healthcare - associated infections ( hais ) are those infections in patients receiving medical treatment in a healthcare facility .
hais include hospital - acquired infections and some patients receiving healthcare treatment on an outpatient basis .
these 2 types of infections have different microbiological patterns and report higher resistance rates than community - acquired infections . finally , a worrisome aspect is the increasing isolation of enterobacteriaceae producing extended - spectrum beta - lactamases ( esbl ) and others multidrug - resistant microorganisms .
patients hospitalized in a urology ward showed a higher prevalence of urinary catheterization in comparison with those in other department and urologic surgery is performed in most of them .
therefore , infections in patients hospitalized in a urology ward may show specif ic characteristics regarding type of infections , microbiological patterns , and resistance rates .
our purpose was to analyze the incidence , risk factors and characteristics of hais in patients hospitalized in a urology ward .
we carried out a prospective observational study for four years ( 2012 to 2015 ) to review hais .
the database included comorbidities , risk factors and microbiological characteristics of all patients admitted in the urology ward .
our objectives were stated at the beginning of the study and the research was initiated in 2012 .
the study excludes patients younger than 16 years old and those admitted for a renal transplantation because they are hospitalized in the pediatric and nephrology ward , respectively .
the study analyzed the incidence , type and risk factors for hais , the microbiological characteristics and resistance to antibiotics .
we used the definition of hais according to friedman criteria as an infection that occurs 48 hours after hospital admission and those in patients receiving dialysis , chemotherapy , outpatient intravenous therapy , resided in a long - term care facility or , hospitalized in the preceding 90 days .
both hais and hospital - associated infections differ to community - associated infections in term of microbiological data and susceptibility to antibiotics .
we also included in our study patients admitted from emergency with an infection related to a previous hospitalization in urology .
patients with negative or contaminated cultures were considered as hais if there were symptoms compatible with infection such as fever , dysuria , lumbar or suprapubic tenderness for urinary infections . surgical site infections ( ssi )
were defined as those infections that occurred after surgery in the place where the surgery took place and included superficial incisional , deep incisional or organ space ssi according to ccd criteria . pathogen identification and antimicrobial susceptibility testing
antibiotic prophylaxis was routinely used before surgical procedure according to a protocol approved by our center . in brief
, we used cephalosporins in the induction of anesthesia before open , laparoscopic or endourologic clean - contaminated surgery in the urinary tract such as transurethral resections and prostatectomies . in patients with an indwelling urinary catheter or risk factors , we recommended perioperative treatment for one day .
when the surgery required bowel management , we used gentamicin and vancomycin . in case implantation of prosthetic devices such as artificial urinary sphincter or penile prosthesis , we recommend antibiotic treatment during at least 3 days .
we collected demographic characteristic and risk factors for infections such as age , sex , hypertension , diabetes mellitus , heart disease , liver disease and immunosuppression and american society of anesthesiologists ( asa ) physical status classification .
we also reviewed urological factors such as prior urinary infection , urinary catheterization , and surgery during the hospitalization .
the research was a prospective investigation , and it does not affect the daily management . therefore , informed consent was not required
the study was approved by the ethic committee of instituto de investigacin hospital 12 de octubre .
the association between demographic variables and risk factors for hais was assessed using chi - square test or fisher exact test for qualitative variables .
continuous variables were compared using the student t - test or analysis of variance with bonferroni as a posthoc test .
a multivariable analysis using a binary logistic regression was performed to analyze factors associated with a higher risk of hais , including those variables with a p - value less than 0.05 in the univariate analysis .
the results are shown as odds ratio ( or ) and 95% confidence intervals ( 95% ci ) .
among 6,546 patients hospitalized in our urology ward , 415 ( 6.3% ) reported some type hai . the incidence of hais decreased from 7.3%6.5% in 20122014 to 4.8% in 2015 .
the percentage of urinary infections among hais increased from 66% in 2012 and 2013 to 80% and 71.2% in 2014 and 2015 , respectively .
conversely , ssi decreased from 30 and 24% in 2012 and 2013 to 14.2% and 18% in 2014 and 2015 .
four hundered twenty - eight hais were reported in 415 patients , more than one type of hais was more commonly found after cystectomy ( the evolution of each type of hais over the time is summarized in table 2 ) .
the univariate analysis showed that higher incidence of infections among patients with older age ( or , 1.01 ; 95% ci , 1.0041.016 ; p=0.001 ) , asa physical status classification iii 
iv ( or , 1.45 ; 95% ci , 1.251.69 ; p<0.001 ) , arterial hypertension ( or , 1.26 ; 95% ci , 1.031.54 ; p=0.020 ) , immunosuppression ( or , 2.08 ; 95% ci , 1.443.00 ; p<0.001 ) , previous urinary infection ( or , 3.44 ; 95% ci , 2.325.12 ; p<0.001 ) , and indwelling urinary catheter before admission ( or , 2.31 ; 95% ci , 1.872.86 ; p<0.001 ) or during the hospitalization period ( or , 1.62 ; 95% ci , 1.252.10 ; p<0.001 ) .
multivariate logistic regression analysis showed that higher asa physical status classification ( or , 1.39 ; 95% ci , 1.151.67 ; p<0.001 ) , immunosuppression ( or , 1.80 ; 95% ci , 1.132.88 ; p=0.013 ) , prior urinary tract infection ( or , 4.465 ; 95% ci , 2.328.57 ; p<0,001 ) , and indwelling urinary catheter prior admission ( or , 1.74 ; 95% ci , 1.322.30 ; p<0.001 ) were independent risk factors for hais ( table 3 ) .
a surgical procedure was performed in 4,952 ( 75.6% ) of patients . among them , the incidence of hais was 4% ( 110 out of 2,737 ) after transurethral surgery , 7.4% ( 23/312 ) after open prostatic surgery , 8.7% ( 33/318 ) renal surgery and 54.2% ( 39/72 ) following radical cystectomy .
the highest incidence of hais after cystectomy was reported in 2012 and 2013 ( 78.6%68.7% ) in comparison with 50%31.8% in 20142015 .
the most commonly isolated pathogens were escherichia coli ( 25.1% ) , followed by species of enterococcus ( 17.5% ) , klebsiella ( 13.5% ) and pseudomonas ( 12.3% ) .
staphylococcus aureus and candida were isolated in a 6.7% and 5.6% of positive cultures , respectively ( fig .
the isolation of klebsiella spp . increased over the time , representing 17% of positive cultures in 2015 .
were the most frequently isolated microorganism in patients with diabetes mellitus , liver disease , immunosuppression and prior urinary infection . in patients with ssi following abdominal or renal surgery ,
e. coli showed resistance rates of 34.9% for amoxicillin+betalactamase inhibitor , 53.5% for fluoroquinolones , 9.3% for amikacin .
. showed resistance rates of 39.3% for third generation cephalosporins and 4.4% for carbapenems . among cultures
where e. coli was isolated , 24.7% were esbl - producing bacteria and 34.7% whether klebsiella was isolated .
. showed resistance rates of 26.7% for amoxicillin / ampicillin , 47.8% for fluoroquinolones and 1.7% for vancomycin .
pseudomonas aeruginosa showed resistance rate of 40.5 for piperacillin / tazobactam , 33.3% for carbapenems and 26.2% for amikacin .
however , if esbl - producing bacteria were isolated , the appropriateness of empirical treatment decreased to 81.2% .
isolation of esbl - producing bacteria or enterococcus and patients who underwent radical cystectomy showed a higher rate of inappropriate empirical antibiotic treatment .
the mortality rate among patients who suffered from hais was 2.4% in comparison with 0.3% in those who no suffer from hais .
risk factors for mortality were immunosuppression ( or , 6.7 ) and inadequate empirical antibiotic treatment ( or , 2.2 ) .
mortality causes in patients who suffered from hais were related to infection in 8 out of 10 .
. however , few articles evaluated this topic in urological patients . among these , it should be pointed of the european society of infections in urology ( esiu - eau ) which reviewed hais in urology departments since more than ten years ago .
such studies are essential as hais in urological patients have some special features such as higher incidence of urolithiasis , lower urinary tract symptoms , higher prevalence of previous urinary infections .
furthermore , patients admitted in urology ward frequently had an indwelling urinary catheter . in patients hospitalized in a general ward
on the other hand , among patients in a urology ward , a surgical procedure is frequently carried out , 75% according to our data .
endourological transurethral procedures constitute 55% of surgeries performed . therefore , urinary infections are the most common type of hais ( 70% )
. data from non - urology departments showed that urinary infections represent 15%57% of hais .
both , urinary catheter , and surgical procedure are well - established risk factors for hais .
surgery of the urinary tract and urinary catheter must be evaluated together . furthermore , 19% had an indwelling catheter before admission . indwelling urinary catheter and the duration of catheterization are the main risk factors for healthcare - associated urinary tract infections with the higher incidence among patients with urinary catheter before admission ( or , 1.74 ) .
although antimicrobial treatment is not required in case of asymptomatic catheter - bacteriuria , adequate perioperative prophylaxis is needed before surgery .
prior transurethral surgery , a urinary culture should be advised to tailor the antibiotic prophylaxis or treatment before surgery .
apart from , urinary catheter and urological surgery , some characteristics increased the risk of hais .
our results are in concordance with other studies that demonstrated that comorbidities such as immunosuppression , diabetes , obesity , liver dysfunction , malnutrition are related to an increased risk of hais . in our series ,
higher asa physical status classification is associated with higher incidence of hais , 4.5% among asa i  ii and 8% in asa iii  iv . moreover ,
previous antibiotic treatment and urinary infections are also risk factors to focus due to a higher incidence of infection and a different microbiological pattern . according to our data , in patients with previous urinary infection ,
it has been described that when several risk factors are associated , there is an increased risk of isolation pathogens with higher resistance rate such as klesiella spp . or pseudomonas spp . or candida spp . .
our study demonstrated a reduction in the incidence of infection from 7.3% in 2012 to 4.8% in 2015 .
several reasons may explain the evolution of the incidence of infections . in our opinion ,
doctors , nurses and all personnel working with patients are aware of infections , and different measures are implemented to prevent infections . among them , a correct hand hygiene and avoid rings or watches . on the other hand ,
urinary catheter control has improved with prompt removal and reducing unnecessary placement . a program reviewing
the appropriateness of urinary catheter has demonstrated that decrease the percentage of catheterization and the prevalence of infections .
otherwise , we review our results periodically , so we are informed about our infection rates and we can design strategies to prevent them .
moreover , we identify some risk factors for infections that they are also related to specific microbiological patterns . the effect of our research monitoring hais is demonstrated with the evolution of patients with suspicion of infection where cultures were not taken .
the percentage of patients without culture decreased from 6.1% in 2012 to 0.0% and 3.5% in 2014 and 2015 , respectively .
finally , antimicrobial prophylaxis is a key point as is used to prevent infections after diagnostic or therapeutics procedures .
perioperative prophylaxis must be chosen to take into account the type of surgery , the contamination burden , and some aspects related to specific risk factors of the patient , such as comorbidities , immunosuppression , indwelling catheters or a previous urinary infection . among the different types of hais ,
the total number of ssis were 35 in 2012 , 28 in 2013 , 15 in 2014 and , 17 in 2015 .
apart from monitoring and be aware of infections , others reason could explain the reduction in ssis .
several studies demonstrated that laparoscopic nephrectomy and cystectomy are associated with lower rates of ssis .
secondly , hand antisepsis using alcohol - based solutions may reduce the incidence of ssis .
radical cystectomy reported the highest incidence of hais , up to 50% in our series , and ssi is the most common type of hais .
demonstrated a reduction in the incidence of ssi from 32% to 18% with the standardization in suturing , drain removal and surgical dressing management .
finally , it should be pointed out that there is a higher incidence of infections after renal surgery in comparison with transurethral surgery .
although a laparoscopy approach is frequently performed , open surgery is required in some cases .
currently , open approach is indicated in patients with a complex surgery , and it is associated with risk factors for hais such as higher amount of bleeding , longer operating time , longer hospitalization and in some cases , a contaminated surgical filed . moreover , although urinary catheter is removed earlier after renal surgery than in transurethral surgery , drainage is usually used .
therefore , it is necessary to remove all drainages as soon as possible , and the management of the wound must be optimized .
the microorganism most commonly isolated is entero - bacteriaceae , 59% in our series . among them
, e. coli is the most frequent , 40% according to global prevalence study on infections in urology and 25% in our department .
data from study on the prevalence of nosocomial infections in spain study carried out in several hospitalization wards , showed that e. coli accounted 15%17% of positive cultures and enterobacteria 33% .
enterococcus is isolated in 17.5% and is the most common microorganism in patients with ssis after abdominal surgery . when enterococcus is suspected antibiotics such as vancomycin are recommended as high susceptibility
pseudomonas are commonly isolated , 13.5% and 12.3% in our series , respectively . according to gpiu data , klebsiella spp .
and pseudomonas accounted 11.1% and 10.8% . the main awareness related to the isolation of non - e .
resistant to carbapenems were found . moreover , if previous urinary infection , diabetes mellitus , liver disease or immunosuppression ; klebsiella was the most frequently isolated pathogen .
both , our data , and gpiu reported resistance to quinolones and third generation cephalosporins up to 50% .
the highest resistance rate is found in south europe , asia , and south america .
the resistance rate is related to the prescription of antibiotics , and an appropriate selection of antibiotics may reduce resistances .
this point may be demonstrated with lower resistance to aminoglycosides in our department in comparison with gpiu . in our center , aminoglycosides are not usually prescribed as prophylaxis before surgery .
multiresistant pathogens are frequently isolated in a urology ward ; esbl - producing bacteria were found in 34.3% of cultures where enterobacteriaceae were isolated .
isolating of esbl - producing bacteria is a key point in prevention of hais as frequently cross - resistance is found .
risk factors described for esbl - producing bacteria are older age , male sex , diabetes mellitus , urinary catheter and prior urinary infections .
therefore , rationalization of antibiotic usage and select empirical antibiotics adequately is essential to achieve better outcomes .
observational studies are useful to improve outcomes and reduce the incidence of hais . for instance , in our department , the incidence of hais was 7.3% at the beginning of the research and 4.8% in 2015 .
one of the strengths of the study is that we used a clinical definition of hais , including patients with sterile cultures .
lower incidences are reported if only positive cultures are taking into account , and higher incidence is found in studies carried out evaluating hais in one day due to patients with and infections have longer hospitalization period .
however , it included patients during a period of 4 years , and the results may be extrapolated to similar hospitals in the area .
on the other hand , patients who suffer hais after discharge may be not included .
however , hais is developed after discharge and the patient required admission to our hospital ; the hais was associated with the previous hospitalization in the urology ward .
prospective monitoring of hais and an adequate knowledge of the microbiological patterns may decrease the incidence of infections in patients hospitalized in a urology ward .
comorbidities , higher asa physical status classification , previous urinary infections a urinary catheter are risk factors for hais .
were the most frequently isolated microorganism in patients with diabetes mellitus , liver disease , immunosuppression and prior urinary infection .
 purposehealthcare - associated infections ( hais ) in urological patients have special features due to specific risk factors . 
 our objective was to evaluate the characteristics and risk factors for hais in patients hospitalized in a urology ward.materials and methodswe evaluated prospectively , from 2012 to 2015 , the incidence , types and risk factor for hais , microbiological and resistance patterns.resultsthe incidence of hais was 6.3% . 
 the most common types were urinary infections ( 70.5% ) and surgical site infections ( 22.1% ) . 
 univariate analysis showed an increased risk of hais among patients with american society of anesthesiologists physical status classification system iii  
 iv ( odds ratio [ or ] , 1.39 ; p<0.001 ) , immunosuppression ( or , 1.80 ; p=0.013 ) , previous urinary infection ( or , 4.46 ; p<0,001 ) , and urinary catheter before admission ( or , 1.74 ; p<0.001 ) . 
 the surgical procedures with the highest incidence of hais were radical cystectomy ( 54.2% ) and renal surgery ( 8.7% ) . 
 the most frequently isolated microorganisms were escherichia coli ( 25.1% ) , enterococcus spp . 
 ( 17.5% ) , klebsiella spp . 
 ( 13.5% ) and pseudomonas aeruginosa ( 12.3% ) . 
 enterococcus sp was the most common microorganism after radical cystectomy and in surgical site infections , e. coli showed resistance rates of 53.5% for fluoroquinolones , 9.3% for amikacin . 
 the percentage of extended - spectrum betalactamase producing e. coli was 24.7% . 
 klebsiella spp 
 . showed resistance rates of 47.8% for fluoroquinolones , 7.1% for amikacin and 4.3% for carbapenems . 
 enterococcus spp showed resistance rates of 1.7% for vancomycin and ; p. aeruginosa of 33.3% for carbapenems and 
 26.2% for amikacin.conclusionscomorbidities , previous urinary infections , and urinary catheter are risk factors for hais . 
 the microorganisms most commonly isolated were e. coli , enterococcus and p. aeruginosa . 
 prospective monitoring may decrease the incidence of infections . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSIONS