polyomavirus infectious disease (MONDO_0005927, a Monarch Disease Ontology term) can be described as follows. Infections with polyomavirus, which are often cultured from the urine of kidney transplant patients. Excretion of bk virus is associated with ureteral strictures and cystitis, and that of jc virus with progressive multifocal leukoencephalopathy (leukoencephalopathy, progressive multifocal).