Human Papillomavirus Infection and Reinfection in Adult Women: the Role of Sexual Activity and Natural Immunity

Abstract

There is paucity of data on whether or not women can be re-infected with human papillomavirus (HPV) types to which they were exposed earlier in life and on the role of natural immunity. The observation of HPV infection at older ages may be explained by reactivation of a latent infection or new exposure from sexual activity. Our objective was to analyze the association between re-infection and sexual activity. We analyzed data from 2462 women enrolled in the Ludwig-McGill cohort and followed every 4-6 months for up to 10 years. We performed HPV typing and viral load measurements via polymerase chain reaction and determined HPV-16 seroreactivity at enrolment. Incidence of infection and re-infection were estimated for individual types. Adjusted relative risks (RR) for the association between infection/re-infection and new sexual partners were calculated using Cox regression. Rates of initial infection and re-infection post-clearance were statistically comparable. RRs of initial infection or re-infection were consistently associated with new sexual partners (2.4 [95%CI: 2.0-3.1] for first infection, 3.7 [1.1-13.8] for re-infection with the same type, and 2.3 [1.5-3.7] for re-infection with a different type). Re-infection in older women was also associated with new sexual partners (RR=2.8, 95%CI: 1.4-5.3) as were new infections with HPV-16 among women with serological evidence of prior HPV-16 exposure (RR=3.0, 95%CI: 1.6-5.3). Viral loads at initial infection and at re-infection were comparable. HPV infection and re-infection were strongly associated with sexual activity. This study suggests that natural immunity does not play a role in controlling the extent of re-infections.

Seroepidemiology of High-Risk HPV in HIV-Negative and HIV-Infected MSM: The H2M Study

“…Some studies observed a reduced risk of subsequent HPV infection in anti-HPV seropositive individuals (25)(26)(27). However, findings have been inconsistent (24,28,29) and the immune correlate (i.e., the antibody level which results in effective immunity) is unknown. Antibody levels elicited after HPV vaccination are 1 to 4 logs higher than after natural infection and have been shown to be highly protective against incident infection with vaccine-type HPV (30,31).…”

Detection of Genital HPV Infection Using Urine Samples: a Population Based Study in India

“…Population studies from various parts of India found increased HPV prevalence as age advances (Sankaranarayanan et al, 2005;Asiaf et al,2012;Srivastava et al, 2012). Highest HPV prevalence occurs soon after initiation of sexual activity among young women in the age group of 18-24 years and gradually comes down with a second peak after the fifth decade of life (Trottier et al, 2010). In this context WHO recommendation of screening of women 35 years or above and every five years for three tests in life time will be a more cost effective approach in resource poor settings (Aggarwal, 2014).…”

Epidemiology of Mucosal Human Papillomavirus (HPV) Infections Among Adult and Children

“…Recent evidence shown that re-infection with HPV (with a different or either a same genotype) is a common occurrence (Trottier et al, 2010). Prior infection with HPV does not provide women with adequate immunity against subsequent infections.…”

“…Moreover, it has been shown that an infection with a specific genotype does not decrease the probability of being infected by a phylogenetically-related genotype (Thomas et al, 2000). Recent studies have shown that re-infection with a same genotype, as well as incident infection in older women who had multiple lifetime sexual partners, are associated with new sexual partners suggesting that infection in adult women may results not only from reactivation (infections acquired at a young age that never completely cleared but become undetectable and appeared later in life) but also from new exposure via sexual activity (Trottier et al, 2010;Munoz et al, 2004).…”