Early natural history of incident, type-specific human papillomavirus infections in newly sexually active young women.

BACKGROUND Characterizing short-term detection patterns of young women's incident α-genus human papillomavirus (HPV) infections may further our understanding of HPV transmission. METHODS Between 2000 and 2007, we followed 18- to 22-year-old female university students with triannual HPV DNA and Papanicolaou testing. Using Kaplan-Meier methods, we estimated duration of detectable, type-specific incident infections; time to redetection (among infections that became undetectable); and time to cervical lesion development after incident infection. We evaluated risk factors for short-term persistent versus transient infection with logistic regression. RESULTS Three hundred three incident, type-specific infections were detected in 85 sexually active women. Median time to first negative test after incident infection was 9.4 (95% CI: 7.8-11.2) months; 90.6% of infections became undetectable within 2 years. About 19.4% of infections that became undetectable were redetected within 1 year. Cervical lesions were common and 60% were positive for multiple HPV types in concurrent cervical swabs. Incident HPV detection in the cervix only (vs. the vulva/vagina only or both sites) was associated with short-term transience. CONCLUSIONS Although most incident infections became undetectable within 2 years, redetection was common. Cervical lesions were a common early manifestation of HPV infection. IMPACT It remains unclear whether potentially modifiable risk factors can be identified to reduce infection duration (and transmission likelihood).