To ask the Scottish Executive what changes have occurred in the prevalence of human papilloma virus (HPV) genotypes in the last five years and which genotypes are the most prevalent.
Extensive human papilloma virus (HPV) type-specific testing is a relatively recent development. As yet there is no data to allow any changes over the past five years to be evaluated. However, in many countries, including Scotland, the normal prevalence of HPV in unvaccinated populations has been estimated and published within the scientific literature.
The prevalence of HPV varies by age and the prevalence and distribution of genotypes varies by severity of HPV-related disease.
In a study of cervical cancers diagnosed in Scotland, HPV was detected in 88% of invasive cervical cancers tested. Of these: 64% were type 16; 20% type 18; 6.5% type 45; 5% type 31; 3% type 33. All other specific types were detected in less than 1% of samples, aside from type 6 which was detected in 1.2%, but in all cases was as a co-infection with another High Risk HPV type. Overall 10% of HPV infections detected were within a multiple infection.
In unvaccinated populations of women with normal cervical cytology overall prevalence of HPV varies according to age. In a large study in the North of England HPV prevalence with High Risk (oncogenic) types of HPV varied from 22.3% in 20 to 29 year olds to 5.8% in 50 to 64 year olds.
With respect to HPV genotypes - a meta-analysis of studies from around the world compared HPV types in 1 million women with normal cytological findings. This included 21 studies from northern Europe, eight of which were from the UK. The findings showed that overall prevalence of HPV among 97,242 Northern European women of all ages was 10%. Within Europe the most prevalent subtypes were 16; 31, 18, 39, (33,66), 6, (45, 52, 51,58). (Brackets indicate HPV types with equal prevalence.)
Within Scotland a study of 3,444 women attending screening in one NHS board found that among 3089 women of all ages (<25 to >55) with normal cytology 12.7% were positive for HPV. 8.3% had a High Risk type identified; 6.5% a Low Risk type. 4.5% of women with normal cervical cytology were infected with multiple HPV types. The most prevalent HPV types among these women with normal cytology were: 16; (18,51), 31, 52, 45, 73, 59, 56, 33, 58, 39 with other types each identified in less than 1% of samples. (Brackets indicate HPV types with equal prevalence).