Urinary Tract Infection in Patients with Indwelling Catheter
Henry F. Alavaren, M.D.,* Jodor A. Lim, M.D.,** Melecia Antonio-Velmonte, M.D.**** and
Myrna T. Mendoza, M.D.***
(*Resident Physician; PSMID-Unilab JuniorAwardee, 1993, **Resident Physician, ***Assistant Professor and
****Associate Professor and Chief, Infectious Diseases Section, Department of Medicine University of the
Philippines -Philippine General Hospital Medical Center Taft Avenue, Manila)
A total of 178 adult patients with indwelling urethral catheters were studied from June to August 1993 to
determine the incidence of bacteriuria and identify the risk factors for development of bacteriuria. Urinalysis and urine
cultures were done initially and then daily thereafter until the catheters were removed or until the patients developed
significant bacteriuria on 2 consecutive cultures. A colony count of ≥ 103 cfu/ml, of urine was considered significant.
Results showed that 44 (24.7%) developed bacteriuria or 7 bacteriuria per 100 person-days with catheter. Average time
of occurrence after insertion of catheters was 3.9 days with a range of 2-11 days. Development of bacteriuria was not
affected by sex, age, steroid or antibiotic intake and the technique of catheter insertion. Risk factors identified were
open drainage system, daily meatal care and prolonged catheterization. Pseudomonas aeruginosa and E. coli were the
most common bacteria isolated. [Phil J Microbiol Infect Dis 1993; 22(2):65-74]
Key Words: urinary tract infection, indwelling urinary catheters, bacteriuria, Pseudomonas aeruginosa, E. coli
Nosocomial infections are significant source of morbidity and mortality. It also means
extra expenses once it sets in because of prolonged hospital stay and additional hospital needs.
Because of these, activities toward prevention and control of hospital-acquired infections have
been made since the 1950's.
In the United States, nosocomial infections occur in about 5% of patients admitted in
acute-care hospitals.1 In a surveillance study done by the Infection Control Committee of the
Philippine General Hospital (PGH) in 1989,2 the prevalence was 16.3%.
Nosocomial urinary tract infections (UTI) remain a significant contributor to the over-all
prevalence or incidence of nosocomial infections. It affects approximately 2 per 100 patients
admitted to acute-care hospitals in the United States,3 or more than 0.8 million patients yearly. At
the PGH, it is second to respiratory tract infections with a prevalence rate of 25.3%.
Urethral catheter is a major predisposing factor in the development of nosocomial UTI
and catheter-associated bacteremia. About 80% of nosocomial UTI are associated with the use of
urethral catheters.4 Most nosocomial UTI can be benign but a systemic complication which is
gram-negative bacteremia can develop in 30-40% of patients. Prevention of nosocomial UTI and
its complications would therefore reduce the rate of morbidity and mortality and expenses
secondary to the infection.
This study was conducted to determine the incidence of bacteriuria, its onset after
insertion, and the predisposing factors following insertion of indwelling catheters. It is hoped that
the results of this study will serve as a basis for the formulation of guidelines for prevention of
PATIENTS AND METHODS
From June to August 1993, admitted patients 16 years and above who were for
indwelling urethral catheterization from the Medical, Surgical and Obstetric units were included
in the study. The sex, age, date of admission, diagnosis, underlying medical problems,
concomitant medications, date and indications for indwelling catheterization were recorded.
Patients with confirmed UTI before catheterization were excluded.
Indwelling urethral catheters were inserted by nursing personnel, clinical clerks, interns
or residents following varying procedures.
Samples of urine after insertion of catheters were collected aseptically within 2 hours
from the time of insertion for baseline urine cultures and microscopic examinations. Thereafter,
daily urine cultures and urinalysis were done until the catheters were removed or until a
significant bacteriuria occurred on 2 consecutive cultures, Subsequent urine samples were
collected by one investigator by aspirating urine from the rubber catheter with a sterile syringe
with gauge 26 needle after disinfecting the rubber catheter with 70% alcohol. Urine cultures were
done by inoculating urine samples on primary plating media: blood agar plates and McConkey
agar using a calibrated loop (0.01ml.). A colony count > 103 cfu/ml, of urine was considered
1. Daily temperatures, HR, RR, BP
2. Daily physical examinations with particular attention to the findings related to urethral
catheterization (e.g., urethral discharge, meatal inflammation).
3. Subjective complaints related to catheterization were noted daily,
4. Medications such as antibiotics, steroids and other immunosuppressive agents that
were used concomitantly were recorded.
5. Observation as to the catheter care (pre-catheterization and while on catheter).
For demographic profile, frequencies and percentage distribution were obtained for each
variable. Risk factors determination employed the univariate analysis for each individual variable.
Chi-square and Odds Ratios were utilized. Stratification of one risk factor against another
rutilized the Mantel-Haenzell Chi-square test for significance.
Presentation, analysis, and interpretation
A total of 178 patients were entered into the study. There were 99 (55.6%) males and 79
(44.4%) females with a male: female ratio of 1.25:1. Majority (22.5%) of patients belonged to the
age group 16 - 25. Their age ranged from 16 - 92 with a mean age of 42.03 years. Thirty-eight
percent of the subjects came from Adult Major Medical Unit and 19.7% from the Medical Ward.
About 31% of patients were non-medical (Figure 1).
The most common underlying illness was pneumonia found in 23.6% of patients
followed by hypertension in 18.5%, cerebrovascular in 17.4%, PTB in 8.9%, leptospirosis in
7.3% and organophosphate poisoning in 4.5% of patients (Table 1).
Sixty-two percent of patients were taking antibiotics and penicillin was the most
commonly used antibiotic. Only 14% of patients were taking steroids.
The indications for indwelling catheterization (Table 2) were output monitoring in
31.5%, incontinence in 29.8%, and retention in 11.8% of patients. In 26.9% of patients, the
indication was surgical operation.
Table 1. Distribution of common underlying illnesses
Diagnosis Frequency Percentage
Pneumonia 42 23.6
Hypertension 33 17.4
PTB 16 8.9
Leptospirosis 13 7.3
Organophosphate poisoning 6 4.5
Diabetes Mellitus 8 4.5
Congestive heart failure 7 3.9
Bronchial asthma 6 3.4
Multiple injuries (Trauma) 6 3.4
Table 2. Indications for catheterization
Indication Frequency Percentage
Incontinence 53 29.8
Output monitoring 56 31.5
Retention 21 11.8
Abdominal 21 11.8
Pelvic 18 10.1
Genito-urinary 4 2.2
Neurosurgical 5 2.8
Total 178 100.00
Povidone iodine antiseptic solution was commonly used for pre-catheterization cleansing
in 74.7% of patients. Urinary catheters were inserted by the interns in almost 89%, by clinical
clerks in 10% and nurses or residents in less than 2% of patients (Figure 2).
Figure 1. Distribution by department Figure 2. Personnel Inserting Catheter
Table 3 shows the type of catheter drainage system employed in this study population and
the type of catheter care done. Open drainage system was still employed in 31.5% while majority
(68.5%) had closed drainage system. Catheter care was not applied in 56.1% of patients, while
daily meatal care using soap and water was applied in 44%.
The duration of catheterization, the distribution of bacteriuria as to sex and as type of
drainage is shown in Table 4. Forty-four out of 178 patients (24.72%) developed bacteriuria or an
incidence of 7 bacteriuria per 100 person-days with indwelling catheter. There were 7 males and
8 females with bacteriuria per 100 person-days with catheter. There were 15 bacteriuria and 4
bacteriuria per 100 person-days with catheter in patients with open and closed drainage system,
respectively. Bacteriuria occurred as early as the second day of catheterization. The longest
duration of catheterization was 12 days. The mean time onset of bacteriuria was 3.9 days.
Regardless of age, sex or type of drainage, in this study, bacteriuria can occur as early as the
second day of catheterization. There was correlation between duration of catheterization and
occurrence of bacteriuria (p<0.05).
Table 3. Type of drainage and catheter care
Indication Frequency Percentage
Open 56 31.5
Closed 122 68.5
None 358 56.1
Use of soap and water 280 43.9
Table 4. Incidence of Bacteriuria
Day (+) Bacteriuria
of # of Male Female Open Close Cumulative
Cath Spec No. (%) No. (%) No. (%) No (%) Freq (%)
1 178 0 0 0 0 0 0
2 178 1 (2.3) 2 (4.5) 2 (4.5) 1 (2.3) 3 6.5
3 127 13 (29.5) 10 (22.7) 18 (40.9) 5 (11.4) 26 58.8
4 71 4 (9.1) 4 (9.1) 3 (6.8) 5 (11.4) 34 77.0
5 35 3 (6.8) 2 (4.5) 1 (2.3) 4 (9.1) 39 88.4
6 17 2 (4.5) 1 (2.3) 1 (2.3) 2 (4.5) 42 95.2
7 11 0 0 0 0 42 95.2
8 6 0 0 0 0 42 95.2
9 6 1 (2.3) 0 0 1 (2.3) 43 97.6
10 5 0 0 0 0 43 97.6
11 2 1 (2.3) 0 0 1 (2.3) 44 10.0
12 2 0 0 0 0 44 100
Total 638 25 (56.8) 19 (43.2) 25 (56.8) 19 (43.2)
Earliest onset of bacteriuria - 2nd day
Longest duration of catheterization - 12 days
Mean time onset of bacteriuria - 39 days
Incidence of bacteriuria: = 44/178 = 24.72% or 7 cases/100 person-days with catheter
Sex incidence: Male - 7 cases/100 person-days with catheter
Female - 8 cases/100 person-days with catheter
Type of drainage: Open - 15 cases/100 person-days with catheter
Closed - 4 cases/100 person-days with catheter
Association between duration of catheterization and bacteriuria: N = 6; p = <0.05
About 50% of bacteriuria among males occurred on the 6th day of catheterization. In
females, 100% of bacteriuria developed on the same day. In open drainage system, 88.5% of
bacteriuria developed on the 3rd day of catheterization and 100% developed on the 6th day while
in closed drainage system, only about 38% of bacteriuria developed on the 6th day of
The cumulative frequency of bacteriuria is shown in Figure 3. More than 50% of
bacteriuria developed on the 3rd day of catheterization and about 95% developed as early as the
6th day of catheterization.
Among those with bacteriuria, 56.8% were males while 43.2% were females. There was
however no significant difference in the incidence of bacteriuria in both sexes (Odds Ratio=1.07,
95% CI: 0.38-1.55) [Figure 4].
Figure 3. Cumulative frequency of bacteriuria Figure 4. Cumulative frequency of bacteriuria by sex
Figure 5 shows the cumulative frequency of bacteriuria as to the type of drainage.
Incidence of bacteriuria was 56.8% and 43.2% of patients with open and closed drainage system,
respectively. The difference in the two groups was statistically significant (Odds Ratio=4.37, 95%
CI: 2.18 -8.76). Open drainage was associated with more incidence of bacteriuria.
Figure 5. Cumulative frequency of bacteriuria as to
the type of drainage
Majority (27.3%) of patients with bacteriuria belonged to the age group 16-25. There was
no statistically significant difference in the incidence of bacteriuria in all age groups.
In 34.1% of patients with bacteriuria no catheter care was applied while 65.9% of patients
had daily catheter care using soap and water. The difference in the incidence of bacteriuria in
those with catheter care and in those without was statistically significant (Odds Ratio=0.31, 95%
CI: 0.19 -0.52) [Table5]. Patients in whom catheter care was done were associated with more
incidence of bacteriuria. The difference was significant regardless of the type of drainage.
Antibiotics and steroids intake, type of antiseptics used during insertion and the person
inserting the catheter were also considered and analyzed as possible risk factors for development
of bacteriuria. No association between bacteriuria and the above-mentioned factors was shown.
The clinical manifestations in patients with bacteriuria were fever in 36.4% of patients,
suprapubic tenderness in 25%, and urgency in13.6% of patients.
Almost 21% of bacteria isolated were Pseudornonas aeruginosa and 18.2% were E. coli,
Acinetobacter anitratum 11.3% and Klebsiella ozaenae 9.1%. S. saprophyticus was isolated in
4.5% and S. aureus in 2.3% (Table 6). A direct relationship between the number of pus cells in
the urine and bacteriuria (p<0.01) was observed in this study (Table 7).
Table 5. Association between bacteriuria and the type of catheter care (N = 638)
Catheter care (+) (-)
None 15 (34.1) 330 (60.0)
Use of Soap and water 29 (65.9) 220 (40.0)
Total 44 (100.0) 550 (100.0)
Odds Ratio: 0.3120 (95% CI : 0.19-0.52)
Table 6. Organisms isolated in bacteriuria (N = 44)
Organisms Frequency Percentage
Pseudomonas aeruginosa 9 20.5
E. coli 8 18.2
Acinetobacter anitratum 5 11.3
Klebsiella ozaena 4 9.1
Enterobacter agglomerans 4 9.1
Candida spp 4 9.1
Klesiella pneumoniae 2 4.5
Pseudomonas spp. 2 4.5
S. saprophyticus 2 4.5
S. aureus 2 4.5
S. epidermidis 1 2.3
Enterobacter sakazakii 1 2.3
Acinetobacter wolfii 1 2.3
Arizona spp. 1 2.3
Edwardsiella spp. 1 2.3
Providencia rettgerii 1 2.3
Providencia stuartii 1 2.3
Klebsiella oxytoca 1 2.3
Salmonella group E 1 2.3
Table 7. Association between pyuria and bacteriuria
Catheter Care (+) (-)
0-3 2 373
4-7 2 118
8-11 10 47
12-15 36 6
16-19 21 3
20-25 13 1
26-40 1 1
41-55 1 1
Chi-square for linear trend: 308.617 (p <0.01)
Nearly all (80%) nosocomial UTI occur in patients with indwelling urinary catheters.
Nosocomial UTI occasionally results from direct introduction of urethral microorganisms at the
time of catheterization.3,13 Microorganisms can migrate to the bladder along the outside of the
catheter in the peri-urethral mucosal sheath (between the catheter and the urethral mucosa),3,11,13
the trans-urethral route, or along the internal lumen of the catheter after the collection bag or
catheter-drainage tube junction has been contaminated (intraluminal).
Bacteriuria may also occur as a result of entry of microorganisms into the collecting
system and ascend through the lumen of the urinary catheter into the bladder.2 Retrograde spread
of organisms from the collecting bag to the bladder occurs within 24-48 hours in nearly all such
patients. Risk factors associated with infection during catheterization are grouped into the
alterable and unalterable factors.3 Alterable factors include indications for catheterization, length
of catheterization, catheter care techniques and type of drainage system. Unalterable factors are
usually host factors associated with an increased risk of infection during or after instrumentation
and that include female sex, older age, severe underlying illness and meatal colonization.
The risk of developing bacteriuria in women exceeds that of men by approximately two-
fold in each decade of life.3 Among young, sexually active women, the prevalence of UTI is 5%
which is 30-50 times higher than among men. The incidence increases with age.22 In this study,
sex was not identified as risk factor for bacteriuria. In other reports, age is a significant factor for
bacteriuria with older age being associated with bacteriuria than the younger age. Without regard
to the sex, the risk of catheter-associated bacteriuria increases with age.15 Ninety-five per cent of
deaths and 83% of bacteremic episodes occur in patients over 50 years of age. However, in our
study, there was no association between age and the development of bacteriuria probably because
there were few elderly patients included.
Concomitant medications in catheterized patients may pose a risk for the development of
bacteriuria. Steroids for instance, especially in chronic use would theoretically predispose a
patient to infection by rendering the body immunosuppressed. However, this was not observed in
this study. Steroid intake of patients in this study was not associated with increased incidence of
Antibiotic intake was likewise not found to be posing a risk for bacteriuria in this study.
No direct evidence was found to implicate antibiotic intake itself as a risk factor for occurrence of
bacteriuria. On the other hand, intake of antibiotics would lead to colonization of unusual
pathogens in the urinary tract and would also increase acquisition of antibiotic-resistant
Type of drainage is a commonly recognized risk for bacteriuria with open drainage
associated with increased and early onset of bacteriuria in patients with indwelling urethral
catheters. After 4 days of catheterization, 100% of patients with indwelling urethral catheters
draining into an open system would be expected to have infection.13 The closed method on the
other hand only delays but not prevent the development of UTI. Studies have shown that over
20% of patients catheterized and maintained on closed drainage in busy hospital wards may be
expected to become infected.13
In our study, open drainage was associated with increased incidence of bacteriuria
(p<0.01) than the closed drainage and that even with closed drainage, bacteriuria still occurred in
10.7% of patients (about 43% of those who developed bacteriuria). In our study, of the 3 patients
who developed bacteriuria on the 2nd day of catheterization, 2 had open drainage system and one
had closed system.
Theoretically, meticulous catheter care should prevent or delay the development of
bacteriuria in patients with indwelling urethral catheters. Efforts to reduce the incidence of
catheter-associated infections have been directed towards preventing microorganisms at the
meatus from entering the bladder. Measures directed toward this objective include aseptic
catheter insertion, daily meatal cleansing and daily application of antimicrobial ointments or
solutions. These measures have theoretical values and can be expected to delay or prevent the
onset of infection. However 2 recent prospective, controlled studies have shown that these
measures were ineffective in reducing the frequency of catheter-associated infection in patients
on closed urinary drainage.13,14 Our study also showed that incidence of bacteriuria was higher
among patients in whom daily meatal care was applied compared to those in whom catheter care
was totally not done (p<0.01). Mobilization of the catheter during catheter care could irritate the
bladder mucosa inviting colonizers to ascend and invade the mucosal epithelium and proliferate.
Several studies have shown that the risk of developing bacteriuria increases with the
duration of the catheterization.11 About 50% of hospitalized patients catheterized longer than 7-10
days developed bacteriuria.
The average daily incidence of bacteriuria was 9.5%. This observation of increasing
incidence of bacteriuria with increasing duration of catheter was valid only up to the 6th day of
catheterization (p<0.05), beyond which, there was no more correlation because100% of patient
have developed bacteriuria.
Catheter-associated UTI are caused by variety of pathogens, including Escherichia coli,
Klebsiella, Proteus, Enterococcus, Pseudomonas, Enterobacter, Serratia, and Candida. Many of
these microorganisms are part of the patients' endogenous bowel flora, but they can also be
acquired by cross-transmission from other patients or hospital personnel or by exposure to
contaminated solutions or non-sterile equipment.13
Situations like immunosuppression, steroid intake, or antibiotic intake would change the
usual patterns of pathogens in catheter-associated bacteriuria.19In several reports, E. coli is the
most common uropathogen.3,23,24 Pseudornonas aeruginosa proved also to be a common
microorganisms isolated after by E. coli.
CONCLUSIONS AND RECOMMENDATIONS
1. The incidence of bacteriuria in patients with indwelling urethral catheters is 24.72% or
7 per 100 person-days with catheter.
2. The onset of bacteriuria in patients with indwelling urethral catheters is as early as the
2nd day of catheterization.
3. Risk factors associated with increased incidence of bacteriuria were: open drainage
system, daily catheter care done and prolonged indwelling catheterization.
4. Pseudomonas aeruginosa and E. coli are the common micro-organisms isolated in
patients with significant bacteriuria.
1. Indwelling urethral catheters should be avoided whenever possible and should neverbe
resorted to unless with absolute indications,
2. Catheters should be removed when they are no longer needed.
3. Strict asepsis should be observed and insertion should be done by trained personnel.
Before catheterization, preparation of meatal or perineal areas should always be observed using
an antiseptic or germicidal preparation. Handwashing should be done immediately before and
after manipulation of catheter site or apparatus.
4.Closed catheter drainage system should be employed in all cases. In an event where a
break is present anywhere in the system, the entire system should be replaced.
5. Frequent inspection to maintain free downhill flow must be done, making sure that no
obstruction is present.
1. CDC. Guidelines for Prevention of Catheter. Related UTI. In: Guidelines for Prevention and Control of Nosocomial Infection
1982. Center for Disease Control, Atlanta.
2. ICC Bulletin, PGH Infection Control Committee. Nosocomial Infection Prevalence Study in PGH for 1989. 1990; III(1)..
3. Bennet, JV, Brachmann, PS. Nosocomial Urinary Tract Infection, Hospital Infection, 2nd ed 1986. pp 375-384.
4. Mandell, Douglas, Bennet. Principles and Practice of Infectious Diseases. 3rd ed 1990. pp 2205-2215.
5. Glenister HM, Taylor IJ, Barlett CL, Cooke EM, MacKintosh CA, Leigh DA. An eleven-month incidence study of infections in
wards of a district general hospital. J Hospital Infect 1992; 261-273.
6. Liedberg H. Catheter-induced urethral inflammatory reactions and urinary tract infections. An experimental and clinical study. J
Urology 1989; suppl.
7. Patton JP, Nash DB, Abrutyn E. Urinary yract infection: Economic consideration. Med Clin North Am 1991; 75(2).
8. Garibaldi RA, Burke JP, Dickman ML, Smith CB. Factors predisposing to bacteriuria during indwelling urethral catheterization.
N Engl J Med 1974, 291:215-18.
9. Finkelherg Z, Kunin CM. Clinical evaluation of closed urinary drainage system. JAMA 1969; :201.
10. Stature WE. Guidelines for prevention of catheter-associated urinary tract infection. Ann Intern Med 1975; 82:386.
11. Garibaldi RA, et al. Meatal colonization and catheter associated bacteriuria. N Engl J Med 1980; 303-316.
12. Garibaldi RA, Mooney BR, Epstein BJ, Bratt MR. An evaluation of daily bacteriologic monitoring to identify preventable
episodes of catheter-associated urinary tract infection. Infect Control 1982; 3:466.
13. CDC. Guidelines for Prevention of Catheter-Related UTI. 1981. Atlanta, CDC.
14. Kunin CM, McCormarck RC. Prevention of catheter-induced urinary tract infection by sterile closed drainage. N Engl J Med
15. Hooton TM, Haley RM, Culver DH. The joint association of multiple risk factors with the occurrence of nosocomial infections.
Am J Med 1981; 70:960.
16. Korsenowski OM. Urinary tract infection in the impaired host. Med Clin North Am 1991; 75(2):391-404.
17. Lye WC, Chan RR, Lee EJ. Urinary tract infection in patients with diabetes mellitus. J Infect 1992; 24(2):169.74.
18. Gonick P, Schwartz AR. Nosocomial UrinaryTract Infection, 1976.
19. Asher EF, Oliver BG, Fry DE. Urinary tract infections in the surgical patients. Am J Surg 1988; 54(7):466-469.
20. ICC-PGH. Guidelines for Determining Presence and Classification of Infections, 1991.
21. Daifuku R, Stature WE. Association of rectal and urethral colonization with urinary tract infection in patients with indwelling
Catheters. JAMA 1984; 252:202-28.
22. Eriksen NH, Poulsen PN. Urinary tract infection: Etiology, diagnosis, and treatment with effective antibiotics. Nord Medicine
23. Gransden WR, Eykyn SJ, Philipps I, Rowe B. Bacteremia due to E. coil: A study of 861 episodes. Rev lnfect Dis 1990;
24. Lohr JA, Donowitz LG, Sadler JE. Hospital acquired urinary tract infection. Pediatr 1989; 83(2):193-199.
25. Holliman R, Seal DV, Archer H, Doman S. Controlled trial of chemical disinfection of urinary drainage bag. Reduction in
hospital-acquired catheter-associated infection. British J Urol 1987; 60(5):419-422.
26. Ruggieri MR, Hans DM, Levin RM. Reduction of bacterial adherence to catheter surface with heparin. J Urol 1987; 138(2):423-