Incidence and Duration of Cervical Human Papillomavirus 6, 11, 16, and 18 Infections in Young Women: An Evaluation from Multiple Analytic Perspectives

Department of Health Economic Statistics, Merck Research Laboratories, North Wales, PA 19454-1099, USA.
Cancer Epidemiology Biomarkers & Prevention (Impact Factor: 4.13). 05/2007; 16(4):709-15. DOI: 10.1158/1055-9965.EPI-06-0846
Source: PubMed


To estimate the incidence and duration of cervical human papillomavirus (HPV)-6, HPV-11, HPV-16, and HPV-18 infections in a population of young American women.
The study population consisted of U.S. women who at baseline were 16 to 23 years of age, reported zero to five lifetime sexual partners, never having been pregnant, and never having had a prior abnormal Papanicolaou test and were enrolled in the placebo arm of a randomized multicenter clinical trial of a HPV-16 L1 virus-like particle vaccine. Women underwent type-specific endocervical/ectocervical swab HPV DNA testing at approximately 6-month intervals for up to 48 months of follow-up. To contribute person-time in the analyses of type-specific HPV incidence, a woman must have had at least three satisfactory swab specimens available and been negative for the relevant HPV type (HPV-6, HPV-11, HPV-16, or HPV-18) on her first two trial swabs. The duration of incident HPV infections was estimated using Kaplan-Meier survival analysis methods.
Person-years of exposure ranged by type-specific analysis from 2,645 to 3,188, with an incidence rate per 100 person-years of 3.6 for HPV-6, 0.4 for HPV-11, 5.4 for HPV-16, and 2.1 for HPV-18. With censoring at the time of treatment for cervical intraepithelial neoplasia, where done, the mean duration of incident infections was 9.3, 8.4, 18.2, and 16.4 months, respectively, for HPV-6 (n = 103), HPV-11 (n = 13), HPV-16 (n = 142), and HPV-18 (n = 62). When the duration of HPV infections was truncated at the time of cervical intraepithelial neoplasia detection (any grade), where applicable, mean duration figures were 8.4, 8.1, 14.0, and 15.1 months for HPV-6, HPV-11, HPV-16, and HPV-18 infections, respectively.
Previous studies of the mean duration of cervical HPV infection have been based on prevalent infections and/or featured relatively short duration of follow-up. This study tested women for HPV infection over a period of up to 48 months and observed a mean duration of incident HPV-16/HPV-18 infections approximately twice that of HPV-6/HPV-11.

  • Source
    • "After zur Hausen’s discovery of the association between persistent infection by oncogenic types of HPV and cervical cancer [2], epidemiological studies and experimental research into the development of preventive vaccines began. Since that time, our knowledge of the virus in subjects with HPV-associated lesions has increased, revealing the great complexity of the ecosystem of this pathogen [3-5]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Human Papillomavirus (HPV) is the most common sexually transmitted infection. In Italy, HPV vaccination is now offered free of charge to 12-year-old females. However, some regional health authorities have extended free vaccination to other age-groups, especially to girls under 18 years of age. We conducted a multicentre epidemiological study to ascertain the prevalence of different genotypes of HPV in young Italian women with normal cytology, with the aim of evaluating the possibility of extending vaccination to older females. The study was performed in 2010. Women aged 16-26 years with normal cytology were studied. Cervical samples were analyzed to identify the presence of HPV by PCR amplification of a segment of ORF L1 (450 bp). All positive HPV-DNA samples underwent viral genotype analysis by means of a restriction fragment length polymorphism assay. Positivity for at least one HPV genotype was found in 18.2% of the 566 women recruited: 48.1% in the 16-17 age-class, 15.4 in the 18-20 age-class, 21.9% in the 21-23 age-class, and 15.5% in the 24-26 age-class; 10.1% of women were infected by at least one high-risk HPV genotype. HPV-16 was the most prevalent genotype. Only 4 (0.7%), 4 (0.7%) and 3 (0.5%) women were infected by HPV-18, HPV-6 and HPV-11, respectively. Of the HPV-DNA-positive women, 64.1% presented only one viral genotype, while 24.3% had multiple infections. The HPV genotypes most often involved in multiple infections were high-risk. A high prevalence was noted in the first years of sexual activity (48.1% of HPV-DNA-positive women aged 16-17 years); HPV prevalence subsequently declined and stabilized.The estimate of cumulative proportions of young women free from any HPV infection at each age was evaluated; 93.3% and 97.1% of 26 year-old women proved free from HPV-16 and/or HPV-18 and from HPV-6 and/or HPV-11, respectively. Our findings confirm the crucial importance of conducting studies on women without cytological damage, in order to optimise and up-date preventive interventions against HPV infection, and suggest that vaccinating 26-year-old females at the time of their first pap-test is to be recommend, though this issue should be further explored.
    Full-text · Article · Dec 2013 · BMC Infectious Diseases
  • Source
    • "Typically, the progression from persistent infection to cervical cancer is very slow, often requiring a period of 20 years or longer [23]. This is associated with a low economic benefit of a HPV vaccination programme in the short term and therefore urges the need for economic assessment in the long term. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The policy of population-wide human papillomavirus (HPV) vaccination has been debated as the introduction of such a programme in a low-resource country faces the risk of insufficient cost-effectiveness. To assess the potential healthcare spending changes after the introduction of a HPV16/18 population-wide vaccination programme in Lithuania. For a cost-effectiveness analysis, we used mathematical simulation and epidemiological data modelling based on a Lithuanian female population. We performed comparative analysis of an annual 12-year-old girls population-wide vaccination programme combined with cervical cancer screening programme compared to the screening programme strategy only. HPV vaccination would gain an average of 35.6 life years per death avoided or up to 284.8 thousand life years would be gained over 90 years in total. The programme costs would be 2932.58 EUR per life year gained. All costs associated with the introduction of the vaccination programme could be recovered in 48 years. The HPV vaccination programme in Lithuania has the potential to generate up to 40.07 million EUR of economic returns annually compared with the current practice of the cervical screening alone. In Lithuania the HPV16/18 vaccination programme would be economically effective only in the long term. The investment costs of HPV16/18 vaccination have the potential to be recovered.
    Full-text · Article · Jul 2012 · Scandinavian Journal of Public Health
  • Source
    • "The study by Brown et al. (1999) also showed the presence of 23 different genotypes of HPV in the GWs samples. In addition to low-risk HPV-6 and HPV-11, which are associated with almost 90% of the cases, high-risk HPV types were also detected in some GW specimens (Dianzani et al., 2004; Insinga et al., 2007). "
    [Show abstract] [Hide abstract]
    ABSTRACT: External genital warts (EGW) are relatively common sexually transmitted diseases. In the majority of cases, low-risk human papilomaviruses (HPV), such as HPV-6 and HPV-11, are responsible but, high-risk types may also be detected and this has a bearing on vaccines for cervical cancer prevention. In this study the incidence of the high-risk HPV types 16, 18, 33 and 52 in EGWs of females from the southwest of Iran was assessed. Seventy-nine women with EGWs participated in this study. Quantitative real-time PCR with gene specific primers and probes for the E6 gene of HPV-16, 18, 33 and 52, were used for the detection of HPV DNA in the tissue and blood samples. Of the 79 tissue specimens, 13 (16.5%) were HPV positive, only genetic materials of HPV-16 and HPV-18 being detected, twelve patients (15.2%) were positive only for HPV-18 and the coexistence of HPV-16 and HPV-18 was shown in one patient. Only one plasma sample showed evidence of HPV-16 with very low viral load. Our data showed that high-risk HPV types can be found in the tissue specimens of EGW samples obtained from female patients in the Southwest of Iran, with HPV-18 as the most abundant type; however, additional studies with a larger population are required to prove the finding and help to determine the most appropriate type of virus for vaccine design for Iranian women.
    Full-text · Article · Jan 2011 · Asian Pacific journal of cancer prevention: APJCP
Show more