Acute pyelonephritis

Pyelonephritis is a severe infectious inflammatory disease of the renal parenchyma , calices and pelvis that can be acute , recurrent or chronic ( BMJ Best practice )

Ascending infection ( a complication ) which spreads from the urinary bladder to the kidneys

Spread can be- hematogenous ( less common , seen more commonly in debilitated , chronically ill patients , immunosuppressed )- ascending infection from lower urinary tract

Can involve one or both kidneys

pregnant

uncontrolled diabetes

h/o kidney transplant

urinary anatomical abnormalities

acute or chronic kidney failure

immunocompromised

hospital acquired bacterial infection

chronic catheterization or recent urinary tract instrumentation

older age / frailty

Infection caused by a typical pathogen in an immunocompetent patient with normal urinary tract and renal function

Enteric bacteria enter the bladder and ascend to the kidneys

E.coli ( Gr -ve bacteria ) - accounts for > 90 % of all pyelonephritis cases

E coli has unique ability to adhere and colonize the urinary tract & kidneys and E coli inflammation can cause scarring of the renal parenchyma

Elderly patients , men , urologically compromised or institutionalized patients - less virulent E coli strains , non - E coli gram - ve bacilli , Gr...