Human Papillomavirus: Biology and Pathogenesis

The human papillomavirus (HPV) is one of the most common causes of sexually transmitted disease in both men and women around the world, especially in developing countries, where the prevalence of asymptomatic infection varies from 2 to 44%, depending on the population and studied region (Sanjosé et al., 2007). Most HPV infection is transient and some studies show that the majority of sexually active individuals are exposed to and acquire infection from this virus at some phase in their lives (Baseman and Koutsky, 2005; Trottier and Franco, 2006). HPV infection is more prevalent in young adults, at the beginning of their sexual activity, with a subsequent decline in the prevalence rate with increasing age, likely as a result of development of an immune response against the virus and reduction of sexual activity (Castle et al., 2005; Fernandes et al., 2009; Chan et al., 2010).