| design and methods of a population-based natural history study of cervical neoplasia in a rural province of costa rica: the guanacaste project. | this paper reports on the enrollment phase of a population-based natural history study of cervical neoplasia in guanacaste, a rural province of costa rica with consistently high rates of invasive cervical cancer. the main goals of the study are to investigate the role of human papillomavirus (hpv) infection and its co-factors in the etiology of high-grade cervical neoplasia, and to evaluate new cervical cancer screening technologies. to begin, a random sample of censal segments was selected and ... | 1997 | 9180057 |
| population-based study of human papillomavirus infection and cervical neoplasia in rural costa rica. | human papillomavirus (hpv) is the main cause of cervical neoplasia. because few population-based studies have investigated the prevalence of type-specific infection in relation to cervical disease, we studied a high-risk population, estimating the prevalence of hpv infection and the risk associated with various hpv types. | 2000 | 10716964 |
| description of a seven-year prospective study of human papillomavirus infection and cervical neoplasia among 10000 women in guanacaste, costa rica,. | the guanacaste study ("guanacaste project," or gp), was designed to investigate the role of human papillomavirus (hpv) infection and its cofactors in the development of cervical neoplasia and to evaluate new cervical cancer screening technologies. the follow-up phase of the gp was designed to study why a small proportion of women infected with hpv develop cervical intraepithelial neoplasia grade 2 (cin 2), cin 3, or cancer (these three together are globally referred to as > or = cin 2, that is, ... | 2004 | 15030652 |
| age-related changes of the cervix influence human papillomavirus type distribution. | approximately 15 human papillomavirus (hpv) types cause virtually all cervical cancer whereas other hpv types are unrelated to cancer. we were interested in whether some noncarcinogenic types differ from carcinogenic in their affinity for the cervical transformation zone, where nearly all hpv-induced cancers occur. to examine this possibility, we tested cervical specimens from 8,374 women without cervical precancer and cancer participating in a population-based study in guanacaste for >40 hpv ty ... | 2006 | 16424061 |
| human papillomavirus types by age in cervical cancer precursors: predominance of human papillomavirus 16 in young women. | in a population-based study conducted in guanacaste, costa rica, we investigated the human papillomavirus (hpv) types detected in 233 cases of cervical intraepithelial neoplasia (cin) 2/3 and cancer by age. cin2+ and cin3+ in young women were significantly more likely to be associated with hpv 16 than the same lesions in older women (80% of cin3+ were associated with hpv 16 among women ages 18-26 years compared with only 32% among women older than 55 years; ptrend=0.018). there were no differenc ... | 2009 | 19273486 |
| longitudinal study of human papillomavirus persistence and cervical intraepithelial neoplasia grade 2/3: critical role of duration of infection. | the natural history of human papillomavirus (hpv) infections in older women is critical for preventive strategies, including vaccination and screening intervals, but is poorly understood. in a 7-year population-based cohort study in guanacaste, costa rica, we examined whether women's age and the duration of carcinogenic hpv infections influenced subsequent persistence of infection and risk of cervical intraepithelial neoplasia grade 2 (cin 2) or worse disease. | 2010 | 20157096 |
| efficacy of a bivalent hpv 16/18 vaccine against anal hpv 16/18 infection among young women: a nested analysis within the costa rica vaccine trial. | anal cancer remains rare (incidence of about 1·5 per 100,000 women yearly), but rates are increasing in many countries. human papillomavirus (hpv) 16 and 18 infections cause most cases of anal cancer. we assessed efficacy of an as04-adjuvanted hpv 16 and hpv 18 vaccine against anal infection with hpv 16, hpv 18, or both (hpv 16/18). | 2011 | 21865087 |
| Longitudinal Analysis of Carcinogenic Human Papillomavirus Infection and Associated Cytologic Abnormalities in the Guanacaste Natural History Study: Looking Ahead to Cotesting. | Background. Few studies have addressed the timing of cervical cytologic abnormalities and human papillomavirus (HPV) positivity during the course of an infection. It remains largely unknown how infections detected by HPV and cytology wax and wane relative to each other. The aim of this analysis was to assess the longitudinal relationship of abnormal cytology and HPV positivity in a 7-year prospective study of 2500 women in Guanacaste, Costa Rica.Methods. At each semiannual or annual visit, cervi ... | 2011 | 22147792 |