Cytological diagnosis of virus-infected cells in cervical smears. Value in gynecologic and obstetric practice.

Herpes simplex virus is a common cause of infection of the female genital tract. The infection can be diagnosed by the cytopathologist from the appearances of multinucleate giant cells in Papanicolaou smears. The cytological diagnosis of this infection is of value to the gynecologist in identifying subclinical infection and in confirming clinically suspicious disease. The validity of the cytological diagnosis can be established by virus isolation or electron microscopy. Although other infections of the female genital tract such as wart virus infection, cytomegalovirus infection, and chlamydial infection can be detected by cytological methods, the reliability of the cytological approach has yet to be established. Nevertheless, cytology has provided a powerful stimulus for research into the prevalence of wart virus infection of the cervix, which has been shown to be much more common than was previously supposed, and may be a factor in cervical carcinogenesis. Cytological examination of smears of urinary sediment has proven to be a reliable method of detecting human polyomavirus excretion in pregnancy. Active infection of the urinary tract occurs in 3.2% of pregnant women who represent an "at risk group" with altered immunological function.