In the last few years much attention has been focused on the implementation of human papillomavirus detection in population based screening programmes to identify women at risk for cervical cancer. Short-term fluctuations in prevalence of human papillomavirus were investigated within a single menstrual cycle. The highest prevalence was found at the follicular phase (55%), whereas the cumulative prevalence was 75%. (Schiffman et al, 1993;Chichareon et al, 1998;Ngelangel et al, 1998; Liaw et al, 1999;Walboomers et al, 1999;Andersson et al, 2001;Lehtinen et al, 2001). A systematic review on the role of HPV testing within a cervical cancer screening program showed that the high risk HPV prevalence in CIN 1 ranged from 30 to 65%, in CIN 2 from 40 to 70% and in CIN 3 from 60 to 90% (Cuzick et al, 1999). Furthermore, HPV can be detected in almost all cervical carcinomas (Walboomers et al, 1999).The estimated point prevalences of genital HPV infections detected by PCR based methods among populations of women with cytological normal cervical smears range from 1.5 to 44.3%, with a weighted average of 16.2% (Xi and Koutsky, 1997) and show an age-related pattern (Melkert et al, 1993). The highest prevalences are found in women in their early twenties (de Villiers et al, 1992;Melkert et al, 1993). Newly acquired genital HPV is usually transient in women with normal cervical cytology (Evander et al, 1995). The mean duration of cervical HPV infection in a healthy population varies between 8.2 -13.5 months (Ho et al, 1998;Franco et al, 1999). Short-term fluctuations of an individual's HPV status, however, are still a matter of debate. Several studies have reported a fluctuating expression of HPV (Ho et al, 1998;Schneider et al, 1992;Wheeler et al, 1996), probably due to differences in viral load, inadequate sampling or reactivation of endogenous infection (Woodman et al, 2001). Single point measurements of HPV 16 in cervical smears are of limited value for assessment of an individual's HPV status .Before incorporation of HPV testing in screening programs for prevention of cervical cancer it is important to gain more insight in the actual prevalence of HPV, influenced by short-term fluctuations. The aim of this study was to investigate the presence of cervical HPV in the different phases of a single menstrual cycle in women with regular cycles.
MATERIALS AND METHODSCervical samples for HPV detection and cytological examination were obtained from 20 women visiting the outpatient clinic for fertility problems at the University Medical Centre Nijmegen, the Netherlands. Only women with regular menstrual cycles were included. Patients with cervical treatment for abnormal cervical cytology in the past 10 years were not included in the study. After giving informed consent, patients were interviewed regarding their medical history, smoking habits, use of contraceptives and sexual behaviour.Cervical smears for HPV detection and cytological classification were obtained using the Cervex brush (Rovers, Oss, the Netherlands).On a weekly bas...