Integrating human papillomavirus testing as a point-of care service using GeneXpert platforms: Findings and lessons from a Kenyan pilot study (2019-2020)

Triage of HPV positivity in a high HIV prevalence setting: A prospective cohort study comparing visual triage methods and HPV genotype restriction in Botswana

OBJECTIVE

Guidelines for effective triage following positive primary high-risk human papillomavirus (HPV) screening in low- and middle-income countries with high human immunodeficiency virus (HIV)-prevalence have not previously been established. In the present study, we evaluated the performance of three triage methods for positive HPV results in women living with HIV (WLHIV) and without HIV in Botswana.

METHODS

We conducted baseline enrollment of a prospective cohort study from February 2021 to August 2022 in South-East District, Botswana. Non-pregnant women aged 25 or older with an intact cervix and no prior diagnosis of cervical cancer were systematically consented for enrollment, with enrichment of the cohort for WLHIV. Those who consented completed a questionnaire and then collected vaginal self-samples for HPV testing. Primary HPV testing for 15 individual genotypes was conducted using Atila AmpFire® HPV assay. Those with positive HPV results returned for a triage visit where all underwent visual inspection with acetic acid (VIA), colposcopy, and biopsy. Triage strategies with VIA, colposcopy and 8-type HPV genotype restriction (16/18/31/33/35/45/52/58), separately and in combination, were compared using histopathology as the gold standard in diagnosing cervical intraepithelial neoplasia (CIN) 2 or worse (CIN2+).

RESULTS

Among 2969 women enrolled, 1480 (50%) tested HPV positive. The cohort included 1478 (50%) WLHIV; 99% were virologically suppressed after a mean of 8 years on antiretroviral therapy. In total, 1269 (86%) women had histopathology data for analysis. Among WLHIV who tested positive for HPV, 131 (19%) of 688 had CIN2+ compared with 71 (12%) of 581 in women without HIV. Screening by 8-type HPV genotype restriction was more sensitive as triage to detect CIN2+ in WLHIV 87.79% (95% CI: 80.92-92.85) and women without HIV 85.92% (95% CI: 75.62-93.03) when compared with VIA (WLHIV 62.31% [95% CI: 53.39-70.65], women without HIV 44.29% [95% CI: 32.41-56.66]) and colposcopy (WLHIV 70.77% [95% CI: 62.15-78.41], women without HIV 45.71% [95% CI: 33.74-58.06]). However, 8-type HPV genotype restriction had low specificity in WLHIV of 30.88% (95% CI: 27.06-34.90) and women without HIV 37.06% (95% CI: 32.85-41.41). These results were similar when CIN3+ was used as the outcome. When combining 8-type HPV genotype restriction with VIA as the triage strategy, there was improved specificity to detect CIN2+ in WLHIV of 81.65% (95% CI: 78.18-84.79) but dramatically reduced sensitivity of 56.15% (95% CI: 47.18-64.84).

CONCLUSIONS

Eight-type HPV genotype restriction is a promising component of effective triage for HPV positivity. However, novel triage strategies in LMICs with high HIV prevalence may be needed to avoid the trade-off between sensitivity and specificity with currently available options.

CLINICAL TRIALS REGISTRATION

This study is registered on Clinicaltrials.gov no. NCT04242823, https://clinicaltrials.gov/ct2/show/NCT04242823.

Positivity rates, trends and experiences of health workers on human papillomavirus screened using genexpert in Uganda: a three-year retrospective cohort study

INTRODUCTION

Cervical cancer is a major public health issue in Uganda, with high incidence due to limited screening especially in rural areas. In 2019, HPV DNA testing using GeneXpert was rolled out to improve screening access. Assessing progress and challenges since its introduction is important.

AIM

To determine genotype distribution and explore health worker experiences with HPV screening using GeneXpert in Uganda.

METHODS

We conducted a retrospective cohort study where HPV screening data from 66 GeneXpert labs from March 2021-May 2023 country wide was analyzed. We used descriptive statistics to provide percentages and proportions from the data. Seven focus group discussions and five interviews were done with health workers to understand experiences.

RESULTS

We extracted 24,497 HPV tests that were done, and 39.1% were HPV positive. Other high-risk HPV genotypes were the most common at 65%, followed by HPV 16 (17%) and HPV 18/45 (18%). 15% of the HPV positive cases had more than one genotype. Qualitative findings showed inconsistent health worker knowledge, high workload, and complex care seeking behaviors as main challenges. It also revealed low community awareness, care seeking from traditional healers, CONCLUSION: HPV DNA testing has been expanding since its rollout, but the yield of HPV cases is lower than expected, signaling need to address supply-side challenges. Limited information on HPV among health workers especially community health workers, demand-side barriers like myths, medical pluralism and social norms must also be tackled through trainings of health workers and awareness campaigns engaging communities. Although access to GeneXpert services has increased, health system weaknesses pose bottlenecks to screening HPV. Targeted interventions are required to strengthen HPV diagnosis, prevent cervical cancer and save lives.

A portable all-in-one microfluidic device with real-time colorimetric LAMP for HPV16 and HPV18 DNA point-of-care testing

Screening for high-risk human papillomavirus (HPV) infection is one of the most important preventative measures for cervical cancer. However, fast, convenient, and low-cost HPV detection remains challenging, especially in resource-limited settings. Here, we report a portable all-in-one device (PAD) for point-of-care testing (POCT) for HPV16 and HPV18 DNA in cervical swabs. The PAD was engineered to integrate modules for extraction-free sample lysis, loop-mediated isothermal amplification (LAMP) with lyophilized reagent beads, and real-time colorimetric signal sensing into a single miniaturized device, considerably shortening the sample-to-result time to 15 min. The precision liquid handling in the completely sealed microfluidic chip is achieved by a uniquely designed pressure-balanced automatic liquid flow mechanism, thereby eliminating the need for manual manipulation of liquids and thus the risk of biohazards. The PAD employs an improved real-time colorimetric LAMP (rcLAMP) assay with a limit of detection (LOD) of 1 copy/μL, enabled by enhanced assay chemistry to maximize the reaction kinetics. To validate this device for clinical application, we tested 206 clinical cervical swab samples and obtained a sensitivity of 92.1% and a specificity of 99.0%. This custom PAD enabled by microfluidic and electronic engineering techniques can be configured for the simultaneous detection of HPV16 and HPV18 or other pathogens in point-of-care applications.

Feasibility and acceptability of an HPV self-testing strategy: lessons from a research context to assess for ability to implement into primary care at a national level in Botswana

Background

The WHO strategy for cervical cancer elimination strives to achieve 70% coverage with high-performance cervical screening. While few low- and middle-income countries have achieved this, high-risk human papillomavirus (hrHPV) self-testing creates the possibility to rapidly upscale access to high-performance cervical screening across resource settings. However, effective hrHPV screening requires linkage to follow-up, which has been variable in prior studies. This study developed and tested an implementation strategy aimed at improving screening and linkage to follow-up care in South East District in Botswana.

Methods

This study performed primary hrHPV self-testing; those with positive results were referred for a triage visit. Withdrawals for any reason, loss-to follow-up between hrHPV test and triage visit, and number of call attempts to give hrHPV results were also documented. Acceptability of the program to patients was measured as the proportion of patients who completed a triage visit when indicated, meeting the a priori threshold of 80%. Feasibility was defined as the proportion of participants receiving the results and attending follow-up. To assess the associations between participant characteristics and loss-to-follow-up we used log-binomial regressions to estimate risk ratios and 95% confidence intervals (CI).

Results

Enrollment of 3,000 women occurred from February 2021 to August 2022. In total, 10 participants withdrew and an additional 33 were determined ineligible after consent, leaving a final cohort of 2,957 participants who underwent self-swab hrHPV testing. Half (50%) of participants tested positive for hrHPV and nearly all (98%) of participants received their hrHPV results, primarily via telephone.  Few calls to participants were required to communicate results: 2,397 (82%) required one call, 386 (13%) required 2 calls, and only 151 (5%) required 3-5 calls. The median time from specimen collection to participant receiving results was 44 days (IQR, 27-65). Of all hrHPV positive participants, 1,328 (90%) attended a triage visit.

Discussion

In a large cohort we had low loss-to-follow-up of 10%, indicating that the strategy is acceptable. Telephonic results reporting was associated with high screening completion, required few calls to participants, and supports the feasibility of hrHPV self-testing in primary care followed by interval triage.