HPV – the ‘common cold’ of the vagina

Many Australian women appear to be confused over the timing and purpose of the current cervical cancer screening test due to new regulations that increase the time between pap smears from two years to five.

The Department of Health has revised the Cervical Screening Test to test directly for the Human Papillomavirus (HPV).

If the woman is not infected with HPV they will not need to return to have a pap smear for another five years.

Melissa Ledger, Acting Education and Research Direct at Cancer Council WA, wants to stress that HPV is a highly common virus that humans will encounter and expel during their lifetime.

The sexually transmitted infection has over 100 types and will affect almost 80 per cent of Australians.

“Once you are first sexually active you are going to be exposed to various types of HPV and usually the body is really great at clearing them,” says Ms Ledger.

“Some people call it the ‘common cold’ of sexually transmitted diseases because nearly eight out of ten people will experience HPV infection at some point in their life and your body will naturally clear it out in two years or so.”

Long term infections are caused by high risk HPV types and are classed like this because they are oncogenic, meaning they cause cancer.

“It’s the long term infections that your body doesn’t clear that causes the cancer risk,” she says.

The types of HPV that commonly cause cervical cancer are 16 and 18 and these are the types of HPV the new cervical screening test is looking for which result in 70 to 80 per cent of all cancer cases.

Other types of HPV responsible for a smaller proportion of cancer results are 31, 33, 45, 52 and 58.

Together with types 16 and 18, they cause 90 per cent of cervical cancers.

However, this introduces the new confusion about why women still need to get smears even if they were vaccinated against HPV strains in high school.

“In the past the Australian government has been rolling out vaccinations that protected against four types of HPV,” says Ms. Ledger.

“The vaccine introduced this year to high school girls and boys will protect against nine types of HPV and will protect against 90 per cent of cervical cancers.”

“You still need screening because there is still a risk of getting cervical cancer because you weren’t vaccinated against the other types [before the new vaccine].”

But if women still need to get tested, how is the new test different from the old one and why has it even been revised?

Over 20 years of screening the Australian rate of cervical cancer has been halved and recently results have shown rates plateau – therefore there was an opportunity to review how to better locate cervical cancer in a vaccinated population.

“The new Cervical Screening Test is now directly looking for HPV which causes cervical cancer rather than looking for abnormal cells,” says Ms. Ledger.

“Normally we were already waiting for HPV to be around for a long time and start damaging DNA in cervical cells, now we catch it a step earlier before the cell damage starts,” she says.

The new Cervical Screening Test recommends receiving your first screening at 25, or two years after your last pap smear, although some women are concerned about waiting so long to get checked even if they have been sexually active for some time before 25.

However, Ms Ledger puts these fears to rest.

“There needs to be long-term persistent infection with HPV to start with before the cervical cancer, which is very slow growing, begins damaging cells.

“The body can sometimes take up to two years to get rid of the virus so we like to give it the opportunity to do that before we start tampering with women’s bodies,” she says.

Despite this, Ms. Ledger urges young women to still get checked.

“You are still not 100 per cent protected and even with the new vaccination there is still a chance you may be infected with the 10 per cent of strains that the vaccination does not immunise against.”

So, what happens if you are infected with a high risk type of HPV?

Ms Ledger says that the cells are analysed to see whether they are starting to change or grow abnormally.

“This is why the test is so good because we are already filtering women who have high risk HPV,” says Ms. Ledger.

“If you haven’t got these types then you are unlikely to develop cervical cancer and there is no point having this test frequently.”