Acute pyelonephritis in adults: an update

Recent advances in pathogenesis, changes in antimicrobial susceptibility of uropathogens and new therapeutic guidelines have resulted in a growing interest in acute pyelonephritis. New virulence factors of uropathogens have been described as well as a possible link between antibiotic resistance and lower virulence in Escherichia coli. Resistance to commonly used antimicrobials, such as ampicillin, first-generation cephalosporins, trimethoprim-sulphametoxazole, fluoroquinolones and even second- and third-generation cephalosporins, is increasing among uropathogens not only in nosocomial urinary tract infections, but in community-acquired infections as well. At the same time, some risk factors associated with resistance have been discovered. From the clinical point of view, while acute pyelonephritis typically produces an easy-to-diagnose clinical picture, in certain groups of patients, such as the elderly or diabetics, the clinical picture may be less obvious and outcomes more severe. Recent advances in diagnostic imaging, including scintigraphy, have helped in the diagnosis of urinary tract infections. The local prevalence of antimicrobial resistance, the patient's risk of infection due to antimicrobial-resistant uropathogens, the need for hospital admission and the severity of the clinical picture have to be taken into account in the selection of empirical antimicrobial therapy of acute pyelonephritis. (C) 2003 Lippincott Williams Wilkins.