Approximately types of papillomaviruses have been described; types 6 and 11, the most common types of human papillomavirus HPVcause genital warts, while types 16, 18, 31, and 45 are associated with the overwhelming majority of cases of cervical dysplasia and cervical cancer.
Routes of Transmission: HPV is primarily transmitted through sexual contact, especially genital contact; mother-to-infant transmission can occur during passage through an infected birth canal.
Health Effects: HPV infection is clinically silent, but after a latent period it is the cause of cervical dysplasia low- and high-grade squamous intraepithelial lesions and cervical cancer in women. HPV also causes ano-genital and other types of warts in men and women as well as recurrent respiratory papillomatosis in young children.
The virus is also associated with squamous cell cancers of the vagina, vulva, anus, and penis and possibly with squamous cell cancers at other mucosal and skin sites. More than 80 percent of sexually active individuals will acquire genital HPV infection by age The prevalence of rossz leheletet érző férgek HPV infection is also very high, exceeding 25 percent in U.
Nearly 6. However, 70 percent of these infections are cleared by the immune system within 12 months, and 90 percent within 24 months.
Persistent infection with high-risk HPV types leads first to low-grade and then to high-grade squamous intraepithelial lesions of the cervix in women. In the United States it is estimated that 1, women develop low-grade squamous intraepithelial lesions andwomen develop high-grade squamous intraepithelial lesions annually.
If undetected hpv dna vagy rna vírus untreated, high-grade squamous intra-epithelial lesions can progress to cervical cancer, of which there are approximately 11, new cases in the United States each year, which lead to 3, deaths annually. The incidence and prevalence of HPV infection are similar in most geographic regions of the world, but the incidence of and mortality from cervical cancer vary greatly, depending on the availability and use of pap smear screening for cervical dysplasia.
Low- and high-grade squamous intraepithelial lesions can be managed using various modalities whose aim is to prevent the development of cervical cancer. Correct and consistent use of male condoms may reduce the incidence of genital HPV infection by about 70 percent. Vaccines: Two formulations of HPV vaccine are licensed and approved for use in the United States: a bivalent vaccine containing types 16 and 18 and a quadrivalent vaccine containing types 6, 11, 16, and It is also recommended routinely for males.