A publication in a prestigious magazine, The Lancet Hiv, and an epidemiological study that brought together data from 64 different international studies conducted in over 50 research centers with expertise in HPV infection and operating throughout the world. In particular on HPV anal infection and related pre-cancerous and cancerous lesions (HSIL +). For Italy, the IRCCS Istituto San Gallicano and Istituto Regina Elena, which collected data on a population of almost 1000 males who have sex with HIV-positive and negative males (MSM): a small part of the total series studied, consisting of about 30,000 men.
The survey shows that the population of males having sex with males (MSM) is the most affected by HPV anal infection and related pre-cancerous and cancerous lesions (HSIL +), and that HIV infection represents the most strong determinant of HSIL + anal. In fact, the study estimated that, among HIV-positive MSMs, one in two individuals may have HSIL + anal lesions. The risk of having this type of injury tends to increase with age.
Starting from accurate data, collected with comparable standard methods and procedures, the study produced very robust estimates of the prevalence of anal infection and HSIL + lesions in men from different countries of the world, age, sexual orientation and clinical condition. Among heterosexuals, a prevalence of high-risk HPV was estimated at 6.9% and HPV16, the main cause of the tumor evolution of the infection, at 1.8%. Among those with HIV infection, the reported prevalences were 26.9% and 8.7%, respectively. Conversely, among MSM the prevalences increased up to 41.2% for high-risk HPV and 13.7% for HPV16, with a higher frequency in the presence of HIV infection (74.3% and 28, 5%, respectively).