Type-dependent association between risk of cervical intraepithelial neoplasia and viral load of oncogenic human papillomavirus types other than types 16 and 18.

Studies of the clinical relevance of human papillomavirus (HPV) DNA load have focused mainly on HPV16 and HPV18. Data on other oncogenic types are rare. Study subjects were women enrolled in the atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL) triage study who had ≥1 of 11 non-HPV16/18 oncogenic types detected during a 2-year follow-up at 6-month intervals. Viral load measurements were performed on the first type-specific HPV-positive specimens. The association of cervical intraepithelial neoplasia grades 2-3 (CIN2/3) with type-specific HPV DNA load was assessed with discrete-time Cox regression. Overall, the increase in the cumulative risk of CIN2/3 per 1 unit increase in log10 -transformed viral load was statistically significant for four types within species 9 including HPV31 (adjusted hazard ratio [HR adjusted ] = 1.32: 95% confidence interval [CI], 1.14-1.52), HPV35 (HR adjusted = 1.47; 95% CI, 1.23-1.76), HPV52 (HR adjusted = 1.14; 95% CI, 1.01-1.30) and HPV58 (HR adjusted = 1.49; 95% CI, 1.23-1.82). The association was marginally significant for HPV33 (species 9) and HPV45 (species 7) and was not appreciable for other types. The per 1 log10 -unit increase in viral load of a group of species 9 non-HPV16 oncogenic types was statistically significantly associated with risk of CIN2/3 for women with a cytologic diagnosis of within normal limits, ASC-US, or LSIL at the first HPV-positive visit but not for those with high-grade SIL. Findings suggest that the viral load-associated risk of CIN2/3 is type-dependent, and mainly restricted to the species of HPV types related to HPV16, which shares this association.

Short-term natural history of high-risk human papillomavirus infection in mid-adult women sampled monthly.

Characterizing short-term HPV detection patterns and viral load may inform HPV natural history in mid-adult women. From 2011-2012, we recruited women aged 30-50 years. Women submitted monthly self-collected vaginal samples for high-risk HPV DNA testing for 6 months. Positive samples were tested for type-specific HPV DNA load by real-time PCR. HPV type-adjusted linear and Poisson regression assessed factors associated with (i) viral load at initial HPV detection and (ii) repeat type-specific HPV detection. One-hundred thirty-nine women (36% of 387 women with ≥4 samples) contributed 243 type-specific HR HPV infections during the study; 54% of infections were prevalent and 46% were incident. Incident (vs. prevalent) detection and past pregnancy were associated with lower viral load, whereas current smoking was associated with higher viral load. In multivariate analysis, current smoking was associated with a 40% (95% CI: 5-87%) increase in the proportion of samples that were repeatedly positive for the same HPV type, whereas incident (vs. prevalent) detection status and past pregnancy were each associated with a reduction in the proportion of samples repeatedly positive (55%, 95% CI: 38-67% and 26%, 95% CI: 10-39%, respectively). In a separate multivariate model, each log10 increase in viral load was associated with a 10% (95% CI: 4-16%) increase in the proportion of samples repeatedly positive. Factors associated with repeat HPV detection were similar to those observed in longer-term studies, suggesting that short-term repeat detection may relate to long-term persistence. The negative associations between incident HPV detection and both viral load and repeat detection suggest that reactivation or intermittent persistence was more common than new acquisition.

Rates and determinants of oral human papillomavirus infection in young men.

BACKGROUND: Little is known about the rates and determinants of oral human papillomavirus (HPV) infection, an infection that is etiologically linked with oropharyngeal cancers. METHODS: A cohort of male university students (18-24 years) was examined every 4 months (212 men, 704 visits). Oral specimens were collected via gargle/rinse and swabbing of the oropharynx. Genotyping for HPV-16 and 36 other α-genus types was performed by polymerase chain reaction-based assay. Data on potential determinants were gathered via clinical examination, in-person questionnaire, and biweekly online diary. Hazards ratios (HR) were used to measure associations with incident infection. RESULTS: Prevalence of oral HPV infection at enrollment was 7.5%, and 12-month cumulative incidence was 12.3% (95% confidence interval [CI], 7.0, 21.3). Prevalence of oral HPV-16 was 2.8% and 12-month cumulative incidence was 0.8% (95% CI, 0.1%-5.7%). None of the incident oral HPV infections and 28.6% of the prevalent oral HPV infections were detected more than once. In a multivariate model, incident oral HPV infection was associated with recent frequency of performing oral sex (≥1 per week: HR, 3.7; 95% CI, 1.4-9.8), recent anal sex with men (HR, 42.9; 95% CI, 8.8-205.5), current infection with the same HPV type in the genitals (HR, 6.2; 95% CI, 2.4-16.4), and hyponychium (HR, 11.8, 95% CI, 4.1-34.2). CONCLUSIONS: Although nearly 20% of sexually active male university students had evidence of oral HPV infection within 12 months, most infections were transient. Human papillomavirus type 16 was not common. Sexual contact and autoinoculation appeared to play independent roles in the transmission of α-genus HPV to the oral cavity of young men.