Cervical lesion proportion measure using a digital gridded imaging technique to assess cervical pathology in women with genital schistosomiasis

Abstract

Female genital schistosomiasis (FGS) is characterized by a pattern of lesions which manifest at the cervix and the vagina, such as homogeneous and grainy sandy patches, rubbery papules in addition to neovascularization. A tool for quantification of the lesions is needed to improve FGS research and control programs. Hitherto, no tools are available to quantify clinical pathology at the cervix in a standardized and reproducible manner. This study aimed to develop and validate a cervical lesion proportion (CLP) measure for quantification of cervical pathology in FGS. A digital imaging technique was applied in which a grid containing 424 identical squares was positioned on high resolution digital images from the cervix of 70 women with FGS. CLP was measured for each image by observers counting the total number of squares containing at least one type of FGS associated lesion. For assessment of inter- and intra-observer reliability, three different observers measured CLP independently. In addition, a rubbery papule count (RPC) was determined in a similar manner. The intraclass correlation coefficient was 0.94 (excellent) for the CLP inter-rater reliability and 0.90 (good) for intra-rater reliability and the coefficients for the RPC were 0.88 and 0.80 (good), respectively. The CLP facilitated a reliable and reproducible quantification of FGS associated lesions of the cervix. In the future, grading of cervical pathology by CLP may provide insight into the natural course of schistosome egg-induced pathology of the cervix and may have a role in assessing praziquantel treatment efficacy against FGS. Trial Registration: ClinicalTrials.gov, trial number NCT04115072; trial URL https://clinicaltrials.gov/ct2/show/NCT04115072?term=Female+genital+schistosomiasis+AND+Madagascar&draw=2&rank=1.

Visual diagnosis of female genital schistosomiasis in Zambian women from hand-held colposcopy: agreement of expert image review

“…Reviewers in that study achieved a higher agreement than that described in our study, potentially by undergoing an initial consensus rating exercise to reach agreement on uniform rating of images. However, it is notable that in the Madagascan study, all images were thought to contain FGS lesions, removing the burden of uncertainty and highlighting that in settings where images are known to contain FGS lesions, agreement between reviewers was at best “moderate” 5 . Our approach in the BILHIV study illustrates a real-world scenario where expert reviewers may not necessarily have the opportunity for consensus agreement prior to consultation.…”

“…Previous work on visual-FGS has compared visual imaging to other diagnostic standards 30 or have used computerized algorithms 31 , 32 , or a combination of human reviewers and a digital gridding technique to evaluate visual-FGS 5 . A recent Madagascan study utilized human reviewers together with a digital image gridding technique to review images of women with known FGS-associated clinical lesions and found a Fleiss kappa of 0.55 (“moderate” agreement) for detecting rubbery papules.…”

“…Future additional work in a setting with higher schistosomiasis prevalence would be needed to definitively exclude an association between symptoms, standard Schistosoma, and FGS diagnostics and visual-FGS. Additionally, future work could incorporate artificial intelligence, such as computer algorithms to detect the characteristic color change caused by involvement of the genital mucosa with FGS 32 or the use of digital gridding techniques 5 . Additionally, a initial consensus rating exercise could be incorporated into future work with human expert review for FGS-associated lesions.…”

Knowledge and management of female genital schistosomiasis in sub-Saharan Africa: A scoping review protocol

“…Despite the implementation of the annual MDA aimed at schistosomiasis control and elimination in endemic areas, the disease burden continues to be high in sub-Saharan Africa 54 , 55 with FGS worsening the plight among women of reproductive age. 13 , 27 , 56 , 57 , 58 Studies have revealed a multi-disciplinary approach is required to integrate different efforts to eliminate schistosomiasis. 7 , 34 , 59 Lack of awareness about the disease in schistosomiasis-endemic areas and inadequate knowledge among healthcare workers account for the underreporting and underdiagnosis.…”