In recent years in global health, visual inspection with acetic acid (VIA), or “the vinegar test,” has widely been heralded as a simple and cost-effective cervical cancer screening method for low-resource settings. With the application of dilute vinegar to a woman’s cervix, a trained health care provider can identify patches of tissue that turn white as pre-cancerous lesions and freeze them off with cryotherapy treatment in the same visit.
This “single visit approach” (SVA) or “see-and-treat” paradigm offers obvious advantages over what was, until recently, the standard screening exam for cervical cancer: the Papanicolaou (Pap) smear. Pap smears are very efficacious, but infrastructure-intensive tests, and many of the world’s poorest countries lack laboratory facilities and specialized health personnel (pathologists, cytotechnologists) to analyze Paps. Additionally, infrastructure for delivering test results and providing several appointments worth of follow-up care (colposcopy/biopsy, minor surgeries) for patients tends to be severely limited in low-resource settings.
While demonstration projects and clinical trials of VIA show great success, there are many challenges associated with VIA when one looks beyond the context of the clinical trial. I have previously written about the high turnover of staff trained in the method and the low quality of some VIA-cryotherapy training courses in Guatemala, where I have been working for the past several years. Recently, my colleague Peter Rohloff and I published an article highlighting additional challenges faced by VIA practitioners and trainers in Guatemala. The most significant of these challenges, in our opinion, is the broken link between VIA and cryotherapy.
One of the major justifications for VIA in LMICs is the possibility of preventing cervical cancer with a “single visit” or a “see-and-treat” approach, which eliminates–or at least reduces–the financial and logistical burdens of coordinating follow-up appointments and care for women with abnormal Pap smear results. However, when we interviewed VIA practitioners and conducted observations at VIA clinics in Guatemala, we routinely found that Ministry of Health (MOH) and non-governmental organization (NGO)-sponsored clinics had difficulty offering VIA and cryotherapy within the same visit. Some facilities lack budgets for cryotherapy equipment and perform VIA-only screening campaigns. Other facilities perform cryotherapy for some time until gas cylinders run out or machines break. There is currently no national plan in Guatemala to service cryotherapy machines. And, troublingly, many health care workers who are trained in VIA are not trained in cryotherapy–for example, about 80% of Guatemalan Ministry of Health providers are trained in VIA only, not VIA and cryotherapy.
The result is a disruption of the see-and-treat paradigm. Although this seems to be common knowledge among those working on cervical cancer prevention in the Global South, this phenomenon is surprisingly not well-documented in the literature.
Women with abnormal VIA exams who do not receive same-day cryotherapy treatment run into the very same issues they would if they were seeking follow-up care for an abnormal Pap smear. These women are poor. They live in rural areas, far away from health services, or in urban centers with under-resourced health services. They don’t have access to reliable transportation or money for it if it is available. They have trouble leaving their children behind at home when they must travel for treatment. And very often, they get lost to follow-up. Put another way,when the VIA-cryotherapy link is broken, VIA recapitulates the failures of cytology in low-resource settings.
In order to recouple VIA and cryotherapy, the Guatemalan MOH will require resources to develop cryotherapy equipment monitoring and service plans. Training courses will need to strive to train all providers in both VIA and cryotherapy. In the meantime, in Guatemala, there is a robust non-governmental organization (NGO) sector, which is becoming more and more involved in coordinating cryotherapy referrals. A handful of NGOs has begun to accept cryotherapy referrals from the MOH and other NGOs unable to provide same-day cryotherapy services. NGOs that organize and subsidize women’s treatment are showing success with helping women complete cryotherapy treatments. However, longer-term solutions will be needed, in Guatemala and other countries facing similar issues.
The good news is that various institutions are acting to resolve these problems on a global scale. For example, the United Nations Population Fund (UNFPA) has added cryotherapy equipment to its catalog, which will make it easier for LMICs and those working in low-resource settings to purchase quality equipment for their cervical cancer prevention programs. The Gates Foundation, the Clinton Health Access Initiative, and the Global Cervical Cancer Coalition are all other significant players taking interest in this issue.
A final reflection I’d like to offer is about the danger of accepting evidence-based medicine at face value,uncritically, as the “Truth” (with an authoritative capital “t”). Randomized-controlled trials can certainly tell us about the efficacy and feasibility of interventions under the conditions of a (presumably) closely-supervised study. What they cannot tell us is how new technologies or interventions unfold on the ground–an important insight at the center of the growing field of “implementation science.” As standards of care in cervical cancer prevention shift from Pap smears to VIA to HPV DNA testing and co-testing, it is worth bearing in mind that most public health interventions–however “simple” or “low-resource”–are likely to encounter practical issues and infrastructural challenges that may not be immediately evident from the outcomes of clinical trials. VIA is a case in point: in many contexts, VIA has performed extremely well under trial conditions, but different stories may unfold after the trials and demonstration projects end. As global health practitioners continue to innovate to solve urgent health problems, it will be worthwhile to pay attention to the nitty-gritty, messy, and real-world details of post-clinical trial implementation.
To read the full article about VIA, follow this link:
This Blog was originally published on Global Health Hub Here!