Human papilloma virus, HPV, is the most commonly spread sexually transmitted infection, according to the Centers for Disease Control and Prevention. More than 40 types of this virus can infect the genital area and most do not cause symptoms. HPV is so prevalent that 50 percent of all women and men will develop an HPV infection in their lifetimes. Generally, the body's immune system handles the infection within eight to 13 months, but some strains can hide in the body for years without producing symptoms.
Strains
HPV has several strains, but only four strains are responsible for causing serious infections, according to the National Cancer Institute. The four strains are further divided into two groups, low-risk and high-risk strains. The two low-risk types, HPV-6 and HPV-11, produce lesions that do not turn cancerous, while the high-risk types, HPV-18 and HPV-18, produce lesions that are responsible for causing cervical and other cancers. The chances of contracting an HPV infection can be reduced though the use of condoms or prevented by being inoculated with the Gardasil vaccine.
Transmission and Incubation Period
HPV is spread by intimate skin-to-skin contact, according to Rutgers University, making it most likely to be spread through sexual contact. The incubation period, or the time from when the infection occurs to when symptoms might appear, can be from a few months to a year. In addition, many infections do not show any symptoms at all. An HPV infection arises from the virus causing normal cells on infected skin to grow abnormally.
Genital Warts
Low-risk strains of HPV can cause a specific type of wart to form in genital areas, called condylomata acuminata, according to the website for the American Congress of Obstetricians and Gynecologists. These warts can be located around the vulva, cervix, and inside or outside the vagina, on the penis in men and around the anus in either sex. Occasionally, the warts spread to the surrounding skin. Genital warts appear as flat, cauliflower-like or stalk-like growths, singly or in groups. Genital warts can be diagnosed on sight by a medical professional during an office visit. Genital warts from low-risk strains will not turn cancerous.
Oral and Respiratory Lesions
HPV can also cause the formation of warts and blisters around the mouth, tongue and palate, transmitted through oral sex with an infected partner, according to the Mouth Cancer Foundation. Oral HPV infections are possible though both high-risk and low-risk strains of the virus, so some oral lesions can be cancerous. It is possible to develop a serious throat infection from HPV called recurrent respiratory papillomatosis, or RRP. With RRP, fleshy, wart-like tumors can develop in adults, transmitted via sexual contact, or in children, who are infected during birth from their mother having genital warts.
Cervical and Other Cancers
According to the National Cancer Institute, more than 11,000 women develop cervical cancer in the United States per year. It has been determined that persistent HPV is the cause of virtually all cervical cancers. Noticeable symptoms of cervical cancer might not appear until the latter stages of the disease, but early cell changes in the cervix can be detected through a simple Pap smear. Abnormal vaginal bleeding is the most common symptom of advanced cervical cancer. Lesions from oral HPV infection can turn into mouth cancer when caused by the high-risk strains.
References
- Centers for Disease Control and Prevention: Genital HPV Infection
- National Cancer Institute: Human Papillomaviruses and Cancer: Questions and Answers
- Rutgers University: HPV
- American Congress of Obstetricians and Gynecologists: Human Papillomavirus Infection
- Mouth Cancer Foundation: Human Papilloma Virus
