Human papillomavirus infection and reinfection in adult women: the role of sexual activity and natural immunity.
There is a paucity of data on whether or not women can be reinfected with human papillomavirus (HPV) types to which they were exposed to earlier in life and on the role of natural immunity. The observation of HPV infection at older ages may be explained by the reactivation of a latent infection or new exposure from sexual activity. Our objective was to analyze the association between reinfection and sexual activity. We analyzed data from 2,462 women enrolled in the Ludwig-McGill cohort and followed every 4 to 6 months for up to 10 years. We performed HPV typing and viral load measurements via PCR and determined HPV-16 seroreactivity at enrollment. Incidence of infection and reinfection were estimated for individual types. Adjusted relative risks (RR) for the association between infection/reinfection and new sexual partners were calculated using Cox regression. Rates of initial infection and reinfection postclearance were statistically comparable. RRs of initial infection or reinfection were consistently associated with new sexual partners [2.4 (95% confidence intervals; 95% CI, 2.0-3.1) for first infection, 3.7 (1.1-13.8) for reinfection with the same type, and 2.3 (1.5-3.7) for reinfection with a different type]. Reinfection 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 serologic evidence of prior HPV-16 exposure (RR, 3.0; 95% CI, 1.6-5.3). Viral loads at initial infection and at reinfection were comparable. HPV infection and reinfection were strongly associated with sexual activity. This study suggests that natural immunity does not play a role in controlling the extent of reinfections.
Division of Cancer Epidemiology, McGill University, Department of Social and Preventive Medicine and Ste-Justine Hospital, University of Montreal, Montreal, Canada.
Helen
H
Trottier
Silvaneide
S
Ferreira
Patricia
P
Thomann
Maria C
MC
Costa
Joao S
JS
Sobrinho
José Carlos M
JC
Prado
Thomas E
TE
Rohan
Luisa L
LL
Villa
Eduardo L
EL
Franco
D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology*; D015994:Incidence; D008137:Longitudinal Studies; D008875:Middle Aged; D027383:Papillomaviridae / Q000472:pathogenicity*; D030361:Papillomavirus Infections / Q000276:immunology / Q000821:virology*; D015995:Prevalence; D012008:Recurrence; D012307:Risk Factors; D012725:Sexual Behavior; D012747:Sexual Partners; D015229:Sexually Transmitted Diseases, Viral / Q000453:epidemiology / Q000209:etiology*; D019562:Viral Load; D055815:Young Adult
D004279:DNA, Viral