Papillomavirus infections (anogenital) are the most common sexually-transmitted infections in the US. Every year in the US, about 14 million people are infected with HPV and about 26,000 new cancers are attributed to this virus: cervical (66%), vaginal (55%), anal (79%), and oropharyngeal (62%).
CASES/YEAR
14,000,000 (US); 280,000,000 (Global)
OTHER NAMES
Human papillomavirus infections (oncogenic); HPV-associated cancer; Anogenital warts; Condylomata acuminatum; Recurrent respiratory papillomatosis (Related Infection);
INCUBATION
As long as two years (usually 3-4 months); [Harrison ID, 2nd Ed, p. 821] 1-20 months (usually 2-3 months); [CCDM]
INITIAL SYMPTOMS
Dysplasia and cancer of cervix, vagina, vulva, penis, and anus; HPV16 is linked to many oropharyngeal cancers; [MMWR, Jan. 31, 2014] "Most genital HPV infections are asymptomatic, subclinical, or unrecognized." [CCDM]
COMMENTS
EPIDEMIOLOGY:
"Human papillomavirus (HPV) infection is the most common sexually transmitted infection in men and women in the United States." Every year in the United States, about 14 million people are infected with HPV and about 26,000 new cancers are attributed to this virus. HPV causes a large percentage of certain cancers: cervical (66%), vaginal (55%), anal (79%), and oropharyngeal (62%). [MMWR, January 31, 2014] Some types of HPV cause common skin warts. See "Papillomavirus infections (warts)." HPV types 16, 18, and probably other types, which cause intraepithelial neoplasia and carcinoma, are difficult to see and diagnose clinically. Endocervical lesions should be treated after Pap smear results because dysplasia may dictate additional treatment. [Merck Manual, p. 1703] Most visible genital warts are caused by HPV type 6 or 11. Types 16 and 18 are associated with 70% of cancers (cervical, vulvar, anal, and penile dysplasia). [CCDM, p. 301] HIV infection increases the risk for frequency and severity of anogenital warts and cancers. [PPID, p. 1920]
FINDINGS:
HPV infection causes intraepithelial neoplasia of the cervix (CIN) and other anogenital sites. [Cecil, p. 2185] Anogenital warts include condylomata acuminata (cauliflower-like lesions), papular warts, flat warts, and keratotic warts (crust-like lesions similar to seborrheic keratoses). Visible warts are not usually associated with oncogenic types. HPV nucleic acid tests are not recommended. Anogenital warts may look like the secondary syphilis lesions (condylomata lata). [ABX Guides: Genital/Anogenital Warts] The role of DNA testing for HPV types in screening for cervical cancer is still evolving. [Wallace, p. 766]
RELATED INFECTIONS:
Women clear 70% of HPV infection within 12 months and 90% within 2 years. Vertical transmission can occur during vaginal delivery. [Cohen, p. 577] "Warts caused by genital types can also rarely occur in the mouth and upper respiratory tract, producing a serious condition known as recurrent respiratory papillomatosis, which can cause hoarseness and even airway compromise. [Cecil, p. 2187] Recurrent respiratory papillomatosis is "a rare but important condition in which warts grow in the throat and airway." [MMWR, January 31, 2014]
DIAGNOSTIC
Clinical; Pap smears are the primary method of screening every 3 years beginning at age 21; [Harrisons, p. 432] Also anoscopy for anogenital warts; Role in management of NAAT for HPV DNA not yet clear; [Merck Manual, p. 1703]
SIGNS & SYMPTOMS
-
S papules or plaques
-
S warty growth of the skin
-
*cancer
ENTRY
Skin or Mucous Membranes (Includes Conjunctiva), Sexual Contact
RISK FACTORS
- AIDS patients
- Cancer patients
TREATMENT
The Advisory Committee on Immunization Practices (ACIP) at CDC recommends the quadrivalent HPV vaccine to all boys and girls 11-12 years old and to all 13-26 year-olds who have not been previously vaccinated. After vaccination, cervical cancer screening is still recommended. [Harrison ID, p. 771]
REFERENCES FOR CASES/YEAR
1. (US) >95% of cervical cancers contain oncogenic (high-risk) types of HPV DNA; Other cancers associated with HPV are of the penis, anus, vagina, vulva, and head & neck. [Harrison ID, 2nd Ed, p. 820] Estimated 14 million new cases of genital HPV infection every year in the US; [Cecil, p. 2185]
2. (Global) 290 million women infected; 270,000 die every year from cervical cancer (70% caused by types 16 & 18); [Fact sheets from WHO 2013] Use 20 X US rate = 280 million new cases every year;