Differences Among Low-Risk and High-Risk HPV

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Differences Among Low-Risk and High-Risk HPV

HPV caused by sexual intercourse (Genital HPV) can be categorized to low-risk and high-risk.

  • Low-Risk HPV: Not carcinogenic, but could cause skin warts on or around the genitals or anus area. For example, HPV types 6 and 11 cause 90% of all genital warts.
  • High-Risk HPV: Carcinogenic, and more than 10 high-risk HPV types have been identified. HPV types 16 and 18, would cause most of the HPV-related cancers such as cervical cancer (female), penile cancer (male) etc.

Cervical cancer may develop if high-risk HPVs are infected persistently.

Associate with which types of HPV?

Low-Risk HPV common types: HPV 6 & 11
High-Risk HPV common types: HPV 16 & 18

Potential health problems

Normally, HPV can be eliminated by the immune system within two years. However, if the virus cannot be eliminated, various HPV-related diseases or cancers will be developed. Women have higher risks of developing HPV-related cancers than males.

Low-Risk HPV

Genital warts: commonly found in vagina, cervix, vulva, penis, anus, rectum or urethra. Less commonly, mother may pass the virus to newborn baby during labor3.

Warts in the throat: this is a rare condition called recurrent respiratory papillomatosis, or RRP4. When this occurs in children it is called juvenile-onset RRP (JORRP) and can cause tumor in the throat.

High-Risk HPV

Cervical cancer: For women, precancerous cervical lesions will be developed if the high-risk HPV cannot be cleared by the immune system. If the condition worsens, the first stage of Cervical Intraepithelial Neoplasia (CIN1) will be developed in five years, and cervical cancer might eventually be developed.

Other uncommon but serious cancers: vulva, vaginal anal and oropharyngeal cancer (rear throat, meaning the parts nearby the base of the tongue and the tonsils)

Incubation period

Low-Risk HPV: Normally around 7 to 14 days
High-Risk HPV: Several years. Infected people may not develop symptoms, but they will carry the virus throughout their life

Note: The World Health Organization identifies HPV 6, 11, 16 and 18 as the most common HPV types. In Hong Kong, the Centre for Health Protection identifies HPV 11, 16 and 18 as the most common HPV types.