Rieth KKS, et al. - This study was conducted to assess the prevalence of oropharyngeal human papillomavirus (HPV) and to study the spatial connection between the virus and crypt biofilm in tonsil tissue. Results confirmed the presence of biofilm in the tonsillar crypts in a substantial proportion of tonsil tissues and could be identified reproducibly. Human papillomavirus was seen to colocalize in the crypt biofilm. With regard to the determination of HPV prevalence rates in the oropharynx, this finding had important implications, thereby demonstrating its possible role in the pathogenesis of HPV-related oropharyngeal carcinoma.