HPV (Human Papillomavirus) infection can be detected through various types of tests, and the choice of test depends on the purpose of screening or diagnosis. HPV is a common sexually transmitted infection that can lead to cervical cancer, so early detection is important. The primary tests used for cervical HPV infection detection include:
HPV-induced changes in the cervical epithelium can be detected by microscopic examination of exfoliated cells, known as the Papanicolaou (Pap) cytology test or Pap Smear (Pap Test):
A Pap smear is a routine screening test used to detect abnormal changes in cervical cells, often caused by HPV infection. During a Pap smear, a healthcare provider collects a sample of cervical cells using a speculum and a brush or spatula. The cells are then sent to a laboratory where they are examined under a microscope to check for any abnormalities or signs of HPV infection.
Cervical HPV infection can be detected through an HPV nucleic acids amplification test (NAAT) (DNA or mRNA) performed on cervical or vaginal samples. HPV DNA tests identify the virus by detecting its genetic material, specifically the viral DNA. On the other hand, HPV mRNA tests identify transcripts of the viral E6 and E7 oncoproteins, which play a crucial role in the process of HPV-induced oncogenic transformation of epithelial cells [2].
The HPV DNA test detects the presence of high-risk HPV strains (types associated with cervical cancer) in cervical cells. Similar to a Pap smear, a healthcare provider collects a cervical cell sample, but this sample is specifically tested for the presence of HPV DNA. This test is often used with a Pap smear or as a primary screening method for women over the age of 30.
HPV mRNA test detects the presence of HPV by measuring the presence of HPV messenger RNA (mRNA) in cervical cells. It is primarily used in conjunction with Pap smears to assess the risk of cervical cancer in certain cases.
Visual Inspection with Acetic Acid (VIA) and Visual Inspection with Lugol's Iodine (VILI) involve the application of acetic acid (VIA) or Lugol's iodine (VILI) to the cervix. Abnormalities in cervical tissue can be visualized by changes in color and texture after the application of these substances. While not as sensitive as molecular tests, VIA and VILI are low-cost methods that can be used in resource-limited settings for initial screening [3].
HPV NAATs, cervical cytology, and visual inspection with acetic acid are used to identify women who have, or are at risk of, cervical precancerous lesions and early invasive cancer.
Colposcopy is a procedure used when abnormal results are obtained from a Pap smear or HPV test.
A colposcope, which is a magnifying instrument, is used to closely examine the cervix and vaginal walls.
If abnormal areas are identified, a biopsy may be taken for further evaluation .
If abnormal cervical tissue is detected during a colposcopy or other screening test, a biopsy may be performed. During a biopsy, a small sample of tissue is removed from the cervix and examined under a microscope to confirm the presence of HPV-related changes and assess their severity.
WHO recommends the use of validated HPV DNA NAATs on self-collected vaginal or provider-collected cervical samples in a screen-and-treat approach, or in a screen, triage and treat approach, starting at the age of 30 years and repeated at 5–10-year intervals [2].
The new European Union cervical cancer recommendations prioritize HPV (human papillomavirus) testing among women aged 30 to 65 every 5 years, taking into account vaccination status. In addition to updating screening programs, for HPV eradication it is recommended to ensure vaccination coverage in the eligible population under 15 years of age [4].
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