Learn more about the sex (virus) and the city

There's a sexually transmitted virus going around, and it's wreaking havoc in your body without you knowing.

Human papillomavirus (HPV), a microbe more widespread than human immunodeficiency virus (HIV), is the leading cause of cervical cancer, warts, and other health problems.

Unlike its publicity-hungry cousin however, HPV is relatively unknown - till now.

Shape asks experts to reveal the top eight things you need to know about it.

1. It 's just as, if not more, serious than HIV

While HIV hogs the limelight for its role in Acquired Immune Defi ciency Syndrome (Aids), a condition that signifi cantly weakens the body's immunity, HPV is no less deadly.

This sexually transmitted virus infects skin and mucus membranes, giving rise to warts and a variety of cancers including that of the cervix, anus, vagina, and vulva.

Of the 120 known HPV strains, more than 30 affect the genitals. In particular, problematic subtypes 16 and 18 are responsible for nearly 70 per cent of all cervical cancers, the seventh most common one among Singaporean women.

The other cause of worry is the prevalence of HPV.

An estimated 50 to 70 per cent of sexually active women will have - or have had - at least one HPV infection in their lives.

"It's harder to detect, so many people may end up spreading an infection they didn't know they had in the first place," says Associate Professor Tan Hak Koon, senior consultant at the department of Obstetrics & Gynaecology in Singapore General Hospital.

Shocking fact: An estimated 50 to 70 per cent of sexually active women will have - or have had - at least one HPV infection in their lives.

2. It's killing you softly

The virus can lay dormant - and not show warning signs - for years before developing into cervical intraepithelial neoplasia (CIN). This refers to abnormal changes in cervical cells, which can lead to cancer if left untreated.

"It will be too late by the time symptoms like vaginal infections, itchy privates, and white patches show up. These are indicators of late-stage cancer," says Prof Tan.

Don't panic just yet: In 90 per cent of cases, the body is able to clear the virus naturally within two years, according to the US Centre for Disease Control and Prevention.

Another piece of good news? It'll take a sinister turn only if you have a weak immune system, says Dr Christopher Chong, urogynaecologist at Chris Chong Women and Urogynae Clinic.

Those who do not manage to clear the virus may end up with a persistent long-term infection, which is an important risk factor for the development for cancer.

High-risk groups include pregnant women, HIV patients, those on chemotherapy, and people with a long-term dependence on medications like steroids and antibiotics.

Infertile

3. It can cause oral cancer

Apart from cervical cancer, the same strains of HPV also cause cancer in the oral cavity, a disease that has become increasingly common among local women.

Engaging in oral sex is said to be one of the risk factors.

In fact, a study in the New England Journal of Medicine found that those who have had oral sex with six or more partners are at eight times more risk of developing cancer in the tonsils than those with fewer bed buddies.

Symptoms include changes in voice, an inability to swallow, an unexplained persistent cough, and mouth sores that last for more than two weeks.

4. Left untreated, it could make you infertile

Cancer isn't the only complication. Treatments for more advanced stages of CIN can also hamper your ability to conceive.

These often involve removing pre-cancerous cells through freezing, burning or biopsy, which may cause a reduction of mucus in the cervix.

This makes it harder for the sperm to reach the egg.

The treatment also weakens the cervix, and increases the risk of miscarriage. Similarly, pelvic radiotherapy, typically used in late-stage cervical cancer, leads to early menopause and an end of egg production.

Even virgins get it

5. Having multiple sex partners ups your risk of infection

What you consider to be a healthy sex life may jeopardise your well-being.

The greater the number of sex partners, the higher your odds of contracting HPV, says the Health Promotion Board of Singapore. This in turn ups your risk of warts and cancers.

Being in a long-term relationship doesn't mean you're safe either.

If your partner had contracted HPV from previous sexualencounters, it's likely that you would be infected too.

The silver lining: Once you stay monogamous, there's no risk of passing the infection back and forth between each other as you cannot get reinfected by the same strain of virus, say Dr Don Dizon and Dr Michael Krychman, coauthors of Questions & Answers About Human Papilloma Virus (HPV).

6. Even virgins get it

Reckon it affects only "bad girls"? Think again.

Even without full-fledge intercourse, HPV can infect the skin, mouth and reproductive organs, as infection can occur with skin-to-skin contact.

Petting, sharing contaminated sex toys, and even kissing can allow viruses to enter cells if there are micro tears in skin.

Vaccination

7. There's a vaccination against it

Currently, two forms of vaccines are available here. Both protect against 70 per cent of HPV strains that cause cervical cancer - one fights subtypes 16 and 18 while the other targets these in addition to strains 6 and 11, which cause warts.

These start to take effect within a week of the first shot, and reach maximum efficacy after three doses.

Women aged between nine and 26 are advised to get the jabs.

They should last for a lifetime, as the body would have acquired the ability to launch more antibodies to counter a new attack, says Dr Chong.

However, because they're considered relatively new vaccines (the first batch was administered 10 years ago), only time will tell if booster injections are required, says Dr Chia Yin Nin, senior consultant at KK Women's and Children's Hospital.

Older women

8. Older women should still consider getting the jab

Although they're most effective if administered before you first do the deed, vaccinations work for sexually active women aged above 26 years too.

"The cut-off age recommended by Health Sciences Authority was set because initial trials were done on women in this age group," explains Dr Chia.

In the meantime, studies have found that the majority of women who are already sexually active are exposed to just one strain of the virus, so they can still get protection against other HPV subtypes through vaccination, she adds.

Get a copy of the December 2011 issue of SHAPE Singapore to read about the latest news in health, fitness, beauty and nutrition. SHAPE Singapore published by SPH Magazines is available at all newsstands now. Bang Wei-Tin is a senior writer with SHAPE Singapore magazine by SPH Magazines. Check out more stories at SHAPE Singapore online, www.shape.com.sg.