Cervical coinfection with human papillomavirus (HPV) types and possible implications for the prevention of cervical cancer by HPV vaccines.

Coinfection with multiple types of human papillomavirus (HPV) and its implications for the development of efficacious HPV vaccines is a subject of great interest. To describe the occurrence of concurrent infection with multiple HPV types and to determine whether genital HPV infection modifies the risk of acquiring a new HPV infection with another HPV type, 1610 subjects were monitored for an average of 4.1 years in Bogota, Colombia. Information on risk factors for HPV infection and cervical cells was collected for detection of HPV DNA of 36 types at study entry and at 6 consecutive 6-month follow-up visits. Clustering or the concurrent acquisition of multiple types occurred more often than would be expected by chance. Subjects with incident HPV-16 or -18 infection had 5-7 times higher odds of acquiring a subsequent HPV-58 infection than subjects not infected with HPV-16 or -18. This might affect the protection conferred by effective HPV vaccines.

Incidence, duration, and determinants of cervical human papillomavirus infection in a cohort of Colombian women with normal cytological results.

Data on the incidence and determinants of human papillomavirus (HPV) infection in women >30 years old are scarce. To address this, a cohort of 1610 women--15-85 years old, HPV negative, and with normal cytological results at baseline--was monitored every 6 months for an average of 4.1 years. Information on risk factors and cervical samples for cytological testing and detection and typing of HPV DNA were obtained at each visit. The incidence of high-risk types was higher than that of low-risk types (5.0 vs. 2.0 cases/100 woman-years). The age-specific incidence curve for high-risk types was bimodal, whereas the incidence of low-risk types gradually decreased with age. Infections with high-risk types lasted longer than infections with low-risk types (14.8 vs. 11.1 months). In this cohort of cytologically normal women, the incidence of cervical HPV infection was high, and the epidemiological profile of high-risk HPV types was different from that of low-risk types.

Population-based type-specific prevalence of high-risk human papillomavirus infection in middle-aged Swedish women.

Human papillomavirus (HPV) DNA testing can be used to identify women at risk of the development of cervical cancer. The cost-effectiveness of HPV screening is dependent on the type-specific HPV prevalence in the general population. The present study describes the prevalence and spectrum of high-risk HPV types found in a large real-life population-based HPV screening trial undertaken entirely within the cervical screening program offered to middle-aged Swedish women. Cervical brush samples from 6,123 women aged 32-38 years were analyzed using a general HPV primer (GP5+/6+) polymerase chain reaction-enzyme immunoassay (PCR-EIA) combined with reverse dot-blot hybridization for confirmation and HPV typing by a single assay. In this study, 6.8% (95% CI 6.2-7.5) (417/6,123) were confirmed as high-risk HPV positive. Infections with 13 different high-risk HPV types were detected, of which HPV 16 was the most prevalent type (2.1%; 128/6,123), followed by HPV 31 (1.1%; 67/6,123). Any one of the HPV types 18, 33, 35, 39, 45, 51, 52, 56, 58, 59, or 66 was detected in 3.6% (223/6,123) of the women. Infection with two, three, and five types simultaneously was identified in 32, 5, and 1 women, respectively. The combination of PCR-EIA as a screening test and reverse dot-blot hybridization as a confirmatory test, was found to be readily applicable to a real-life population-based cervical screening. The type-specific HPV prevalence found support in previous modeling studies suggesting that HPV screening may be a favorable cervical screening strategy.