Quantitative HPV Genotyping in Screening of Anal Intraepithelial Neoplasia in HIV-positive Patients

The pathophysiology from anal HPV infection to Anal Intraepithelial Neoplasia is less well understood than cervical HPV infection. In cervical screening programs it is well accepted that the sole presence of a high-risk HPV strain (irrespective of number of viral particles) is sufficient to justify further investigation and treatment. The investigators hypothesize that in anal HPV infection not only the presence but the extent of HPV infection (single genotype viral load) or combination of different HPV genotypes (cumulative viral load) is of importance in determining the risk of anal dysplasia.