Abstract

A complicated urinary tract infection (UTI) is an infection associated with a condition, such as a structural or functional abnormality of the genitourinary tract, or the presence of an underlying disease that interferes with host defence mechanisms, which increase the risks of acquiring infection or of failing therapy. A broad range of bacteria can cause a complicated UTI. The spectrum is much larger than in uncomplicated UTIs and bacteria are more likely to be resistant to antimicrobials, especially in a treatment related complicated UTI. Enterobacteriaceae are the predominant pathogens, with Escherichia coli being the most common pathogen. However, non-fermenters (e.g. Pseudomonas aeruginosa) and Gram-positive cocci (e.g. Staphylococci and Enterococci) may also play an important role, depending on the underlying conditions. Treatment strategy depends on the severity of the illness. Treatment encompasses three goals: management of the urological abnormality, antimicrobial therapy, and supportive care when needed. Hospitalization is often required. To avoid the emergence of resistant strains, therapy should be guided by urine culture whenever possible. If empirical therapy is necessary, the antibacterial spectrum of the antibiotic agent should include the most relevant pathogens. A fluoroquinolone with mainly renal excretion, an aminopenicillin plus a β-lactam inhibitor (BLI), a Group 2 or 3a cephalosporin or, in the case of parenteral therapy, an aminoglycoside, are recommended alternatives (LE: 1b, GR: B). In case of failure of initial therapy, or in case of clinically severe infection, a broader-spectrum antibiotic should be chosen that is also active against Pseudomonas, e.g. a fluoroquinolone (if not used for initial therapy), an acylaminopenicillin (piperacillin) plus a BLI, a Group 3b cephalosporin, or a carbapenem, with or without combination with an aminoglycoside. The duration of therapy is usually 7-14 days (LE: 1b, GR: A), but has sometimes to be prolonged for up to 21 days. Until predisposing factors are completely removed, true cure without recurrent infection is usually not possible. Therefore, a urine culture should be carried out 5-9 days after the completion of therapy and also 4-6 weeks later.

• Keywords: Urinary tract Infection, Bacteriuria, Pyuria