Problems in the management of urinary tract infections - Clinical, epidemiological and laboratory studies

Lawson, David Hamilton (1973) Problems in the management of urinary tract infections - Clinical, epidemiological and laboratory studies. MD thesis, University of Glasgow.

Abstract

The work described in this thesis was undertaken to elucidate certain aspects of the management of urinary tract infections. The early part of the thesis is concerned with assessing the role of screening tests in the identification of bacteriuria in the first trimester of pregnancy. This is important since it has been claimed that virtually all pregnant patients who develop urinary tract infections (U.T.I.) in late pregnancy have asymptomatic bacteriuria in the first trimester. To test this hypothesis a simple screening procedure was carried out on a large proportion of pregnant patients attending a local maternity hospital. As a result a group of patients with asymptomatic bacteriuria was detected. Long-term follow-up of all patients screened revealed that the proportion of those developing U.T.I. in late pregnancy and who had an initially positive screening test was low. This result called in question the value of a single test as a means of preventing subsequent U.T.I. In view of the importance of this finding for practitioners a further theoretical assessment of the value of such screening tests was undertaken using as a basis the published data on the subject. This review indicated that even under optimal conditions the sensitivity of the screening test in predicting subsequent U.T.I. is low - a finding which suggests that it is inefficient as a means of drastically reducing the incidence of U.T.I. in pregnancy. An assessment of the role of routinely screening the urine of all patients with symptoms of U.T.I. in general practice was then undertaken. The study failed to provide evidence of the value of routinely screening the urine of all patients attending their practitioners with symptoms of U.T.I. The main benefit to accrue from this procedure was that those with a positive modified Addis count (as a reflection of the leucocyte excreta on rate in the urine) and bacteriuria had a higher recurrence rate than patients without these features. Nevertheless repeated recurrences were rare - only 2.7% patients being referred to the hospital for further investigation. The result of long-term anti-bacterial therapy on 66 patients with established U.T.I. was then reviewed. All patients had had recurrent U.T.I. with frequent demonstrations of bacteriuria and failure to respond to short-term courses of therapy. A three-month course of the indicated anti-bacterial agent was found to be effective in relieving symptoms and in sterilising the urine for a period of one year in 49% of the patients. Patients with normal intravenous pyelograms fared better than those with abnormal ones. One half of the recurrences in the two years after therapy occurred within three months of stopping the drugs. Several factors other than frank infection have been implicated in the development of U.T.I. For example, it has been suggested that long-terra high dosage analgesic consumption pre-disposes individuals to renal disease which then frequently becomes infected. Likewise it has been suggested that diabetes mellitus pre-disposes patients to U.T.I. Certain aspects of these hypotheses were tested in two studies reported here: firstly using data collected by the Boston Collaborative Drug Surveillance Programme (B.C.D.S.P.) investigation into the relationship between long-term analgesic intake and renal disease was undertaken. This cross-sectional data failed to reveal a positive association between excessive analgesic intake and either renal disease or impaired renal function. Moreover there was no evidence of a dose-response relationship in patients regularly consuming 'over-the-counter' analgesic preparations and these, admittedly crude, parameters of renal disease. The data therefore suggests that if such a relationship exists it is either a subtle one which rarely causes major renal disease or it occurs only in a sub-population of the large group of long-term analgesic users. (Abstract shortened by ProQuest.).

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Keywords: Medicine, Epidemiology
• Date of Award: 1973
• Depositing User: Enlighten Team
• Unique ID: glathesis:1973-72324
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 24 May 2019 15:12
• Last Modified: 24 May 2019 15:12
• URI: https://theses.gla.ac.uk/id/eprint/72324