The Volokh Conspiracy - Transmission of Genital HPV Through the Hands:

A 1999 article reports:

Objective: To determine whether patients with genital warts carry human papillomavirus (HPV) DNA on their fingers.

Methods: 14 men and eight women with genital warts had cytobrush samples taken from genital lesions, finger tips, and tips of finger nails. Samples were examined for the presence of HPV DNA by the polymerase chain reaction.

Results: HPV DNA was detected in all female genital samples and in 13/14 male genital samples.

HPV DNA was detected in the finger brush samples of three women and nine men. The same HPV type was identified in genital and hand samples in one woman and five men.

Conclusion: This study has identified hand carriage of genital HPV types in patients with genital warts. Although sexual intercourse is considered the usual mode of transmitting genital HPV infection, our findings raise the possibility of transmission by finger-genital contact.

(Sex Transm Inf 1999;75:317--319)

I don't know whether the study has since been confirmed or undermined, though some casual searches suggested this possibility is being taken seriously, but the magnitude of the risk is unknown. If you know more than I do about this, please post something on the subject in the comments.

Likewise, while my casual assumption is that if hand-genital transmission is possible, hand-hand transmission followed by hand-genital transmission by the recipient (i.e., a woman shakes an HPV carrier's hand, and then transfers the HPV to her hand when touching her own genitals), I'm not sure whether that's right. Of course, even if it's not, this means that an HPV-positive parent could transmit the virus to an infant or a toddler when wiping, washing, or examining the child. (Mother-to-newborn transmission of HPV is also possible, though my vague sense from a few snippets I've seen is that it's not seen as a major likely source of serious disease.) In any case, given the recent debates about HPV immunization, I'd be happy to hear more about this from those who know.

The world seems to be an even ickier place than I had thought.

	[Eugene Volokh, February 10, 2007 at 11:40pm] Trackbacks Transmission of Genital HPV Through the Hands: A 1999 article reports: Objective: To determine whether patients with genital warts carry human papillomavirus (HPV) DNA on their fingers. Methods: 14 men and eight women with genital warts had cytobrush samples taken from genital lesions, finger tips, and tips of finger nails. Samples were examined for the presence of HPV DNA by the polymerase chain reaction. Results: HPV DNA was detected in all female genital samples and in 13/14 male genital samples. HPV DNA was detected in the finger brush samples of three women and nine men. The same HPV type was identified in genital and hand samples in one woman and five men. Conclusion: This study has identified hand carriage of genital HPV types in patients with genital warts. Although sexual intercourse is considered the usual mode of transmitting genital HPV infection, our findings raise the possibility of transmission by finger-genital contact. (Sex Transm Inf 1999;75:317--319) I don't know whether the study has since been confirmed or undermined, though some casual searches suggested this possibility is being taken seriously, but the magnitude of the risk is unknown. If you know more than I do about this, please post something on the subject in the comments. Likewise, while my casual assumption is that if hand-genital transmission is possible, hand-hand transmission followed by hand-genital transmission by the recipient (i.e., a woman shakes an HPV carrier's hand, and then transfers the HPV to her hand when touching her own genitals), I'm not sure whether that's right. Of course, even if it's not, this means that an HPV-positive parent could transmit the virus to an infant or a toddler when wiping, washing, or examining the child. (Mother-to-newborn transmission of HPV is also possible, though my vague sense from a few snippets I've seen is that it's not seen as a major likely source of serious disease.) In any case, given the recent debates about HPV immunization, I'd be happy to hear more about this from those who know. The world seems to be an even ickier place than I had thought. Related Posts (on one page): Transmission of Genital HPV Through the Hands: "100% Preventable by Behavioral Change": Libertarianism and Communicable Disease: HPV Immunization and Risky Personal Choices: Perverse Effects of HPV Immunizations? Cost-Effectiveness of HPV Immunizations: HPV Immunization in Texas: