CERVICAL CANCER SCREENING: HPV TESTING & VIA
The goal of HPV DNA testing is to detect the presence of genetic material from certain high-risk strains of the Human Papillomavirus (HPV) in cells from a woman’s cervix.
• HPV testing involves the collection of a cervical or vaginal sample using a swab similar to a Q-tip.
• The swab is then tested for the presence of HPV DNA.
Nearly all cases of cervical cancer develop from persistent, untreated HPV infection, so HPV testing, linked with timely treatment, may be the most effective way to prevent cervical cancer.
HPV TESTS: WHAT IS AVAILABLE?
In the United States, Hybrid Capture II (HC2) is used to test for the presence of HPV DNA. However, this test requires a full-scale laboratory and electricity, making it unsuitable for many low-resource settings.
Another HPV test, called careHPV, was developed by Qiagen with support from PATH and the Bill and Melinda Gates Foundation. CareHPV was designed specifically for use in low-resource settings. It is portable, rapid, and can be performed by a minimally trained health worker.
One of the benefits of HPV DNA testing is that women have the option of collecting their own sample and bypassing the traditional speculum exam, which many women find uncomfortable. Furthermore, because of the accuracy of the test, a woman who receives a negative test result will not have to be screened again for 5 years.
Visual inspection of the cervix with acetic acid (VIA) is a low-tech, low-cost method of cervical cancer screening.
• VIA is a simple procedure in which a healthcare provider applies 3-5% acetic acid (vinegar) to the cervix and looks for areas that change color.
• Normal cervical tissue is unaffected by the application of vinegar, but damaged tissue, such as the tissue in cervical precancer, turns white with visible borders.
ADVANTAGES TO VIA:
• The results are available immediately and can be followed up with cryotherapy if abnormal or precancerous cells are found.
• VIA requires nothing more than a flashlight, speculum, an ounce of vinegar, and cotton swabs.
• Eliminates the need for laboratories.
• VIA does not require transportation of specimens.
• Medical providers of all levels can perform this procedure – generalist physicians, OBGYNs, nurses, and midwives.
DISADVANTAGES OF VIA:
• Variability of sensitivity and specificity of test.
• Variability in specificity can lead to unnecessary treatment, and wasted resources.
• Subjectivity of test results in different results depending on the clinician reading the test.
• Lack of standard global guidelines for use of VIA
PATH – PATH: Visual Inspection with Acetic Acid (VIA): Evidence to Date
Pan American Health organization – PAHO: A critical review of selected articles
Johns Hopkins – Jhpiego: Cervical Cancer Prevention