Dear Sir,In the last decade, only a few novel genital human papillomavirus (HPV) types have been cloned. The last types reported 5 years ago were HPV89, 90 and 91. 1 This may reflect that the most prevalent types were isolated and characterized earlier, and not many mucosal types are left to discover. Recently cloned types 92, 93, 94, 95 and 96 were isolated from skin lesions and belong to the cutaneous Beta Papillomavirus genus which has a less important influence on human health.2-5 It was thus unusual that 2 independent research teams nearly simultaneously cloned and sequenced a novel HPV type that infects the anogenital mucosa, results that were presented by both groups at the 23rd International Papillomavirus Conference and Clinical Workshop 2006 in Prague. 6,7 We were greatly interested in the following article by Chen et al. which was published on line March 9, 2007 in this journal 8 , on molecular characterization of HPV97 isolate cloned from a healthy Costa Rican women. Their work clearly demonstrates the relatedness of HPV97 with types 18 and 45, and classifies HPV97 in alpha 7 species. They have also demonstrated that HPV97 oncoproteins degrade p53 and bind pRb in vitro. Since HPV97 was detected in only 2 of 1,796 women tested, the authors suggested that HPV97 prevalence in the general population is probably very low. Our results complement their findings by describing a similar HPV97 isolate that was cloned in our laboratory in 2006 as well as the prevalence of HPV97 in a cohort of HIV-seropositive men having sex with men.The individual from whom the first isolate of HPV97 was obtained in our laboratory 7 was an HIV-seropositive 48-yearold male living in Montreal who was born in Peru. The initial sample tested in May 2005 was a paraffin-embedded anal biopsy with a histopathological diagnosis of low-grade anal intraepithelial neoplasia (AIN-1). The 450-bp L1 amplicon generated with MY09-MY11 PCR from this sample displayed a unique, yet unknown RsaI restriction pattern. PCR-sequencing of the amplicon revealed a new HPV-like sequence having 86% of sequence homology with types 18 and 45. As the DNA extracted from formalin-fixed, paraffin-embedded tissues is usually partially degraded, the whole genome of the novel type was cloned from DNA extracted from a cell suspension obtained with an anal swab collected 3 months before the biopsy. Besides the novel type, this sample also contained HPV types 33, 58, 70, 71 and possibly 52, as assessed by Roche's Linear Array HPV Genotyping Test. To clone the whole genome of the novel virus from a mixture of several HPV types, we amplified human genomic and episomal viral DNA by rolling circle amplification (RCA) according to a previously published protocol. 9 For the details of cloning, please refer to the electronic supplementary material.Sequencing revealed a genome of 7,843 bp coding for the complete set of HPV early and late genes (Gene Bank accession number: EF436229). The virus has 81.9% and 83.7% homology with whole genomes of HPV types 18 and 45, respectively....