Bacteriuria of pregnancy--a critical appraisal

Asymptomatic bacteriuria screening for developing countries using a modified water quality test kit

Between 2% and 15% of pregnant women unknowingly experience asymptomatic bacteriuria (ASB), defined as ≥105 CFU per milliliter of urine in the absence of symptoms. ASB increases the risk of adverse pregnancy outcomes including pyelonephritis, preterm labor, and low-birth weight infants. While pregnant women in the United States are routinely screened for ASB, those in developing countries with limited resources and funding lack an accurate mechanism for ASB screening. Aquagenx water quality test kits detect Escherichia coli, the most common causative agent of ASB, and total coliform bacteria in drinking water via colorimetric and fluorescent indicators. We found that the Aquagenx system is compatible with human urine and then proceeded to develop an ASB screening protocol using disposable inoculating loops. Our protocol diagnosed artificial ASB- samples (104 CFU/mL E. coli) with a false positive (FP) rate of 33% (n = 18) and ASB+ (105 CFU/mL E. coli) with a false negative (FN) rate of 5.6% (n = 18). Clinical sample testing with our protocol revealed a FP rate of 0% in ASB- samples (n = 28) and a FN rate of 0% in ASB+ samples caused by coliforms (n = 13). Aquagenx did not detect ASB in nine clinical samples with non-coliform etiological agents due to the limitations of the technology. However, with very high accuracy for detection of E. coli and other causative agents that collectively account for 90.1% of ASB cases, these kits could be used as a diagnostic ASB screening tool in developing countries in which there is currently no alternative to urine culture.IMPORTANCEAsymptomatic bacteriuria (ASB) affects 2%-15% of pregnant women and can result in adverse maternal and fetal outcomes if left undetected and untreated. In the United States and other developed nations, pregnant women are regularly screened for ASB via urine culture. However, in low-resource countries where bacterial culture is not available, dipstick testing is used. Although accurate in cases of symptomatic bacteriuria, dipstick detection is ineffective for detecting ASB. Here, we made use of an existing water quality field test for ASB urine screening, which would be readily deployable in low-resource settings. We optimized a dilution protocol for sampling patient urine within the detection limits of the Aquagenx kit technology. Overall, we were able to detect ASB samples with Gram-negative pathogens that collectively account for 90% of all ASB cases. Utilization of this repurposed technology for proactive medical screening may help prevent adverse pregnancy and birth outcomes due to ASB.

Magnitude and associated factors of bacterial urinary tract infections among paediatric patients in Arba Minch, southern Ethiopia

Bacterial urinary tract infections (UTI) commonly occur in children; if left untreated, they may result in severe consequences such as uro-sepsis and renal damage. This study aimed to determine the bacterial profile, antimicrobial susceptibility patterns and associated factors among paediatric patients suspected of urinary tract infections in Arba Minch General Hospital (AMGH). An institution-based cross-sectional study was conducted from 01 October 2020 to 31 January 2021. A convenient sampling technique was used to recruit the participants; data were collected using a pre-tested questionnaire. To quantify the bacteria (as per the Kass count, >10⁵CFU/ml), midstream urine samples were streaked onto bacteriological media. Isolates were identified by following standard procedures. The antibiotic susceptibility test was performed as per the Kirby-Bauer disc diffusion technique. Data were analyzed using SPSS software. Out of the 246 children included, 38 (15.4%) were found to be positive for significant bacteriuria. Isolates of Escherichia coli, 9/38 (23.7%), and Staphylococcus aureus, 9/38 (23.7%), were the most predominant. The majority of Gram-negative bacterial (GNB) isolates showed resistance towards amoxicillin-clavulanate (89.5%), ampicillin (84.6%), and ceftazidime (81%). Likewise, 76.9 and 76.5% of Gram-positive bacteria (GPB), respectively, had shown resistance towards co-trimoxazole and tetracycline. Multi-drug and extensively drug resistance were detected respectively in the case of 68.4 and 15.8% of the total isolates; ESBL production was found in 57.1% of GNB, whereas 55.6% of S. aureus were methicillin-resistant S. aureus (MRSA). The process of un-circumcision was significantly associated with UTI [(adjusted odds ratio= 3.578; 95% confidence interval: 1.263 - 10.13; p=0.016)].

Magnitude and antimicrobial susceptibility profiles of Gram-Negative bacterial isolates among patients suspected of urinary tract infections in Arba Minch General Hospital, southern Ethiopia

The emergence of drug-resistant Gram-negative bacterial uropathogens poses a grave threat worldwide, howbeit studies on their magnitude are limited in most African countries, including Ethiopia. Therefore, measuring the extent of their drug resistance is essential for developing strategies to confine the spread. A cross-sectional study was conducted at title hospital from 01 June to 31 August 2020. Midstream urine specimens were collected and inoculated onto MacConkey agar. Positive urine cultures showing significant bacteriuria as per the Kass count (>105 CFU/mL) were further subjected to biochemical tests to identify the type of uropathogens. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disk diffusion technique, and potential carbapenemase producers were phenotypically determined by the modified carbapenem inactivation method as per the CLSI guidelines. Data were analyzed using SPSS version 26; P-value <0.05 was considered statistically significant. Totally, 422 patients were included, and the majority were females (54.7%). The prevalence of carbapenem-resistant Gram-negative uropathogens was 12.9%, and 64.7% of them were carbapenemase producers. Klebsiella pneumoniae (n = 5) was the predominant carbapenemase producer, followed by Pseudomonas aeruginosa (n = 4). Consumption of antibiotics prior to six months of commencement of the study, the presence of chronic diseases and hospitalizations were statistically associated with UTI caused by carbapenem-resistant Gram-negative uropathogens. Carbapenemase producers were resistant to most of the antibiotics tested. Our findings highlight the need for periodic regional bacteriological surveillance programs to guide empirical antibiotic therapy of UTI.

Asymptomatic Bacteriuria and Pyuria in Premenopausal Women

BACKGROUND

Asymptomatic bacteriuria and pyuria in healthy women often trigger inappropriate antimicrobial treatment, but there is a paucity of data on their prevalence and persistence.

METHODS

To evaluate the prevalence and persistence of asymptomatic bacteriuria and pyuria in women at high risk of recurrent urinary tract infection, we conducted an observational cohort study in 104 healthy premenopausal women with a history of recurrent urinary tract infection with daily assessments of bacteriuria, pyuria, and urinary symptoms over a 3-month period.

RESULTS

The mean age of participants was 22 years, and 74% were white. Asymptomatic bacteriuria events (urine cultures with colony count ≥105 CFU/mL of a uropathogen on days with no symptomatic urinary tract infection diagnosed) occurred in 45 (45%) women on 159 (2.5%) of 6283 days. Asymptomatic bacteriuria events were most commonly caused by Escherichia coli, which was present on 1.4% of days, with a median duration of 1 day (range, 1-10). Pyuria occurred in 70 (78%) of 90 evaluable participants on at least 1 day and 25% of all days on which no symptomatic urinary tract infection was diagnosed. The positive predictive value of pyuria for E. coli asymptomatic bacteriuria was 4%.

CONCLUSIONS

In this population of healthy women at high risk of recurrent urinary tract infection, asymptomatic bacteriuria is uncommon and, when present, rarely lasts more than 2 days. Pyuria, on the other hand, is common but infrequently associated with bacteriuria or symptoms. These data strongly support recommendations not to screen for or treat asymptomatic bacteriuria or pyuria in healthy, nonpregnant women.

Diagnosis, Treatment, and Prevention of Urinary Tract Infection

UTI may involve the lower or upper urinary tract and may be uncomplicated or complicated. The emphasis of this chapter is uncomplicated UTI. The diagnosis of uncomplicated cystitis (bladder infection) and pyelonephritis (kidney infection) is usually easily made based on the clinical presentation, whereas the diagnosis in patients with complicated UTI is often more complex. Thus uncomplicated cystitis is usually manifested by dysuria, frequency and/or urgency without fever, and pyelonephritis is usually manifested by fever and back pain/costovertebral angle tenderness. However, pyuria is usually present with UTI, regardless of location, and its absence suggests that another condition may be causing the patient's symptoms. Treatment of cystitis is usually straightforward with one of several effective short-course antimicrobial regimens, although antimicrobial resistance continues to increase and can complicate treatment choices in certain areas. Likewise, antimicrobial resistance has complicated our management of uncomplicated pyelonephritis since resistance of uropathogens to the fluoroquinolone class, the mainstay of oral treatment for pyelonephritis, is increasing worldwide, and some of the other agents used for cystitis are not recommended for pyelonephritis due to low tissue levels. The goal of prevention of recurrent cystitis is to minimize the use of antimicrobials and there are several research efforts in progress to develop effective and safe antimicrobial-sparing preventive approaches for this common condition.

The Uriscreen Test to Detect Significant A symptomatic Bacteriuria During Pregnancy

BACKGROUND

Asymptomatic bacteriuria (ASB) occurs in 2-11% of pregnancies and it is a clear predisposition to the development of acute pyelonephritis, which, in turn, poses risk to mother and fetus. Treatment of bacteriuria during pregnancy reduces the incidence of pyelonephritis. Therefore, it is recommended to screen for ASB at the first prenatal visit. The gold standard for detection of bacteriuria during pregnancy is urine culture, but this test is expensive, time-consuming, and labor-intensive.

OBJECTIVE

To determine the reliability of an enzymatic urine screening test (Uriscreen; Savyon Diagnostics, Ashdod, Israel) for detecting ASB in pregnancy.

METHODS

Catheterized urine samples were collected from 150 women who had routine prenatal screening for ASB. Patients with urinary symptoms, active vaginal bleeding, or who were previously on antibiotics therapy were excluded from the study. Sensitivity, specificity, and the positive and negative predictive values for the Uriscreen were estimated using urine culture as the criterion standard. Urine cultures were considered positive if they grew >10(5) colony-forming units of a single uropathogen.

RESULTS

Twenty-eight women (18.7%) had urine culture results indicating significant bacteriuria, and 17 of these 28 specimens had positive enzyme activity. Of 122 samples with no growth, 109 had negative enzyme activity. Sensitivity, specificity, and positive and negative predictive values for the Uriscreen test were 60.7% (+/-18.1), 89.3% (+/-5.6), 56.6%, and 90.8%, respectively.

CONCLUSION

The Uriscreen test had inadequate sensitivity for rapid screening of bacteriuria in pregnancy.

Delta Neutrophil Index as a Marker for Differential Diagnosis between Acute Graft Pyelonephritis and Acute Graft Rejection

Introduction

The delta neutrophil index (DNI) is the fraction of circulating immature granulocytes, which reflect infectious and/or septic condition. Acute graft pyelonephritis (AGPN) versus acute graft rejection is a frequently encountered diagnostic and therapeutic dilemma in kidney transplant recipients, but little is known about the clinical usefulness of DNI value in the differentiation of the two conditions.

Material & Methods

A total of 90 episodes of AGPN or acute graft rejection were evaluated at the Kangdong Sacred Heart Hospital between 2008 and 2014. We performed retrospective analysis of demographic, clinical, and laboratory parameters data. Receiver operating curves (ROC) and multivariate logistic regression were conducted to ascertain the utility of DNI in discriminating between AGPN and acute graft rejection.

Results

AGPN group had significantly higher DNI values than acute graft rejection group (2.9% vs. 1.9%, P < 0.001). The area under the ROC curve for DNI value to discriminate between AGPN and acute graft rejection was 0.85 (95% confidence interval [CI]; 0.76–0.92, P < 0.001). A DNI value of 2.7% was selected as the cut-off value for AGPN, and kidney transplant recipients with a DNI value ≥ 2.7% were found to be at a higher risk of infection than those with a DNI < 2.7% (odd ratio [OR] 40.50; 95% CI 8.68–189.08; P < 0.001). In a multivariate logistic regression analysis, DNI was a significant independent factor for predicting AGPN after adjusting age, sex, log WBC count, log neutorphil count, log lymphocyte count, CRP concentration, and procalcitonin concentration (OR 4.32; 95% CI 1.81–10.34, P < 0.001).

Conclusions

This study showed that DNI was an effective marker to differentiate between AGPN and acute graft rejection. Thus, these finding suggest that DNI may be a useful marker in the management of these patients.

Diagnosis of asymptomatic bacteriuria and associated risk factors among pregnant women in mangalore, karnataka, India

BACKGROUND

Asymptomatic bacteriuria (AB) is common inwomen and increases in prevalence with age or sexual activity. Prompt detection and treatment of this condition and associated factors decreases complications like acute pyleonephritis, intrauterine growth retardation and preterm labour. Chromogenic media is a versatile tool in rapid primary screening of the causative organisms considerably reducing daily routine workload.

AIM

To determine the prevalence of AB among pregnant women in a tertiary care set-up and analyse the contributory risk factors, its effects on pregnancy and the role of chromogenic media in the laboratory diagnosis of these cases.

MATERIALS AND METHODS

Urine samples of all pregnant women attending pre-natal check-ups with no genitourinary complaints, history of fever or antibiotic intake were collected for Gram stain, culture and antibiotic sensitivity tests. A second urine specimen for culture and sensitivity testing was obtained from those with significant bacteriuria. The results were compared with patients showing negative urine cultures.

RESULTS

The overall prevalence of this clinical condition in our study was 13.2%. The significant isolates were Klebsiella pneumonia and E.coli and the most common risk factor was a previous history of urinary tract infection. The isolates were easily identified by using chromogenic agar ( HiCrome ) but colonies of uncommon pathogens like Acinetobacter and Streptococcus species appeared white and needed further identification.

CONCLUSION

Screening of pregnant women for AB at first prenatal checkup helps analyse the associated factors and prevents its effects on pregnancy. The use of a chromogenic media can enhance reporting accuracy and will be an effective tool to monitor these cases routinely.

Effect of honey in preventing gingivitis and dental caries in patients undergoing orthodontic treatment

OBJECTIVES

THIS STUDY WAS CONDUCTED TO INVESTIGATE THE FOLLOWING: (1) the effects of chewing honey on plaque formation in orthodontic patients, (2) the effect of chewing honey on dental plaque bacterial counts, (3) determine if honey possesses antibacterial effects on bacteria recovered from plaques.

METHODS

Female orthodontic patients (n = 20, 12-18 years of age) participated in this randomized controlled study. The effects of honey were compared to treatment with either 10% sucrose or 10% sorbitol that served as positive and negative controls, respectively. The pH of plaque was measured using a digital pH meter prior to baseline and at 2, 5, 10, 20, and 30 min after chewing honey or rinsing with control solutions and the numbers of Streptococcus mutans, Lactobacilli, and Prophymonas gingivalis in respective plaques were determined. The antibacterial activity of honey was tested against commonly used antibiotics using the disk diffusion method.

RESULTS

Significant differences in pH were observed in the honey and sucrose groups compared to the pH observed in the sorbitol group (p ⩽ 0.001). The maximum pH drop occurred at 5 min in both the honey and sucrose groups; however the pH in the honey group rapidly recovered 10-20 min after exposure and did not drop below the critical decalcification pH of 5.5. On the other hand, the pH following sucrose exposure fell <5.5 and was associated with a 30 min recovery time. The pH observed for the sorbitol group did not change over time. Bacterial counts were significantly reduced in the honey group compared to the other treatment groups (p ⩽ 0.001) and honey significantly inhibited the growth of all studied strains compared to inhibition observed with antibiotics (p ⩽ 0.001).

CONCLUSIONS

Honey can be used as an alternative to traditional remedies for the prevention of dental caries and gingivitis following orthodontic treatment.

Preanalytical requirements of urinalysis

Urine may be a waste product, but it contains an enormous amount of information. Well-standardized procedures for collection, transport, sample preparation and analysis should become the basis of an effective diagnostic strategy for urinalysis. As reproducibility of urinalysis has been greatly improved due to recent technological progress, preanalytical requirements of urinalysis have gained importance and have become stricter. Since the patients themselves often sample urine specimens, urinalysis is very susceptible to preanalytical issues. Various sampling methods and inappropriate specimen transport can cause important preanalytical errors. The use of preservatives may be helpful for particular analytes. Unfortunately, a universal preservative that allows a complete urinalysis does not (yet) exist. The preanalytical aspects are also of major importance for newer applications (e.g. metabolomics). The present review deals with the current preanalytical problems and requirements for the most common urinary analytes.

Voided midstream urine culture and acute cystitis in premenopausal women

BACKGROUND

The cause of acute uncomplicated cystitis is determined on the basis of cultures of voided midstream urine, but few data guide the interpretation of such results, especially when gram-positive bacteria grow.

METHODS

Women from 18 to 49 years of age with symptoms of cystitis provided specimens of midstream urine, after which we collected urine by means of a urethral catheter for culture (catheter urine). We compared microbial species and colony counts in the paired specimens. The primary outcome was a comparison of positive predictive values and negative predictive values of organisms grown in midstream urine, with the presence or absence of the organism in catheter urine used as the reference.

RESULTS

The analysis of 236 episodes of cystitis in 226 women yielded 202 paired specimens of midstream urine and catheter urine that could be evaluated. Cultures were positive for uropathogens in 142 catheter specimens (70%), 4 of which had more than one uropathogen, and in 157 midstream specimens (78%). The presence of Escherichia coli in midstream urine was highly predictive of bladder bacteriuria even at very low counts, with a positive predictive value of 10(2) colony-forming units (CFU) per milliliter of 93% (Spearman's r=0.944). In contrast, in midstream urine, enterococci (in 10% of cultures) and group B streptococci (in 12% of cultures) were not predictive of bladder bacteriuria at any colony count (Spearman's r=0.322 for enterococci and 0.272 for group B streptococci). Among 41 episodes in which enterococcus, group B streptococci, or both were found in midstream urine, E. coli grew from catheter urine cultures in 61%.

CONCLUSIONS

Cultures of voided midstream urine in healthy premenopausal women with acute uncomplicated cystitis accurately showed evidence of bladder E. coli but not of enterococci or group B streptococci, which are often isolated with E. coli but appear to rarely cause cystitis by themselves. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases.).

The pre-analytical challenges of routine urinalysis

An effective diagnostic strategy for urinalysis should be based on standard procedures for collection, transport, sample preparation and analysis. In view of a better reproducibility of the analyses, the pre-analytical requirements become stricter. Various sample methods can cause significant pre-analytical errors. It is a challenge for the laboratory to control the steps in the pre-analytical phase that contribute to pre-analytical variability. To reduce the variability, it is necessary to look at the pre-analytical process as a complete entity, from test ordering to the moment of specimen processing. Clinical laboratories are responsible for the clinical and financial outcome of this phase. In a culture of increasing productivity, lower costs and improving quality, the challenge is to use several tools designed to standardize and optimize urinalysis. Despite advances in the performance of analytic systems, the pre-analytical phase of modern urinalyses has not been studied very thoroughly. This review of the literature lights on different problems in current pre-analytical requirements for particle and test strip analysis of urine samples.

Genetic variation of the human urinary tract innate immune response and asymptomatic bacteriuria in women

Background

Although several studies suggest that genetic factors are associated with human UTI susceptibility, the role of DNA variation in regulating early in vivo urine inflammatory responses has not been fully examined. We examined whether candidate gene polymorphisms were associated with altered urine inflammatory profiles in asymptomatic women with or without bacteriuria.

Methodology

We conducted a cross-sectional analysis of asymptomatic bacteriuria (ASB) in 1,261 asymptomatic women ages 18-49 years originally enrolled as participants in a population-based case-control study of recurrent UTI and pyelonephritis. We genotyped polymorphisms in CXCR1, CXCR2, TLR1, TLR2, TLR4, TLR5, and TIRAP in women with and without ASB. We collected urine samples and measured levels of uropathogenic bacteria, neutrophils, and chemokines.

Principal Findings

Polymorphism TLR2_G2258A, a variant associated with decreased lipopeptide-induced signaling, was associated with increased ASB risk (odds ratio 3.44, 95%CI; 1.65–7.17). Three CXCR1 polymorphisms were associated with ASB caused by gram-positive organisms. ASB was associated with urinary CXCL-8 levels, but not CXCL-5, CXCL-6, or sICAM-1 (P≤0.0001). Urinary levels of CXCL-8 and CXCL-6, but not ICAM-1, were associated with higher neutrophil levels (P≤0.0001). In addition, polymorphism CXCR1_G827C was associated with increased CXCL-8 levels in women with ASB (P = 0.004).

Conclusions

TLR2 and CXCR1 polymorphisms were associated with ASB and a CXCR1 variant was associated with urine CXCL-8 levels. These results suggest that genetic factors are associated with early in vivo human bladder immune responses prior to the development of symptomatic UTIs.

Pregnancy complications and birth outcomes of pregnant women with urinary tract infections and related drug treatments

Maternal urinary tract infections in pregnancy showed an association with a higher rate of preterm birth in previous studies. The aim of this study was to check this relationship, and in addition to evaluate the efficacy of recent medical treatments. The population-based large control (without any defects) data set of the Hungarian Case-Control Surveillance System of Congenital Abnormalities was evaluated. Of 38,151 newborn infants, 2188 (5.7%) had mothers with urinary tract infections during pregnancy, and 90% of these maternal diseases were prospectively and medically recorded. The prevalence of pre-eclampsia and polyhydramnios showed an association with urinary tract infections during pregnancy. Pregnant women with urinary tract infections in pregnancy had a somewhat shorter gestational age (0.1 week) and a higher proportion of preterm births (10.4% vs 9.1%). These differences were correlated with the severity of urinary tract infections. However, the preterm-inducing effect of maternal urinary tract infections is preventable by some antimicrobial drugs such as ampicillin, cefalexin and cotrimoxazole. In conclusion, maternal urinary tract infections during pregnancy increase pre-eclampsia and polyhydramnios, and in addition the rate of preterm birth; however, the latter is preventable by appropriate drug treatments.

Asymptomatic bacteriuria and symptomatic urinary tract infections during pregnancy

Urinary tract infections are common complications of pregnancy; upper tract infections in particular may lead to significant morbidity for both the mother and fetus. Bacteriuria is a significant risk factor for developing pyelonephritis in pregnant women. Therefore, proper screening and treatment of bacteriuria during pregnancy is necessary to prevent complications. All women should be screened for bacteriuria in the first trimester, and women with a history of recurrent urinary tract infections or anomalies should have repeat bacteriuria screening throughout pregnancy. Treatment of bacteriuria should include 3-day therapy with appropriate antimicrobials, and women should be followed closely after treatment because recurrence may occur in up to one third of patients.

Recurrent urinary tract infection in the female

PURPOSE OF REVIEW

Recurrent urinary tract infection is a common problem and can affect women of all ages, particularly the elderly and pregnant women. Obstetricians and gynaecologists need to have up-to-date knowledge of the diagnosis, pathophysiology and management of this condition.

RECENT FINDINGS

The diagnosis of urinary tract infection is made on the basis of symptoms and bacteriuria of more than 103 bacteria per ml. Host and bacterial virulence factors are important in the pathogenesis of recurrent urinary tract infections. General host factors predisposing to recurrent infection are genetic factors, ageing, the menopause, urogenital dysfunction, sexual behaviour, and previous pelvic surgery. Urinary tract infection is common in pregnancy, and recent studies have suggested an association with mental retardation and developmental delay. Women with recurrent urinary tract infection in pregnancy should be considered for long-term antibiotic prophylaxis. Intravaginal oestrogens and cranberry juice have been found to be effective for prevention, although more research is required. Women with recurrent urinary tract infection should have at least a 3-day course of trimethoprim or cotrimoxazole, or a 5-day course of beta-lactams or nitrofurantoin, with perhaps a 10-day course in the elderly. Women with frequent urinary tract infection (more than three episodes per year) should be offered prophylactic antibiotics, which can be patient-initiated, postcoital, or long-term low-dose therapy. In the future, vaccines against specific uropathogenic bacteria may be useful in urinary tract infection prophylaxis.

SUMMARY

More research is required, by all medical disciplines, on various aspects of urinary tract infection.

Use of antibiotics to treat bacteriuria of pregnancy in the Nordic countries. Which antibiotics are appropriate to treat bacteriuria of pregnancy?

Bacteriuria in pregnancy with or without clinical symptoms is frequent and increases the risk of pyelonephritis, preterm labour, and low birth weight infants. Commonly used antibiotics such as ampicillin (pivampicillin), amoxicillin, trimethoprim, and sulphonamide are currently associated with a high degree of resistance of the most common pathogen in the urinary tract, Escherichia coli. During the past few decades a number of new and efficient antibacterial antibiotics have been developed. The presumption that a specific drug is safe for both the pregnant woman and the foetus depends on how widely the drug has been used. A recent survey among general practitioners and obstetricians in Denmark, Finland, Norway, and Sweden confirmed that the beta-lactam antibiotic pivmecillinam and nitrofurantoin are the most commonly used agents in the treatment of bacteriuria in pregnancy in the Nordic countries. However, a surprisingly high number of physicians reported that they prescribe sulphonamides during the first two trimesters in spite of resistance of E. coli and possible adverse effects on the foetus.

A prospective study of asymptomatic bacteriuria in sexually active young women

BACKGROUND

Asymptomatic bacteriuria is common in young women, but little is known about its pathogenesis, natural history, risk factors, and temporal association with symptomatic urinary tract infection.

METHODS

We prospectively evaluated 796 sexually active, nonpregnant women from 18 through 40 years of age over a period of six months for the occurrence of asymptomatic bacteriuria (defined as at least 10(5) colony-forming units of urinary tract pathogens per milliliter). The women were patients at either a university student health center or a health maintenance organization. Periodic urine cultures were taken, daily diaries were kept, and regularly scheduled interviews were performed. Escherichia coli strains were tested for hemolysin, the papG genotype, and the ribosomal RNA type.

RESULTS

The prevalence of asymptomatic bacteriuria (the proportion of urine cultures with bacteriuria in asymptomatic women) was 5 percent (95 percent confidence interval, 4 percent to 6 percent) among women in the university group and 6 percent (95 percent confidence interval, 5 percent to 8 percent) among women in the health-maintenance-organization group. Persistent asymptomatic bacteriuria with the same E. coli strain was rare. Symptomatic urinary tract infection developed within one week after 8 percent of occasions on which a culture showed asymptomatic bacteriuria, as compared with 1 percent of occasions when asymptomatic bacteriuria was not found (P<0.001). Asymptomatic bacteriuria was associated with the same risk factors as for symptomatic urinary tract infection, particularly the use of a diaphragm plus spermicide and sexual intercourse.

CONCLUSIONS

Asymptomatic bacteriuria in young women is common but rarely persists. It is a strong predictor of subsequent symptomatic urinary tract infection.

Urinary tract infections in pregnancy

Although pregnancy does not increase the prevalence of ASB in women, it does enhance the progression rate from asymptomatic to symptomatic disease. Furthermore, ASB is associated with preterm delivery. Given the fact that identification and eradication of ASB in pregnant women can lower the likelihood of pyelonephritis and prevent preterm delivery, every gravida should be systematically screened for ASB and appropriately treated. In the authors' opinion, a first-trimester urine culture remains the screening test of choice; reliance on symptoms to prompt screening is inadequate because the state of pregnancy can provoke frequency and nocturia. Multiple antibiotic regimens for ASB are safe during pregnancy and effective.

Urinary tract infections

Urinary tract infection in women has its origin, predominantly, via ascending bacteria from the periurethral microflora. Asymptomatic bacteriuria, except for the pregnant patient, need not be treated. E. coli is the most common bacterium to cause UTIs, and is usually susceptible to oral antibiotics. Patients who are hospitalized with an indwelling Foley catheter or who have undergone instrumentation, tend to be infected with a bacterium other than E. coli. Patients with uncomplicated cystitis can effectively be treated with an oral antibiotic (Table 1) for 3 days. Patients who do not respond to empiric therapy have a recurrence within 2 weeks of treatment, or who have a recurrence within the first week after treatment, should have a pretreatment.

Detection, significance, and therapy of bacteriuria in pregnancy. Update in the managed health care era

Profound physiologic and anatomic changes of the urinary tract during pregnancy contribute to the increased risk for symptomatic urinary tract infection in women with bacteriuria. Asymptomatic bacteriuria is the major risk factor for developing symptomatic UTIs during pregnancy and may be associated with adverse effects on maternal and fetal health. Because most symptomatic UTIs develop in women with bacteriuria earlier in pregnancy, treatment of bacteriuria is undertaken to prevent symptomatic infections. All pregnant women should be screened at the first antenatal visit, which is reliably and inexpensively done with a dipstick culture. Short-course therapy should be given to women with bacteriuria and clearance of bacteriuria should be documented after therapy is complete. Failure to eliminate bacteriuria with repeated therapy or recurrence with the same organism is indicative of renal parenchymal infection or a structural abnormality. All women with persistent bacteriuria or recurrent infection should have follow-up cultures and a urologic evaluation after delivery.

Diagnosis and treatment of uncomplicated urinary tract infection

Acute uncomplicated urinary tract infection is one of the most common problems for which young women seek medical attention and accounts for considerable morbidity and health care costs. Acute cystitis or pyelonephritis in the adult patient should be considered uncomplicated if the patient is not pregnant or elderly, if there has been no recent instrumentation or antimicrobial treatment, and if there are no known functional or anatomic abnormalities of the genitourinary tract. Most of these infections are caused by E. coli, which are susceptible to many oral antimicrobials, although resistance is increasing to some of the commonly used agents. Review of the published data suggests that a 3-day regimen is more effective than a single-dose regimen for all antimicrobials tested. Regimens with trimethoprim-sulfamethoxazole seem to be more effective than those with beta lactams, regardless of the duration. Because of increasing resistance to trimethoprim-sulfamethoxazole, an alternative regimen such as nitrofurantoin (in a 7-day regimen), a fluoroquinolone, or an oral third-generation cephalosporin may be a better empiric choice in some areas. Acute pyelonephritis caused by highly virulent uropathogens in an otherwise healthy woman may be considered an uncomplicated infection. The optimal treatment duration for acute uncomplicated pyelonephritis has not been established, but 10- to 14-day regimens are recommended. We prefer to use antimicrobials that attain high renal tissue levels, such as a fluoroquinolone, trimethoprim-sulfamethoxazole, or an aminoglycoside, for pyelonephritis. Acute uncomplicated cystitis or pyelonephritis in healthy adult men is uncommon but is generally caused by the same spectrum of uropathogens with the same antimicrobial susceptibility profile as that seen in women.

Bacteriuria in pregnancy: a comparison of Bangladeshi and Caucasian women

During a 5-year period all urine culture results from pregnant Caucasian and Bangladeshi women booked for confinement at the Royal London Hospital, London, UK, were reviewed to determine race-specific rates of bacteriuria. The results showed that the overall prevalence of bacteriuria in the Caucasian group was 6.3% compared to 2.0% for the Bangladeshi women. Caucasian women were found to be at significantly greater risk across all pregnancy outcome and history categories, with the greatest risk observed in grand multiparous women (RR: 4.7, 95% CI: 2.8-8.3). Pregnancies that resulted in preterm delivery showed a strong association of bacteriuria in Caucasian women which was not seen in the Bangladeshi women (RR: 4.4, 95% CI: 2.0-8.7). The data suggest that Caucasian women have a significantly higher prevalence of bacteriuria in pregnancy than their Bangladeshi neighbors. Differences in hygiene practices and clothing may explain the observed differences in the bacteriuria rates.

Complications of pregnancy in women after childhood reimplantation for vesicoureteral reflux: an update with 25 years of followup

Surgery for the correction of vesicoureteral reflux has been performed routinely since the early 1960s. In 1986 a large group of women who underwent childhood ureteral reimplantation surgery was contacted and surveyed concerning infections, pregnancies and other complications. A notably high rate of cystitis and pyelonephritis was found during pregnancy. Because 9 years have passed and many more pregnancies have occurred, we contacted this cohort again as well as a new cohort of historical controls to reassess long-term complications of childhood ureteral reimplantation in children. Of 67 women who underwent reimplantation with an average followup of 25 years 62 were contacted of whom 75% had urinary tract infections after becoming sexually active and 65% had urinary tract infections with pregnancies. Of 141 pregnancies 57 (40%) were complicated by urinary tract infections and 21 (15%) terminated in spontaneous abortion. Of 37 women with primary vesicoureteral reflux and no surgery with an average followup of 25.5 years there was a 15% prevalence of urinary tract infections with pregnancy in 21. Of 75 pregnancies in this group 14 (18%) terminated in spontaneous abortion. Women with urinary tract infections and reflux as children have high rates of cystitis with the onset of sexual activity whether or not they underwent reimplantation as children. Those who underwent reimplantation as children are at significant risk of urinary tract infection in pregnancy but not at a higher risk of miscarriage than the general population. Education, screening and antibiotic prophylaxis during pregnancy should be considered.

Urogenital infection in preeclampsia

OBJECTIVE

The purpose of this study was to determine whether the incidence of urinary tract infections and postpartum endometritis were increased in preeclamptic pregnancies.

METHOD

We conducted a retrospective study of 13852 pregnant women, using a perinatal database at The Johns Hopkins Hospital, over the past 5 years. The incidence of urinary tract infections and postpartum endometritis was analyzed using the chi-squared test and logistic regression analysis. Statistical significance was set at P < 0.05.

RESULTS

There were 345 (2.5%) mild preeclamptics and 440 (3.2%) severe preeclamptics. The incidence of urinary tract infections and postpartum endometritis in preeclamptic patients was significantly higher than that in non-hypertensive pregnant patients. After controlling for confounding variables, severe preeclampsia was still found to be an independent significant risk factor for both urinary tract infections and postpartum endometritis.

CONCLUSION

Our data show a significant increase in urogenital infection in preeclamptic pregnancy. This may reflect higher rates of underlying renal disease and placental bed abnormalities occurring in preeclampsia.

Suppressed antibody and interleukin-6 responses to acute pyelonephritis in pregnancy

This study examined the effect of pregnancy on the host response to acute pyelonephritis. Urine and serum samples were obtained at the time of diagnosis and after two weeks, from non-pregnant and pregnant women with acute pyelonephritis. The samples were analyzed for interleukin-6 (IL-6) and specific antibody activity to antigens extracted from the Escherichia coli strain infecting each patient. The host response to infection was further quantitated as fever, C-reactive protein, and renal concentrating capacity. Acute pyelonephritis in non-pregnant and pregnant women was accompanied by a significant serum and urine antibody response. The serum antibody response was significantly lower in the pregnant group. The IL-6 levels in serum and urine at diagnosis were significantly higher in the non-pregnant compared to the pregnant women. These results demonstrate that the immunosuppression of pregnancy includes the mucosal IL-6 and specific antibody responses to acute pyelonephritis caused by E. coli.

Controversies in the laboratory diagnosis of community-acquired urinary tract infection

Urine samples constitute the largest single category of specimens examined in most medical microbiology laboratories. The everyday nature and apparent simplicity of urinary tract infection belies the intense debate and controversy regarding the optimal methods of collection, transport and processing of urine specimens and reporting of results. There is considerable variation in the interpretation of quantitative culture results between laboratories and the etiology of abacterial cystitis remains unclear. Microscopy to detect pyuria provides information on an important indicator of inflammation and it has been proposed that detection of urinary antibody may provide similar information. Neither of these indices of host response is suitable for use in a screening test for urinary infection however, although they may usefully contribute to the interpretation of significance of culture results. The development of screening tests and automated systems continues, but at present microscopy and culture remain the most important techniques for laboratory diagnosis. However, these techniques have so far failed to provide an etiological diagnosis for abacterial cystitis and this remains a major area for research.

Management of urinary tract infections in pregnancy: a review with comments on single dose therapy

Most investigators agree that the adverse effects of urinary tract infections in pregnancy can be abrogated by effective early detection and treatment. However, the optimal methods for screening and treatment remain controversial. Although single-dose therapy has not been applied to pregnant women with acute pyelonephritis, most but not all studies which have compared single-dose with longer courses of beta-lactam or other antibiotics in pregnant asymptomatic bacteriuric women have shown no differences in outcome. This paper reviews recent trials of single-dose treatment of bacteriuria in pregnant women.

Urogenital tract infections in pregnancy at King Edward VIII Hospital, Durban, South Africa

OBJECTIVES

To evaluate the role of detecting asymptomatic bacteriuria and endocervical infections in the black prenatal patients attending King Edward VIII Hospital (KEH), Durban, with the view of justifying a screening programme. Screening for syphilis and human immunodeficiency virus (HIV) infection were also evaluated.

SUBJECTS

181 asymptomatic black prenatal patients attending the antenatal clinic for their first antenatal visit volunteered for the study and gave their written consent.

DESIGN

Examination of each prenatal patient included obtaining of endocervical swabs to detect endocervical infections (C trachomatis, N gonorrhoeae), serum for syphilitic and HIV testing, and a midstream specimen of urine for microscopy and culture.

RESULTS

Asymptomatic bacteriuria was found in 5.6% of patients in this study. Cervical infections were diagnosed microbiologically in 8.2% of women. These were N gonorrhoeae in 4.1% and C trachomatis in 4.7%. Serological tests for sexually transmitted diseases showed the presence of syphilis in 7.6% and antibody to the HIV in 1.9%. Overall, one or more sexually transmitted diseases were found in 16.5% of the women studied.

CONCLUSIONS

This study suggests that all women presenting for routine antenatal care in a setting such as Durban should be screened for lower genital tract infections. Ideally this should include a midstream urine specimen for culture, serum for syphilitic and HIV antibody testing and endocervical swabs for sexually transmitted pathogens. In developing communities, however, more reliable and cheaper methods of endocervical screening need to be available before antenatal screening for cervico-vaginal infections can be justified.

Definitions, classification, and clinical presentation of urinary tract infections

Urinary tract infections encompass a spectrum of clinical and pathologic conditions involving various parts of the urinary tract. Each syndrome has its own unique epidemiology, natural history, and clinical manifestations. Basic terminology used in describing urinary tract infections is defined in this article. A classification of these infections and their clinical features is presented.

Epidemiology, natural history, and management of urinary tract infections in pregnancy

The urinary tract undergoes profound physiologic and anatomic changes during pregnancy that facilitate the development of symptomatic UTIs in women with bacteriuria. Although the adverse effects of asymptomatic bacteriuria on maternal and fetal health continue to be debated, it is clear that asymptomatic bacteriuria is the major risk factor for developing symptomatic UTI and that symptomatic infections are associated with significant maternal and fetal risks. Because the majority of symptomatic UTIs develop in women with bacteriuria earlier in pregnancy, treatment of bacteriuria is undertaken to prevent symptomatic infections. All women should be screened at the first antenatal visit, which is reliably and inexpensively done with a dipstick culture. Short-course therapy is as effective as prolonged therapy and should be followed with a repeat culture to document clearing of the bacteriuria. Failure to eliminate bacteriuria with repeated therapy or recurrence with the same organism is indicative of renal parenchymal infection or a structural abnormality. All women with persistent bacteriuria or recurrent infection should have follow-up cultures and a complete urologic evaluation after delivery.

The epidemiology of urinary tract infection and the concept of significant bacteriuria

Urinary tract infections (UTI) are among the most common infections afflicting man. Urinary tract infections in young adult women are usually uncomplicated, but are often recurrent and cause considerable morbidity. Urinary tract infections in pregnant women, elderly patients, and catheterized patients warrant special attention because of their association with increased morbidity and possibly with increased mortality. Diagnosis of UTI is usually based on quantitation of uropathogens in voided urine. The traditional criteria for significant bacteriuria, greater than or equal to 10(5) uropathogens per ml of voided urine, is insensitive for detecting acute symptomatic cystitis in men and women and should be replaced with a lower colony count threshold.

The optimal management of lower urinary tract infections

Lower urinary tract infection is a common problem for women, and tends to be recurrent. It is not associated with significant long term morbidity. Optimal management for symptomatic infection is short course antimicrobial therapy. For women with frequent, symptomatic, recurrent infection a number of therapeutic options are available including single dose self-treatment, extended low dose prophylaxis, or post-intercourse prophylaxis. For women who do not wish to experience any symptomatic episodes, prophylactic therapy, either continuous or during risk situations particularly post-intercourse, are other options. Which therapeutic strategy is followed should be based on patient preference.