HPV refers to a common group of viruses primarily transmitted through various forms of physical or sexual contact involving the genital area, even when protective measures such as condoms are used. HPV affects all genders.
There are over 100 distinct types of HPV. Most people will contract some form of HPV during their lifetime, with the majority experiencing no noticeable symptoms. However, specific strains can cause papillomas (warts); for example, HPV 6 and 11 are responsible for approximately 90% of anogenital warts.
Fourteen types of HPV are currently classified as oncogenic (cancer-causing), and thus are known as high risk (hrHPV). Persistent infection with hrHPV is a significant risk factor for developing cervical squamous cell dysplasia, a condition that, if left untreated, can progress to cervical cancer.
In most cases, the body's immune system clears the virus naturally within 12 to 24 months (WHO, 2022), making it harmless for most people.
If you have ever had any sexual contact, you may have HPV. It is passed on through skin-to-skin contact. For HPV that affects the genitals, this includes vaginal, anal and oral sex. You can also get HPV through touching the genital area and sharing sex toys.
It is important to note that a person could contract HPV after just one instance of non-penetrative sex with a person who has HPV. Condom use is not sufficient to prevent transmission of HPV. Women who have sex with women and who report no history of sex with men can also contract HPV, as skin-to-skin contact can transmit HPV infection. This is why HPV infection is extremely common in young people in their first decade of sexual activity. The incidence of genital HPV infections peaks between 18 and 30 years of age. Almost all sexually active people will be infected at some point in their lives, usually without symptoms.
Despite extensive research on persistent infections, no definitive reasons have been found for why some infections last longer than others. There is conflicting evidence about whether certain HPV subtypes are more likely to persist. Additionally, it's unclear if being infected with one subtype of HPV affects the body's ability to clear another subtype. The immune system is responsible for clearing the virus, but the presence of HPV does not mean there are abnormal cervical cells.
Several factors can increase the risk of developing or maintaining a HPV infection, including smoking, early initiation of sexual activity, and having a compromised immune system. One of the most effective ways a woman can reduce her risk of persistent HPV infection is by quitting smoking.
Viral latency is a feature of the life cycle of some viruses. HPV latency occurs when the virus persists in the basal layer of the epithelium in an inactive state and can reactivate later due to changes in the immune environment. This can be because of an immunosuppressive state brought about by co-infection (with HIV for example) or as a result of waning immunocompetency (with age for example). This can explain why a person with a previous negative HPV test (latent infection), who has had no further exposure to the virus, could test positive at a later date (reactivated infection).
When the virus is in its latent phase, it cannot influence the DNA of the cervical epithelium and does not pose a risk.
CervicalCheck provides free cervical screening tests to women and those with a cervix, aged 25-65 years, who are normally resident in the Republic of Ireland.
Please check the CervicalCheck Eligibility Framework.
- 25 to 29 years old – screening is performed every 3 years
- 30 to 65 years old – screening is performed every 5 years
- If a woman over 25 and under 66, normally resident in Ireland, attends for a screening test and has not received a letter of invitation, check her eligibility. If she is due for screening, you may take her test and submit her screening form without a CSP (Cervical Screening Programme) ID. A CSPID will be allocated when her sample is processed.
- In line with the CervicalCheck eligibility framework, women who have never been screened within the programme and are over 65 years old (i.e., from their 66th birthday) are not eligible. Samples from these women are rejected by programme laboratories, and no result is issued.
The online eligibility checker should always be used prior to taking a cervical screening test.
Cervical screening appointments must be offered to any eligible client as soon as reasonably possible, even if the person requesting the appointment is not a registered patient of the practice.
Reference:
Contract with Registered Medical Practitioners for the Provision of a Primary Care Based Cervical Screening Service under the National Cervical Screening Programme (clause 4.2.1). by clicking here
Once a woman receives an invitation letter from CervicalCheck the invite remains valid until she attends for her screening test. She will receive her first invite on or just after her 25th birthday. She will then receive an invitation each time she is eligible for another test. The invitation does not have an expiration date, but it is important that she attends for her screening test when she is invited to get the most benefit from screening.
Cervical cancer is very rare in women under 25 years of age. The minimum age for participation in CervicalCheck continues to be 25 years. This is an evidence–based recommendation arising from international research that shows that the risk of screening women under 25 years outweighs the benefits. Many people who are HPV detected at this age have transient infections, with or without abnormal cells. HPV infections often clear spontaneously and the abnormal cells can regress over time in this age group. In other words, in women under 25 years of age, the prevalence of HPV is usually high, but clearance of HPV is also high, whereas the probability of progression to high grade CIN or cervical cancer is very low. Women under 25 years, if screened, may be offered unnecessary colposcopy treatment that could impact their fertility in the future and increase their risk of having a pre-term birth.
Higher rates of vaccinated women now make up this age cohort and therefore they have an even lower risk of cervical cancer.
HPV infection is more prevalent in this age group hence they are tested more frequently.
HIQA's (2017) Health Technology Assessment (HTA) on the introduction of HPV primary screening in the Republic of Ireland, commissioned by the National Screening Service, indicates that the optimal strategy includes primary HPV testing followed by liquid-based cytology triage, with screenings every five years from age 25 to 65. However, due to the higher rates of HPV infections and cervical abnormalities in younger women, a longer interval could increase the risk of interval cancers—cancers that develop between screenings. Although HPV infections in younger women often clear up on their own, and cytological abnormalities usually regress if the infection is not persistent, increasing the screening frequency to every three years for women aged 25-29 improves early detection of cervical disease and clinical outcomes for this group.
Link to HTA: HTA of HPV testing for cervical cancer screening (2017)
Screening intervals for women aged 30-65 years are set at five years based on evidence that HPV screening is highly effective in detecting cervical cancer risk.
The 2017 HIQA HTA recommended that the screening interval for the HPV screening programme should be 5 years for all women from 30 years to 65 years. The report concluded that the combination of HPV primary screening and cytology triage with a 5-year interval would: ‘improve the efficiency of the CervicalCheck programme (that is, women would require fewer lifetime screens to achieve similar benefits compared to the old primary cytology programme)’. Primary HPV screening has a high negative predictive value of 93.8-99.7% (HIQA HTA). This means that a negative test is extremely likely to be a true negative for HPV and, therefore, for cell changes. Because HPV is the causative agent for cervical cell changes and cancer and given that the natural history of cell changes progressing to cancer is usually 15-20 years, a negative HPV test assesses women as being at a low risk of developing significant cell changes within 5 years. Evidence from long term follow up of women who have had primary cytology and primary HPV screening shows that a negative baseline HPV test has twice the protection against having high grade cell changes at six years than a negative cytology test has at three years.
All women will become eligible for their screening test 1 calendar month before the next screening test due date, regardless of whether they are on a 1-year, 3-year or 5-year recall.
A 3 month repeat screening test must NOT be taken before 3 calendar months have elapsed. Any test taken before the 3-month period is not processed by the programme laboratory and payment is not processed by PCRS and you will end up in a situation where the woman will require a further screening test.
When a cervical screening test returns an unsatisfactory or indeterminate result, or there is any disturbance to the cells of the cervix, it is necessary to wait at least three calendar months before repeating the test. This waiting period is important for several reasons:
- Regeneration of cervical epithelium: the cervical epithelium (the layer of cells lining the cervix) needs time to regenerate after the initial test. If a repeat test is performed too soon, the cervical cells may not have fully recovered or regenerated, potentially affecting the accuracy of the test results.
- Optimal conditions for testing: allowing time between tests helps to avoid potential issues such as inflammation or irritation that could interfere with the accuracy of the results. This ensures that the repeat test provides a clearer and more accurate assessment of the cervix.
By adhering to this three calendar month waiting period, sample takers aim to obtain the most accurate and reliable results, which is crucial for proper diagnosis and management of cervical health.
A 3 month repeat screening test must NOT be taken before 3 calendar months have elapsed. Any test taken before the 3-month period is not processed by the programme laboratory and payment is not reimbursed, and you will end up in a situation where the woman will require a further screening test.
Yes, women who have received the HPV vaccine are still eligible for cervical screening, will continue to receive invite letters from the Programme and should continue to attend. The cervical screening test in use detects the presence of 14 high-risk or oncogenic HPV subtypes (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68). The HPV vaccine does not protect against all of these subtypes.
For example, the quadrivalent vaccine (introduced since 2010) protects against low-risk HPV strains 6 and 11 (which cause anogenital warts) and high-risk strains 16 and 18 (which are responsible for 70% of cervical cancers). Women who received this vaccine will only be protected against these specific strains and not against all the other 12 high-risk HPV types tested in cervical screening.
From September 2019, the Gardasil 9 vaccine has been introduced into the national immunisation programme, replacing the quadrivalent vaccine. Gardasil 9 offers broader protection against HPV types 16, 18, 31, 33, 45, 52, 58 (linked to cervical, vulvar, and vaginal cancers), and HPV types 6 and 11 (linked to anogenital warts).
Despite vaccination, it’s important for women to attend screening as the vaccine does not guarantee complete protection against all HPV types. Women should be informed that a positive HPV result is still possible and advised of the continued importance of participating in cervical screening.
For more information on cervical cancer screening and prevention strategies, refer to the WHO Immunization, Vaccines, and Biologicals: Human Papillomavirus Vaccines HPV at Human Papillomavirus Vaccines HPV.
The following link outlines the WHO recommendations regarding cervical cancer screening and elimination: WHO 2020 Global strategy to accelerate the elimination of cervical cancer as a public health problem.
If a current HPV test result is negative after a previous positive result, it’s important to understand the implications:
- Current risk: Since the introduction of primary HPV screening in Ireland in 2020, along with HPV testing performed in colposcopy (2012) and HPV triage in primary care (2015), many women are still undergoing their first HPV tests. If the woman’s current HPV ‘not detected’ result indicates that there is no active HPV infection at present, this is very reassuring as it indicates the absence of active HPV infection.
- Future Infections: It’s important to note that a past HPV infection does not provide immunity against future infections due to the presence of various HPV subtypes. Additionally, the infection may become latent and later reactivate. Therefore, ongoing screening remains crucial to assess and manage any new risks.
In summary, a current ‘not detected’ HPV test result is reassuring as it indicates the absence of active HPV infection. Regular screening helps ensure that any potential risk of CIN is identified and managed appropriately.