Infectious Disease Compendium

BK Virus


A Pollyanna virus, it always sees the best in everyone. Sorry. It’s a polyoma virus.

Has decoy cells in the urine.

Epidemiologic Risks

80% are infected and the primary infection is asymptomatic or a mild uri. It then spreads to the kidneys.

Reactivates in renal transplant kidneys (PubMed), usually 9 to 12 months after transplant. Not found in the Whopper, despite the name (BK was the initials of the first patient in which it was discovered).


Hemorrhagic cystitis, reactivation can accelerate kidney transplant rejection and ureteral stenosis.

Diagnose with urine PCR.

Can also have Decoy cells on the UA: epithelial cells infected with virus.


Maybe cidofovir (PubMed) (PubMed) but it is very nephrotoxic, so likely a destroy the village to save it situation.