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The Ins and Outs of Catheter-Associated Urinary Tract Infection
The Ins and Guts of Catheter-Associated Urinary Tractlnfection Bronwen fv1ander Clinical Consultant Infection Control
Western Hospital Gardon Street Footscray 30 I 1
O
ver half of all urinary tract infections (UT/s! in hospitals
are hospital-acquired (nosocomial) '. UTls comprise 2040% of all nosocomlClllnfectiom'l. More than 80% of nosocomial UTls are related co the presence o f an indwelling
catheter (fOC)J. Whilst JDCs are Cln essential component in
modern medical care (at least 10% of patients are catheterised at some stage), It IS estimated that about 30% o f
catheter days could be aVOided".
UTls contrrbute to significant morbidity and mortality in
hospitalised patients. For most WIth symptoms. infection remains in the bladder. However. haemorrhagic cystitis.
secondal)' bacteraemia. pyelonephntis, renal abscess and infection a t other sites of the body. can occur.... Whilst less than 0 .5% of cathetemed patients develop symptomatIC bacteraemia, the frequency of catheterisation in hospitalised patients brings this to a significant number affected. For instance, IDCs have been identified as the source of 15% of nosocomial bacteraemias and a death rate of 13% was attributed directly to UTI·bacteraemia". Treatment and p rolonged hospitalisation of UTI can be costly, estimated in the US.:It between S 150 and $550) '. About 10% of catheterised patients are bacteriuric at the time of catheter Insertion and. o f the rest who are catheterised for at least one day. 10-20% then become bacteriuric-. The Incidence Increases the longer the catheter remains in situ - a risk rate of about 5% per day". Enterobacteriaceae are the most common causatNe organism. particularly E coli and Proteu5 mirabi/is. Patients receiving antibiotics are at risk of Infection with resistant strains of enterobacter; enterococci. P5eUdomonos aeruginoso ond Serratia morcescens 1. Candidal UTIs have also increased in recent years. The risk In nursing hofTle-l)'Pe patlenrs Increases due to their debilitated status. old aged. chronic disease and their increased likelihood of long·term catheterisation. 20-35% of nOrKatheterised nursing home residents are bacteriuric. whilst close to 100% of chronically catheterised residenrs are bacteriurlc '0 ". For long·term IDCs, recurrence o f UTls is possible. These patients have an average of one episode of unexplained fever t::Very I 00 days. which usually resolves. but occasionally can progress to serious infection". Catheterised, elderly. severely III females w h o are not o n antibiotics are more prone to UTI than younger; healthier males on antibiotics). For women. most are caused by enteric gram negative organisms tha t colonise th e perineum. Per;"urethral colonisation usually p recedes UTI by about 2-3 days'). Patients With diarrhoea are at even g reater risk. Bacteriuria In men is usually caused by contamination of the
catheter or drainage bag. with ascension of enteric bacteria from hands of staff or the patient. Certain bacteria are able to attach to uroepithelial cells and to the catheter surface' . M.::lnnose-specific liglands on fimbria or pili of Ecoli, for example, bind w ith mannose receptors of urethral/bladder epith elial cells. Haemogglutinins on fimbria of Pseudomonas aeruginosa stick avidly to catheter material. Biofilm. a protein layer occurring primarily on the inner surface of the catheter; provides further protection'. Accumulation of bacteria, glyocalyx produced by bacteria, protein, crystalline salrs and amorphous cellular debris forms encrustations. which then obstruct urine now and may be a nidus for infection. The presence of the catheter Itself causes tissue trauma and erosion of the mucopolysaccharide coating and epithelium of the bladder and ultimately inflammation" ' ~. This. along With the incomple(e emptying of the bladder; temporary obstructions caused by kinking and encrustations. and the riSK of contamination dUring catheter Insertion or manipulation contributes to the rISks of catheterassociated UTI. VJhilst most catheter-associated bacteriuria is endogenous /self-seededJ, It is estimated that up to I 5% o f nosocomial bacteriuria may occur In small clusters of 2-5 patients'· and in about 18% of IDC-associated bacteriuria, the drainage bag is contaminated before the bladder urine"' ''. This indicates C LOSED DRAINAGE
O "
Bladder
Ascent of bacteria or / " candida via urethra Peri.yrethral aided by to and fro m o vement $e(: r8t ions ___ Organisms from pat ient 's
~ \
V i a l umen
A$Cent of organ isms when integr ity o f closed drainage broken during di$Connection o f tubes (e .g. irrigation I
"""" genital skin Organisms from hands of h o spital slaff during care of the patient Organisms from contaminated local solutio ns or medicaments
- - Hazards of contamination of hands and equipment by infected urine ..... hen bag emptied or changed
Routes of infection in patients with continuous bladder catheterisation.
Source: Shonson DC, Microbiology in Clinicol Proctice, 1982
InI_Controt 7
transmission of Infectton between patients via JUnctions of the catheter. the catheter tubing or the drainage bag. Serrolio morcescens, Pseudomonos oeruginosa Clnd resistant Proteus species are the common organisms in these epidemics. Definitions and Diagnosis Bacteriuria usually refers to microbial colonisation of the urinary trac!, where there is no tissue invasion or clinical symptoms. Symptomatic UTI indicates inflammation in the bladder or kidneys. VJhilst 1(}'20% of patients with an IDC are bacteriuric. about 70% have no related symptoms ' . It is, therefore. difficult to determine the clinical significance of bacteri.?ll counts. For example. Iow baaerial counts of clinical significance in catheterised patients may be caused by medlc.?ltlons or flUids thitt increase urine flOI.\I, partial bacterial Inhibition by concurrent antibiotics, colonisation with slO'vV grOl.\llng organisms leg. Candida or enterOCOCCi). PolymicrobiClI bClcteriuriCl, with or Without symptoms. occurs more often for long-term cCltheteriSCltion. but is also found in Clbout 13% of hospitalised patients with a short term IDCI>· ,•. With symptoms. it is not possible to determine which are the causative organism/sJ. Clinical symptoms are often ambigUOUS, especially in elderly, debilitated. confused patients. The presence of an IDC is even more confusing. Even the presence of pyuria is not necessarily indicative of infection in catheterised patients. Therefore. diagnosis must involve clinical assessment, including the presence of symprems and condition. urinalysis and laboratory results.
bacteriuria spontaneously with removal of the catheter 1>. Antibiotic treatment for asymptomatic bacteriuria IS currently NOT recommended. In long-term IDCs, with asymptomatic bacteriuria. antibiotics only suppress bacteriuria temporarily and risk selection of antibiotIC resistant strains". However. for short- and long-term IDCs, where a UTI is determined or secondary local or systemiC complications occur. intravenous antibiotics are appropriate. local antIbiotic irrigation should not be used. With or Without antibiotics, removal of the catheter is integral re successful treatment of UTI. References I.
2.
3.
4.
S.
Prevention - Better than Cure
"Doctor Paul Beesons admonition to physicians in his clossic editorial in 1958 en/itled, 'The Case Against/he Catheler' lemoins apropos ladoy. Catheters should only be inserted
6.
N).
when absolutely necessary and removed as soon as possible. It is estimated that eClrly catheter remOV.?l1 could prevent .?IS many as 40% of rDC-associated UTls'. Suprapubic catheterisation has a much lower risk of infection'·. Condom drainage is also an alternative, but has been linked With high rates of bacteriuria and penile infectiOns in uncooperative and/or elderly patlents '~ 10. 1' . Behaviour modifICation programmes for chronically incontinent patients have been successful in minimising rDC use'. Antibiotics at the time of Insertion may be useful" " . but risks proliferation of antibiotic resistant enteric bacterial. Studies on silver ion
7.
8.
9.
10.
I I.
12.
13.
14. 1S.
Treatment of Catheter-Related Infection FOf most people With temporary IDCs and asymptomatic bacteriuria, the conditIon is transient. About 40% of patients With persistent asymptomatic bacteriuria clear their
16.
Mclaws Ml, Gold J, King K, et al. The prevalence of nosocomial and community-acquired infections in Australian hospitals. Med} Aust1988; 149: 582-590. Haley RW, Culver OH. VJhite NI. et al. The nationwide nosocomial infection rate. A nev.r need for vital statistics. Am} Epidemiol 1985; 12 (2): 159-167. Garibaldi RA. Hospital-acquired urinary tract infections. In Wenzel R P (Ed.) Prevenlion and Control 01 Nosocom ial Infections (2nd ed./ 1993; Baltimore: WlJliams & Wilkins. Hartsteln Al, Garber Ss. Ward et 031. Nosocomial urinary tract infection: A prospective evaluation of 108 catheterised patients. InFecl Conlrol1981; 2 IS): 380-386. Krieger IN. Kaiser Dl, Wenzel RP, et 031. Nosocomial urinary tract Infections cause wound infections postoperatrvely in surgical patients. 5urg Gyn Obs/ 1983; '56: 3/3-318. Bryan CS. Reynolds KL Hosprtal-acquired bacteremic urinary tract infection. Epidemiology and outcome. } Uro/1984; 132/3/: 494-498. Haley RW Schaberg OR. Crossley KB, et 031. Extra charges and prolongation of stay attributable to nosocomial infectiOns: A prospective interhospltal comparison. Am}Ntec/ 1981; 70: SI-58 . Garibaldi RA. Mooney BR. Epstein B..l. et at An evaluation of daily bacteriologic monitoring to identify preventable episodes of catheter-associated urinary tract infection. Infect ConI 1982; 3(6): 466-470. Stamm WE. Catheter-associated urinary tract Infections: Epldermology. pathogenesis. and prevention. Am} Med 199/; 91 /supp(3B/: 3B6S5-387 IS. Warren NI. Tenney JH. Hoopes JM, et al. A prospective microbiologic study of bacteriuria In patIents With chronic indwelling urethral catheters.} Infect Dis 1982; 146 /6/: 719-723. Nicolle lE. Bjornson J, Harding GKM, et.?lJ. Bacteriuria in elderly institutionalised men. N Engl} Nied 1983; 309 (2): 1420-1425. Warren NJ. Damron 0, Tenney JH. et al. Fever. bacteremia, and death as complications of bacteriuria in women with long-term urethral catheters,} Infect Dis 1987; 155 (6): 1151-1158. Daifuku R. Stamm WE. Association of rectal and urethral colonisation With urinary tract infection in patients with indwelling catheters. JM'\A 1984; 252 (IS): 2028-2030. Warren.IW. Catheter-associated urinary tract InfectIOns. Infecf Dis C!in Norlh Am 1987; 1 (4): 823-855. Montgomerie JZ. Morrow JW Pseudomonas colonisation in patients with spinal cord injury. Am} EpidemioJ 1978; 108 /4/: 328-336. SChabefg OR. Haley RW Hishmith AK. Nosocomial bacteriuria: A prospective study of case clustering and antImICrobial resistance. Ann In/Ivted 1980; 93 : 420-424.
n:
lnIoctionConlrol 8
17 Garlbaldi RA, Burke Jp' Dickman ML et al. Factors predisposing to bacteriuria durrng Indwelling urethral catheterisation. N Engl) N\ed 1974; 29 I' 215-219. 18. Asher EF. Oliver BG, Fry DE. Urinary tract infections in the surgical patient. Am SU(g 1988. 54 (7): 466-469. 19. Sethia KK, Selkon JB, Berry AR, et .::11. Prospective randomized controlled tri.::ll of urethr.::ll versus suprapubic C.::ltheterisation. Br) Surg 1987; 74: 624-625. 20. Johnson ET. The condom c.::ltheter: Urinary tract infection and other complications. South) N\ed 1983; 76 15): 579-582. 2 r. Hirsh DD, Falnsteln V. Musher OM. et 031. Do condom catheter collecting systems cause urinary tract infection? J,AMA 1979: 242 14): 340-341. 22. Nordqvist P. Ekelund p. Edouard L et al. catheter-free geriatnc care: Routines and consequences for clinical infection. care and economy.) Hasp In! 1984; /5): 298-304. 23. Schaeffer AJ. Story KO, Johson SM. Effect of silver oXlde/trlchloroisocyanuric acid antimicrobial urinary
24.
25.
26.
27.
drainage system on catheter-associated bacteriuria. ) U,oI198B; J 39 [I): 69-73 Johnson JR. Roberts Pi.. Olsen RJ. et 031. Prevention of catheter-associated urinary tract infection with a silver oxide-mated urinary catheter: Clinical and microbiologic correlates.) Infect Dis 1990; 162 (5): I 145-11 SO. Cox AJ, Millington RS, Hukins DV/. et 031. Resistance of catheters coated With a modified hydrogel to encrustation during an In vitro test. Urol Res 1989; 17' 353-356. Wong ES. Hooton TM. GUideline for p!'eventlon of catheter-associated urinal)' tract Infections. CDC Prevenlion Guidelines 1991; Internet address: hnp:llwonder.cdc.govJI...VONDERlstaticl"SYSTEM",PREV GUIDllEVEL::=topics.htm"URL::=p00004161 pOOO0416.htm. Harding GKM. Nicolle LE, Ronald AR. et al. H()'IN long should catheter-acquired urinary tract infection in women be treated? Ann Intern Iv\ed 1991; 1 14 (9): 713-7 r 9.
Nosocomial Urinary Tract Infections Geoffrey P/ayford Infectious Diseases Registrar Princess A1exandra Hospital WooIloongabba Old 4 102
N
osocomial urinary tract infections [UTls) are the most common cause of nosocomIal Infeclton. and are an Important cause of septicaemia and monallty. The problem occurs in both acute
Epidemiology Urinary tract infections account for about 40% of all nosocomial infections. and occur In approximately two out of every r 00 hospital admissions. ' The epidemIOlogy of nosocomial UTls IS closely related to the use of indwelling urinal)' catheters. Around 90% are catheter-related and the remainder related to cystoscopy or other urological procedures.' ApproXimately r ().. r 5% of admissions to acute
10 lnfoctionContlO1
Complications As catheterised patients frequently have significant associated comorDldltles, It IS often difficult to accurately define the mortality anributable to nosocomial UTls. H()'INever the acquisition of a nosocomial UTI predicts an overall three-fold increase in mortality. I Bacteraemia occurs in 0.5-4% of patients with nosocomial UTI. and although the crude mortality from thiS is greater than 30%. ~. , the attributable mortality is approximately 13%.· Nosocomial UTls result In significant morbidity. Infection may Involve the entire urinal)' tract. including the bladder, kidneys. p!'ostate and epididymiS. About 2()"30% of patients With asymptomatrc bacteriuria develop pyelonephritis or symptomatic cystitiS.' Renal tract calculi. squamous metaplasia and carCinoma. urethral trauma and strictures. and renal transplant dysfunction have also been associated With the use of catheters and nosocomial UTls. Furthermore UTls may act as a source for other infections. In one study, 2.3 surgical site infections occurred for evel)' J 00 surgical patients with nosocomial UTls .~ Bacteraemia from UTls may also lead to seeding of prosthetiC materials such as heart valves. Joints. and intravascular devices. Over 900,000 episodes of nosocomial UTls occurred in the USA in 1992. at an estimated cost of over USS500 million. These figures are based on an Increased hospital stay of only one day which is probably a conservatIVe estimate. '0 Finally. considerable cost. adverse drug reactions. and selection of resistant organisms result from antibiotics used to (reat UTls. Diagnosis Bacteriuria represents colonisation of the urinary tract Without clinical Of other laboratOf}' evidence of Infection. The p!'esence of symptoms attributable to bacteriuria defines UTI. although these are often atypical or Incomplete. Guidelines to
Western Hospital Gardon Street Footscray 30 I 1
O
ver half of all urinary tract infections (UT/s! in hospitals
are hospital-acquired (nosocomial) '. UTls comprise 2040% of all nosocomlClllnfectiom'l. More than 80% of nosocomial UTls are related co the presence o f an indwelling
catheter (fOC)J. Whilst JDCs are Cln essential component in
modern medical care (at least 10% of patients are catheterised at some stage), It IS estimated that about 30% o f
catheter days could be aVOided".
UTls contrrbute to significant morbidity and mortality in
hospitalised patients. For most WIth symptoms. infection remains in the bladder. However. haemorrhagic cystitis.
secondal)' bacteraemia. pyelonephntis, renal abscess and infection a t other sites of the body. can occur.... Whilst less than 0 .5% of cathetemed patients develop symptomatIC bacteraemia, the frequency of catheterisation in hospitalised patients brings this to a significant number affected. For instance, IDCs have been identified as the source of 15% of nosocomial bacteraemias and a death rate of 13% was attributed directly to UTI·bacteraemia". Treatment and p rolonged hospitalisation of UTI can be costly, estimated in the US.:It between S 150 and $550) '. About 10% of catheterised patients are bacteriuric at the time of catheter Insertion and. o f the rest who are catheterised for at least one day. 10-20% then become bacteriuric-. The Incidence Increases the longer the catheter remains in situ - a risk rate of about 5% per day". Enterobacteriaceae are the most common causatNe organism. particularly E coli and Proteu5 mirabi/is. Patients receiving antibiotics are at risk of Infection with resistant strains of enterobacter; enterococci. P5eUdomonos aeruginoso ond Serratia morcescens 1. Candidal UTIs have also increased in recent years. The risk In nursing hofTle-l)'Pe patlenrs Increases due to their debilitated status. old aged. chronic disease and their increased likelihood of long·term catheterisation. 20-35% of nOrKatheterised nursing home residents are bacteriuric. whilst close to 100% of chronically catheterised residenrs are bacteriurlc '0 ". For long·term IDCs, recurrence o f UTls is possible. These patients have an average of one episode of unexplained fever t::Very I 00 days. which usually resolves. but occasionally can progress to serious infection". Catheterised, elderly. severely III females w h o are not o n antibiotics are more prone to UTI than younger; healthier males on antibiotics). For women. most are caused by enteric gram negative organisms tha t colonise th e perineum. Per;"urethral colonisation usually p recedes UTI by about 2-3 days'). Patients With diarrhoea are at even g reater risk. Bacteriuria In men is usually caused by contamination of the
catheter or drainage bag. with ascension of enteric bacteria from hands of staff or the patient. Certain bacteria are able to attach to uroepithelial cells and to the catheter surface' . M.::lnnose-specific liglands on fimbria or pili of Ecoli, for example, bind w ith mannose receptors of urethral/bladder epith elial cells. Haemogglutinins on fimbria of Pseudomonas aeruginosa stick avidly to catheter material. Biofilm. a protein layer occurring primarily on the inner surface of the catheter; provides further protection'. Accumulation of bacteria, glyocalyx produced by bacteria, protein, crystalline salrs and amorphous cellular debris forms encrustations. which then obstruct urine now and may be a nidus for infection. The presence of the catheter Itself causes tissue trauma and erosion of the mucopolysaccharide coating and epithelium of the bladder and ultimately inflammation" ' ~. This. along With the incomple(e emptying of the bladder; temporary obstructions caused by kinking and encrustations. and the riSK of contamination dUring catheter Insertion or manipulation contributes to the rISks of catheterassociated UTI. VJhilst most catheter-associated bacteriuria is endogenous /self-seededJ, It is estimated that up to I 5% o f nosocomial bacteriuria may occur In small clusters of 2-5 patients'· and in about 18% of IDC-associated bacteriuria, the drainage bag is contaminated before the bladder urine"' ''. This indicates C LOSED DRAINAGE
O "
Bladder
Ascent of bacteria or / " candida via urethra Peri.yrethral aided by to and fro m o vement $e(: r8t ions ___ Organisms from pat ient 's
~ \
V i a l umen
A$Cent of organ isms when integr ity o f closed drainage broken during di$Connection o f tubes (e .g. irrigation I
"""" genital skin Organisms from hands of h o spital slaff during care of the patient Organisms from contaminated local solutio ns or medicaments
- - Hazards of contamination of hands and equipment by infected urine ..... hen bag emptied or changed
Routes of infection in patients with continuous bladder catheterisation.
Source: Shonson DC, Microbiology in Clinicol Proctice, 1982
InI_Controt 7
transmission of Infectton between patients via JUnctions of the catheter. the catheter tubing or the drainage bag. Serrolio morcescens, Pseudomonos oeruginosa Clnd resistant Proteus species are the common organisms in these epidemics. Definitions and Diagnosis Bacteriuria usually refers to microbial colonisation of the urinary trac!, where there is no tissue invasion or clinical symptoms. Symptomatic UTI indicates inflammation in the bladder or kidneys. VJhilst 1(}'20% of patients with an IDC are bacteriuric. about 70% have no related symptoms ' . It is, therefore. difficult to determine the clinical significance of bacteri.?ll counts. For example. Iow baaerial counts of clinical significance in catheterised patients may be caused by medlc.?ltlons or flUids thitt increase urine flOI.\I, partial bacterial Inhibition by concurrent antibiotics, colonisation with slO'vV grOl.\llng organisms leg. Candida or enterOCOCCi). PolymicrobiClI bClcteriuriCl, with or Without symptoms. occurs more often for long-term cCltheteriSCltion. but is also found in Clbout 13% of hospitalised patients with a short term IDCI>· ,•. With symptoms. it is not possible to determine which are the causative organism/sJ. Clinical symptoms are often ambigUOUS, especially in elderly, debilitated. confused patients. The presence of an IDC is even more confusing. Even the presence of pyuria is not necessarily indicative of infection in catheterised patients. Therefore. diagnosis must involve clinical assessment, including the presence of symprems and condition. urinalysis and laboratory results.
bacteriuria spontaneously with removal of the catheter 1>. Antibiotic treatment for asymptomatic bacteriuria IS currently NOT recommended. In long-term IDCs, with asymptomatic bacteriuria. antibiotics only suppress bacteriuria temporarily and risk selection of antibiotIC resistant strains". However. for short- and long-term IDCs, where a UTI is determined or secondary local or systemiC complications occur. intravenous antibiotics are appropriate. local antIbiotic irrigation should not be used. With or Without antibiotics, removal of the catheter is integral re successful treatment of UTI. References I.
2.
3.
4.
S.
Prevention - Better than Cure
"Doctor Paul Beesons admonition to physicians in his clossic editorial in 1958 en/itled, 'The Case Against/he Catheler' lemoins apropos ladoy. Catheters should only be inserted
6.
N).
when absolutely necessary and removed as soon as possible. It is estimated that eClrly catheter remOV.?l1 could prevent .?IS many as 40% of rDC-associated UTls'. Suprapubic catheterisation has a much lower risk of infection'·. Condom drainage is also an alternative, but has been linked With high rates of bacteriuria and penile infectiOns in uncooperative and/or elderly patlents '~ 10. 1' . Behaviour modifICation programmes for chronically incontinent patients have been successful in minimising rDC use'. Antibiotics at the time of Insertion may be useful" " . but risks proliferation of antibiotic resistant enteric bacterial. Studies on silver ion
7.
8.
9.
10.
I I.
12.
13.
14. 1S.
Treatment of Catheter-Related Infection FOf most people With temporary IDCs and asymptomatic bacteriuria, the conditIon is transient. About 40% of patients With persistent asymptomatic bacteriuria clear their
16.
Mclaws Ml, Gold J, King K, et al. The prevalence of nosocomial and community-acquired infections in Australian hospitals. Med} Aust1988; 149: 582-590. Haley RW, Culver OH. VJhite NI. et al. The nationwide nosocomial infection rate. A nev.r need for vital statistics. Am} Epidemiol 1985; 12 (2): 159-167. Garibaldi RA. Hospital-acquired urinary tract infections. In Wenzel R P (Ed.) Prevenlion and Control 01 Nosocom ial Infections (2nd ed./ 1993; Baltimore: WlJliams & Wilkins. Hartsteln Al, Garber Ss. Ward et 031. Nosocomial urinary tract infection: A prospective evaluation of 108 catheterised patients. InFecl Conlrol1981; 2 IS): 380-386. Krieger IN. Kaiser Dl, Wenzel RP, et 031. Nosocomial urinary tract Infections cause wound infections postoperatrvely in surgical patients. 5urg Gyn Obs/ 1983; '56: 3/3-318. Bryan CS. Reynolds KL Hosprtal-acquired bacteremic urinary tract infection. Epidemiology and outcome. } Uro/1984; 132/3/: 494-498. Haley RW Schaberg OR. Crossley KB, et 031. Extra charges and prolongation of stay attributable to nosocomial infectiOns: A prospective interhospltal comparison. Am}Ntec/ 1981; 70: SI-58 . Garibaldi RA. Mooney BR. Epstein B..l. et at An evaluation of daily bacteriologic monitoring to identify preventable episodes of catheter-associated urinary tract infection. Infect ConI 1982; 3(6): 466-470. Stamm WE. Catheter-associated urinary tract Infections: Epldermology. pathogenesis. and prevention. Am} Med 199/; 91 /supp(3B/: 3B6S5-387 IS. Warren NI. Tenney JH. Hoopes JM, et al. A prospective microbiologic study of bacteriuria In patIents With chronic indwelling urethral catheters.} Infect Dis 1982; 146 /6/: 719-723. Nicolle lE. Bjornson J, Harding GKM, et.?lJ. Bacteriuria in elderly institutionalised men. N Engl} Nied 1983; 309 (2): 1420-1425. Warren NJ. Damron 0, Tenney JH. et al. Fever. bacteremia, and death as complications of bacteriuria in women with long-term urethral catheters,} Infect Dis 1987; 155 (6): 1151-1158. Daifuku R. Stamm WE. Association of rectal and urethral colonisation With urinary tract infection in patients with indwelling catheters. JM'\A 1984; 252 (IS): 2028-2030. Warren.IW. Catheter-associated urinary tract InfectIOns. Infecf Dis C!in Norlh Am 1987; 1 (4): 823-855. Montgomerie JZ. Morrow JW Pseudomonas colonisation in patients with spinal cord injury. Am} EpidemioJ 1978; 108 /4/: 328-336. SChabefg OR. Haley RW Hishmith AK. Nosocomial bacteriuria: A prospective study of case clustering and antImICrobial resistance. Ann In/Ivted 1980; 93 : 420-424.
n:
lnIoctionConlrol 8
17 Garlbaldi RA, Burke Jp' Dickman ML et al. Factors predisposing to bacteriuria durrng Indwelling urethral catheterisation. N Engl) N\ed 1974; 29 I' 215-219. 18. Asher EF. Oliver BG, Fry DE. Urinary tract infections in the surgical patient. Am SU(g 1988. 54 (7): 466-469. 19. Sethia KK, Selkon JB, Berry AR, et .::11. Prospective randomized controlled tri.::ll of urethr.::ll versus suprapubic C.::ltheterisation. Br) Surg 1987; 74: 624-625. 20. Johnson ET. The condom c.::ltheter: Urinary tract infection and other complications. South) N\ed 1983; 76 15): 579-582. 2 r. Hirsh DD, Falnsteln V. Musher OM. et 031. Do condom catheter collecting systems cause urinary tract infection? J,AMA 1979: 242 14): 340-341. 22. Nordqvist P. Ekelund p. Edouard L et al. catheter-free geriatnc care: Routines and consequences for clinical infection. care and economy.) Hasp In! 1984; /5): 298-304. 23. Schaeffer AJ. Story KO, Johson SM. Effect of silver oXlde/trlchloroisocyanuric acid antimicrobial urinary
24.
25.
26.
27.
drainage system on catheter-associated bacteriuria. ) U,oI198B; J 39 [I): 69-73 Johnson JR. Roberts Pi.. Olsen RJ. et 031. Prevention of catheter-associated urinary tract infection with a silver oxide-mated urinary catheter: Clinical and microbiologic correlates.) Infect Dis 1990; 162 (5): I 145-11 SO. Cox AJ, Millington RS, Hukins DV/. et 031. Resistance of catheters coated With a modified hydrogel to encrustation during an In vitro test. Urol Res 1989; 17' 353-356. Wong ES. Hooton TM. GUideline for p!'eventlon of catheter-associated urinal)' tract Infections. CDC Prevenlion Guidelines 1991; Internet address: hnp:llwonder.cdc.govJI...VONDERlstaticl"SYSTEM",PREV GUIDllEVEL::=topics.htm"URL::=p00004161 pOOO0416.htm. Harding GKM. Nicolle LE, Ronald AR. et al. H()'IN long should catheter-acquired urinary tract infection in women be treated? Ann Intern Iv\ed 1991; 1 14 (9): 713-7 r 9.
Nosocomial Urinary Tract Infections Geoffrey P/ayford Infectious Diseases Registrar Princess A1exandra Hospital WooIloongabba Old 4 102
N
osocomial urinary tract infections [UTls) are the most common cause of nosocomIal Infeclton. and are an Important cause of septicaemia and monallty. The problem occurs in both acute
Epidemiology Urinary tract infections account for about 40% of all nosocomial infections. and occur In approximately two out of every r 00 hospital admissions. ' The epidemIOlogy of nosocomial UTls IS closely related to the use of indwelling urinal)' catheters. Around 90% are catheter-related and the remainder related to cystoscopy or other urological procedures.' ApproXimately r ().. r 5% of admissions to acute
10 lnfoctionContlO1
Complications As catheterised patients frequently have significant associated comorDldltles, It IS often difficult to accurately define the mortality anributable to nosocomial UTls. H()'INever the acquisition of a nosocomial UTI predicts an overall three-fold increase in mortality. I Bacteraemia occurs in 0.5-4% of patients with nosocomial UTI. and although the crude mortality from thiS is greater than 30%. ~. , the attributable mortality is approximately 13%.· Nosocomial UTls result In significant morbidity. Infection may Involve the entire urinal)' tract. including the bladder, kidneys. p!'ostate and epididymiS. About 2()"30% of patients With asymptomatrc bacteriuria develop pyelonephritis or symptomatic cystitiS.' Renal tract calculi. squamous metaplasia and carCinoma. urethral trauma and strictures. and renal transplant dysfunction have also been associated With the use of catheters and nosocomial UTls. Furthermore UTls may act as a source for other infections. In one study, 2.3 surgical site infections occurred for evel)' J 00 surgical patients with nosocomial UTls .~ Bacteraemia from UTls may also lead to seeding of prosthetiC materials such as heart valves. Joints. and intravascular devices. Over 900,000 episodes of nosocomial UTls occurred in the USA in 1992. at an estimated cost of over USS500 million. These figures are based on an Increased hospital stay of only one day which is probably a conservatIVe estimate. '0 Finally. considerable cost. adverse drug reactions. and selection of resistant organisms result from antibiotics used to (reat UTls. Diagnosis Bacteriuria represents colonisation of the urinary tract Without clinical Of other laboratOf}' evidence of Infection. The p!'esence of symptoms attributable to bacteriuria defines UTI. although these are often atypical or Incomplete. Guidelines to