Multiple high risk HPV infections are common in cervical neoplasia and young women in a cervical screening population

Aims: If human papillomavirus (HPV) testing is to be included within cervical screening programmes, the importance of multiple HPV infections in cervical neoplasia needs to be determined. This study investigated the diversity of multiple HPV types in a routine cervical screening population, and assessed associations with cervical neoplasia. Methods: Overall HPV prevalence, type specific prevalence, and extent of multiple infection were assessed in residual material from 3444 liquid based cytology samples, using real time GP5+/GP6+ polymerase chain reaction for screening and linear array assay for genotyping. HPV status was studied in relation to age and concurrent cytological evidence of dyskaryosis. Results: Twenty per cent of samples were HPV positive. HPV type diversity was broad, and multiple HPV infections occurred in half of the HPV positive samples. Younger women were significantly more likely to harbour multiple high risk HPV (HR-HPV) infections. Infections with multiple HR-HPV types were found in 3.4% of samples negative for neoplasia and in 33.3%, 41.8%, and 40.4% of samples with borderline, mild, or high grade dyskaryosis, respectively. Single HR-HPV infections were found in 4.9%, 38.6%, 45.0%, and 51.1% of negative, borderline, mild, or high grade dyskaryosis samples, respectively. Conclusions: Multiple HR-HPV infections were most prevalent in young women. Multiple HR-HPV infections were not more frequent in high grade than in low grade cervical neoplasia, reflecting common sexual transmission of multiple HR-HPV. Prospective cohort studies linking sequential loss or gain of HPV types with cytological analysis are required to assess the impact of multiple HR-HPV infections on neoplastic progression.