title: Genotype-specific clearance of genital human papillomavirus (HPV) infections among mothers in the Finnish family HPV study.
abstract: The majority of cervical human papillomavirus (HPV) infections in young women are transient, but whether the clearance differs among different HPV genotypes and the different factors predicting genotype-specific clearance are partly unknown. In the Finnish Family HPV Study, 131 of 252 women (mean age, 25.5 years) cleared their infection during the prospective follow-up of 6 years (median, 62.4 months; range, 1.6 to 94.5 months). Cervical scrapings collected at each visit were tested for 24 low-risk and high-risk (HR) HPV types with multiplex HPV genotyping. Poison regression (panel data) was used to estimate predictors for the clearance of species 7 and 9 HPV genotypes. Of all HPV genotypes detected in these women, multiple-type and HPV type 16 (HPV16) infections showed clearance least frequently (46.1% and 50.5%, respectively). The actuarial and crude mean times to first clearance were variable among different genotypes. The actuarial clearance rate (events/person-time at risk) was highest for HPV16 and multiple-type infections, while HPV66 and -82 had the highest crude clearance rate. Independent predictors increasing type-specific clearance of species 7/9 HPV genotypes were older age (incidence rate ratio [IRR] = 1.1; 95% confidence interval [95% CI], 1.03 to 1.18; P = 0.002) and baseline oral HR HPV DNA-negative status (IRR = 2.94; 95% CI, 1.03 to 8.36; P = 0.042), while a higher number of sexual partners during the follow-up decreased the probability of clearance (IIR = 0.35; 95% CI, 0.15 to 0.83; P = 0.018). To conclude, HPV16 and multiple-type infections showed the lowest clearance among young mothers. Increasing age and negative oral HR HPV DNA status at baseline were associated with increased clearance, whereas a higher number of current sexual partners decreased the probability of species 7/9 HPV genotype clearance.
authors.affiliation: Department of Oral Pathology, Institute of Dentistry and Medicity Research Laboratory, Faculty of Medicine, Lemminkäisenkatu 2, 20520 Turku, Finland. karolina.louvanto@utu.fi
authors.forename: Karolina
authors.initials: K
authors.lastname: Louvanto
authors.forename: Kari J
authors.initials: KJ
authors.lastname: Syrjänen
authors.forename: Marjut A M
authors.initials: MA
authors.lastname: Rintala
authors.forename: Seija E
authors.initials: SE
authors.lastname: Grénman
authors.forename: Stina M
authors.initials: SM
authors.lastname: Syrjänen
mesh_terms: D000328:Adult; D000367:Age Factors; D002584:Cervix Uteri / Q000821:virology*; D005260:Female; D005387:Finland; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D027383:Papillomaviridae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D030361:Papillomavirus Infections / Q000821:virology*; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors