High risk genital papillomavirus infections are not spread vertically.

The Medline-indexed literature on risk factors for HPV infection and HPV transmission is critically reviewed. Principles for assay validation and interpretation, reliability of different study designs and principles for interpretation of conflicting reports are discussed. The conclusions arrived at can be summarised as: (1) There is overwhelming epidemiological evidence that the only quantitatively important mode of transmission of infection with oncogenic genital HPV types is sexual. (2) There is also evidence that benign genital HPV types can be transmitted sexually, but the epidemiological data on the benign virus types are less extensive and less clear. (3) Perinatal HPV transmission is unequivocally demonstrated only for the rare disease juvenile respiratory papillomatosis.