These atypical cells with enlarged and hyperchromatic nuclei are indeed infected by a virus;however, the etiologic agent is a type of human polyomavirus known as BK virus rather than CMV suggested.

• 翻译：这些具有大而深染核的细胞确实是病毒感染细胞，但病原是一种称为BK病毒的人类多瘤病毒类感染，而不是CMV。