Pyelonephritis refers to inflammation of the kidney resulting from bacterial infection. The inflammation affects the renal pelvis and parenchyma

Risk factors:

• Female sex
• Structural urological abnormalities
• Vesico-ureteric reflux (urine refluxing from the bladder to the ureters – usually in children)
• Diabetes

Causes:

E. coli is the most common cause (as with lower UTI).

E. coli are gram-negative, anaerobic, rod-shaped bacteria that are part of the normal lower intestinal microbiome. It is found in faeces and can easily spread to the bladder.

Other causes:

• Klebsiella pneumoniae (gram-negative anaerobic rod)
• Enterococcus
• Pseudomonas aeruginosa
• Staphylococcus saprophyticus
• Candida albicans (fungal)

PC

Diagnosis can be made clinically with a history and examination.

Patients have a similar presentation to lower urinary tract infections (i.e. dysuria, suprapubic discomfort and increased frequency) plus the additional triad of symptoms: