Ultrasonography and abdominal radiography versus intravenous urography in investigation of urinary tract infection in men: prospective incident cohort study

Smoking is associated with infection risk in healthy blood donors

OBJECTIVES

There is a gap in knowledge about the effects of smoking on overall infection risk in otherwise healthy populations, possibly leading to underestimation of the dangers of smoking. The present study aimed to examine the association of smoking with the risk of infections in a large cohort of healthy blood donors.

METHODS

This cohort study used questionnaire and health register data from 127 831 Danish blood donors. Multivariable Cox proportional hazards analysis was applied to estimate the association of current smoking with the risk of all-cause infection defined as hospital-based treatment for infection or filled prescriptions of antimicrobials stratified for age and adjusted for relevant confounders.

RESULTS

Among 18 272 current smokers, 12 272 filled an antimicrobial prescription and 2035 received hospital-based treatment for infections. Among 101 974 non-smokers, 65 117 filled a prescription and 8501 received hospital-based treatment for infections. Smokers had a higher risk of all-cause infection than non-smokers (hazard ratio estimates were 1.27 in males and 1.33 in females for hospital-based treatment and 1.11 in males and up to 1.20 in females for filled prescriptions). Smoking was most strongly associated with an increased incidence of respiratory tract infection, abscesses, skin infection, and prescriptions for these ailments (hazard ratio up to 2.29). Furthermore, smokers' risk of filled prescriptions of broad-spectrum penicillin was increased (hazard ratio up to 1.96).

CONCLUSIONS

Current smoking was strongly associated with the risk of hospital-based treatment of infection and filled prescriptions of antimicrobials in a large cohort of healthy individuals. These findings warrant an increased focus on infectious disease risk among smokers.

Rationalising the use of investigation for urinary tract infections: Analysis of 700 patients and proposal for a diagnostic algorithm

AIMS

To evaluate the diagnostic yield of investigations performed on patients with a history of urinary tract infections (UTI).

METHODS

A retrospective review was conducted on patients who underwent cystoscopy and imaging for a history of UTI between 2014 and 2019 in a single UK teaching hospital. Data were collected on demographics, cystoscopy and radiological findings requiring further management. The cohort was stratified by age, gender and a confirmed history of recurrent UTI (rUTI). The subsequent algorithm was re-tested in a second cohort to validate its use.

RESULTS

Seven hundred patients were included in the primary analysis-427 female and 273 males. Three hundred and thirty-one met the criteria of rUTI. The median age was 64 years (18-97). Imaging abnormalities were equally frequent in men 6.3% (15/241) and women 8% (30/380) and the majority noted in patients aged ≥55 years, 30/45 (66.7%). Amongst those who did not meet the definition of rUTI, abnormal imaging was identified in 5%-7% regardless of age group and gender. Cystoscopy abnormalities (n = 24) were twice more likely in males, 5.5%(15/273) than females, 2%(9/427). About 88%(21/24) were identified in patients ≥55 years. There were no positive findings in women <55 years. Applying baseline imaging but confining cystoscopy to those aged ≥55 years and men with a confirmed history of rUTI would have saved 44% of procedures, missed no abnormalities with an overall diagnosis detection rate of 9.8% (69/700). This algorithm was validated in a separate cohort of 63 patients; applying it would have saved 46% (29/63) of cystoscopies with a positive diagnostic rate of 9.5% and no missed findings.

CONCLUSION

To our knowledge this is one of the largest studies reporting the outcomes of investigations for UTI and rUTI. Our result suggests that imaging is a useful baseline assessment, but cystoscopy should be limited to specific subgroups. We propose and validate a simple decision algorithm to manage investigations for referrals for UTI in secondary care.

Imaging features of colovesical fistulae on MRI

OBJECTIVES

MRI is routinely used in the investigation of colovesical fistulae at our institute. Several papers have alluded to its usefulness in achieving the diagnosis; however, there is a paucity of literature on its imaging findings. Our objective was to quantify the MRI characteristics of these fistulae.

METHODS

We selected all cases over a 4-year period with a final clinical diagnosis of colovesical fistula which had been investigated with MRI. The MRI scans were reviewed in a consensus fashion by two consultant uroradiologists. Their MRI features were quantified.

RESULTS

There were 40 cases of colovesical fistulae. On MRI, the fistula morphology consistently fell into three patterns. The most common pattern (71%) demonstrated an intervening abscess between the bowel wall and bladder wall. The second pattern (15%) had a visible track between the affected bowel and bladder. The third pattern (13%) was a complete loss of fat plane between the affected bladder and bowel wall. MRI correctly determined the underlying aetiology in 63% of cases.

CONCLUSIONS

MRI is a useful imaging modality in the diagnosis of colovesical fistulae. The fistulae appear to have three characteristic morphological patterns that may aid future diagnoses of colovesical fistulae. To the authors' knowledge, this is the first publication of the MRI findings in colovesical fistulae.

Approach to urinary tract infections

Urinary tract infection (UTI) is the most common infection experienced by humans after respiratory and gastro-intestinal infections, and also the most common cause of both community-acquired and nosocomial infections for patients admitted to hospitals. For better management and prognosis, it is mandatory to know the possible site of infection, whether the infection is uncomplicated or complicated, re-infection or relapse, or treatment failure and its pathogenesis and risk factors. Asymptomatic bacteriuria is common in certain age groups and has different connotations. It needs to be treated and completely cured in pregnant women and preschool children. Reflux nephropathy in children could result in chronic kidney disease; otherwise, urinary tract infections do not play a major role in the pathogenesis of end-stage renal disease. Symptomatic urinary tract infections occur most commonly in women of child-bearing age. Cystitis predominates, but needs to be distinguished from acute urethral syndrome that affects both sexes and has a different management plan than UTIs. The prostatitis symptoms are much more common than bacterial prostatic infections. The treatment needs to be prolonged in bacterial prostatitis and as cure rates are not very high and relapses are common, the classification of prostatitis needs to be understood. The consensus conference convened by National Institute of Health added two more groups of patients, namely, chronic prostatitis/chronic pelvic pain syndrome and asymptomatic inflammatory prostatitis, in addition to acute and chronic bacterial prostatitis. Although white blood cells in urine signify inflammation, they do not always signify UTI. Quantitative cultures of urine provide definitive evidence of UTI. Imaging studies should be done 3-6 weeks after cure of acute infection to identify abnormalities predisposing to infection or renal damage or which may affect management. Treatment of cystitis in women should be a three-day course and if symptoms are prolonged, then a seven day course of antibiotics should be given. Selected group of patients benefits from low-dose prophylactic therapy. Upper urinary tract infection may need in-patient treatment. Treatment of acute prostatitis is 30-day therapy of appropriate antibiotics and for chronic bacterial prostatitis a low dose therapy for 6-12 months may be required. It should be noted that no attempt should be made to eradicate infection unless foreign bodies such as stones and catheters are removed and correctable urological abnormalities are taken care of. Treatment under such circumstances can result only in the emergence of resistant organisms and complicate therapy further.

Shift in imaging modalities of the urinary tract over a 25-year period and its impact on ionizing radiation doses given to patients

OBJECTIVES

To explore the shift in imaging modalities used when examining the urinary tract over the period 1979-2003 and to see how this shift, together with a radiation protection policy, have influenced the doses of ionizing radiation used.

MATERIAL AND METHODS

Activity reports from a department of radiology were reviewed. Relevant radiation dose estimates were obtained from the Norwegian Radiation Protection Authority.

RESULTS

Ultrasound (US) was introduced in 1983 and has been increasingly used since then. MRI was introduced in 1992 and has been used to some extent when examining the urinary tract. The use of i.v. pyelography decreased by 50% during the review period and the use of plain radiographs remained practically unchanged. The number of CT examinations increased until 1983, but decreased thereafter. The total number of examinations of the urinary tract has increased during the review period, but the radiation doses given have decreased.

CONCLUSIONS

The introduction of US and MRI, together with a radiation protection policy, have reduced the ionizing radiation doses given to this population, in spite of an increase in the total number of examinations of the urinary tract.

[Imaging in the management of urinary tract infections]

This review analyzes the role of imaging in the diagnosis, follow-up and management of urinary tract infections. Uncomplicated infection of the urinary tract is frequent and usually resolves rapidly with treatment; in such cases imaging is unnecessary except to exclude dilatation or the existence of an obstacle. Progression towards complex infection often occurs in patients with predisposing factors. Imaging helps in evaluating the extent of the disease; it has a role in the selection of therapy and interventional procedures.

Urinary tract infections and genitourinary abnormalities in Cameroonian men

OBJECTIVE

To compare the prevalence of genitourinary abnormalities in men diagnosed with urinary tract infection (UTI) in a Cameroonian hospital and those without.

PATIENTS AND METHODS

Consecutive adult men aged 18-75 years, whose midstream urine samples were received for microscopy, culture and sensitivity at the microbiology laboratory of the Yaounde University Teaching Hospital, Cameroon, constituted the study population. Genitourinary abnormalities were diagnosed from history, physical examination, abdominal and transrectal ultrasonography, plain abdominal X-ray, and if indicated urethrocystoscopy and biopsy.

RESULTS

Of the 206 patients who qualified, 179 completed the study and 63 (35.2%) were found to have UTI. A total of 41 (65.1%) patients with UTI (mean age 69.2 years) had at least one genitourinary abnormality, compared to 13 (11.2%) of those without UTI (mean age 61.9 years) (P < 0.001). The age-adjusted prevalence of genitourinary abnormalities was 59.4% in the UTI group and 12.1% in the non-UTI group (P < 0.001). The most frequent genitourinary abnormality in men with UTI was benign prostatic enlargement, followed by urethral stricture. The crude odds ratio (95% confidence intervals) for UTI associated with genitourinary abnormality was 14.77 (6.80-32.05), and the adjusted odds ratio 11.51 (7.08-29.46).

CONCLUSION

Urological evaluation of Cameroonian men with UTI, using simple history taking, physical examination, ultrasound examination and plain abdominal X-ray, could have significant clinical benefits in this tropical African region.