Urinary tract infections - Summary of diagnostic and treatment options

Urinary tract infection (UTI) can take one of several forms, including asymptomatic bacteriuria, cystitis and pyelonephritis. It can lead to local complications including abscess formation and through bacteraemia to metastatic infection and sepsis syndrome. This is defined as the presence of local symptoms with systemic inflammation and is more common in the elderly and the diabetic and immunosuppressed patient. It is an important aspect of the wider problem of nosocomial infection. Complicated UTI is defined as acute or chronic infection usually involving the renal parenchyma and associated with functional or structural urinary tract abnormality. The predominant micro-organism in UTI is Escherichia coli but in hospital acquired and complicated infection the spectrum will include Pseudomonas aeruginosa, Enterococcus spp. and Staphylococcus spp. including Staphylococcus saprophyticus. Uncomplicated UTI includes cystitis and pyelonephritis. Both can recur or relapse through failure of primary therapy. This is more likely in the setting of complicated UTI. The predominant organism is again E. coli. Treatment of UTI includes trimethoprim/sulphamethoxazole (TMP/SMX), cephalosporins, aminopenicillins, nitrofurantoin and fluoroquinolones. TMP/SMX and fluoroquinolones should not be administered to pregnant women or nursing mothers. The choice of antibiotic should reflect local resistance patterns in the hospital or community. Urosepsis should be avoidable by limiting risk factors, e.g. hospitalisation, use of catheters and stents in susceptible individuals.