Human PapillomaVirus (HPV)

Human PapillomaVirus (HPV)

Classification

• Virus
• DNA
• Non-enveloped
• Papovaviridae family.
• Human papillomavirus

Transmission

• Direct contact
• Fomites

Reservoir

• Skin
• Genitals

Molecular biology

• Multiple serotypes (> 75)
• Serotype determines disease.
• Warts are hyperproliferations of keratinized squamous epithelium.
• Malignancy may result inactivation of tumor supressor genes.
• E6 and E7genes of HPV are responsible for carcinogenicity.

1. E6 inhibits p53
2. E7 inhibits Rb

Risk Factor

Presentation

Cutaneous warts

• Serotypes 1, 2, and 4
• Hands, fingers, and soles of feet
• Multiple papillomatosis most common manifestation in childrens.

Anogenital warts (condylomata acuminata) 

• Serotypes 6 and 11
• Low risk HPV
• 90% are benign
• Koilocytes: epithelial cells with structural changes characteristic of HPV infection

Cervical intraepithelial neoplasia

• Serotypes 16, 18, 31, and 33 are preneoplastic
• High risk HPV
• Can progress to squamous cell carcinoma or spontaneously resolve

Squamous cell carcinoma

• Seen in AIDS
• Head, neck, anus, or cervix

Diagnosis

• Koilocytic cells seen on biopsy or Pap smear
• Characteristic nuclear alterations and perinuclear halo seen with HPV infection in the cervical squamous epithelial cells.

• Clinical presentation
• PCR

Treatment

• Cryotherapy
• Electrocautery
• Salicylic acid chemical therapy

Drugs

• Imiquimod
• Induces proinflammatory cytokines
• IFN
• Cidofovir

Prevention

Vaccine

Two types 

1. Quadrivalent :- containing HPV types 6,11,16,18
2. Bivalent :- containing HPV types 16,18

Efficacy 

• Has varied according to the immunologic and virological characteristics of study populations at baseline and according to the endpoints evaluated.
• Most of the time, rates of vaccine efficacy exceed 90%.

Recommended for

• Girls and young women 9-26 years of age.

Administration

• The quadrivalent vaccine is administered intramuscularly as three separate doses, with second dose given at 2months after the first dose and the third dose 6 months after the first dose.

Complications

• Untreated lesions may grow to the point of requiring surgical excision
• Infections with serotypes (16 and18) that have malignant potential

Classification

• Virus
• DNA
• Non-enveloped
• Papovaviridae family.
• Human papillomavirus

Presentation

Cutaneous warts

• Serotypes 1, 2, and 4
• Hands, fingers, and soles of feet
• Multiple papillomatosis most common manifestation in childrens.

Anogenital warts (condylomata acuminata) 

• Serotypes 6 and 11
• Low risk HPV

Cervical intraepithelial neoplasia

• Serotypes 16, 18, 31, and 33 are preneoplastic
• High risk HPV
• Can progress to squamous cell carcinoma or spontaneously resolve

Diagnosis

• Koilocytic cells seen on biopsy or Pap smear
• Characteristic nuclear alterations and perinuclear halo seen with HPV infection in the cervical squamous epithelial cells.

Vaccine

Two types 

1. Quadrivalent :- containing HPV types 6,11,16,18
2. Bivalent :- containing HPV types 16,18

Efficacy 

• Most of the time, rates of vaccine efficacy exceed 90%.

Recommended for

• Girls and young women 9-26 years of age.

Administration

• The quadrivalent vaccine is administered intramuscularly as three separate doses, with second dose given at 2months after the first dose and the third dose 6 months after the first dose.