INVESTIGATORY
PROJECT
BIOLOGY
By
G.R.Kiruthik pranav
XI - A
HUMAN PAPILLALOMA VIRUS
HPV infection is a viral infection that commonly causes skin or mucous membrane growths
(warts). There are more than 100 varieties of human papillomavirus (HPV). Some types of
human papillomavirus (HPV) infection cause warts, and some can cause different types of
cancer.
Most HPV infections don’t lead to cancer. But some types of genital HPV can cause cancer of the
lower part of the uterus that connects to the vagina (cervix). Other types of cancers, including
cancers of the anus, penis, vagina, vulva and back of the throat (oropharyngeal), have been
linked to HPV infection.
These infections are often transmitted sexually or through other skin-to-skin contact. Vaccines
can help protect against the strains of HPV most likely to cause genital warts or cervical cancer.
SYMPTOMS :
In most cases, your body’s immune system defeats an HPV infection before it
creates warts. When warts do appear, they vary in appearance depending on
which kind of HPV is involved:
Genital warts :
These appear as flat lesions, small cauliflower-like bumps or tiny stemlike
protrusions. In women, genital warts appear mostly on the vulva but can also
occur near the anus, on the cervix or in the vagina.
In men, genital warts appear on the penis and scrotum or around the anus.
Genital warts rarely cause discomfort or pain, though they may itch or feel
tender.
Common warts :
Common warts appear as rough, raised bumps and usually occur on the hands
and fingers. In most cases, common warts are simply unsightly, but they can also
be painful or susceptible to injury or bleeding.
Flat warts :
Flat warts are flat-topped, slightly raised lesions. They can appear anywhere, but
children usually get them on the face and men tend to get them in the beard
area. Women tend to get them on the legs.
Cervical cancer :
Nearly all cervical cancers are caused by HPV infections, but cervical cancer may
take 20 years or longer to develop after an HPV infection. The HPV infection and
early cervical cancer typically don’t cause noticeable symptoms. Getting
vaccinated against HPV infection is your best protection from cervical cancer.
Because early cervical cancer doesn’t cause symptoms, it’s vital that women have
regular screening tests to detect any precancerous changes in the cervix that
might lead to cancer. Current guidelines recommend that women ages 21 to 29
have a Pap test every three years.
Women ages 30 to 65 are advised to continue having a Pap test every three years,
or every five years if they also get the HPV DNA test at the same time. Women
over 65 can stop testing if they’ve had three normal Pap tests in a row, or two
HPV DNA and Pap tests with no abnormal results.
Causes :
HPV infection occurs when the virus enters your body, usually through a cut,
abrasion or small tear in your skin. The virus is transferred primarily by skin-to-
skin contact.
Genital HPV infections are contracted through sexual intercourse, anal sex and
other skin-to-skin contact in the genital region. Some HPV infections that result in
oral or upper respiratory lesions are contracted through oral sex.
If you’re pregnant and have an HPV infection with genital warts, it’s possible your
baby may get the infection. Rarely, the infection may cause a noncancerous
growth in the baby’s voice box (larynx).
Warts are contagious. They can spread through direct contact with a wart. Warts
can also spread when someone touches something that already touched a wart.
Risk factors:
HPV infections are common. Risk factors for HPV infection include:
Number of sexual partners. The more sexual partners you have, the more likely
you are to contract a genital HPV infection. Having sex with a partner who has had
multiple sex partners also increases your risk.
Age. Common warts occur mostly in children. Genital warts occur most often in
adolescents and young adults.
Weakened immune systems. People who have weakened immune systems are at
greater risk of HPV infections. Immune systems can be weakened by HIV/AIDS or
by immune system-suppressing drugs used after organ transplants.
Damaged skin. Areas of skin that have been punctured or opened are more prone
to develop common warts.
Personal contact. Touching someone’s warts or not wearing protection before
contacting surfaces that have been exposed to HPV — such as public showers or
swimming pools — might increase your risk of HPV infection.
Complications:
Oral and upper respiratory lesions. Some HPV infections cause lesions on your
tongue, tonsils, soft palate, or within your larynx and nose.
Cancer. Certain strains of HPV can cause cervical cancer. These strains might also
contribute to cancers of the genitals, anus, mouth and upper respiratory tract.
Prevention:
Common warts
It’s difficult to prevent HPV infections that cause common warts. If you have a
common wart, you can prevent the spread of the infection and formation of new
warts by not picking at a wart and not biting your nails.
Plantar warts
To reduce the risk of contracting HPV infections that cause plantar warts, wear
shoes or sandals in public pools and locker rooms.
Genital warts
You can reduce your risk of developing genital warts and other HPV-related
genital lesions by:
Being in a mutually monogamous sexual relationship
Reducing your number of sex partners
Using a latex condom, which can reduce your risk of HPV transmission
HPV vaccines
Gardasil 9 is an HPV vaccine approved by the U.S. Food and Drug Administration
and can be used for males and females to protect against cervical cancer and
genital warts.
The Centers for Disease Control and Prevention (CDC) recommends routine HPV
vaccination for girls and boys ages 11 and 12, although it can be given as early as
age 9. It’s ideal for girls and boys to receive the vaccine before they have sexual
contact and are exposed to HPV. Research has shown that receiving the vaccine at
a young age isn’t linked to an earlier start of sexual activity.
Once someone is infected with HPV, the vaccine might not be as effective or
might not work at all. Also, response to the vaccine is better at younger ages than
older ones. But, if given before someone is infected, the vaccine can prevent most
cases of cervical cancer.
The Centers for Disease Control and Prevention (CDC) recommends that all 11-
and 12-year-olds receive two doses of HPV vaccine at least six months apart.
Younger adolescents ages 9 and 10 and teens ages 13 and 14 can also receive
vaccination on the updated two-dose schedule. Research has shown that the two-
dose schedule is effective for children under 15.
Teens and young adults who begin the vaccine series later, at ages 15 through 26,
should continue to receive three doses of the vaccine.
The CDC recommends catch-up HPV vaccinations for all people through age 26
who aren’t adequately vaccinated.
The U.S. Food and Drug Administration recently approved the use of Gardasil 9
for males and females ages 9 to 45. If you’re age 27 to 45, discuss with your
doctor whether he or she recommends that you get the HPV vaccine.
Diagnosis :
Your doctor might be able to diagnose human papillomavirus (HPV) infection by
looking at your warts.
If genital warts aren’t visible, you’ll need one or more of the following tests:
Vinegar (acetic acid) solution test. A vinegar solution applied to HPV-infected
genital areas turns them white. This may help in identifying difficult-to-see flat
lesions.
Pap test. Your doctor collects a sample of cells from your cervix or vagina to send
for laboratory analysis. Pap tests can reveal abnormalities that can lead to cancer.
DNA test. This test, conducted on cells from your cervix, can recognize the DNA of
the high-risk varieties of HPV that have been linked to genital cancers. It’s
recommended for women 30 and older in addition to the Pap test.
