to reduce infection rates significantly in orthopaedic implant surgery. Few countries have set bacterial threshold limits for conventionally ventilated operating rooms, although most recommend 20 air changes per hour to obtain 50-150 colony forming units/m(3) of air. There are no standardized methods for bacterial air sampling or its frequency. With the use of HEPA filters in operating theatre ventilation, there is a tendency to apply cleanroom technology standards used in industry for hospitals. These are based on measuring the presence of particles of varying sizes and numbers, and are better suited than bacterial sampling. Environmental bacterial sampling in operating theatres should be limited to investigation of epidemics, validation of protocols, or changes made in materials which could influence the microbial content.

Risk factors for persistent carriage of methicillin-resistant Staphylococcus aureus.

We determined risk factors associated with persistent carriage of methicillin-resistant Staphylococcus aureus (MRSA) among 102 patients enrolled in a double-blind, placebo-controlled trial of nasally administered mupirocin ointment. MRSA decolonization was unsuccessful in 77 (79%) of 98 patients who met the criteria for evaluation. By univariate analysis, 4 variables were found to be associated with persistent MRSA colonization (P < .1 for all 4): absence of mupirocin treatment, previous fluoroquinolone therapy, > or = 2 MRSA-positive body sites, and low-level mupirocin resistance. After multivariable Cox proportional hazards modeling, the presence of > or = 2 positive body sites (adjusted hazard ratio [AHR], 1.7; 95% confidence interval [CI], 1.0-2.9) and previous receipt of a fluoroquinolone (AHR, 1.8; 95% CI, 1.0-3.3) were independently associated with MRSA persistence, whereas nasal mupirocin tended to confer protection (AHR, 0.6; 95% CI, 0.4-1.0). Low-level mupirocin resistance was observed in 9 genotypically different MRSA strains and was not independently associated with chronic MRSA carriage (AHR, 1.5; 95% CI, 0.9-2.5). Our findings suggest that multisite MRSA carriage and previous receipt of a fluoroquinolone are independent risk factors for persistent MRSA colonization.

Outbreak of Enterobacter cloacae related to understaffing, overcrowding, and poor hygiene practices.

OBJECTIVE: To determine the cause and mode of transmission of a cluster of infections due to Enterobacter cloacae. DESIGN AND SETTING: Retrospective cohort study in a neonatal intensive-care unit (NICU) from December 1996 to January 1997; environmental and laboratory investigations. SUBJECTS: 60 infants hospitalized in the NICU during the outbreak period. MAIN OUTCOME MEASURES: Odds ratios (OR) linking E. cloacae colonization or infection and various exposures. All available E. cloacae isolates were typed and characterized by contour-clamped homogenous electric-field electrophoresis to confirm possible cross-transmission. RESULTS: Of eight case-patients, two had bacteremia; one, pneumonia; one, soft-tissue infection; and four, respiratory colonization. Infants weighing <2,000 g and born before week 33 of gestation were more likely to become cases (P<.001). Multivariate analysis indicated that the use of multidose vials was independently associated with E. cloacae carriage (OR, 16.3; 95% confidence interval [CI95], 1.8-infinity; P=.011). Molecular studies demonstrated three epidemic clones. Cross-transmission was facilitated by understaffing and overcrowding (up to 25 neonates in a unit designed for 15), with an increased risk of E. cloacae carriage during the outbreak compared to periods without understaffing and overcrowding (relative risk, 5.97; CI95 2.2-16.4). Concurrent observation of healthcare worker (HCW) handwashing practices indicated poor compliance. The outbreak was terminated after decrease of work load, increase of hand antisepsis, and reinforcement of single-dose medication. CONCLUSIONS: Several factors caused and aggravated this outbreak: (1) introduction of E. cloacae into the NICU, likely by two previously colonized infants; (2) further transmission by HCWs' hands, facilitated by substantial overcrowding and understaffing in the unit; (3) possible contamination of multidose vials with E. cloacae. Overcrowding and understaffing in periods of increased work load may result in outbreaks of nosocomial infections and should be avoided.

Routine disinfection of patients' environmental surfaces. Myth or reality?

We have evaluated the need for daily disinfection of environmental surfaces not contaminated by biological fluids, in patient areas of a medical unit with two wings [North (N) and South (S)] at the University Hospitals of Geneva, Switzerland. Weekly bacteriological monitoring of surfaces was carried out at random (N = 1356 samples). In the S wing (control), we used detergent/disinfectant for daily cleaning of the floors and furniture. In the N wing we began by using a detergent for floors and furniture; after four weeks the results suggested changing to a rotation of detergent, dust attracting disposable dry mops and disinfectant. During this period the furniture was cleaned with an active oxygen-based compound. The average differences in contamination before and after cleaning floors were (mean reduction in bacterial counts and 95% confidence intervals; CI95): disposable mops: 92.7 cfu/24 cm2 (CI95; 74-112), active oxygen based compound 111.1 (90-133), and quaternary ammonium compound -0.6 (-27-26). Use of detergent alone was associated with a significant increase in bacterial colony counts: on average by 103.6 cfu (CI95 73-134). The quaternary ammonium compound was inadequate for disinfecting bathrooms and toilets but the active oxygen based compound was satisfactory. For furniture, there was a significant reduction in bacterial counts with both the methods using disinfectants. As the detergent was contaminated, by using it alone for cleaning, we were actually seeding surfaces with bacteria. A total of 1117 patients was studied and we observed no change in the incidence of nosocomial infections during the four months of the trial. In conclusion, uncontrolled routine disinfection of environmental surfaces does not necessarily make it safe for the patient and could seed the environment with potential pathogens.

Randomized, placebo-controlled, double-blind trial to evaluate the efficacy of mupirocin for eradicating carriage of methicillin-resistant Staphylococcus aureus.

Mupirocin has been widely used for the clearance of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage during outbreaks, but no placebo-controlled trial has evaluated its value for eradicating MRSA carriage at multiple body sites in settings where MRSA is not epidemic. In a 1,500-bed teaching hospital with endemic MRSA, 102 patients colonized with MRSA were randomized into a double-blind, placebo-controlled trial and treated with either mupirocin (group M) or placebo (group P) applied to the anterior nares for 5 days; both groups used chlorhexidine soap for body washing. Follow-up screening, susceptibility testing, and genotyping were performed to evaluate treatment success, mupirocin or chlorhexidine resistance, and exogenous recolonization. At baseline, MRSA carriage was 60% in the nares, 38% in the groin, and 62% in other sites (skin lesions, urine). The MRSA eradication rate (all body sites) was 25% in group M (12 of 48 patients), compared to 18% in group P (9 of 50 patients; relative risk [RR], 0.72; 95% confidence interval [CI95], 0.33 to 1.55). At the end of follow-up, 44% of patients (19 of 43) were free of nasal MRSA in group M, compared to 23% (11 of 44) in group P (RR, 0.57; CI95, 0.31 to 1.04). Ten patients developed MRSA infections (three in group M and seven in group P). One mupirocin treatment failure was due to exogenous MRSA recolonization. No MRSA isolate showed chlorhexidine resistance or high-level mupirocin resistance; however, we observed an association (P = 0.003) between low-level mupirocin resistance at study entry (prevalence, 23%) and subsequent treatment failure in both study arms. These results suggest that nasal mupirocin is only marginally effective in the eradication of multisite MRSA carriage in a setting where MRSA is endemic.

Bacterial contamination of the hands of hospital staff during routine patient care.

BACKGROUND: Cross-transmission of microorganisms by the hands of health care workers is considered the main route of spread of nosocomial infections. OBJECTIVE: To study the process of bacterial contamination of health care workers' hands during routine patient care in a large teaching hospital. METHODS: Structured observations of 417 episodes of care were conducted by trained external observers (S.T. and V.S.). Each observation period started after a hand-cleansing procedure and ended when the health care worker proceeded to clean his or her hands or at the end of a coherent episode of care. At the end of each period of observation, an imprint of the 5 fingertips of the dominant hand was taken and bacterial colony counts were quantified. Regression methods were used to model the intensity of bacterial contamination as a function of method of hand cleansing, use of gloves during patient care, duration and type of care, and hospital ward. RESULTS: Bacterial contamination increased linearly with time on ungloved hands during patient care (average, 16 colony-forming units [CFUs] per minute; 95% confidence interval, 11-21 CFUs per minute). Patient care activities independently (P<.05 for all) associated with higher contamination levels were direct patient contact, respiratory care, handling of body fluid secretions, and rupture in the sequence of patient care. Contamination levels varied with hospital location; the medical rehabilitation ward had higher levels (49 CFUs; P=.03) than did other wards. Finally, simple hand washing before patient care, without hand antisepsis, was also associated with higher colony counts (52 CFUs; P=.03). CONCLUSIONS: The duration and type of patient care affect hand contamination. Furthermore, because hand antisepsis was superior to hand washing, intervention trials should explore the role of systematic hand antisepsis as a cornerstone of infection control to reduce cross-transmission in hospitals.

Access to mental health care in an inner-city health district. I: Pathways into and within specialist psychiatric services.

BACKGROUND: Needs for mental health care are likely to be high in urban areas. Purchasers must assess the extent to which these are being met. The pathways to care model provides a framework for this purpose. METHOD: Epidemiological surveys of adults living in deprived multi-ethnic inner-city catchment area were undertaken in psychiatric services, primary care and community settings. Estimated prevalence rates were calculated and the association between clinical and demographic factors and the use of psychiatric services examined. RESULTS: Around a third of people with mental health problems did not consult a GP, and half failed to have their problems recognised by their doctor. Access to psychiatric services and especially to inpatient care was highly restricted. Diagnosis and ethnicity had a marked influence on the use of specialist services. CONCLUSIONS: Many people with psychiatric morbidity are not receiving treatment either from primary care or specialist services. High levels of severe morbidity and compulsory admissions highlight the pressures placed on inner-city psychiatric services.

Access to mental health care in an inner-city health district. II: Association with demographic factors.

BACKGROUND: In addition to clinical and service factors, planners need to take account of the influence of demographic variables, especially ethnicity, on access to mental health care. METHOD: Estimated prevalence rates were calculated from epidemiological surveys undertaken in three settings: psychiatric services, primary care and the general population. Associations between demographic factors and service use were examined using the 'pathways to care' model. RESULTS: Considerable differences in access to mental health care were found, particularly according to ethnicity. The major impediment to Asians accessing care occurred at the interface between primary and secondary care, whereas the most striking feature for Blacks was the poor level of case recognition by GPs. CONCLUSIONS: In order to improve the uptake of mental health care, new initiatives should target those who are most likely to be unwell but least likely to access services. Purchasers and providers need to address differential patterns of use when developing and reviewing services.

Unusual cause of lethal pulmonary aspergillosis in patients with chronic obstructive pulmonary disease.

Two patients admitted to two different medical wards of our institution following respiratory decompensation of chronic obstructive pulmonary disease (COPD) were subsequently transferred to the same room of the medical intensive care unit (ICU) and intubated. Both patients developed invasive pulmonary aspergillosis and died soon after. Because COPD itself is rarely associated with lethal pulmonary aspergillosis, both cases were reviewed, and a retrospective investigation was conducted. Both patients had repeated sputum cultures while on the medical ward before their admission to the ICU; none of the sample grew Aspergillus spp. A. fumigatus was found in tracheal aspirates of both patients from the first day of their intubation while in the ICU. The pulmonary condition of both patients worsened, and invasive aspergillosis was diagnosed by bronchoalveolar lavage. Despite therapy with amphotericin B, the patients died 16 and 22 d after intubation, respectively. Both deaths were attributed to pulmonary aspergillosis; autopsy confirmed a massive pneumonia of the five lobes due to A. fumigatus in one patient. Investigation revealed that an air filter had been replaced 30 h before the first patient was admitted to the room. Experimental air filter replacement performed 12 d after the second patient died revealed the presence of A. fumigatus on the surface of the filters as well as a 10-fold increase in room air fungal counts during the procedure. This study shows that exposure to high concentrations of airborne Aspergillus spp. related to air filter change was associated with fatal invasive aspergillosis in two mechanically ventilated patients. Such infection can be prevented by the establishment and application of guidelines for air filter replacement.

Digital ischemia and occult malignancy.

Since the early transcript by Raynaud and Trousseau, there has been wide acceptance of the association of occult malignancy and peripheral vascular disease. Recently, there have been a few case reports of acute onset monophasic digital ischemia heralding an occult malignancy. It appears that the site and tumor types seem unimportant in the development of ischemia; tumor resection however, usually results in rapid improvement of the affected digit. The mechanism remains to be established.

Efficacy of autologous peritoneum as a biological membrane in cardiac surgery.

The risks for reoperative cardiac surgery are related to the presence of intrapericardial adhesions and the possibility of catastrophic injury at repeat sternotomy. In an attempt to develop an improved pericardial substitute and vascular patch, the feasibility of using autologous peritoneum was evaluated. Twelve mongrel dogs were studied. A peritoneal-rectus fascia patch, including the overlying posterior rectus sheath was harvested, via a lateral abdominal incision, and stored in normal saline. In the first group of six animals, a pulmonary artery (PA) window was created and then closed with the peritoneal-rectus fascia patch. In the second group a secundum atrial septal defect was created and then closed with the peritoneal patch on cardiopulmonary bypass (CPB). In each animal, the peritoneal-rectus fascia patch was used to permit pericardial closure. Autopsies performed at 90 days postoperatively revealed only slight intrapericardial adhesion formation and a mild epicardial reaction. Histological examination of the peritoneal-rectus fascia patches revealed intact morphology with active fibroblasts and smooth muscle cells. Proline 14C absorption and autoradiography detected viable cells in the implanted patches. These findings suggest that a peritoneal-rectus fascia allograft could be useful as a biological membrane, and as a satisfactory pericardial substitute in the development of strategies to reduce the risk for reoperative cardiac surgery.

Evaluation of the Wellcolex Colour Salmonella Test for detection of Salmonella spp. in enrichment broths.

The Wellcolex Colour Salmonella Test was evaluated for detection of Salmonella spp. in enrichment broths of 1,010 stool samples. In 39 specimens, Salmonella spp. could be isolated from the selenite F broth (SF). Wellcolex agglutination indicative of the presence of Salmonella spp. was noted with the SF in 36 cases, 34 of which were in agreement with the subculture results. Therefore, relative to subculture, the sensitivity and specificity of the Wellcolex-selenite F procedure were 87 and 99%, respectively. Five false-negative results were noted. The gram-negative broth (GN) subculture revealed only 23 Salmonella spp. (59% sensitivity). The Wellcolex agglutination procedure applied to the GN indicated Salmonella spp. for 21 samples; its sensitivity was 70% and its specificity was 99% compared with GN subcultures. The Wellcolex agglutination procedure applied to the SF performed better than the agglutination of GN or direct plating procedures and detected 17 of the 39 Salmonella spp. at least 24 h earlier than did culture.