Multiply beta-lactam resistant Enterobacter cloacae infections linked to the environmental flora in a unit for cardiothoracic and vascular surgery

A recurrent and transesophageal echocardiography-associated outbreak of extended-spectrum β-lactamase-producing Enterobacter cloacae complex in cardiac surgery patients

Background

We report a recurrent outbreak of postoperative infections with extended-spectrum β-lactamase (ESBL)–producing E. cloacae complex in cardiac surgery patients, describe the outbreak investigation and highlight the infection control measures.

Methods

Cases were defined as cardiac surgery patients in Ghent University Hospital who were not known preoperatively to carry ESBL-producing E. cloacae complex and who postoperatively had a positive culture for this multiresistant organism between May 2017 and January 2018. An epidemiological investigation, including a case-control study, and environmental investigation were conducted to identify the source of the outbreak. Clonal relatedness of ESBL-producing E. cloacae complex isolates collected from case patients was assessed using whole-genome sequencing–based studies.

Results

Three separate outbreak episodes occurred over the course of 9 months. A total of 8, 4 and 6 patients met the case definition, respectively. All but one patients developed a clinical infection with ESBL-producing E. cloacae complex, most typically postoperative pneumonia. Overall mortality was 22% (4/18). Environmental cultures were negative, but epidemiological investigation pointed to transesophageal echocardiography (TEE) as the outbreak source. Of note, four TEE probes showed a similar pattern of damage, which very likely impeded adequate disinfection. The first and second outbreak episode were caused by the same clone, whereas a different strain was responsible for the third episode.

Conclusions

Health professionals caring for cardiac surgery patients and infection control specialists should be aware of TEE as possible infection source. Caution must be exercised to prevent and detect damage of TEE probes.

Emergency Preparedness

Outbreaks of infectious diseases during peacetime or in disaster/war-related conditions, may most often need an effective crisis management in the hospital. The emergency preparedness in hospitals may vary within, and between countries, dependent on endemic and epidemic conditions, capacity, knowledge and economy. Lack of preparedness may result in a high risk of disease burden and death and cause a high economic impact on the health care.

Tracing and Preventing Infections

A total of 10–20% of somatic patients experience hospital infections during/after hospitalization. Pneumonia, sepsis, surgical site infections and urinary tract infections are most often associated with patient-related use of medical devices for approximately 65% of cases, while nontechnical equipment may be linked to 35% of cases. It is resource-intensive to detect the cause of infection outbreaks and even more expensive not to take action. Unexplained causes of outbreaks may lead to uncertainty and reduced activity at the hospital. To trace and prevent hospital outbreaks, joint efforts from hospital management, microbiology and infection control are needed. This chapter is focused on practical measures to trace and prevent hospital outbreaks.

Preliminary assessment of photoactivated antimicrobial collagen on bioburden in a murine pressure ulcer model

OBJECTIVE AND BACKGROUND DATA

Overcoming bacterial antibiotic resistance requires alternative strategies. The ability of photoactivated collagen-embedded flavins (PCF) to reduce bioburden in infected pressure ulcers was investigated.

DESIGN AND METHODS

Two pressure ulcers were created on the dorsum of female BALB/C mice (n=40, 35 g) maintaining a 5 mm skin bridge between lesions. Ulcers and surrounding skin were covered with Tegaderm™ and inoculated with 0.1 mL of 1 × 10(5) colony-forming units (CFU)/mL methicillin-resistant Staphylococcus aureus (MRSA). Fluid was permitted to reabsorb for 10 min. In experiment 1, one wound from each animal was treated using PCF and photoradiation (PCF+R, n=12) or photoradiation alone (R, n=11). Composite dressing-treated wounds received 1 × 1 cm PCF discs. Overlying Tegaderm was excised, and PCF was placed over the wound and again covered with Tegaderm. Wounds were irradiated at 455 ± 5 nm (350 mW, 1 cm spot diameter, 15 min) using a diode laser 10 min after placement. Controls received no PCF or photoradiation (C, n=12). Animals were euthanized 24 h post-therapy. Quantitative bacterial counts (CFU/g tissue) were determined. In experiment 2, composite dressing-treated wounds were irradiated at 455 ± 5 nm (350 mW, 1 cm spot diameter, 15 min) using a diode laser 10 min after daily PCF placement (0, 1, 2, or 3 treatments, n=8/group). Controls received no treatment. Wounds were cultured daily. Animals were euthanized on day 7 post-infection. Quantitative bacterial counts were determined.

RESULTS

PCF+R significantly reduced bacterial counts at 24 h (experiment 1, p<0.0001; experiment 2, p<0.05). The bacterial counts in rats receiving photoradiation alone were no different from those of untreated controls (experiment 1, p=0.24). PCF+R produced a 2-3 log reduction in bacterial counts (experiment 2, p<0.001). Antibacterial effects increased with number of treatments, and persisted for several days post-therapy (p<0.002).

CONCLUSIONS

PCF+R inhibited bacterial growth in this model. This effect increased with successive treatments, persisting several days post-therapy. Further studies to optimize this treatment modality are warranted.

Subtractive hybridization yields a silver resistance determinant unique to nosocomial pathogens in the Enterobacter cloacae complex

The heterogeneity and the increasing clinical importance of the Enterobacter cloacae complex have often been discussed. However, little is known about molecular factors causing pathogenicity within this nomenspecies. Here, we analyzed the genetic differences between an avirulent plant isolate and a pathogenic strain causing an outbreak with septicemia in three patients. We identified an IncHI-2 plasmid as a major difference between these two strains. Besides resistance to several antibiotics, this plasmid encoded a silver resistance determinant. We further showed that this sil determinant was present not only in the analyzed outbreak strain but also in the vast majority of clinical isolates of the E. cloacae complex, predominantly in (sub)species that frequently cause nosocomial infections. The identified sil determinant was highly conserved within the E. cloacae complex and mediated resistance to up to 600 μM silver nitrate. As silver is often used as a disinfectant and treatment for burn wounds, we present here an important fitness factor within the clinically most prevalent subspecies of the E. cloacae complex. This provides a possible explanation for their unequal involvement in nosocomial and especially burn wound infections.

Mediastinitis in pediatric cardiac surgery: Prevention, diagnosis and treatment

In spite of advances in the management of mediastinitis following sternotomy, mediastinitis is still associated with significant morbidity. The prognosis is much better in pediatric surgery compared to adult surgery, but the prolonged hospital stays with intravenous therapy and frequent required dressing changes that occur with several therapeutic approaches are poorly tolerated. Prevention includes nasal decontamination, skin preparation, antibioprophylaxis and air filtration in the operating theater. The expertise of the surgical team is an additional factor that is difficult to assess precisely. Diagnosis is often very simple, being made on the basis of a septic state with wound modification, while retrosternal puncture and CT scan are rarely useful. Treatment of mediastinitis following sternotomy is always a combination of surgical debridement and antibiotic therapy. Continued use of numerous surgical techniques demonstrates that there is no consensus and the best treatment has yet to be determined. However, we suggest that a primary sternal closure is the best surgical option for pediatric patients. We propose a simple technique with high-vacuum Redon's catheter drainage that allows early mobilization and short term antibiotherapy, which thus decreases physiological and psychological trauma for patients and families. We have demonstrated the efficiency of this technique, which is also cost-effective by decreasing intensive care and hospital stay durations, in a large group of patients.

Enterobacter cloacae infection of an expanded polytetrafluoroethylene femoral-popliteal bypass graft: a case report

Introduction

Enterobacter cloacae infections are common among burn victims, immunocompromised patients, and patients with malignancy. Most commonly these infections are manifested as nosocomial urinary tract or pulmonary infections. Nosocomial outbreaks have also been associated with colonization of certain surgical equipment and operative cleaning solutions. Infections of an aortobifemoral prosthesis, an aortic graft, and arteriovenous fistulae are noted in the literature. To our knowledge, this is the first isolated account of an E. cloacae infection of a femoral-popliteal expanded polytetrafluoroethylene bypass graft.

Case presentation

A 68-year-old Caucasian man presented with fever and rest pain in the right lower extremity five months after the placement of a vascular expanded polytetrafluoroethylene graft for femoral-popliteal bypass. Computed tomography angiography demonstrated peri-graft fluid that was aspirated percutaneously with image guidance and cultured to reveal E. cloacae. The graft was revised and then removed. The patient completed a six-week course of ceftazidime and is currently without signs of infection. There were no other reports of E. cloacae graft infections in any patients receiving treatment in the same surgical suite within a month of this report.

Conclusion

Isolated cases of E. cloacae infection of surgical bypass grafts are rare (unique in this setting). Clinicians should have a high index of suspicion for device contamination in such cases and should consider testing for possible microbial reservoirs. Graft removal is required due to the formation of biofilm and the recent emergence of Enterobacteriaceae producing extended-spectrum beta-lactamase in community acquired infections.

Methicillin-Resistant Staphylococcus Species in a Cardiac Surgical Intensive Care Unit: A 5-Year Experience

OBJECTIVES

Methicillin-resistant Staphylococcus is a growing problem in intensive care units (ICUs). The aim of this study was to describe the epidemiology of methicillin-resistant Staphylococcus isolates in a cardiac surgical ICU over a 5-year period and to determine the risk factors and outcome of this condition.

METHODS

During the period from January 1998 to July 2003, the clinical data of all adult patients who underwent cardiac surgery in a university hospital were prospectively recorded in a database; the perioperative clinical variables and microbiologic data were studied by means of univariate and multivariate analysis in order to identify risk factors for the development of methicillin resistance and in-hospital death.

RESULTS

Methicillin-resistant Staphylococcus species strains were isolated in 118 of 6,423 patients operated on during the study period (7.6 cases per 1,000 days of ICU stay), with a constant prevalence rate throughout the years. Methicillin-resistant Staphylococcus species have been the most frequently isolated microorganisms in the authors' ICU; 75% of Staphylococcus aureus and 95% of coagulase-negative staphylococci were methicillin resistant. In-hospital mortality in methicillin-resistant Staphylococcus-positive patients was 50.0% (59/118), whereas it was 1.7% (108/6305) in other patients (p < 0.0001). On multivariate analysis, methicillin-resistant Staphylococcus species isolation was the single risk factor with the strongest association with in-hospital death (odds ratio, 8.5; 95% confidence interval 4.9-14.7). In the present series, there were no isolates of vancomycin-resistant species (Enterococcus species or Staphylococcus species).

CONCLUSIONS

Staphylococcus species represent the most frequently isolated microorganisms in the authors' ICU. In-hospital mortality in cardiac surgical patients is strongly correlated to the isolation of methicillin-resistant Staphylococcus.

Management of an outbreak of Enterobacter cloacae in a neonatal unit using simple preventive measures

Enterobacter cloacae is becoming an increasingly important nosocomial pathogen. Outbreaks of E. cloacae in intensive care units and burns units have been described frequently. In December 1999, a neonate with line sepsis was transferred from a university hospital to the neonatal unit of the Diakonessen Hospital. Blood culture yielded E. cloacae. An outbreak of E. cloacae was occurring in the university hospital at that time. In February 2000, a second neonate in our hospital developed line sepsis caused by E. cloacae. Direct measures taken included cohorting of infected children, disinfection of incubators, thermometers and wards, and screening patients. Of nine neonates, seven were colonized with E. cloacae. Despite these measures, the outbreak continued. Forty-one patients were screened; 15 were colonized. Environmental searches yielded E. cloacae in a sink and on two thermometers. Sixteen isolates were typed by arbitrarily primed PCR using four primers. All the patient isolates and the two isolates from thermometers were identical. The strain isolated from the sink was unrelated. Amplified fragment length polymorphism typing showed that the outbreak clone was identical to that in the university hospital. After the introduction of disposable thermometer covers, E. cloacae colonization slowly decreased.

Comparative efficacy of teicoplanin and cefazolin for cardiac operation prophylaxis in 3027 patients. The ESPRIT Group

OBJECTIVE

Cephalosporins, especially cefazolin, are widely used in the prevention of postoperative wound infections after cardiac operations. As more and more Staphylococcus aureus and Staphylococcus epidermidis strains are becoming resistant to cephalosporins and other antibiotics, alternative agents, such as glycopeptides, are often used as prophylaxis. We performed a multicenter double-blind randomized controlled trial comparing teicoplanin, a glycopeptide antibiotic, with cefazolin.

METHODS

A total of 3027 adult patients undergoing elective coronary artery bypass grafting, valve operations, or both were randomized to a single dose of teicoplanin (15 mg/kg) or a 2-day course of cefazolin (2 g initial dose, followed by 1 g every 8 hours for 6 more doses). Patients were followed up for a total of 6 months postoperatively. The primary objective was to compare, between groups, the incidence of surgical infections up to 30 days postoperatively. Secondary objectives were incidence of other infections, other complications, and death.

RESULTS

A total of 3027 patients were randomized to receive either teicoplanin (n = 1518) or cefazolin (n = 1509). Thirty days postoperatively, there was a trend to more deep sternotomy wound infections in the teicoplanin group (31 vs 18, P =. 087), which became significant by 6 months (36 vs 19, P =.032). One hundred percent of the gram-positive strains infecting patients were susceptible to teicoplanin, whereas 8.3% were resistant to cefazolin. Pneumonia and urinary tract infections were more common in the teicoplanin group. Deep wound infections of the leg were more common in the cefazolin group.

CONCLUSIONS

Cefazolin was more effective prophylaxis than teicoplanin against postoperative wound infections after elective cardiac operations. Infection rates were low with either treatment.

A three-year survey of nosocomial and community-acquired infections, antibiotic treatment and re-hospitalization in a Norwegian health region

In Norway, hospital-acquired infections (HAI) were analysed by repeated point prevalence studies (four each year) performed simultaneously at 14 hospitals in a health region (860,000 inhabitants) during the period 1996-1998. The study included 3200 beds and 121,000 discharged patients each year, and was initiated by and co-ordinated from the regional university hospital; Ullevål University Hospital (UHH). An overall prevalence rate of HAI of 6.5% (interhospital variation 1.4-11.7%) was found for the 32,248 patients studied. The rate of HAI was reduced from 7.7% in 1996 to 5. 9% in 1998. Smaller hospitals (<200 beds) generally had lower rates of HAI, community acquired infections (CAI), postoperative infections and use of antibacterial agents, than the large regional hospital (1200 beds). HAI was reduced in non-operated patients from 5.8% in 1996 to 4.4% in 1998 and in operated patients from 13.2% in 1996 to 10.5% in 1998. The risk of developing HAI was twice as high after surgery. From 1996 to 1998 there was a reduction in: urinary tract infections from 2.4% to 1.7%, lower respiratory tract infections from 1.5% to 0.8% and postoperative wound infections from 5.7% to 4.3%, while septicaemia (from 0.5% to 0.4%) remained unchanged. Re-hospitalization because of HAI was registered in 0.6% (interhospital variation 0.3-1.1%) of patients. The CAI rate in hospitals increased from 8.3% in 1996 to 10.8% in 1998. Approximately 16% (variation:14.4-20.6%) of the patients had an infection. The total use of antibacterial agents was 19.2% in 1996, 16.6% in 1997 and 17.8% in 1998 (variation: 14.9-23%).

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.

Biochemical profiles and serotypes of nosocomial Enterobacter cloacae strains in Northern Norway: biochemical identification problems with commercial test systems

During a period of 2 years, 118 strains of Enterobacter cloacae were collected consecutively in connection with nosocomial infections in Northern Norway; identified by conventional methods and by the API 20E system. The API 20E profile 3305573 predominated and was present in 73 of 118 strains. Among 96 serotyped strains, 73 were serotypable, 20 nontypable and two polyagglutinable. Predominating serotypes were 3 (29 strains), 8 (21 strains) and 23 (nine strains). When the API 20E profiles of the 118 strains were read in the new ATB (automated computer-assisted) 20E data base system, 97 of 118 (82.2%) strains were identified as E. cloacae. The 118 strains were tested in the new ATB Rapid ID 32E and ATB ID 32E (ATB system, bioMérieux, France) systems. Only 69 of 118 (58.5%) strains were identified as E. cloacae in both systems. The ATB Rapid ID 32E identified 97 of 118 strains (82.2%), and the ATB ID 32E only 80 of 118 strains (67.8%). Among 73 serotypable strains, the ATB Rapid ID 32E identified 79.5% as E. cloacae, while the ATB ID 32E identified only 64.4%. Among 40 serotypable strains with API 20E profile 3305573, all 40 were identified as E. cloacae by the ATB Rapid ID 32E, while only 27 (67.5%) by the ATB ID 32E system. Further improvements may increase the value of biochemical identification of E. cloacae in diagnostic work.

The effects of 'in-use' surgical handwashing on the pre- and postoperative fingertip flora during cardiothoracic and orthopaedic surgery

Two operating teams (25 persons) were followed for two months with fingerprint samples taken preoperatively; before and after 'in-use' surgical handwashing; and immediately postoperatively, with and without surgical gloves. The mean time for handwashing for the cardiothoracic team (CT) was 2 min and for the orthopaedic team (OT) was 3.5 min. A closer observation of 10 persons revealed a great individual variation in washing techniques, in spite of standard guidelines. The CT team performed eight, and the OT team nine sterile operations with an average duration of 3 h and 20 min and 2 h and 40 min, respectively. Surgical handwashing resulted in fingertip sterility in 111/118 (94.1%) cases; in 61/66 (92.4%) samples from the surgeons and in 50/52 (96.2%) samples from the assistants. Postoperative fingerprinting with gloves on showed sterile conditions in 85/91 (93.4%) samples; 57/59 (96.6%) from the surgeons and 28/32 (87.5%) from the assistants. Immediately after removal of the gloves, 43/67 (64.2%) of fingerprint samples from the surgeons and 13/48 (27.1%) from the assistants were still sterile. Coagulase-negative staphylococci (CNS) and Bacillus species predominated in fingerprint samples. Of the 105 CNS strains tested, 11.4% were methicillin resistant. Only five strains of Staphylococcus aureus were isolated; in 4/5 cases from the OT. This study illustrates that in spite of standard guidelines, there is great individual variation in surgical handwashing. However, in most instances, the bacteria are eradicated from the fingertips. Even after surgery for 2-3 h, there may still be a residual effect of the hand disinfecting agent in half of the cases.

Biotyping, phage typing, and O-serotyping of clinical isolates of Enterobacter cloacae

The purpose of this study was to make an independent evaluation of the methods of bio-, phage-, and O-serotyping which had been used only in the laboratory of origin, and to assess the extent of possible cross-infection of Enterobacter cloacae in a Danish university hospital. The material consisted of 237 clinical isolates of E. cloacae from the clinical microbiology laboratory at Hvidovre Hospital. The typability of bio-, phage-, and serotyping was 100%, 83%, and 85%, respectively. Reproducibility of serotyping was 90% and of phage typing 96% if two major differences were allowed to differentiate between patterns. O-serotyping had the highest discriminatory power and combination of all typing methods further increased discrimination. Outbreaks of E. cloacae were not evident in clinical departments, but cross-infections from one department to another could not be completely ruled out. We concluded that the combination of bio-, phage- and O-serotyping is sufficiently discriminating and will be satisfactory in the majority of clinical situations.

Enterobacter cloacae cross-colonization in neonates demonstrated by ribotyping

The intestinal colonization by Enterobacter cloacae strains with a derepressed cephalosporinase was studied in a paediatric ward between February 1990 and January 1991. Environmental sampling was performed simultaneously. Fifty-two isolates were recovered from 200 neonates (stool, blood) and 14 strains were isolated from the neonatal environment. An epidemiological study based on the typing of 36 Enterobacter cloacae isolates was carried out using antibiotyping, biotyping and ribotyping methods. The isolates selected were from 21 neonates (24 isolates), the neonatal ward environment (8 isolates) and from other wards (4 isolates). Thirty-two isolates had the same antibiotic resistance pattern, corresponding to a derepressed cephalosporinase and resistance to the following aminoglycosides: kanamycin, gentamicin, tobramycin and netilmicin. No predominant biotyping pattern could be established. Ribotyping done with two endonucleases (EcoRI and BamHI) showed 28 Enterobacter cloacae isolates to have a single pattern. Ribotyping was the most discriminating method used in this study, permitting identification of cross-contamination with Enterobacter cloacae in the paediatric ward.

Ribotyping of selected isolates of Enterobacter cloacae and clinical data related to biotype, phage type, O-serotype, and ribotype

In order to evaluate if ribotyping of selected isolates of Enterobacter cloacae could further elucidate the epidemiology, we performed ribotyping of 109 isolates indistinguishable by bio-, phage-, and O-serotyping, with inconclusive typing results, or from patients with more than one isolate. Ribotyping provided additional information, and some cases of cross-infection or common source of infection were revealed. Under the supposition that isolates sharing the same ribotype were of the same origin, problems arose with respect to bio-, O-sero, as well as phage typing; in particular a remarkable number of isolates showed differences in phage type. In order to identify possible virulence characteristics of certain types, clinical data were related to bio-, phage-, O-sero-, and ribotype. Biotype 66 was significantly more frequent among blood culture isolates (P = 0.001), but this might have reflected the presence of a certain strain in the environment of the intensive care unit, where patients were more likely to develop bacteraemia; serotype 04 was significantly more frequent among isolates from the urinary tract (P = 0.02), and serotype 013 was more frequent among women (P = 0.05). One ribotype was found only among community-acquired isolates, which might suggest that it is a frequent but less virulent strain.

Handwashing and disinfection of heavily contaminated hands—effective or ineffective?

Hands are among the principal vehicles for transfer of nosocomial pathogens in hospitals. Often, outbreaks of infection are thought to be caused by a lack of compliance with handwashing guidelines, rather than due to the inadequacy of the handwashing agents used. In this study the effectiveness of proper handwashing and the use of three different hand disinfectants: ethanol 70% (E), isopropanol 40% (I) and alcoholic chlorhexidine (70%) (AC) was compared using three volunteers whose fingertips were heavily contaminated with a succession of bacteria including: Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Enterobacter cloacae. After each contamination, thorough handwashing and application of one disinfectant on the hands were performed three times. Fingerprint-samples were taken before and 1 min after application of the disinfectants. Thorough handwashing with an ordinary liquid soap ('Sterisol') did not reduce the confluent growth of bacteria on fingertips for any of the species used (197 examinations). Only AC had a significant effect on fingers heavily contaminated with S. aureus (126 examinations; AC compared with E and I; P less than 0.0002 and P less than 0.0002 respectively), but did not completely eradicate the bacteria. After contamination with Ent. cloacae (118 examinations), none of the three agents were particularly effective, but E and AC seemed to be somewhat more effective than I (P less than 0.0002 and P less than 0.01 respectively). When successive contamination was performed using all bacterial species, AC was the most effective decontaminant. However, Ent. cloacae was still present on the fingertips after 15 repeated courses of handwashing and applications of disinfectants. Bathing of hands in AC for 20s completely eradicated all bacteria from the hands. The study demonstrates that, when heavily contaminated, an ordinary handwashing followed by disinfectants is not enough to eradicate potentially pathogenic bacteria from the hands.

Surgical wound infection

Wound infections remain a major source of postoperative morbidity, accounting for about a quarter of the total number of nosocomial infections. Today, many of these infections are first recognized in the outpatient clinic or in the patient's home due to the large number of operations done in the outpatient setting. This leads to errors in establishing the true incidence of their occurrence but undoubtedly decreases the overall real cost and length of hospital stay. The pathogens implicated in the development of wound infections remain largely the human microorganisms from the exogenous environment and the endogenous organ microflora. Many perioperative factors have been identified that increase the incidence of the development of postoperative wound infection. Avoidance of these factors as well as the appropriate use of perioperative antibiotic prophylaxis has decreased the incidence of wound infection. During the last decade many studies have reported on the individual risk factors that favor the development of postoperative infectious complications in various surgical procedures. It is hoped that this knowledge may allow for prospective alterations in the preventative and therapeutic modalities in the high-risk patient in the studies designed in the 1990s. The use of effective infection surveillance both in the hospital and in the outpatient setting is mandatory in order to collect meaningful data. The use of computer technology will greatly facilitate the proper surveillance, analysis, and control of infections in the surgical patient.