BACKGROUND: Persistent human papillomavirus (HPV) infection is the most important risk factor for cervical cancer, and understanding genotype-specific HPV persistence is essential for elucidating the natural history of HPV infections.
METHODS: In the Finnish Family HPV Study, 329 pregnant women (mean age, 25.5 years) were recruited during the third trimester of pregnancy and were followed up for 6 years. Multiplex HPV genotyping for 27 low- and high-risk HPV types was used to define genotype-specific prevalence at each visit. Generalized estimating equation models were constructed to estimate predictors of type-specific persistence (positive results at 2 consecutive visits) of species 7 and 9 HPV genotypes.
RESULTS: HPV16 was the most common type, followed by HPV types 18, 31, 35, 45, 58, 70, and 6. Prevalence of multiple infections ranged from 21% to 45%. Persistence was most prolonged for HPV types 35, 58, and 52, with durations of 38.7, 32.1, and 24.2 months, respectively, and was equal for multiple-type infections and HPV16, with durations of 21 and 24 months, respectively. Independent predictors of type-specific persistence of species 7 and 9 HPV genotypes were age (odds ratio, 1.13 [95% confidence interval, 1.02-1.25]; P=.017), oral sex (odds ratio, 0.37 [95% confidence interval, 0.17-0.81]; P=.013), and young age (<13 years) at initiation of smoking (odds ratio, 0.51 [95% confidence interval, 0.27-0.98]; P=.046).
CONCLUSION: HPV16 was the most frequent persisting HPV genotype followed by multiple infections. Early initiation of smoking, practicing oral sex and older age increase the risk for persistence of species 7 and 9 HPV genotypes.
- DNA, Viral/genetics
- Longitudinal Studies
- Papillomavirus Infections/epidemiology
- Pregnancy Complications, Infectious/virology
- Risk Factors
- Time Factors