I. DISEASE HISTORY/ ETIOLOGY/ STATISTICS

HPV - The most commonly transmitted STD in the U.S.
Human Papilloma Virus (HPV) is a most commonly transmitted sexually transmitted disease in the United States. About 79 million Americans are currently infected with HPV, and about 14 million people become newly infected each year.  About 360,000 people in the U.S. get genital wars each year.  It is so easily transmitted through sexual contacts (virginal, anal, or oral sex), it is said that about 90% of college-age women have infected with this virus, and almost of all sexually active individuals are infected at some point of their lives.  HPV does not just infect to women, but men as well. 

What are the characteristics of HPV?
HPV viruses are small non-enveloped double-stranded DNA viruses, that belong to papillomavirus family. There are over 150 types of HPV, and many of them are asymptomatic, but some cause to form warts, and the other cause to develop cancer. They are differentiated by the genetic sequence of capsid. About 40 types of HPV infect the genital tract; of the 13 HPV types are designated as human carcinogens (e.g. high-risk type HPV).  Especially, types 16 and 18 are responsible for 70% of cervical cancers worldwide.  Among non-carcinogenic types (e.g., low-risk type HPV), types 6 and 11 are responsible for 90% of genital warts. 
  

Figure from: http://www.cancer.org/cancer/cancercauses/othercarcinogens/infectiousagents/hpv/hpvandhpvtesting/hpv-and-hpv-testing-about-hpv

Discovery of HPV as a oncogenic virus

The association of HVP and cervical cancer is now commonly known, however, the fact that HPV causes cervical cancer was first suspected by Prof. Harald zur Hausen in 1976.  Later in 1983, he identified specific types of HPV (16 and 18) were directly accountable for the development of cervical cancer.  Prof. Hausen received the Nobel Prize in physiology or medicine in 2008 for his works connecting HPV infections and cervical cancer.    

  

SYMPTOMS

About 90% of infections are asymptomatic and disappear within two years with a help of body’s immune system.  In most case, low-risk HPVs cause skin warts most commonly in hands.  Low-risk genital HPVs cause warts on genitals and anus in women and men.  Warts appear on the head or shaft of the penis, or at the opening of vagina, or around the anus.  Due to the obvious STD, they have a huge emotional impact on infected individuals.  In rare cases, low-risk genital HPVs infect mouth, neck and throat. Warts could be painful, but most of warts disappear over the period of time without treatments.  High-risk genital HPVs cause cervix cancer in women if not treated at the early stage of the abnormal cell development.  Less commonly, high-risk genital HPV can cause anal or oral cancer in men and women. 

DETECTION

Papanicolau smear test (Pap smear test) is used to detect cervical cancer.  It does not particularly detect the HVP infections, but because HVP infection accounts 70% of cervical cancer, it is worth mentioned here.  Pap smear test is a cytological test to see if the cervix has abnormal or pre-cancerous cells.  In the procedure, the small amount of cells are collected from the cervix and are examined under microscope.  If cells are found to be abnormal or cancerous, HVP infection is suspected.  To verify if the abnormality is caused by HVP, additional HVP DNA test is conducted for gene fingerprinting.    

  http://www.cdc.gov/std/stats13/other.htm
  http://www.cdc.gov/std/hpv/hpv-factsheet-march-2014.pdf
"Discoverer of AIDS and Cancer Virus Win Nobel"
http://www.nytimes.com/2008/10/07/health/07nobel.html?oref=slogin&_r=0
https://microbewiki.kenyon.edu/index.php/File:Mandel%27sTable.jpg