Transmission of HPV in general
Transmission of HPV through routes other than sexual is definitely possible. One may be exposed to HPV simply by shaking hands as suggested in the finding of HPV virus under fingernails.
Sexually Transmitted Infections 1999 Oct;75(5):317-9:
Detection of human papillomavirus DNA on the fingers of patients with genital warts.
Sonnex C, Strauss S, Gray JJ, Department of GU Medicine, Addenbrooke's Hospital, Cambridge, England.
“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.
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.
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.”
Condoms offer little protection against HPV since any skin-to-skin contact can result in transmission of the virus.
Am J Epidemiol 2003 Feb 1;157(3):218-26:
Genital human papillomavirus infection: incidence and risk factors in a cohort of female university students.
Winer RL, Lee SK, Hughes JP, Adam DE, Kiviat NB, Koutsky LA. Department of Epidemiology, University of Washington, Seattle, WA 98103, USA.
"Incidence data on human papillomavirus (HPV) infection are limited, and risk factors for transmission are largely unknown. The authors followed 603 female university students in Washington State at 4-month intervals between 1990 and 2000. At each visit, a sexual and health questionnaire was completed and cervical and vulvovaginal samples were collected to detect HPV DNA. At 24 months, the cumulative incidence of first-time infection was 32.3% (95% confidence interval: 28.0, 37.1). Incidences calculated from time of new-partner acquisition were comparable for enrolled virgins and nonvirgins. Smoking, oral contraceptive use, and report of a new male sex partner––in particular, one known for less than 8 months before sex occurred or one reporting other partners––were predictive of incident infection.
Always using male condoms with a new partner was not protective. Infection in virgins was rare, but any type of nonpenetrative sexual contact was associated with an increased risk. Detection of oral HPV was rare and was not associated with oral-penile contact. The data show that the incidence of HPV associated with acquisition of a new sex partner is high and that nonpenetrative sexual contact is a plausible route of transmission in virgins."
Scand J Infect Dis 1996;28(3):243-6:
Transmission of genital human papillomavirus infections is unlikely through the floor and seats of humid dwellings in countries of high-level hygiene.
Puranen M, Syrjanen K, Syrjanen S Department of Pathology, University of Kuopio, Finland.
"To evaluate the transmission of genital human papillomavirus (HPV) through the floor and seats of humid dwellings, samples were collected with a toothbrush from the floor and seat surfaces of humid dwellings; showers, saunas and dressing rooms. The survey included 3 bathing resorts, 1 indoor swimming pool, 2 schools and 2 private homes. Polymerase chain reaction (PCR) was used to amplify the human beta-globin gene and HPV DNA. The results for HPV DNA amplification were confirmed by Southern blot hybridization under low stringency using a probe mixture of HPV types 6, 16, 18 and 31. beta-globin could be amplified only from 3 sample taken from a dressing room of and indoor public swimming pool. No HPV DNA-positive samples were found. These results indicate that transmission of genital HPV infection via floor or seat surfaces in the above dwellings in general or family use is highly unlikely."
Rev Med Virol 1999 Jan-Mar;9(1):15-21:
High risk genital papillomavirus infections are spread vertically.
Rice PS, Cason J, Best JM, Banatvala JE. Department of Virology, Guy's, Kings and St Thomas' Medical School, Kings College London, St Thomas' Hospital, UK.
"It is well recognized that high-risk human papillomaviruses (HPVs) are spread by sexual activity, but the possibility of non-sexual transmission remains controversial. We present evidence for vertical transmission from at least 30% HPV positive mothers to their infants, resulting in persistent infection in children. That the mother is the source of infant infection has been confirmed by DNA sequencing. We also discuss the evidence for oral HPV-16 infection in children.
In our own studies, HPV-16 DNA was detected in buccal cells from 48% children, aged 3-11 and transcriptionally active infection was confirmed in some children. Other studies have reported prevalences of 19%-27% among children less than 11 years of age. Studies that have failed to detect high-risk HPVs in children have used techniques which were insufficiently sensitive to detect the low levels of virus present. Serological studies also suggest that < or = 45% prepubertal children have acquired HPV-16. Thus, convincing evidence is now available for vertical transmission of high risk HPVs, which probably results in widespread infection among children. The consequences of such infections remain to be elucidated."
J Med Virol 1998 Nov;56(3):210-6:
Presence of antibodies to human papillomavirus virus-like particles (VLPs) in 11-13-year-old schoolgirls.
Cubie HA, Plumstead M, Zhang W, de Jesus O, Duncan LA, Stanley MA. Regional Clinical Virology Laboratory, City Hospital, Edinburgh, Scotland, United Kingdom.
"To allow meaningful approaches to vaccine development, it is important to know the extent of exposure to human papillomavirus (HPV) within the general population, and particularly the age at which the at risk population is infected. The humoral response to human papillomavirus is directed largely to conformationally-dependent epitopes on the whole virion. Virus-like particles (VLPs) of HPV types 1, 2, and 16 were produced using a baculovirus expression system, and were used in the intact state as antigen in an indirect ELISA. Anonymised serum samples from a cohort of Edinburgh schoolgirls were tested for the presence of IgG antibodies directed against the VLPs. The reproducibility of the ELISA was assured by repeated testing of control samples, and by testing all samples in duplicate and, where possible, on several occasions.
Of 1,192 tested with the HPV16 VLPs, 90 (7.6%) were classified as clearly positive, and a further 87 (7.3%) were positive but close to the cutoff calculated by comparison with a group of consistently negative sera. Antibodies to HPV2 were detected in 37.5% (407/1,139) and antibodies to HPV 1 in 51.9% (558/1,076) of the schoolgirls. Antibodies to both HPV1 and HPV2 were found frequently, being present in 29.7% (295/ 993) of samples tested; 40 samples had antibodies to all three types. The significance of these results is discussed."
J Clin Microbiol 1999 Jul;37(7):2270-3:
Detection of human papillomavirus types 6 and 11 in pubic and perianal hair from patients with genital warts.
Boxman IL, Hogewoning A, Mulder LH, Bouwes Bavinck JN, ter Schegget J. Department of Virology, Academic Medical Center, 1105 AZ, Amsterdam, The Netherlands.
"Genital human papillomavirus (HPV) types 6 and 11 are of clinical importance due to their role in the development of anogenital warts. A pilot study was performed to investigate whether DNAs from HPV types 6 and 11 are present in hairs plucked from the pubic and perianal regions and eyebrows of patients with genital warts at present and patients with a recent history of genital warts. Genital HPV DNA was detected in 9 of 25 (36%) pubic hair samples and in 11 of 22 (50%) perianal hair samples by the CPI/CPIIg PCR. After sequencing of 17 of 20 samples, HPV type 6 or 11 was detected in 6 of 25 (24%) hair samples from the pubis and 8 of 22 (36%) hair samples from the perianal region. These types were not detected in plucked eyebrow hairs. In contrast, the HPV types associated with epidermodysplasia verruciformis were detected in similar proportions (62%) in both samples of pubic and eyebrow hairs.
Moreover, HPV type 6 and 11 DNAs were detected in pubic hairs plucked from two patients who had been successfully treated and who did not show any lesion at the time of hair collection; this finding is an argument that HPV DNA may persist in this region. The presence of genital HPV types in plucked pubic and perianal hair suggests that there is an endogenous reservoir for HPV which may play a role in the recurrences of genital warts."