What is HPV infection?
Human Papillomavirus (HPV) is a type of virus most frequently transmitted through sexual contact. HPV can affect anyone who is sexually active, both women and men. It is estimated that 80% of sexually active individuals will get HPV infection at some point in their lifetime. Many people who have HPV may not show any signs or symptoms. They can transmit the virus to others without knowing it.
What type of diseases does HPV cause?
There are many types of HPV virus strains. Those considered as ‘High risk group’ include strain 16,18,31,33,45,52,58. They are responsible for causing >75% of cervical cancer and >50% of vaginal and vulvar cancer in women. In men, they can also cause anal and penile cancers. These high risk HPV strains do not cause genital warts.
Those in ‘Low risk group’ such as strain 6,11 cause >90% of anogenital warts in both genders. Anogenital warts can look like bumps. Sometimes, they’re shaped like cauliflower. These warts may not be visible immediately; they can show up weeks or months after someone has been infected. These low risk HPV strains are not responsible for causing cancers in the genitalia.
In some infected cases, the infection will clear on its own; but when it does not, genital warts, precancerous lesions or cancers can develop and progress. It is not known who will and who will not clear the HPV infection.
Human Papillomavirus (HPV) test is a screening test done for detection of the DNA (genetic materials) of the high risk HPV virus strains (e.g. 16 and 18) in one’s body. With the presence of high risk HPV strains, the risk of cervical cells turning abnormal in the future is higher, which means the patient should then be followed up at a closer interval.
According to MOH guidelines, Human Papillomavirus (HPV) testing is recommended as the primary screening test for women aged 30 years and above who have ever had sex, at a screening interval of 5 years.
For women aged 25-69 years, who have ever had sex, pap smear can be used as the primary screening test once every 3 years.
How is HPV test conducted? – HPV Test Singapore
Sample collection of HPV test is similar to the pap smear screening, where a speculum is inserted to the vagina then samples of the cervical cells will be taken using a soft brush.
It can be done in the clinic under an outpatient setting without any special preparation. It is important to try not to schedule the test during the menstrual period. After the test, one can proceed with normal daily activities.
Depending on the test result, the screening interval for future tests will be decided. If the test result comes back positive, patients will either be advised to go for a more regular follow up or referred for a colposcopy procedure if deemed necessary.
Benefits of early detection
Having a HPV test will allow for early detection of abnormal cervical cells and any early changes of precancerous or cancerous lesions can be picked up at earlier stages before they start progressing.
Early detection saves lives because treatment rendered at earlier stages for abnormal cells is more effective and has a better prognosis as compared to late stages.
Treatment methods for diseases caused by HPV infection
For genital warts, treatment can be either by application of topical imiquimod cream or by cryotherapy applied directly to the lesions.
For precancerous cervical lesions, removal of abnormal parts of the cervix can usually be done through laser excisional surgery (LEEP). Surgery, chemotherapy and/or radiotherapy may be needed for more advanced stages of cervical cancer.
Prevention of HPV infection
Barrier methods of contraception such as condoms lowers the risk of HPV transmission.
Other than early detection through HPV testing, the recommended way for HPV prevention is to go for HPV vaccination, which is usually given through injection in the muscle and can be completed in a 6 month interval.
In Singapore, there are various types of HPV vaccines available. Examples include Cervarix, Gardasil-4 and Gardasil-9 vaccines.
Cervarix vaccine offers protection against high risk cancer-causing HPV strains 16 and 18. It does not have protection against anogenital warts.
Gardasil offers protection against both high and low risk strains. Gardasil-4 protects against HPV strain 6,11,16,18 and Gardasil-9 offers additional protection of 5 extra strains 31,33,45,52,58 on top of the usual 4 strains. Both Gardasil vaccines are effective for prevention against both anogenital warts and cancers.
HPV vaccine works best when given before a person has any contact with the HPV strains. Gardasil-9 vaccine can be given to both males and females as young as aged 9, up to 45 year old. Even after being vaccinated, regular screening intervals as per MOH guidelines is still advisable.
Since 2005, our women’s clinics have been treating both local and foreign patients with women’s sexual health and reproductive health-related issues. Our women’s health doctors are experienced in diagnosing, treating and managing a wide array of women’s health-related issue like contraception, emergency contraception, oral contraceptive pills, contraceptive patch, contraceptive implants, Intra Uterine Device (IUD), vaginal infections, bacterial vaginosis, vaginal odour, vaginal itch, vaginal lumps & bumps, Dyspareunia (Pain during sex), bleeding after sex, Vaginismus, Uriniary Tract Infections (UTI), Pap Smear, Premarital screening, fertility screening, preconception screening, breast screening, cervical cancer vaccination, period & menstrual issues and weight loss treatment.
Article by Dr Goh Lit Ching – anchor doctor at DTAP@DUO