Human papillomavirus

Classification

Realm: Monodnaviria
Order: Zurhausenvirales
Family: Papillomaviridae
Genus: Papillomavirus
Species: Human papillomavirus

Structure

Genome: Double-stranded DNA (dsDNA)
Capsid Shape: Icosahedral
Envelope: Non-enveloped
Size: ~55 nm in diameter
Special Features: Infects epithelial cells; some strains have oncogenic potential

Transmission & Epidemiology

Natural Habitat: Humans
Geographic Distribution: Worldwide
Human Association: Pathogenic
Transmission: Direct skin-to-skin or mucosal contact, primarily through sexual contact

Human papillomavirus (HPV) is a common viral pathogen that infects epithelial cells, causing warts and, in some cases, leading to cancerous transformations.

Virulence Factors: E6 and E7 oncoproteins (inhibit tumor suppressors p53 and Rb), ability to evade immune response, persistence in epithelial cells
Associated Diseases: Cutaneous and genital warts, cervical cancer, oropharyngeal cancer, anal cancer
Clinical Symptoms: Asymptomatic in many cases, warts (common, plantar, genital), abnormal cervical cytology, lesions in oral and anogenital regions
High-Risk Groups: Sexually active individuals, immunocompromised patients, individuals with multiple sexual partners, those without HPV vaccination

The oncogenic potential of high-risk HPV types (e.g., HPV-16, HPV-18) and their ability to integrate into host DNA make them a significant global health concern, especially in cervical cancer development.

The diagnosis of Human papillomavirus infection involves both clinical examination and laboratory-based screening methods.

Diagnostic Methods

Pap Smear (Cytology): Detects abnormal cervical cells associated with HPV infection
HPV DNA Testing: Identifies high-risk HPV strains linked to cancer
Colposcopy: Visual inspection of cervical lesions for precancerous changes
Biopsy: Confirms histological changes in affected tissues
Visual Inspection with Acetic Acid (VIA): A cost-effective screening method used in low-resource settings

Treatment Approaches

Vaccination: HPV vaccines (e.g., Gardasil, Cervarix) protect against high-risk and wart-causing strains
Topical Treatments: Salicylic acid, imiquimod, and podophyllotoxin for warts
Cryotherapy & Laser Therapy: Used for the removal of persistent warts and precancerous lesions
Surgical Intervention: Loop electrosurgical excision procedure (LEEP) or conization for high-grade cervical dysplasia

Prevention Strategies

HPV vaccination (e.g., Gardasil, Cervarix) to protect against high-risk and wart-causing HPV types
Regular cervical screening (Pap smears, HPV DNA tests) for early detection of precancerous changes
Use of barrier protection (e.g., condoms) to reduce the risk of transmission
Public education on HPV transmission, risk factors, and cancer prevention
Encouraging vaccination in both males and females for herd immunity

Preventing Human papillomavirus infections infections involves vaccination, routine screenings, and public awareness efforts to reduce HPV-associated cancers.

Global Impact

Human papillomavirus is one of the most common sexually transmitted infections, with certain high-risk types causing nearly all cases of cervical cancer worldwide.

~600K

Approximately 600,000 new cases of HPV-associated cancers are diagnosed worldwide each year, with cervical cancer being the most prevalent.

Despite the availability of vaccines and screening programs, HPV remains a major global health issue, particularly in regions with limited access to healthcare and vaccination.