Human papillomaviruses ( human warts ) . Dr. Mohammed Arif. Associate professor, Consultant virologist, Head of the virology unit.
Human papillomaviruses ( Human warts ). Human papillomaviruses (HPV ) are classified within the family papillomaviridae. They are non- enveloped, with icosahederal nucleocapsid, composed of 72 star shaped capsomeres . The viral genome is ds-DNA . They replicate in the skin and the mucosal surfaces of the genitalia, anus, mouth and air way .
Human papillomaviruses . Approximately 130 HPV types have been identified. About 30 – 40 HPV types are transmitted through sexual contact and infect the anogenital region.
Types of human warts . 1 – Skin warts . 2 – Genital warts . 3 – Genital cancers . 4 - Oral papillomas ( laryngeal warts ) .
1- Skin warts . Skin warts are non-cancerous skin growths. Three types of skin warts: 1- Common warts. 2- Flat warts . 3- Plantar warts .
Skin warts . 1- Common warts . Caused by types 1, 2 & 7. Found anywhere of the skin , especially on regions subject to abrasion such as hands, feet , elbows and knees. They are about 5-mm in diameter with a rough surface( cauliflower ), slightly raised above the surrounding skin .
Common warts . Do not usually cause genital warts . Not associated with cancer .
Skin warts . 2- Flat warts : Smaller, flatter and more numerous . Seen mainly on the face, forehead , and arms . Not associated with the development of cancer .
Skin warts . 3- Plantar warts : Found on the soles of the feet . They grow inwards . Cause pain on walking .
Anogenital warts ( condylomata acuminata ). Anogenital warts ( venereal warts ) are common sexually transmitted disease . They are transmitted by direct sexual contact . Types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68 are considered high risk sexually transmitted and may lead to cervical cancer, vulvar cancer, penile cancer and anal cancer . Types 5, 11, 42, 43, 44, 55 and others are considered low risk because they are rarely associated with cancer .
Anogenital warts . Anogenital warts may appears any where on the genital area of males and females . Some anogenital infections are silent without any signs and symptoms . Some are flesh, large, moist, flat or raised, appear in clusters on the genital area .
Anogenital warts and cervical cancer . HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68 are associated with cervical cancer, vulvar ulcer, anal cancer and penile cancer ( the high risk warts ). These types have the ability to alter the structure of the cell in the uterus or around the anus area causing cancer . Some of the genital warts are found inside the vagina, causing vaginal bleeding and discharge .
anogenital warts and cervical cancer . Some of warts are found around the urethral opening, Causing bleeding during urination . Women suffer from genital warts are strongly advised to have regular PAP-smear test every six months .
Oral papillomas ( laryngeal warts ) . Seen mainly in young children . They grow rapidly to obstruct the airway and continue to recur despite repeated surgical removal .
Prevention of cervical cancer A recombinant vaccine ( Gardasil ) that is highly effective against HPV types 6, 11, 16, and 18, which account for 70 % of cervical cancer, is available . The vaccine is given as three injections. It is recommended for girls between the age s of 11 and 26 years .
Treatment . Small warts can be removed by cryosurgery ( freezing ), electrocautery ( burning) or laser treatment . Large warts are removed by surgery .