HPV infection and it’s role in the genesis of abnormal Pap smears
What is genital HPV?
HPV is a virus that is passed on during skin to skin contact. It is extremely common in both women and men who have ever had sex. It can also be transmitted during passage through the birth canal, ie, is able to be contracted from one’s mother. Around 80% of men and women will have HPV at some time in their life. Thus, it is a very common and usually asymptomatic infection. It is very contagious and there are around forty to fifty kinds of genital HPV. These are called “subtypes” and around fifteen are classified as high risk due to their association with causing cervical cancer. Low risk HPV such as type 6 and 11 cause about 90% of genital warts and most low grade squamous interepithelial lesions (LSIL) on Pap smears. HPV type 16 and 18 cause 70% or more of cervical cancers. It is important to remember that most HPV infections are subclinical, ie, not noticed by the patient and transient. The immune system appears to clear the virus within one or two years.
How is HPV transmitted?
The virus enters the body through tiny breaks in the skin but is not spread via blood or body fluids. A Pap smear can sometimes detect abnormal changes caused by HPV.
What are low grade changes?
Low grade of mild abnormal Pap smear changes almost always reflect short-term HPV infection. Most of these infections will clear within one to two years.
HPV and Infidelity
Patients often ask how or why they contracted HPV. The important thing to remember is that this does not mean that one’s partner has had other concurrent relationships as HPV infection can persist for many years without symptoms. An HPV infection may have been contracted a long time ago and may even have been contracted during birth.
Is it wise to abstain from sex if I have HPV?
There is no reason to stop having sex if you have HPV changes on a Pap smear. Further, condoms offer limited protection against HPV as they do not cover all of the genital skin.
Can HPV be treated?
Treatment of the virus itself is not needed as one’s body’s immune system usually clears the infection. If the HPV infection persists and causes cell changes, these changes can be treated but this is not always required. It is also important to remember that HPV may exist in the skin or the cervix without causing any apparent Pap smear changes.
Can I be re-infected with HPV?
Usually you cannot be reinfected with the same kind of HPV as your body will almost likely develop immunity against it. However, you can be infected with new HPV types.
Should I have the HPV vaccine (Gardisil or Cervarix) if I have got or already have had HPV?
The simple answer is yes. You might like to think of the HPV vaccine in a similar way to the seasonal ‘flu vaccination. There is no practical way of working out what kinds of ‘flu you may have been exposed to before and what you may be immune to. The vaccination for the ‘flu virus covers the most likely kinds of ‘flu going around that year. These might be entirely different to the flu that you have had before. If you have a ‘flu vaccination and have already had the ‘flu previously, at worst it may be simply a waste of time or money but will probably cover you against types of ‘flu that you have not yet been exposed to. The exact same logic applies to HPV vaccination. Even though one might be over 26, HPV vaccination is still useful. It costs around $450.00 and is given over three injections which can be done at either your general practitioner or myself.
Is it wise to have an HPV test?
An HPV test is usually taken as a swab from the cervix, almost the same as a Pap smear. Because HPV is so very common in women aged under 30, the test is very often positive and knowing this does not change one’s management. It is also important to remember that usually the infection will clear by itself. The HPV test costs around $80.00 and is usually only free of charge for women who have had treatment for a high grade abnormality or those who are having annual Pap smears for another reason.
What are the reasons for having a HPV test?
HPV tests are currently only recommended for those who have had treatment for a high grade abnormality in the initial follow-up period. In these cases we look for disappearance of the HPV from the system, which means that there is a very high chance of not having any further abnormal cells in the future.
What is the cervical cancer vaccine?
The vaccine helps to prevent infection with HPV types that causes around 70% of cervical cancers. It is most effective if given to girls prior to the onset of sexual activity at around the age of 9 or 12. Therefore, the vaccine will probably be less effective or usual in sexually active women who may already have been exposed to HPV. It is important to remember that the vaccine, like the ‘flu vaccination, is not absolutely effective against HPV. Therefore, vaccinated women should continue to have Pap tests.
More information regarding HPV, Pap smear and cervical cancer can be obtained on the website www.papscreen.org.au.