Kidney Infections


A bacterial infection of the kidney is termed “pyelonephritis”.

The usual route of bacteria to the kidney is from a bladder infection. The bacteria causing the bladder infection “ascend” into the kidney and result in an infection. Individuals with a kidney infection are sick and usually experience high fever, nausea and vomiting, flank/back pain, as well as lower abdominal pain.

Predisposing factors include: recurrent bladder infections, kidney stones, structural abnormalities of the kidneys and urinary tract (such as vesicoureteral reflex in children), neurogenic bladder (a condition where the bladder does not eliminate urine appropriately), and prostate disease such as BPH (benign prostate hyperplasia) in men.

Symptoms of a Kidney Infection

Individuals that have a kidney infection are ill and require immediate medical attention. High fever, nausea/vomiting, flank/back pain and lower abdominal pain are invariably present.

Evaluation and Treatment

When a kidney infection is suspected, a urine analysis to look for clues is undertaken along with a urine culture as most kidney infections are caused by a bladder infection. Blood cultures are also obtained to identify the offending bacterium which helps guide appropriate antibiotic therapy.

Individuals diagnosed with a kidney infection require IV antibiotics and subsequent oral antibiotics for 10-14 days.

When clinical improvement is delayed, or in individuals with repeated bouts of pyelonephritis, an imaging study may be obtained (CT scan, ultrasound, abdominal x-ray) to rule out any structural abnormality of the urinary tract.

If a structural abnormality is identified, surgery may be indicated to correct the problem to reduce/prevent repeated infections.