Human Papillomavirus (HPV)

By: Emmie Glancy

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Symptoms

  • Genital warts (can be raised, flattened, pink, or flesh colored,) can be multiple or just one, small or large, and they appear on the genital areas.

  • The types of warts include genital warts, common warts, and plantar warts.

  • If the HPV spreads and causes cervical cancer, it does not usually show symptoms until the cancer is at an advanced age. These symptoms are; irregular bleeding between menstrual cycles, or bleeding after sexual intercourse, back, leg, or pelvic pain, fatigue, weight loss, loss of appetite, a single swollen leg, and/or vaginal discomfort or discharge that has an odor.

Causes

Human Papillomavirus is a sexually transmitted disease. It only occurs after the virus enters the body. To get inside the body, the virus can get into cuts, scrapes, open wounds, and other openings in the body. Skin to skin is required to spread the disease. HPV is mostly spread through sexual intercourse, but can be passed to a child in a mother's womb, if she has the virus.

Treatment

Warts caused by HPV will eventually go away most of the time. There is no cure for the virus, so the warts can come back in different places or the same places. Wart removers like salicylic acid (removes warts,) Imiquimod (enhances the immune system so it can fight the virus,) Podofilox (removes warts,) and Trichloroacetic acid (used to burn off warts,) can be used for warts caused by HPV. The warts can also be removed by various surgical procedures, i.e, freezing with liquid nitrogen, burning with an electrical currents, surgical removal, or laser surgery.

Prevention

There are various vaccines for HPV. Often, the virus cures itself alone, but can lead to cervical, anal, or throat cancer if untreated. The two major vaccines are Gardasil and Cervarix. Gardasil is safe for women and men to use between the ages 9-25. Cervarix is just for females, and can be given to women ages 10-25. However, no vaccines are 100% effective, and the only way to prevent getting HPV is not having sexual intercourse. The vaccines are not a cure, but can be preventative for up to 5 years. Typically, the vaccines are given to children 10-12, or before children are exposed to sexual activity and the virus.

Virus Replication

HPV uses the lysogenic cycle and the lytic cycle. Human Papilloma virus can be asymptomatic. The virus can not bind to live cells, so it has to bind to basal epithelial cells. The virus replicates in the epithelial cells after it infects the cell. HPV gets into microabrasians, or other places the basement membrane of the cell is exposed. To replicate, the virus manipulates the E6 and E7 proteins. It modifies the proteins so it can replicate the genomes, and allow the virus to spread.
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Lysogenic Cycle Steps

The lysogenic cycle is the longer of the two cycles (lysogenic and lytic,) and does not kill the host. Human Papillomavirus uses the lysogenic cycle, then is triggered into the lytic cycle.

  1. First, the virus attaches to the host cell membrane and injects DNA into the cell.
  2. The viral DNA goes into the host cell chromosome.
  3. The viral DNA circulates (forms a circle around the DNA.)
  4. The viral DNA attaches to the host cells DNA.
  5. The hosts' cells copy the DNA and transmit them to daughter cells.
  6. After many cell divisions (mitosis) the viral DNA produces infected cells.
  7. The lytic cycle is triggered.

Lytic Cycle Steps

The lytic cycle is a shorter, and more deadly cycle.

  1. First, the virus attaches to the host cell and injects its DNA into the cell.
  2. The viral DNA circulates around the cell.
  3. New viral DNA and proteins are synthesized and assembled in the host cell.
  4. The cell lyses (bursts,) killing the cell and spreading the virus.

Immune Cells and Their Response

When a body is infected with HPV, the immune system uses innate and adaptive immunity to fight off the virus. The immune system repels the infections with strong localized cell mediated immune responses. Some innate defensive that the body uses are the skin and mucous membranes, and phagocytes, fever, NK cells, antimicrobial proteins, and inflammation. The adaptive responses the immune cells use are B-Cells and T-Cells. T-Cells warn B-Cells about the virus, and kill the virus.

Myths and Facts About HPV

Myth:
  • Only women can get HPV.
Fact:
  • Men can get HPV too. Most sexually active people get an HPV infection at least once in their lives.


Myth:

  • If you don't have sex, you can't get HPV.

Fact:

  • HPV can be spread by any skin-to-skin contact, oral, anal, or vaginal sex.


Myth:

  • All strains of HPV cause cancer.
Fact:
  • HPV can cause various types of cancer, including penile, cervical, vulvar, and vaginal cancer. But not all strains of HPV cause cancer.


Myth:

  • People diagnosed with HPV always have symptoms.
Fact:
  • Most people infected with HPV do not show any symptoms. Genital warts can occur, but cancers caused by HPV usually do not show symptoms until late in the stage.