Twenty per cent of cytology samples from routine cervical screening clinics in Edinburgh, UK, were found to be positive for human papillomavirus (HPV). Multiple high risk HPV (HR-HPV) infections were most prevalent in young women, who usually have higher levels of sexual activity, and in around 40% of samples with all grades of dyskaryosis.

The addition of HR-HPV testing to cervical screening programmes may enhance the programmes’ accuracy by identifying those individuals at greater risk of disease progression. This study showed that the detection of multiple HR-HPV was not a significantly better predictor of high grade cervical neoplasia being no more frequent in high grade than low grade dyskaryosis. The finding probably reflects the common sexual transmission of multiple HR-HPV types together.

Participating clinics in Edinburgh used a liquid based cytology method which has the advantage that the residual suspension not used for cytology can be used for microbiological testing. The extent of multiple infection was 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.

Future prospective cohort studies that link sequential loss or gain of HPV types with cytological analysis will be able to assess the impact of multiple HR-HPV infections on neoplastic progression.