APMIS 2009 Feb;117(2):108-14
Department of Virology, Statens Serum Institut, Artillerivej 5, Copenhagen, Denmark.
Genital human papillomavirus infection (HPV) is common and usually harmless. However, chronic cervical infection with high-risk HPV types can cause cell changes that may eventually lead to cancer. To determine the frequency of individual HPV types among mixed infections, we examined the type distribution among cervical specimens from more than 1000 Danish women. We also examined the HPV type distribution and the frequency of single and multiple HPV types for specimens from 113 women who underwent conization and were diagnosed with cervical intraepithelial neoplasia grade II or worse (CIN2+). Using microarray technology, we found that 49% of the HPV-positive patients were infected with multiple HPV types. Among the CIN2+ diagnosed women, this frequency was 41%. The most frequently found high-risk HPV type was HPV-16, which was found in 25% of the HPV-positive cervical specimens. Among the HPV positive CIN2+ diagnosed women, 48% were HPV-16 positive. Women younger than 30 years of age had a higher frequency of multiple infections (61%) than women older than 30 years (39%). We conclude that cervical infection with multiple HPV types is common among women in all age groups and among women with or without the diagnosis of CIN2+.