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[Microbiology](https://durgical.com/en/microbiology/) · [Other DNA viruses](https://durgical.com/en/microbiology/groups/other-dna-viruses/)

# Human papillomavirus

- Virus
- Non-enveloped (naked)
- Exam priority: high

A very common sexually spread virus; some types cause warts and others, when they persist, cause cervical cancer.

Updated 2026-11-01

Also called: HPV, papillomavirus

## Key points

- 6 and 11 = warts and laryngeal papillomas; 16 and 18 = cancer.
- E6 blocks p53 and E7 blocks Rb: two cell-cycle brakes are lost.
- The koilocyte is the typical cell on cytology.
- The vaccine prevents, it does not treat: ideally given at 9 to 14 years, before exposure.

## At a glance

**Shape**
Icosahedral, non-enveloped

**Genome**
Circular double-stranded DNA

**Envelope**
Non-enveloped (naked)

**Family**
Papillomaviridae

**Size**
About 55 nm

## Morphology

- Naked icosahedral capsid, very hardy in the environment
- Infects the basal squamous epithelium of skin and mucosa
- Typical cytopathic effect: koilocytes (cells with a clear perinuclear halo and wrinkled nucleus)

## Transmission

- Sexual contact (vaginal, anal or oral), even without visible warts
- Skin-to-skin contact for common warts
- From birth canal to newborn: the origin of juvenile recurrent respiratory papillomatosis

**Reservoir:** Humans

### Isolation precautions

What the care team adds to standard precautions.

- Standard

## Virulence factors

- The E6 oncoprotein drives degradation of p53
- The E7 oncoprotein inactivates the retinoblastoma protein (Rb) and releases the cell cycle
- In high-grade lesions the viral DNA is often integrated into the host genome
- Most infections clear on their own; cancer risk lies in persistent high-risk types

## Diseases it causes

- Anogenital warts (condylomas) and skin warts [Human papillomavirus (HPV) infection →](https://durgical.com/en/conditions/human-papillomavirus-infection/)
- Intraepithelial lesions and cervical cancer [Cervical cancer →](https://durgical.com/en/conditions/cervical-cancer/)
- Laryngeal (recurrent respiratory) papillomatosis and laryngeal cancer [Laryngeal cancer →](https://durgical.com/en/conditions/laryngeal-cancer/)
- Cancer of the anus, vulva, vagina, penis and oropharynx

## Clinical picture

- Types 6 and 11 (low risk): genital warts and laryngeal papillomas
- Types 16 and 18 (high risk): cause most cervical cancers; type 16 is the most oncogenic
- Persistent infection is usually silent until a precancer or cancer appears

## Diagnosis

- High-risk HPV DNA test for screening
- Cervical cytology (Pap smear): koilocytes and intraepithelial lesions
- Colposcopy with biopsy to confirm
- Warts are diagnosed by how they look

## Treatment

There is no specific antiviral. Warts are treated by local destruction (cryotherapy, excision, laser) or topical immune modifiers such as imiquimod; cervical precancers are excised or ablated.

Drug class only; doses and regimens are set by the clinician from the current guideline.

## Prevention

- Vaccination before sexual debut
- Cervical screening: cytology and HPV DNA testing by age
- Condoms lower, but do not remove, the risk

**Vaccine:** Virus-like particle vaccine. Colombia's PAI uses the quadrivalent vaccine (6, 11, 16 and 18). The schedule (how many shots and for which groups, boys included) has been updated in recent years following WHO advice; the reference is the Ministry of Health's current PAI guideline.

## In Colombia

Colombia's Ministry of Health screens with cytology from 25 to 29 years and with HPV DNA testing from 30 to 65 years, using visual inspection in remote areas. Cervical cancer remains a leading cause of cancer death in women.

## Memory aid

The small numbers (6 and 11) only leave warts; as the number climbs to 16 and 18, so does the danger: cancer.

## Test yourself

Think of the answer, then tap the question to see it.

## Which HPV oncoproteins inactivate p53 and Rb?

E6 drives degradation of p53 and E7 inactivates the retinoblastoma protein (Rb).

## Which HPV types cause most genital warts?

Types 6 and 11, which are low risk for cancer and also cause laryngeal papillomatosis.

## Which cell is characteristic of HPV infection on cytology?

The koilocyte: a squamous cell with a clear halo around an enlarged, irregular nucleus.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/microbiology/human-papillomavirus/)

## Related

- [Hepatitis B virus](https://durgical.com/en/microbiology/hepatitis-b-virus/)
- [Molluscum contagiosum virus](https://durgical.com/en/microbiology/molluscum-contagiosum-virus/)

## Related conditions

- [Human papillomavirus (HPV) infection](https://durgical.com/en/conditions/human-papillomavirus-infection/)
- [Cervical cancer](https://durgical.com/en/conditions/cervical-cancer/)
- [Laryngeal cancer](https://durgical.com/en/conditions/laryngeal-cancer/)

## What the colours mean

**Gram-positive**
Thick peptidoglycan wall: stains purple.

**Gram-negative**
Thin wall with an outer membrane: stains pink.

**Acid-fast**
Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain.

[← Back to the group: Other DNA viruses](https://durgical.com/en/microbiology/groups/other-dna-viruses/)

Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Human papillomavirus and cancer](https://www.who.int/news-room/fact-sheets/detail/human-papilloma-virus-and-cancer) (WHO, 2024); [Clinical Overview of HPV](https://www.cdc.gov/hpv/hcp/clinical-overview/index.html) (CDC, 2024); [Cáncer de cuello uterino](https://minsalud.gov.co/salud/publica/ssr/Paginas/Cancer-de-cuello-uterino.aspx) (Ministerio de Salud y Protección Social de Colombia, 2024); [Genital warts](https://medlineplus.gov/ency/article/000886.htm) (MedlinePlus (NLM), 2024).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/microbiology/human-papillomavirus/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/human-papillomavirus/