Prevalence Of Bacteriuria Research Articles

Consequences of asymptomatic bacteriuria in the elderly

Asymptotic bacteriuria increases with advancing age for the ambulatory population. Men and women who are resident in long-term care facilities have an exceptionally high prevalence of bacteriuria. Despite this high prevalence and a high incidence of bacteriuria, urinary infection contributes little to morbidity and mortality in the elderley. While urinary infection is the most common source of bacteremic infection in the elderly, episodes of symptomatic urinary are infrequent relative to respiratory, gut, and skin infections. Substantial long-term complications of asymptomatic bacteriuria in the elederly have not been identified and there is no convincing evidence that asymptotic bacteriuria is associated with impaired survival. Further studies of the impact of asymptomatic bacteriuria in elderly populations to better define the association with symptomatic infection are needed.

Uncomplicated urinary tract infections in pregnant and non-pregnant women

Urinary tract infections (UTIs) are still one of the most common bacterial infections in pregnant and non-pregnant women. It is estimated that about 10-20% of all women suffer from a UTI at some point in life. The presence of UTI is defined as the existence of urinary symptoms such as frequency of urination and dysuria with or without bacteriuria or pyuria. The prevalence of bacteriuria in females varies from less than 1% in infants to 10% and more in older women. There are major differences in the clinical features between young and elderly women depending on the different pathogenesis, microbiology and general condition. Especially for elderly women, symptomatic and asymptomatic bacteriuria presents a risk factor for bacteraemia, sepsis and also increased mortality. During pregnancy, the prevalence of bacteriuria does not change but there are some changes in the pathogenesis that increase the rate of pyelonephritis. Asymptomatic bacteriuria rarely resolves spontaneously during this time. For non-pregnant women, short therapy strategies are recommended, preferably 3 days of trimethoprim-sulphamethoxazole (TMP/SMX) or quinolones. In pregnant women, therapy with amoxycillin or an oral cephalosporin is considered optimal.

Bacteriuria, bacterial virulence and host factors in diabetic patients.

The prevalence of bacteriuria as well as bacterial virulence and host factors were studied in 514 diabetic outpatients and 405 nondiabetic controls. The prevalence of bacteriuria was not significantly higher in diabetic women (15/239, 6.3%) than in age-matched nondiabetic women (8/236, 3.4%). In diabetic and nondiabetic men, the prevalence was also similar but lower than in women. E. coli was found in 55% of urine cultures with significant growth from diabetic patients, while in 91% of positive cultures from nondiabetic controls. Most E. coli strains lacked ability of P-fimbriae-mediated adhesion and aerobactin-mediated iron uptake, indicating low bacterial virulence. Long-term metabolic control (HbA1c), prevalence of retinopathy, neuropathy and previous foot ulcers were similar in bacteriuric and nonbacteriuric diabetic patients, matched according to gender, age, and duration of diabetes. Renal function was also similar, though the frequency of proteinuria and elevated blood pressure tended to be higher in the bacteriuric than in the noninfected group. Eight-three percent of the bacteriuric patients reported previous urinary tract infections but only 61% of nonbacteriuric patients (p = 0.07). As compared to non-diabetic women, diabetic women reported significantly more previous urinary tract infections (p < 0.01). In conclusion, the prevalence of bacteriuria in diabetic outpatients was not significantly higher than in non-diabetic outpatients or healthy volunteers. No studied host factor was clearly associated with bacteriuria in diabetic patients, although proteinuria and hypertension tended to be more common. The infecting E. coli strains were of low virulence.

Urinary tract infections in long-term care facilities.

Urinary tract infection, or bacteriuria, is common in residents of long-term care facilities (LTCFs). The prevalence of bacteriuria in noncatheterized residents of LTCFs has been reported to be 15% to 50% in studies performed in several different countries (Table). As with most other age groups, the prevalence is greater for women than men. The female to male ratio is, however, lower than in younger populations.The incidence of bacteriuria is also extremely high. In one group of severely functionally disabled elderly men, 45 new infections/100 patient years were observed, with 10% of nonbacteriuric residents becoming bacteriuric in each three-month period. An institutionalized population in Greece had initial prevalences of bacteriuria of 19% for men and 27% for women, with an additional 11% and 23% of the non-bacteriuric population, respectively, developing a positive urine culture at 6 or 12 months from admission.4 A nursing home population of elderly women in Philadelphia, with an initial prevalence of bacteriuria of 25%, had an additional 8% of the initially nonbacteriuric subjects identified with a positive urine culture each six-month period of follow-up.

The case against screening urinalyses for asymptomatic bacteriuria in children

• Screening children for asymptomatic bacteriuria to prevent pyelonephritis and renal scarring is widely recommended, but its cost-effectiveness has not been established. We reviewed published studies to determine the costs and benefits of screening toilet-trained, asymptomatic children for bacteriuria. Given the sensitivity and specificity of current screening methods (approximately 80% each) and the prevalence of bacteriuria in asymptomatic children (approximately 1% in girls and 0.03% in boys), screening 100 000 children would result in 19 897 (20%) false-positive tests; initial screening and two urine cultures to confirm the diagnosis of asymptomatic bacteriuria would miss 28% of 515 children with true bacteriuria, and cost nearly $2.9 million. There is no evidence that detection and treatment of children with asymptomatic bacteriuria prevents subsequent pyelonephritis or renal scarring. Screening for bacteriuria in asymptomatic children is costly, fails to prevent pyelonephritis or renal scarring, and should be discontinued as a part of routine well-child care. ( AJDC . 1992;146:343-346)

Scanning electron microscopy of bacterial biofilms on indwelling bladder catheters.

Fifty Foley bladder catheters that had been indwelling for periods ranging from 3 to 83 days (mean 35 days) were examined for the presence of bacterial biofilm. Scanning electron microscopy on freeze-dried cross-sections and fixed, critical point-dried longitudinal sections revealed biofilm formation on the luminal surfaces of 44 of the catheters. Culture of urine samples and sonicates from catheters revealed that the prevalence of bacteriuria was less than that of catheter colonization. A wide range of nosocomial species were found colonizing the catheters, Escherichia coli being most often isolated. The bacterial composition of the biofilms ranged from single species to mixed communities containing up to four species. There was no relationship between the length of time that the catheter had been in situ and the extent of biofilm formation. The biofilms varied in thickness from 3 to 490 microns and were visible as layers of bacterial cells up to about 400 cells deep, embedded in a matrix.

Effect of external urinary collection system on colonization and urinary tract infections with Pseudomonas and Klebsiella in men with spinal cord injury.

Urinary tract infection of men with spinal cord injuries has been associated with a high incidence of colonization of the patients with gram-negative bacilli. We have examined the factors influencing colonization of 119 patients with Pseudomonas and Klebsiella and studied methods of reducing this colonization. The urethra, perineum, rectum, and drainage bag of all patients were cultured on selective media at two week intervals until discharge. The use of the external urinary collection system (EUCS) was discontinued in a group of patients at night, in an attempt to reduce colonization. Pseudomonas and Klebsiella were isolated from one or more body sites in 65 percent and 69 percent of total culture days. The urethra, perineum, rectum, and drainage bags were reservoirs of Pseudomonas and Klebsiella in men with spinal cord injuries, even in the absence of urinary tract infections. The EUCS proved to be an important factor influencing colonization. Pseudomonas and Klebsiella colonization was higher in patients using the EUCS. Removal of the EUCS at night reduced urethral colonization with Pseudomonas, but did not significantly reduce urethral colonization with Klebsiella. The prevalence of bacteriuria with Pseudomonas and Klebsiella was not significantly influenced by the use of the EUCS.

Characteristics of bacteriuria in a homogeneous maternity hospital population

Bacteriuria and urinary tract infection are a common cause of morbidity in pregnancy. Recent evidence has, however, questioned the magnitude of this risk and the effectiveness of therapy in reducing it. To clarify matters, a prospective study on 3123 ante-natal women was carried out. Screening for bacteriuria was carried out by culturing a mid-stream specimen of urine. Treatment was given to all patients with a positive culture and was based on antibiotic sensitivity testing. Repeat culture was performed 1 week after completion of therapy. The prevalence of bacteriuria in our population was 4.74%. Over half of these patients were asymptomatic. 67% of those with bacteriuria at screening were symptomatic or had a past history of urinary tract infection. Escherichia coli was the predominant organism cultured. The most effective antibiotic was Nitrofurantoin, which was sensitive in over 90% of isolates. Late urinary tract infection occurred in 3.52% of patients. There was no increase in maternal or foetal complications amongst those with bacteriuria. We concluded that it might be more cost-effective to confine screening to those patients who are symptomatic or have a past history of urinary tract infection.

The case against screening urinalyses for asymptomatic bacteriuria in children.

Screening children for asymptomatic bacteriuria to prevent pyelonephritis and renal scarring is widely recommended, but its cost-effectiveness has not been established. We reviewed published studies to determine the costs and benefits of screening toilet-trained, asymptomatic children for bacteriuria. Given the sensitivity and specificity of current screening methods (approximately 80% each) and the prevalence of bacteriuria in asymptomatic children (approximately 1% in girls and 0.03% in boys), screening 100,000 children would result in 19,897 (20%) false-positive tests; initial screening and two urine cultures to confirm the diagnosis of asymptomatic bacteriuria would miss 28% of 515 children with true bacteriuria, and cost nearly $2.9 million. There is no evidence that detection and treatment of children with asymptomatic bacteriuria prevents subsequent pyelonephritis or renal scarring. Screening for bacteriuria in asymptomatic children is costly, fails to prevent pyelonephritis or renal scarring, and should be discontinued as a part of routine well-child care.

Bacteriuria in the elderly: a review

The prevalence of urinary infection increases with age, reaching over 50% for both sexes amongst the highly functionally disabled institutionalized elderly. The factors promoting such a high prevalence of bacteriuria are not clearly determined, but are likely multifactorial. Bacteriuria is, generally, asymptomatic. Treatment of asymptomatic bacteriuria in the institutionalized elderly has not been shown to be beneficial. In particular, treatment does not prevent subsequent symptomatic episodes or influence mortality. Antimicrobial therapy is, however, associated with adverse effects, and promotes the emergence of resistant organisms. Early recurrence is the rule following therapy in the institutionalized elderly and prolonged periods free of bacteriuria are seldom achieved. Symptomatic infection may manifest as invasive infection or irritative symptoms. Ascertainment of the presence or absence of symptoms in the impaired nursing home population may be difficult. The chronic genitourinary symptoms observed in many of these patients are not, however, due to urinary infection.

"Escherichia coli bacteriuria and Contraceptive Method"

We evaluated the effects of contraceptive method on the occurrence of bacteriuria and vaginal colonization with Escherichia coli in 104 women who were evaluated prior to having sexual intercourse, the morning after intercourse, and 24 hours later. After intercourse, the prevalence of E coli bacteriuria increased slightly in oral contraceptive users but dramatically in both foam and condom users and diaphragm-spermicide users. Twenty-four hours later, the prevalence of bacteriuria remained significantly elevated only in the latter two groups. Similarly, vaginal colonization with E coli was more dramatic and persistent in users of diaphragm-spermicide and foam and condoms. Vaginal colonization with Candida species, enterococci, and staphylococci also increased significantly in diaphragm-spermicide users after intercourse. We conclude that use of the diaphragm with spermicidal jelly or use of a spermicidal foam with a condom markedly alters normal vaginal flora and strongly predisposes users to the development of vaginal colonization and bacteriuria with E coli.

Bacteriuria in elderly female subjects

Bacteriuria in elderly female subjects is diagnosed by the finding of ⩾105 CFU/ml of the same organism in a pure growth in two consecutive voided urine samples. Recent work has shown that screening tests for bacteriuria can be accurately used in elderly subjects. The prevalence of bacteriuria in elderly subjects is much higher than that in younger subjects, a finding which is due to a number of factors including changes in immunity, a higher prevalence of structural abnormalities of the genitourinary tract and changes in periurethral bacterial colonization.

Escherichia coli Bacteriuria and Contraceptive Method

We evaluated the effects of contraceptive method on the occurrence of bacteriuria and vaginal colonization with Escherichia coli in 104 women who were evaluated prior to having sexual intercourse, the morning after intercourse, and 24 hours later. After intercourse, the prevalence of E coli bacteriuria increased slightly in oral contraceptive users but dramatically in both foam and condom users and diaphragm-spermicide users. Twenty-four hours later, the prevalence of bacteriuria remained significantly elevated only in the latter two groups. Similarly, vaginal colonization with E coli was more dramatic and persistent in users of diaphragm-spermicide and foam and condoms. Vaginal colonization with Candida species, enterococci, and staphylococci also increased significantly in diaphragm-spermicide users after intercourse. We conclude that use of the diaphragm with spermicidal jelly or use of a spermicidal foam with a condom markedly alters normal vaginal flora and strongly predisposes users to the development of vaginal colonization and bacteriuria with E coli.

Screening for Bacteriuria in Japanese School Children

Bacteriuria was screened among 28,202 healthy school children, 14,575 boys and 13,627 girls, by dipstick and dipslide methods and also by pour plate culture. The prevalence of bacteriuria was 0.06% in boys and 0.52% in girls after the third screening. A high rate of false negative results with the dipstick test and a high rate of false positive results with the dipslide culture method using Microstix-3 were observed. About 60% of screened children continued to have bacteriuria persistently for 9 months after the third screening, which was followed by monthly urine cultures. Anomalies of the urinary tract were detected in 9 of 26 children with persistent bacteriuria.

Dipstick urinalysis screening of asymptomatic adults for urinary tract disorders. II. Bacteriuria

Using criteria adopted by the US Preventive Services Task Force, we evaluated use of the dipstick urinalysis to screen for bacteriuria. When the leukocyte esterase and nitrite dipstick tests are combined, the positive predictive value for detecting bacteriuria exceeded 12% in groups with a 5% or higher prevalence of bacteriuria: women who are pregnant, diabetic, or over 60 years of age and all institutionalized elderly. Conventional antimicrobial regimens for asymptomatic bacteriuria have proved efficacious only for pregnant women. We conclude that pregnant women should be screened for bacteriuria, but with the more sensitive urine culture, because treatment prevents serious fetal and maternal sequelae. Dipstick screening may be justified in women who are over 60 years of age or diabetic. The prevalence of bacteriuria in other groups is too low to justify screening. (JAMA. 1989;262:1220-1224)

Female Urinary Tract Infection in Primary Health Care: Bacteriological and Clinical Characteristics

Female patients with symptoms of urinary tract infection (n = 1136) were studied in primary health care with respect to (a) clinical symptoms as predictors of bacteriuria; (b) relation between aetiological agent and clinical picture, especially for P-fimbriated Escherichia coli; and (c) clinical findings in cases with 10(2)- less than 10(5) CFU/ml of E. coli. Prevalence of bacteriuria (greater than or equal to 10(5) CFU/ml) was 61%. Concurrence of urgency/frequency and dysuria, short duration of symptoms and hematuria increased the probability of bacteriuria and were also significantly more frequent among cases with low counts of E. coli (10(2) less than 10(5) CFU/ml in pure culture or mixed flora) than among cases with sterile urine, indicating an aetiological role of E. coli in many of those cases. Infections with P-fimbriated E. coli were as benign as the P-fimbriae-negative. The rate of P-fimbriation was 29% in specimens containing greater than or equal to 10(5) CFU/ml of E. coli, 30% among specimens with less than 10(5) CFU/ml in pure culture and 10% in specimens containing less than 10(5) CFU/ml of E. coli in mixed culture. Patients infected with Klebsiella, Enterobacter or Proteus did not show a higher rate of previous urinary tract disease or anomalies.

Bacteriuria in Non-catheterized Elderly Patients in the First Eight Days of Hospital Stay

One hundred and sixty-one non-catheterized consecutive acute geriatric admissions were screened for bacteriuria on the day following admission, both in the morning and in the afternoon and seven days later--morning and afternoon. The prevalence of bacteriuria was 29% on admission. A correlation between bacteriuria and leucocyturia was shown. The patients were admitted with a variety of medical illnesses but in no case was a diagnosis of urinary-tract infection made prior to admission. There was a significant relationship between incontinence and bacteriuria on admission; 12% of abacteriuric patients became bacteriuric between day 1 and day 7 following admission. Escherichia coli accounted for 51% of the isolates on admission to hospital. Bacteriuria was associated with increased mortality within 1 year following admission to hospital.

Socio-biological correlates of bacteruria in Saudi pregnant women

Prevalence and socio-biological correlates of bacteriuria in Saudi pregnant women were investigated at King Fahd Hospital of the University, Al-Khobar, Saudi Arabia. Midstream sample specimens of urine were used for identification of significant bacteriuria (greater than or equal to 10.5 organisms of single species per milliliter of urine). The prevalence of bacteriuria was found to be 14.2%. It was more common in women below 20 years of age and among the parous as against the nullipara women. Bacteriuria was significantly associated with socio-economic conditions. It was higher in those with a low family income, of large family size (10+) and living in over-crowded conditions. Only one-fourth (25.8%) of bacteriuric women were symptomatic. Almost half (45.8%) had a past history of urinary tract infection. To identify the problem of urinary tract infection in a vulnerable group of women, as well as to reduce the load on laboratory facilities, it is suggested that routine antenatal screening for bacteriuria should be advocated on a selective basis, i.e. for the young teenage parous women, those coming from disadvantaged socio-economic conditions and in patients with a past history of urinary tract infection.

No specific association between primary biliary cirrhosis and bacteriuria?

160 consecutive patients with primary biliary cirrhosis (PBC) (M:F, 13:147; total samples 286), 140 patients with other chronic liver disease (CLD) (M:F, 75:65; total samples 200), and 28 patients with primary Sjogren's syndrome (all F; total samples 37), were examined for bacteriuria over 6 months by midstream urine (MSU) examination. The overall prevalence of bacteriuria in PBC was 11.2% (7.5% on first MSU), in CLD 12.1% (10.7% on first MSU), 18.4% in the 65 female CLD patients, 10.7% in Sjögren's syndrome patients (3.5% on first MSU). The prevalence of bacteriuria was related to the age of the patient ( P < 0.02) in PBC and to the presence or absence of cirrhosis in both PBC and CLD ( P < 0.02). There was no difference in the prevalence of bacteriuria between PBC and CLD patients taken as a whole or among females alone, cirrhotic or non-cirrhotic groups. In a second prospective study of the cumulative incidence of bacteriuria in PBC versus CLD and Sjögren's no significant differences between groups was observed but among 29 PBC patients the cumulative proportion of positive tests for bacteriuria after 5 months (monthly testing) was 34%. We conclude that there is no specific association between PBC and bacteriuria compared with the prevalence of bacteriuria in other CLD.

The prevalence of bacteriuria among high risk neonates in Nigeria.

Among the 446 high risk neonates studied for significant bacteriuria and pyuria in the neonatal wards of the Obafemi Awolowo University teaching hospital Complex, Ile-Ife, 7.6% and 5.8% were positive for significant bacteriuria and pyuria respectively, while none of the 81 infants in the control group were positive. Males and females were similarly affected and there was no seasonal variation in the prevalence of pyuria or bacteriuria. It is noteworthy that 25 (96%) of the 26 pyuria neonates also had bacteriuria emphazising the significance of pyuria as a possible screening method for urinary tract infections in neonates. The clinical problems in the neonates studied included prematurity, low birthweight, neonatal jaundice, fever, CNS symptoms, ophthalmia neonatorum, prolonged rupture of the membranes (PROM), respiratory distress, septic cord/skin, diarrhoea, vomiting and feeding problems. Only prematurity and low birthweight were significantly associated with bacteriuria in the neonates studied. The organisms encountered in this study were Escherichia coli (58.4%), Klebsiella species (35.3%) and Proteus species (5.9%). Of the bacterial isolates, 67% were sensitive to Ampicillin and 97% to Gentamycin. The combination of these antibiotics was effective in all cases in the present study. The study has highlighted the need for routine urine culture in our high risk neonates.