Condoms should provide some HPV protection

[guiliu53]

From Michelle's paper:
HPV incidence is inversely associated with the frequency of condom use. Female college students who reported using condoms during all vaginal intercourse were 70% less likely to acquire a new infection than women who reported using condoms less than 5% of the time, after adjusting for the number of new partners and estimated number of previous partners of the male partner.

Original data source: Winer, et al; N Engl J Med. 2006 Jun 22;354(25):2645-54. Condom use and the risk of genital human papillomavirus infection in young women.

[carajbro]

Consistent Condom Use Reduces the Genital Human Papillomavirus Burden Among High-Risk Men: The HPV Infection in Men Study. Campbell et al., J Infect Dis. 2013., 208(3): 373-384. "The risk of HPV acquisition was 2-fold lower among men with no steady sex partner who always used condoms, compared with those who never used condoms (hazard ratio, 0.54), after adjustment for country, age, race, education duration, smoking, alcohol, and number of recent sex partners. The probability of clearing an oncogenic HPV infection was 30% higher among nonmonogamous men who always used condoms with nonsteady sex partners, compared with men who never used condoms (hazard ratio, 1.29), after adjustment for country, age, race, education duration, marital status, smoking, alcohol, and number of recent sex partners. No protective effects of condom use were observed among monogamous men." = 46% protection for male acauisition

[guiliu53]

Condom use promotes regression of human papillomavirus-associated penile lesions in male sexual partners of women with cervical intraepithelial neoplasia. Bleeker MCG, Hogewoning CJA, Voorhorst FJ, et al. Int J Cancer. 2003;107(5):804-810. This study randomized male partners of women with cervical lesions to condom use or non-condom use to observe the impact on penile lesion regression. It found that among men randomized to the condom group, the duration of flat penile lesions was shorter (7.4 months vs 13.9 months) and that the likelihood of clearance was higher (HR 2.1, 95% CI 1.2–3.7). But only 80% of the lesions were HPV-positive.

[carajbro]

Wen LM, Estcourt CS, Simpson JM, Mindel A. Risk factors for the acquisition of genital warts: are condoms protective? Sex Transm Infect 1999; 75: 312–6.

[carajbro]

Applying 70% protection against female HPV acquisition with condom use and 46% protection against male HPV acquisition with condom use. No differences by HPV type.

[guiliu53]

[darcyrao]

A study of female college students and their male partners (263 couples) in Canada reported that condom use was associated with reduced HPV prevalence in men whose female partner was infected (OR 0.64, 95% CI 0.50, 0.81) and but was not significant for women whose male partner was infected (OR 0.88, 95% CI 0.69, 1.11). But the analysis only included data from the enrollment visit, at which point the relationship duration would have been less than 6 months, so women may have had more pre-existing persistent infections than men.

A review by Lam et al. (2014) reports on inconsistent evidence of the protection from condoms, but points out the difficulties in measuring this effect. These include that a) condoms are not always used consistently, b) condoms are more likely to be used with casual/new sex partners, so there is confounding that may not be able to be adequately adjusted for, c) reporting of condom use is often inaccurate. Also condoms are only partially effective, so with enough acts even those who use them may get an infection. And some studies don't control for the infection status of the partners, which may introduce bias related to point b.

I think there is sufficient evidence and biologic plausibility for protection of HPV infection with condoms. There is also reason to believe that protection might be higher for females than males, if females are most likely to get infection in the vaginal canal/cervix, which would be protected with a condom, whereas males could get infection on the lower penile shaft or scrotum. So let's use values of a 70% reduction in acquisition for females (95% CI: 0.1, 0.6) and a 46% reduction for males (95% CI 0.31, 0.95).