Incisional Surgical Site Infection in Kidney Transplantation

Surgical site infections after kidney transplantation are independently associated with graft loss

Surgical site infections (SSIs) are common health care-associated infections. SSIs after kidney transplantation (K-Tx) can endanger patient and allograft survival. Multicenter studies on this early posttransplant complication are scarce. We analyzed consecutive adult K-Tx recipients enrolled in the Swiss Transplant Cohort Study who received a K-Tx between May 2008 and September 2020. All data were prospectively collected with the exception of the categorization of SSI which was performed retrospectively according to the Centers for Disease Control and Prevention criteria. A total of 58 out of 3059 (1.9%) K-Tx recipients were affected by SSIs. Deep incisional (15, 25.9%) and organ/space infections (34, 58.6%) predominated. In the majority of SSIs (52, 89.6%), bacteria were detected, most frequently Escherichia coli (15, 28.9%), Enterococcus spp. (14, 26.9%), and coagulase-negative staphylococci (13, 25.0%). A BMI ≥25 kg/m2 (multivariable OR 2.16, 95% CI 1.07-4.34, P = .023) and delayed graft function (multivariable OR 2.88, 95% CI 1.56-5.34, P = .001) were independent risk factors for SSI. In Cox proportional hazard models, SSI was independently associated with graft loss (multivariable HR 3.75, 95% CI 1.35-10.38, P = .011). In conclusion, SSI was a rare complication after K-Tx. BMI ≥25 kg/m2 and delayed graft function were independent risk factors. SSIs were independently associated with graft loss.

Epidemiology of surgical site infections after solid organ transplants in the period 2015-2019: A single-center retrospective cohort study

Surgical site infections (SSI) are severe complications of solid organ transplant (SOT). This retrospective study assessed the epidemiology of and outcomes associated with invasive primary SSI (IP-SSI) occurring within 3 months of transplantation in adult SOT recipients at Duke University over a 5-year period (2015-2019). Among 2073 consecutive SOT recipients, 198 IP-SSI were identified. The IP-SSI rate declined over the period (14.4% in 2015 vs. 8.3% in 2019) and was higher among multi-organ compared with single-organ transplants (33.9% vs. 8.1%, p < .01). SOT recipients with IP-SSI had longer hospital stays than patients without SSI (30.0 vs. 17.0 days, p < .01). Transplant hospitalization (9.6% vs. 2.2%, p < .01), 6-month (11.6% vs. 3.3%, p < .01), and 1-year mortality (15.7% vs. 5.8%, p < .01) were higher in SOT recipients with IP-SSI than in those without. While Gram-positive bacteria were the most common pathogens, urogenital Mollicute and atypical Mycobacteria were identified as an unexpected cause of IP-SSI, particularly among lung transplant recipients. The median time to IP-SSI was 24.0 (IQR 13.8-48.3) days, although the time to IP-SSI varied based on organ transplanted and the causative pathogen. IP-SSI is an important and potentially modifiable complication of SOT, associated with prolonged hospitalizations and reduced survival, particularly in the lung transplant population.

Carbapenemase-producing Enterobacteriaceae in transplant patients

Carbapenemase-producing Enterobacteriaceae (CPE) are a serious public health concern and represent a major threat to immunocompromised hosts, including solid organ (SOT) and stem cell transplant (HSCT) recipients. Transplant patients are at particular risk of developing CPE colonization and/or infection due to their frequent exposure to prolonged courses of broad-spectrum antibiotics, altered immunocompetence and exposure to invasive procedures and immunosuppressive drugs. Gut colonization with CPE, in particular carbapenem-resistant Klebsiella pneumoniae, may occur before or after SOT in 2%-27% of patients and among 2%-9% of HSCT and has been associated with increased risk of developing CPE infections. In endemic areas, CPE infections occur in up to 18% of SOT, and HSCT patients can account for 5%-18% of all patients with CPE bacteraemia. Mortality rates up to 70% have been associated with CPE infections in both patient populations. The rapid initiation of an active therapy against CPE is advocated in these infections. Therapeutic options, however, are limited by the paucity of novel compounds that are currently available and by potential antibiotic-associated toxicities. Therefore, a multidisciplinary approach involving infection control and antimicrobial stewardship programmes still represents the mainstay for the management of CPE infections among transplant patients. The evidence for the use of prevention strategies such as CPE-targeted perioperative prophylaxis or gut decolonization is still scarce. Large, multicentre trials are required to better define prevention strategies and to guide the management of CPE infections in the transplant setting.

Evidence to support a drain-free strategy in kidney transplantation using a retrospective comparison of 500 consecutively transplanted cases at a single center

Introduction

Routine placement of surgical drains at the time of kidney transplant has been debated in terms of its prognostic value.

Objectives

To determine whether the placement of a surgical drain affects the incidence rate of developing wound complications and other clinical outcomes, particularly after controlling for other prognostic factors.

Methods

Retrospective analysis of 500 consecutive renal transplant cases who did not (Drain-free, DF) vs. did (Drain, D) receive a drain at the time of transplant was performed. The primary outcome was the development of any wound complication (superficial or deep) during the first 12 months post-transplant. Secondary outcomes included the development of superficial wound complications, deep wound complications, DGF, and graft loss during the first 12 months post-transplant.

Results

388 and 112 recipients had DF/D, respectively. DF-recipients were significantly more likely to be younger, not have pre-transplant diabetes, receive a living donor kidney, receive a kidney-alone transplant, have a shorter duration of dialysis, shorter mean cold-ischemia-time, and greater pre-transplant use of anticoagulants/antiplatelets. Wound complications were 4.6% (18/388) vs. 5.4% (6/112) in DF vs. D groups, respectively (P = 0.75). Superficial wound complications were observed in 0.8% (3/388) vs. 0.0% (0/112) in DF vs. D groups, respectively (P = 0.35). Deep wound complications were observed in 4.1% (16/388) vs. 5.4% ((6/112) in DF vs. D groups, respectively (P = 0.57). Higher recipient body mass index and ≥ 1 year of pre-transplant dialysis were associated in multivariable analysis with an increased incidence of wound complications. Once the prognostic influence of these 2 factors were controlled, there was still no notable effect of drain use (yes/no). The lack of prognostic effect of drain use was similarly observed for the other clinical outcomes.

Conclusions

In a relatively large cohort of renal transplant recipients, routine surgical drain use appears to offer no distinct prognostic advantage.

Effect of subcutaneous tissue depth on outcomes of kidney transplantation

Although post-kidney transplant (KT) wound complications are associated with elevated body mass index (BMI), BMI is not an accurate surrogate of obesity. On the other hand, subcutaneous depth (SQD) measurement is a direct marker of truncal obesity. We examined outcomes of differing intraoperative SQD measurements in 113 KT-only recipients over 20 months. Recipients' median age was 51 years; median BMI, 28 kg/m²; and mean SQD, 2.9 cm. Patients were stratified into groups of SQD ≤2.5 cm, >2.5-5 cm, and >5 cm. An SQD of >2.5 to 5 cm correlated with a BMI of 30 kg/m² (obesity) and an SQD >5 cm correlated with a BMI >35 kg/m² (severe obesity). Degree of SQD was not associated with more frequent technical complications such as fascial dehiscence, lymphocele formation, renal artery thrombosis/stenosis, urine leak, or ureteral stenosis. However, an SQD >2.5 cm was a risk factor for requiring a wound vacuum-assisted closure device. There was no difference in graft or patient survival among the three SQD groups. Obesity, as measured directly by SQD, was not associated with increased technical complications or poor outcomes after KT. As expected, there was a higher incidence of wound complications in the higher SQD groups requiring intervention.

Prophylactic Wound Drainage in Renal Transplantation: A Systematic Review

Background

Adult kidney transplantation is most commonly into an extraperitoneal potential space, and surgically placed drains are used routinely in many centers. There is limited evidence of clinical benefit for prophylactic drainage in other major abdominal and vascular surgery. Transplantation is, however, a unique setting combining organ dysfunction and immunosuppression, and the risks and benefits of prophylactic drain placement are not known. This study attempts to examine existing literature to determine whether prophylactic intraoperative drains have an impact on the likelihood of perigraft fluid collections and other wound-related complications following kidney transplantation.

Methods

A literature search of MEDLINE and EMBASE was conducted to identify published comparative studies, including recipients receiving prophylactic drains to recipients in whom drains were omitted. The main outcomes were the incidence of peritransplant fluid collections and wound-related complications. Meta-analysis was performed on these data.

Results

Four retrospective cohort studies were deemed eligible for quantitative analysis and 1 additional conference abstract was included in qualitative discussion. A total of 1640 patients, 1023 with drains and 617 without, were included in the meta-analysis. There was a lower rate of peritransplant collections associated with the drain group (RR 0.62; 95% confidence interval, 0.42-0.90). There was no significant difference in the incidence of wound-related complications between the groups (RR 0.85; 95% confidence interval, 0.34-2.11).

Conclusions

These data associate a higher rate of peritransplant fluid collections with omission of prophylactic drainage, without a difference in the incidence of wound-related complications. Further research is required to definitively determine the impact of drains in this patient group.

Intra-abdominal infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

This new guideline from the AST IDCOP reviews intra-abdominal infections (IAIs), which cause substantial morbidity and mortality among abdominal SOT recipients. Each transplant type carries unique risks for IAI, though peritonitis occurs in all abdominal transplant recipients. Biliary infections, bilomas, and intra-abdominal and intrahepatic abscesses are common after liver transplantation and are associated with the type of biliary anastomosis, the presence of vascular thrombosis or ischemia, and biliary leaks or strictures. IAIs after kidney transplantation include renal and perinephric abscesses and graft-site candidiasis, which is uncommon but may require allograft nephrectomy. Among pancreas transplant recipients, duodenal anastomotic leaks can have catastrophic consequences, and polymicrobial abscesses can lead to graft loss and death. Intestinal transplant recipients are at the highest risk for sepsis, infection due to multidrug-resistant organisms, and death from IAI, as the transplanted intestine is a contaminated, highly immunological, pathogen-rich organ. Source control and antibiotics are the cornerstone of the management of IAIs. Empiric antimicrobial regimens should be tailored to local susceptibility patterns and pathogens with which the patient is known to be colonized, with subsequent optimization once the results of cultures are reported.

Infection in Kidney Transplantation

Infection is an important cause of morbidity and mortality after kidney transplantation. It has been estimated that 70% of kidney transplant recipients will experience an infection episode within the first 3 years after transplantation (Dharnidharka et al. 2007). After cardiovascular disease, infection is the second leading cause of death in recipients with allograft function (Snyder et al. 2009). The immunosuppressive therapy required to prevent organ rejection places the kidney transplant recipient at increased risk for donor-derived, nosocomial, and community-acquired infections as well as reactivation of latent pathogens. Pretransplant screening, immunizations, and optimal antibacterial and antiviral prophylaxis can help to reduce the impact of infection. Awareness of the approach to infection in the transplant recipient including diagnostic and management strategies is essential to optimizing outcomes.

Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate's phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.

Minimally Invasive, Laparoscopic, and Robotic-assisted Techniques Versus Open Techniques for Kidney Transplant Recipients: A Systematic Review

CONTEXT

Literature on conventional and minimally invasive operative techniques has not been systematically reviewed for kidney transplant recipients.

OBJECTIVE

To systematically evaluate, summarize, and review evidence supporting operating technique and postoperative outcome for kidney transplant recipients.

EVIDENCE ACQUISITION

A systematic review was conducted in PubMed-Medline, Embase, and Cochrane Library between 1966 up to September 1, 2016, according to Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. Articles were included and scored by two independent reviewers using Group Reading Assessment and Diagnostic Evaluation (GRADE), Newcastle-Ottawa Quality Assessment Scale (NOS), and Oxford guidelines for level of evidence. Main outcomes were graft survival, surgical site infection, incisional hernia, and cosmetic result. In total, 18 out of 1954 identified publications were included in this analysis.

EVIDENCE SYNTHESIS

Included reports described conventional open, minimally invasive open, laparoscopic, and robotic-assisted techniques. General level of evidence of included studies was low (GRADE: 1-3; NOS: 0-4; and Oxford level of evidence: 4-2). No differences in graft or patient survival were found. For open techniques, Gibson incision showed better results than the hockey-stick incision for incisional hernia (4% vs 16%), abdominal wall relaxation (8% vs 24%), and cosmesis. Minimally invasive operative recipient techniques showed lowest surgical site infection (range 0-8%) and incisional hernia rates (range 0-6%) with improved cosmetic result and postoperative recovery. Disadvantages included prolonged cold ischemia time, warm ischemia time, and total operation time.

CONCLUSIONS

Although the level of evidence was generally low, minimally invasive techniques showed promising results with regard to complications and recovery, and could be considered for use. For open surgery, the smallest possible Gibson incision appeared to yield favorable results.

PATIENT SUMMARY

In this paper, the available evidence for minimally invasive operation techniques for kidney transplantation was reviewed. The quality of the reviewed research was generally low but suggested possible advantages for minimally invasive, laparoscopic, and robot-assisted techniques.

Impact of an Infection Control and Antimicrobial Stewardship Program on Solid Organ Transplantation and Hepatobiliary Surgical Site Infections

OBJECTIVE

The goal of this long-term quasi-experimental retrospective study was to assess the impact of a 5-year serial infection control and antimicrobial stewardship intervention on surgical site infections (SSIs).

METHODS

This study was conducted in a tertiary-care public teaching institution over a 5-year period from January 2010 to December 2014. All patients undergoing hepatobiliary surgery and liver, kidney, pancreas, and simultaneous pancreas–kidney transplantation were included. Outcomes were compared between a preintervention group (2010–2011) and a postintervention group (2012–2014).

RESULTS

A total of 1,424 procedures averaged an overall SSI rate of 11.2%. After implementation of the interventions, a decrease of 52.8% in SSI rates from 17.4% to 8.2% was observed (P<.001; odds ratio [OR], 2.1; 95% confidence interval [CI], 1.5–2.9). An overall significant decrease >50% (relative rate; P<.001) was observed in superficial incisional and organ-space infections between pre- and postintervention groups. In addition, a 54.9% decrease from 19.7% to 8.9% (P<.001; OR, 2.2; 95% CI, 1.4–3.5) and a 51.6% decrease from 15.5% to 7.5% (P=.001; OR, 2.2; 95% CI, 1.4–3.5) were observed for SSI rates in hepatobiliary surgery and solid organ transplantation, respectively. The antimicrobial stewardship intervention increased overall conformity to the internal surgical prophylaxis protocol by 15.2% (absolute rate) from 45.1% to 60.3% (P<.003; 95% CI, 5.4–24.9).

CONCLUSIONS

A long-term serial infection control and antimicrobial stewardship intervention decreased SSIs among patients undergoing hepatobiliary surgery and liver, kidney, pancreas, and simultaneous pancreas–kidney transplantation.

Infect Control Hosp Epidemiol 2016;1468–1474

The Distribution and Resistance of Pathogens Among Solid Organ Transplant Recipients with Pseudomonas aeruginosa Infections

Background

Pseudomonas aeruginosa infection remains a life-threatening complication after solid organ transplantation (SOT). We aimed to investigate the distribution and drug susceptibility of pathogens, and clinical characteristics of SOT recipients with Pseudomonas aeruginosa infections.

Material/Methods

A total of 55 SOT recipients who developed 61 episodes of Pseudomonas aeruginosa infections between January 1, 2003 and July 31, 2015 were retrospectively analyzed. The distribution and the drug susceptibility of Pseudomonas aeruginosa were reviewed.

Results

The most common site from which 61 Pseudomonas aeruginosa rods were isolated were the lungs (57.4%, n=37), followed by the blood (27.9%, n=17). There were 35, 18, and 9 recipients accompanied with a serum creatinine level of >1.5 mg/dL, lymphocyte count of <300/mm³, and a serum albumin level of <30 g/L, respectively. Seven patients each presented with white blood cell count of >15 000/mm³ and platelet count of <50 000/mm³. There were 6 (10.9%) cases of septic shocks and 18 (32.7%) deaths. Antibiotic resistance rate of all Pseudomonas aeruginosa to 4 of 10 antibiotics investigated was more than 50%. Of these 61 Pseudomonas aeruginosa isolates, 47.5% were carbapenem-resistant. The rods were relatively sensitive to piperacillin-tazobactam, levofloxacin, amikacin, and cefoperazone-sulbactam (resistance rate <40%).

Conclusions

The clinical presentation of Pseudomonas aeruginosa infections included high body temperature, decreased platelet count, elevated white blood cell count, a high nosocomial origin and mortality, and onset in the late period after transplantation. According to our findings, piperacillin-tazobactam, levofloxacin, amikacin, and cefoperazone-sulbactam, alone or combination, are recommended to treat SOT recipients with Pseudomonas aeruginosa infections.

Surgical site infection after renal transplantation

OBJECTIVE

To identify factors associated with the development of surgical site infection (SSI) among adult patients undergoing renal transplantation

DESIGN

A retrospective cohort study.

SETTING

An urban tertiary care center in Baltimore, Maryland, with a well-established renal transplantation program that performs ~200-250 renal transplant procedures annually.

RESULTS

At total of 441 adult patients underwent renal transplantation between January 1, 2010, and December 31, 2011. Of these 441 patients, 66 (15%) developed an SSI; of these 66, 31 (47%) were superficial incisional infections and 35 (53%) were deep-incisional or organ-space infections. The average body mass index (BMI) among this patient cohort was 29.7; 84 (42%) were obese (BMI >30). Patients who developed an SSI had a greater mean BMI (31.7 vs 29.4; P=.004) and were more likely to have a history of peripheral vascular disease, rheumatologic disease, and narcotic abuse. History of cerebral vascular disease was protective. Multivariate analysis showed BMI (odds ratio [OR] 1.06; 95% confidence interval [CI], 1.02-1.11) and past history of narcotic use/abuse (OR, 4.86; 95% CI, 1.24-19.12) to be significantly associated with development of SSI after controlling for National Healthcare Surveillance Network (NHSN) score and presence of cerebrovascular, peripheral vascular, and rheumatologic disease.

CONCLUSIONS

We identified higher BMI as a risk factor for the development of SSI following renal transplantation. Notably, neither aggregate comorbidity scores nor NHSN risk index were associated with SSI in this population. Additional risk adjustment measures and research in this area are needed to compare SSIs across transplant centers.

Bacterial and fungal infections in the early post-transplant period after kidney transplantation: etiological agents and their susceptibility

BACKGROUND

Infections remain serious complications in solid-organ transplant recipients, despite professional medical care, the introduction of new immunosuppressive drugs, and treatment that decreases the risk of infections.

METHODS

The study covered 295 adult patients undergoing kidney transplantation (KTx) between September 2001 and December 2007. All the patients were followed prospectively for infections from the KTx date and during the first 4 weeks after surgery. Samples of clinical materials were investigated for microbiological cultures. The microorganisms were cultured and identified in accordance with standard bacteriological procedures. Susceptibility testing was carried out through the use of Clinical and Laboratory Standards Institute procedures.

RESULTS

From 295 KTx recipients, 1073 clinical samples were taken for microbiological examination. Positive cultures were 26.9% (n = 289) of all samples tested; 525 strains were collected. Gram-positive bacteria were isolated in 52.2% (n = 274), Gram-negative bacteria were isolated in 40.8% (n = 214), and fungal strains were isolated in 7% (n = 37). Urine specimens (n = 582) were obtained from 84.5% of 245 recipients during the first month after transplantation. Among the isolated bacterial strains (n = 291), the most common were Gram-negative bacteria (56.4%). Gram-positive bacteria comprised 35.7%; fungal strains were found in 23 cases (7.9%). In surgical site specimens (n = 309), Gram-positive bacteria (72.1%) were the most common. Gram-negative bacteria comprised 24.4%. In blood specimens (n = 138), Gram-positive bacteria (81.6%) were the most common. Gram-negative bacteria comprised 15.8%; fungi were isolated in 2.6%. In respiratory tract specimens (n = 13), among the isolated bacterial strains (n = 8), the most common were Gram-positive bacteria (57.1%). Gram-negative bacteria comprised 14.3%; fungi were isolated in 28.6%.

CONCLUSIONS

Urine samples were predominantly positive after KTx. Our study showed Gram-positive bacteria in 52.2% after kidney transplantation. The proportion of isolates of multi-drug-resistant bacterial strains (MRCNS, vancomycin-resistant strains, high-level aminoglycoside-resistant strains, extended-spectrum beta-lactamase producers, and high-level aminoglycoside-resistant strains) was increased. These data indicate the need for strict adherence to infection control procedures in these patients.

Surgical site and early urinary tract infections in 1000 kidney transplants with antimicrobial perioperative prophylaxis

Surgical site infections (SSIs) and early urinary tract infections (UTIs) are well recognized postoperative kidney transplant complications. These complications seldom lead to graft loss, although they may result in significant morbidity with prolonged hospitalization. Thus, perioperative antibiotic prophylaxis (PAP) has traditionally been used in this setting. Between April 1988 and December 2012, we identified 1000 kidney transplant recipients (33 from living donors) who underwent prophylaxis with ceftriaxone before the surgical procedure. A retrospective analysis was conducted to evaluate both the incidence rate and outcome of SSIs and UTIs. Recipients who developed SSIs were also assessed to identify risk factors and potential correlations with different immunosuppressive regimens. A total of 20 SSIs (2%) and 93 UTIs (9.3%) were observed. The most significant risk factor for SSIs was urine leak (15.38%; odds ratio [OR], 12.3; P < .0001) followed by sirolimus-based maintenance immunosuppression therapy (5%; OR, 2.97; P = .04) and induction therapy with either antithymocyte globulin or basiliximab (3.18%; OR, 3.45; P = .01). Sex was identified as the only risk factor for UTI (female vs male, 17.1% vs 4.6%; P < .0001). We believe universal ceftriaxone-based prophylaxis is useful for preventing SSIs and UTIs, considering its effectiveness and safety profile.

Amikacin prophylaxis and risk factors for surgical site infection after kidney transplantation

BACKGROUND

Antibiotic prophylaxis plays a major role in preventing surgical site infections (SSIs). This study aimed to evaluate antibiotic prophylaxis in kidney transplantation and identify risk factors for SSIs.

METHODS

We evaluated all kidney transplantation recipients from January 2009 and December 2012. We excluded patients who died within the first 72 hr after transplantation, were undergoing simultaneous transplantation of another organ, or were below 12 years of age. The main outcome measure was SSI during the first 60 days after transplantation.

RESULTS

A total of 819 kidney transplants recipients were evaluated, 65% of whom received a deceased-donor kidney. The antibiotics used as prophylaxis included cephalosporin, in 576 (70%) cases, and amikacin, in 233 (28%). We identified SSIs in 106 cases (13%), the causative agent being identified in 72 (68%). Among the isolated bacteria, infections caused by extended-spectrum β-lactamase-producing Enterobacteriaceae predominated. Multivariate analysis revealed that the risk factors for post-kidney transplantation SSIs were deceased donor, thin ureters at kidney transplantation, antithymocyte globulin induction therapy, blood transfusion at the transplantation procedure, high body mass index, and diabetes mellitus. The only factor associated with a reduction in the incidence of SSIs was amikacin use as antibiotic prophylaxis. Factors associated with reduced graft survival were: intraoperative blood transfusions, reoperation, human leukocyte antigen mismatch, use of nonstandard immunosuppression therapy, deceased donor, post-kidney transplantation SSIs, and delayed graft function.

CONCLUSION

Amikacin prophylaxis is a useful strategy for preventing SSIs.

[Nosocomial infection in patients receiving a solid organ transplant or haematopoietic stem cell transplant]

Bacterial infections are the most common infections in solid organ transplant recipients. These infections occur mainly in the first month after transplantation and are hospital-acquired. Nosocomial infections cause significant morbidity and are the most common cause of mortality in this early period of transplantation. These infections are caused by multi-drug resistant (MDR) microorganisms, mainly Gram-negative enterobacteria, non-fermentative Gram-negative bacilli, enterococci, and staphylococci. The patients at risk of developing nosocomial bacterial infections are those previously colonized with MDR bacteria while on the transplant waiting list. Intravascular catheters, the urinary tract, the lungs, and surgical wounds are the most frequent sources of infection. Preventive measures are the same as those applied in non-immunocompromised, hospitalized patients except in patients at high risk for developing fungal infection. These patients need antifungal therapy during their hospitalization, and for preventing some bacterial infections in the early transplant period, patients need vaccinations on the waiting list according to the current recommendations. Although morbidity and mortality related to infectious diseases have decreased during the last few years in haematopoietic stem cell transplant recipients, they are still one of the most important complications in this population. Furthermore, as occurs in the general population, the incidence of nosocomial infections has increased during the different phases of transplantation. It is difficult to establish general preventive measures in these patients, as there are many risk factors conditioning these infections. Firstly, they undergo multiple antibiotic treatments and interventions; secondly, there is a wide variability in the degree of neutropenia and immunosuppression among patients, and finally they combine hospital and home stay during the transplant process. However, some simple measures could be implemented to improve the current situation.

Surgical site infections after kidney transplantation--where do we stand now?

BACKGROUND

Kidney transplantation (KTx) is a widely accepted method of renal function replacement therapy. Surgical site infections (SSIs), along with urinary tract infections, are among the most common infective complications after KTx. The purpose of this study was to assess the incidence of SSI in patients after KTx, identify risk factors for SSI, and classify patients in which standard antibiotic prophylaxis could be avoided.

METHODS

Between January 2010 and December 2011, 262 KTxs were performed in our center. Deceased donors', recipients' data, and data related to surgical procedures were collected. SSIs were diagnosed in accordance with the guidelines published by the U.S. Centers for Disease Control and Prevention.

RESULTS

SSIs were diagnosed in 7.25% (19/262) of patients. Of nineteen SSI patients, two (10.5%) were diagnosed with organ-specific SSIs, which eventually led to graft loss; six (31.5%) developed deep incisional SSIs; and eleven (58%) developed superficial incisional SSIs. Through analysis of this extensive data set, we determined the following risk factors for the development of SSI: kidney from extended criteria donors, a cold ischemia time of more than 30 hr, time of surgical procedure longer than 200 min, confirmed diabetes in the recipients, a recipient body mass index higher than 27 kg/m, and occurrence of delayed graft function.

CONCLUSIONS

It may be possible to reduce standard antibiotic prophylaxis to a single dose in patients without known risk factors for SSI. Any opportunity to reduce antibiotic use is crucial in preventing the development of multi-drug-resistant pathogens.

Design and methodology of the Swiss Transplant Cohort Study (STCS): a comprehensive prospective nationwide long-term follow-up cohort

In Switzerland, organ procurement is well organized at the national-level but transplant outcomes have not been systematically monitored so far. Therefore, a novel project, the Swiss Transplant Cohort Study (STCS), was established. The STCS is a prospective multicentre study, designed as a dynamic cohort, which enrolls all solid organ recipients at the national level. The features of the STCS are a flexible patient-case system that allows capturing all transplant scenarios and collection of patient-specific and allograft-specific data. Beyond comprehensive clinical data, specific focus is directed at psychosocial and behavioral factors, infectious disease development, and bio-banking. Between May 2008 and end of 2011, the six Swiss transplant centers recruited 1,677 patients involving 1,721 transplantations, and a total of 1,800 organs implanted in 15 different transplantation scenarios. 10 % of all patients underwent re-transplantation and 3% had a second transplantation, either in the past or during follow-up. 34% of all kidney allografts originated from living donation. Until the end of 2011 we observed 4,385 infection episodes in our patient population. The STCS showed operative capabilities to collect high-quality data and to adequately reflect the complexity of the post-transplantation process. The STCS represents a promising novel project for comparative effectiveness research in transplantation medicine.

Multidrug-resistant bacterial infection in solid organ transplant recipients

The most frequent complication from infection after solid organ transplantation is bacterial infection. This complication is more frequent in organ transplantation involving the abdominal cavity, such as liver or pancreas transplantation, and less frequent in heart transplant recipients. The sources, clinical characteristics, antibiotic resistance and clinical outcomes vary according to the time of onset after transplantation. Most bacterial infections during the first month post-transplantation are hospital acquired, and there is usually a high incidence of multidrug-resistant bacterial infections. The higher incidence of complications from bacterial infection in the first month post-transplantation may be associated with high morbidity. Of special interest due to their frequency are infections by S. aureus, enterococci, Gram-negative enteric and non-fermentative bacilli. Opportunistic bacterial infections may occur at any time on the posttransplant timeline, but are more frequent between months two and six, the period in which immunosuppression is higher. The most frequent bacterial species causing opportunistic infections in organ transplant recipients are Listeria monocytogenes and Nocardia spp. After month six, posttransplantation solid organ transplant patients usually develop conventional community-acquired bacterial infections, especially urinary tract infections by E. coli and S. pneumoniae pneumonia. In this article we review the clinical characteristics, epidemiology, diagnosis and prognosis of bacterial infections in solid organ transplant patients.

Postoperative infection rates in foot and ankle surgery: a comparison of patients with and without diabetes mellitus

BACKGROUND

Patients with diabetes mellitus may be at increased risk for infection following foot and ankle surgery. This study aimed to determine whether patients with a diagnosis of diabetes mellitus have an increased rate of infection following foot and ankle surgery compared with a cohort of patients without diabetes. Furthermore, our study sought to demonstrate whether patients with complicated diabetes are at greater risk of postoperative wound infection than are patients with uncomplicated diabetes or patients without diabetes.

METHODS

We conducted a retrospective review of the charts of 1000 patients who had orthopaedic foot and ankle surgery. The following data were extracted: patient age, sex, history of diabetes mellitus, development of postoperative infection, severity of infection, inpatient or outpatient surgery, use of internal or external fixation, tobacco use, history of organ transplantation, history of rheumatoid arthritis, length of surgery, follow-up time in weeks, and comorbid conditions.

RESULTS

The overall infection rate in this study was 4.8%. Fifty-two percent of all infections occurred in our diabetic study group, which represented only 19% of the patient population. Postoperative infections occurred in significantly more persons with diabetes (13.2%) than in those without diabetes (2.8%). Diabetic patients were five times more likely to experience a severe infection requiring hospitalization compared with patients without diabetes. After removing the patients with neuropathy from the analysis, there was no longer a significant association between diabetes and infection. The presence of complicated diabetes increased the risk of postoperative infection by a factor of ten compared with the risk for patients without diabetes and by a factor of six compared with the risk for patients with uncomplicated diabetes. We did not identify a significantly increased risk of infection in patients with uncomplicated diabetes compared with that in patients without diabetes.

CONCLUSIONS

Patients with diabetes mellitus are at increased risk of severe infection compared with those without diabetes. Patients with uncomplicated diabetes did not have an increased risk of postoperative infection compared with patients without diabetes, whereas patients with complicated diabetes had a significantly higher rate of postoperative infection.

Prevalence of urogenital mycoplasmas and ureaplasmas in women after kidney transplantation

BACKGROUND

The prevalence of urogenital mycoplasmas and ureaplasmas in kidney transplant and hemodialyzed patients was studied.

METHODS

Vaginal and cervical swabs taken from 40 women of the study group and 40 women of the control group were investigated. Identification of ureaplasmas, Mycoplasma genitalium, and human papillomavirus was performed by polymerase chain reaction. Each vaginal slide was evaluated for bacterial vaginosis.

RESULTS

Urogenital mycoplasmas and ureaplasmas were significantly more common in patients from the study group (40%) compared with the control group (27.5%). Mycoplasma hominis and M. genitalium were demonstrated only in a few cases. Ureaplasma parvum was isolated predominantly, but Ureaplasma urealyticum was more common in patients from study group (10%) compared with control group (2.5%). In all U. urealyticum-positive women from the study group, human papillomavirus DNA was detected.

CONCLUSION

Our observation showed the necessity of careful examination of possible atypical pathogens in diagnostic materials from hemodialyzed and kidney transplant patients.