Fast Five Quiz: Are You Prepared to Confront Pyelonephritis?

Vecihi Batuman, MD


February 26, 2018

Acute pyelonephritis shows a seasonal variation in the United States. In Washington state, cases occurred most frequently during the months of July and August among females and during August and September in the male population.

Virulence factors include adhesins, siderophores, protectins, and toxins. No single virulence factor is sufficient or necessary to promote pathogenesis. Apparently, multiple virulence factors are necessary to ensure pathogenesis, although adhesins play an important role.

Uropathogenic Escherichia coli accounts for most uncomplicated pyelonephritis cases and a significant portion of complicated pyelonephritis cases. The following micro-organisms are also commonly isolated:

  • Staphylococcus saprophyticus

  • Klebsiella pneumoniae

  • Proteus mirabilis

  • Enterococcus species

  • Staphylococcus aureus

  • Pseudomonas aeruginosa

  • Enterobacter species

Epidemiologic data on the incidence of pyelonephritis are limited. A population-based study of acute pyelonephritis in the United States found overall annual rates of 15-17 cases per 10,000 females and 3-4 cases per 10,000 males. In males, the age distribution of pyelonephritis is bimodal. Males also demonstrate a peak incidence of pyelonephritis at age 0-4 years. Rates gradually increase after age 35 years and peak at age 85 years.

For more on the etiology and epidemiology of pyelonephritis, read here.


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