Comparison of number of airborne bacteria in operating rooms with turbulent mixing ventilation and unidirectional airflow when using reusable scrub suits and single-use scrub suits.

INTRODUCTION: A low count of airborne bacteria in the operating room is a means to prevent surgical site infection. AIM: To investigate levels of airborne bacteria during surgical procedures in two operating rooms with turbulent mixing ventilation (TMV) and unidirectional airflow (UDAF), both with an air supply of 2600 L/s, when staff used either reusable scrub suits made from a mixed material (dry penetration ≤300 cfu) or single-use scrub suits made from polypropylene (dry penetration ≤100 cfu). MATERIAL AND METHODS: In the TMV-room cfu/m3 air was measured during eight procedures with staff wearing reusable scrub suits and seven procedures with single-use scrub. In the UDAF-room cfu/m3 air was measured during seven procedures with staff wearing reusable scrub suits. FINDINGS: Mean values of cfu/m3 air were 1.3-10.8 in the TMV-room with staff dressed in reusable scrub suits and 0.8-4.0 with staff dressed in single-use scrub suits (P<0.01). Mean values of cfu/m3 air were 0.2-4.5 in the UDAF-room with staff dressed in reusable scrub suits. The difference obtained with reusable scrub suits in the two rooms was significant (P<0.01). CONCLUSIONS: The mode of ventilation affects the cfu levels when staff are dressed in less occlusive scrub suits despite a high air supply. It is possible to decrease the cfu levels in a TMV-room by using scrub suits made from a tight material, thus reaching the same levels that are achieved by less protective scrub suits in a UDAF-room.

Temperature-controlled airflow ventilation in operating rooms compared with laminar airflow and turbulent mixed airflow.

AIM: To evaluate three types of ventilation systems for operating rooms with respect to air cleanliness [in colony-forming units (cfu/m3)], energy consumption and comfort of working environment (noise and draught) as reported by surgical team members. METHODS: Two commonly used ventilation systems, vertical laminar airflow (LAF) and turbulent mixed airflow (TMA), were compared with a newly developed ventilation technique, temperature-controlled airflow (TcAF). The cfu concentrations were measured at three locations in an operating room during 45 orthopaedic procedures: close to the wound (<40cm), at the instrument table and peripherally in the room. The operating team evaluated the comfort of the working environment by answering a questionnaire. FINDINGS: LAF and TcAF, but not TMA, resulted in less than 10cfu/m3 at all measurement locations in the room during surgery. Median values of cfu/m3 close to the wound (250 samples) were 0 for LAF, 1 for TcAF and 10 for TMA. Peripherally in the room, the cfu concentrations were lowest for TcAF. The cfu concentrations did not scale proportionally with airflow rates. Compared with LAF, the power consumption of TcAF was 28% lower and there was significantly less disturbance from noise and draught. CONCLUSION: TcAF and LAF remove bacteria more efficiently from the air than TMA, especially close to the wound and at the instrument table. Like LAF, the new TcAF ventilation system maintained very low levels of cfu in the air, but TcAF used substantially less energy and provided a more comfortable working environment than LAF. This enables energy savings with preserved air quality.

Comparison of two single-use scrub suits in terms of effect on air-borne bacteria in the operating room.

A low level of air-borne bacteria in the operating room air can be achieved if all staff wear clothes made of low-permeability material (i.e. clean air suits). This study investigated if there was a difference in protective efficacy between two single-use scrubs made of polypropylene by testing them during routinely performed orthopaedic surgical procedures. No significant difference in the colony-forming unit count/m3 air was found between the two scrubs, so the choice can be based on which scrub type is more comfortable for staff.

Point-prevalence surveillance of healthcare-associated infections in Swedish hospitals, 2008-2014. Description of the method and reliability of results.

BACKGROUND: In 2007 the Swedish Association of Local Authorities and Regions (SALAR) decided to establish a nationwide system for point-prevalence surveillance of healthcare-associated infections (HCAIs) among hospitalized patients. Surveillance started in 2008 and has since then been performed twice a year (April and October). The documentation of HCAIs is performed by regular clinical physicians and nurses on each hospital ward aided by oral and written instructions. All Swedish publicly financed hospitals (>95% of all hospitals) are included (25,862 beds in 2008 and 24,905 beds in 2013). A total of 88-92% of all inpatients has been covered in each survey. The overall prevalence of HCAI (including psychiatric inpatients) has ranged from 7.8% to 10.0%. AIM: In 2012 SALAR decided to assess the reliability of the prevalence data. METHODS: In all, 1216 patients were assessed for HCAIs by both the regular surveillance teams and teams with expert knowledge on HCAI independently of each other. FINDINGS: The prevalence of HCAI was 8.3% (95% confidence interval: 6.7-9.9) according to the regular teams and 13.1% (11.2-15.0) according to the expert teams. The sensitivity of the regular point-prevalence surveillance was 47% and the specificity 97%. CONCLUSION: The Swedish system for repeated nationwide point-prevalence surveillance of HCAI has had a high coverage of about 90% since it commenced. However, the surveys underestimate the true prevalence of HCAI.

Knowledge and understanding of antibiotic resistance and the risk of becoming a carrier when travelling abroad: a qualitative study of Swedish travellers.

BACKGROUND: Increasing globalisation, with the migration of people, animals and food across national borders increases the risk of the spread of antibiotic-resistant bacteria. To avoid becoming a carrier of antibiotic-resistant bacteria when travelling, knowledge about antibiotic resistance is important. MATERIALS AND METHODS: We aimed to describe the knowledge and understanding of antibiotic-resistant bacteria, and of the risk for becoming a carrier of such bacteria, among Swedish travellers before their travel to high-risk areas. A questionnaire with three open-ended questions was distributed to 100 individuals before departure. RESULTS: The travellers' answers were analysed using content analysis, resulting in the theme 'To be an insecure traveller who takes control over one's own journey'. Our results showed that the travellers were aware of what the term 'antimicrobial resistance' meant, but did not understand its real significance, nor the consequences for the individual nor for society. They also distanced themselves from the problem. Few thought that their travel would entail a risk of becoming a carrier of resistant bacteria. The lack of knowledge caused an uncertainty among the travellers, whom tried to master the situation by using coping strategies. They proposed a number of measures to prevent carriership. The measures were general and primarily aimed at avoiding illness abroad, particularly acute gastro-intestinal infection. CONCLUSIONS: In health care and vaccination clinics, there is a need for improved information for persons intending to travel to high-risk areas, both about the risks of contracting antibiotic-resistant bacteria and about effective preventive measures.

Single-use surgical clothing system for reduction of airborne bacteria in the operating room.

It is desirable to maintain a low bacterial count in the operating room air to prevent surgical site infection. This can be achieved by ventilation or by all staff in the operating room wearing clothes made from low-permeable material (i.e. clean air suits). We investigated whether there was a difference in protective efficacy between a single-use clothing system made of polypropylene and a reusable clothing system made of a mixed material (cotton/polyester) by testing both in a dispersal chamber and during surgical procedures. Counts of colony-forming units (cfu)/m(3) air were significantly lower when using the single-use clothing system in both settings.

Routes and sources of Staphylococcus aureus transmitted to the surgical wound during cardiothoracic surgery: possibility of preventing wound contamination by use of special scrub suits.

OBJECTIVES: 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. METHODS: 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). RESULTS: 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], 1.3-14.91). 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. CONCLUSIONS: 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.

Source and route of methicillin-resistant Staphylococcus epidermidis transmitted to the surgical wound during cardio-thoracic surgery. Possibility of preventing wound contamination by use of special scrub suits.

The objective of this study was to trace the source and route of transmission of methicillin-resistant Staphylococcus epidermidis (MRSE) in the surgical wound during cardio-thoracic surgery, and to investigate the possibility of reducing wound contamination by wearing special scrub suits. In total 65 elective operations for coronary artery bypass grafting (CABG) 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. Samples were taken from the hands of the scrubbed team after surgical scrub but before putting on sterile gowns and gloves, and from 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. Samples were also taken from the wound just before closure. Total counts of bacteria on sternal skin and from the wound (cfu/cm2) were calculated as well as total counts of bacteria in the air (cfu/m3). Strains of MRSE recovered from the different sampling sites were compared by pulsed field gel electrophoresis (PFGE). It was found that wearing special scrub suits did not reduce the number of air-samples where MRSE was found compared with conventional scrub suits. The risk factor most strongly associated with MRSE in the wound at the end of the operation was preoperative carriage of MRSE on sternal skin; RR 2.42 [95% CI 1.43-4.10], P= 0.021. By use of PFGE, it was possible to identify the probable source for four MRSE isolates recovered from the wound. In three cases the source was the patients own skin. Finding MRSE in air-samples, or on the hands of the scrubbed team, were not risk factors for the recovery of MRSE in the wound at the end of operation. In conclusion, with a total bacterial air count around 20 cfu/m3 and a low proportion of MRSE, the reduction of total air counts by use of tightly woven special scrub suits did not reduce air counts of MRSE or wound contamination with MRSE. The patients' sternal skin was the main source for wound contamination with MRSE

Emergence of imipenem resistance in Klebsiella pneumoniae owing to combination of plasmid-mediated CMY-4 and permeability alteration.

Klebsiella pneumoniae BM2974 isolated from an abdominal abcess was resistant to high concentrations of all available beta-lactams, including recently developed third-generation cephalosporins and carbapenems. Isoelectric focusing of beta-lactamases and amplification, cloning and sequencing of the corresponding genes, together with conjugation and transformation experiments, indicated that, in addition to the chromosomally encoded beta-lactamase, the strain produced three plasmid-mediated beta-lactamases with pIs of 5.4, 8.2 and 9.0, which corresponded to TEM-1, SHV-5 and AmpC-type CMY-4, respectively. Strain BM2974 also lacked a major outer membrane protein of c. 40 kDa which was present in the spontaneous imipenem-susceptible revertant BM2974-1. We suggest that imipenem resistance in strain BM2974 is attributable to production of CMY-4 beta-lactamase combined with permeability alteration.

Dispersal of methicillin-resistant Staphylococcus epidermidis by staff in an operating suite for thoracic and cardiovascular surgery: relation to skin carriage and clothing.

Methicillin-resistant Staphylococcus epidermidis (MRSE) is a common cause of deep sternal infections. The aim of the present investigation was to evaluate staff in an operating suite for thoracic and cardiovascular surgery as a possible source of MRSE and the possibility of reducing the amount of MRSE shed into the air by wearing tightly woven scrub suits. A second aim was to compare the results of dispersal obtained in a test chamber with those from an operating room. We studied carriage of MRSE in the nose and on different skin sites and made an experimental study of dispersal of MRSE during exercise in a test chamber and during operations, using two different types of scrub suits. Dispersal of MRSE [defined as > 1% of the total count of colony forming units (CFU) shed into the air] occurred in 25% of women and 43% of men. Nasal carriage was found among 28% in women and 33% in men. Among five skin-sampling sites, carriage of MRSE was most frequent on the cheek (50%) and in the axilla (24%) and least frequent in the perineum (5%). Dispersal of MRSE was however more strongly associated with carriage in the perineum (P = 0.097) than on the cheek (P = 0.5) and in the axilla (P = 0.21). With regard to shedding of bacteria into the air, there was a significant difference in favour of the tightly woven clothes regarding total counts of CFU both in the test chamber (P = 0.02) and the operating theatre (P = 0.002). Regarding MRSE, no such difference was found. We found there were too many dispersers of MRSE among operating department staff to exclude them from work. Although tightly woven scrub suits significantly reduced the amount of bacteria shed into the air, the amount of MRSE was not significantly reduced. Full-scale experiments in operating rooms are not needed when evaluating the protective capacity of different scrub suits as results from a test chamber give conclusive information.

[What hygienic criteria should apply to community care? The risk of infection is increasing when more and more seriously ill patients are treated outside hospital]. / Vilka krav skall ställas på hygienen i den kommunala vården? Smittriskerna ökar när allt fler allt sjukare vårdas utanför sjukhus.

In Sweden, the provision of health care (i.e. non-physician care) of elderly residents in community housing and care facilities has been the statutory responsibility of local authorities since 1992. The Health and Medical Services Act stipulates that such care should be of good quality, As infection control is one aspect of good quality, in 1997 the Dept. of Infection Control at University Hospital, Uppsala, and the six municipalities of the County of Uppsala that are responsible for the care of a total of 4,400 elderly people, launched a joint enterprise to provide the care required by the Act. The program includes the education of staff in the basic concepts of infection control/recruitment of link surses and surveillance of risk factors, in order to minimise nosocomial infections in nursing homes for the elderly.

Chronic ulcers and antibiotic treatment.

This study analysed 656 wound samples from patients with chronic wounds in order to determine the bacterial flora and patterns of antibiotic use and resistance. Almost all wounds (95.1%) were colonised with at least one bacterial species; 26% of all patients were on antibiotic treatment. The total number of bacterial isolates resistant to antibiotics was low.

Sternal wound complications--incidence, microbiology and risk factors.

OBJECTIVE: Sternal wound complications, i.e. instability and/or infection (mediastinitis), are important causes of morbidity in patients undergoing cardiac surgery via median sternotomy. Coagulase negative staphylococci, a normal inhabitant of the skin, have evolved as a cause of sternal wound infections. Since these opportunistic pathogens often are multiresistant, they can cause therapeutic problems. METHODS: From 1980 through 1995 open heart surgery, was performed on 13,285 adult patients. Reoperation necessitated by sternal wound complications occurerd in 203 patients (1.5%). The incidence was 1.7% (168/9987) after coronary artery bypass grafting (CABG group) and 0.7% (35/3413) after heart valve surgery with or without concomitant CABG (HVR group). RESULTS: Factors independently related to sternal complications in the CABG group (variable odds ratio [95% C.I.]): year of surgery, 1.9 [1.3-2.8] in 1990-1992, 2.0 [1.4-2.9] in 1993-1995; female sex, 0.4 [0.2-0.6]; diabetic disease, 1.8 [1.2-2.5]; bilateral ITA procedure, 3.3 [1.1-7.7]; and postoperative dialysis, 3.1 [1.4-6.9]. In the HVR group they were: use of ITA graft, 3.7 [1.7-7.7]; early re-exploration because of bleeding 3.0 [1.1-8.2]; and postoperative dialysis 3.1, [1.4-9.3]. Multivariate models were used to compute the risk for sternal complications in each patient. However, the prognostic models based on these risk scores provided low sensitivity and low predictive value. Patients with sternal wound complications showed no increased early mortality but worse long-term survival even after adjustment for other factors (relative hazard in CABG group 1.9 [1.2-2.8]; in HVR group 2.1 [1.1-4.3]. CONCLUSIONS: The use of ITA grafts seems to be one of the most important factors related to sternal wound complications. However, patients at truly increased risk for this complication could not be identified on the basis of the risk factors considered in this study.