Human papovavirus in a routine urine specimen of a four-year-old boy.

Cellular changes produced by viruses can be readily identified using light microscopy and Papanicolaou stain of a fixed specimen. These findings can then be confirmed by viral culture and/or electron microscopy studies. Human polyomavirus, common in transplant recipients or otherwise immunocompromised patients, is one virus that can be identified using these methods. The following is a case study of a 4-yr-old boy with no known immune impairment who exhibited human papovavirus (polyomavirus) on a routine urine examination. The diagnosis was confirmed by electron microscopy.