The presence of Y chromosomal deoxyribonucleic acid in the female vaginal swab: possible implications for human papillomavirus testing.

BACKGROUND

Vaginal self-sampling for human papillomavirus (HPV) detection is the focus of recent research. However, it has been shown previously that male DNA can be detected in vaginal swabs. The aim of this study was to investigate whether a female vaginal swab may reflect a male active HPV infection.

METHODS

Eleven women volunteered to take vaginal samples. The first sample was taken within hours after unprotected intercourse, the others each following morning for five consecutive days. On these samples, a Y-chromosomal locus, as a surrogate marker for HPV, was amplified by PCR. To investigate the prevalence of male DNA in self-obtained vaginal swabs, 282 swabs from 16 women enrolled in an ongoing HPV follow-up study were tested.

RESULTS

All baseline samples from the 11 women were positive for male DNA. In the follow-up samples, positivity ranged from day 1 till day 5, with a sharp drop from day 2 (91%) to day 3 (36%). Of 282 swabs, 23 (8.2%) were positive for male DNA. However, 10 of these 23 swabs were provided by one single woman.

DISCUSSION

Since HPV can be deposited by the male in the vagina, either through semen, or through exfoliated epithelial cells, our results are of some importance when testing for HPV in vaginal swabs. It is conceivable that women with acquired immunity to HPV, but with an HPV positive partner, are found to be HPV positive in the swab. However, larger studies on more diverse populations are warranted.