Schista! Sub-studies

Developing a multiplex, isothermal molecular diagnostic assay for FGS and HPV

Led by Lucy Smith (PhD Candidate)

Both female genital schistosomiasis (FGS) and human papillomaviruses (HPV) cause significant gynaecological morbidity in sub-Saharan Africa. Although high-resource molecular diagnostic methods exist, women in rural areas without access to medical clinics remain neglected. To address the lack of accessible diagnostics for women in rural areas, my project’s primary aim is to develop a multiplex, isothermal molecular diagnostic assay for both FGS and HPV.

My project is funded by the MRC LID DTP in collaboration with Professor Sanjeev Krishna at St. George’s University of London, and Doctor Bonnie Webster at the Natural History Museum.

Health economics analysis to evaluate the cost-effectiveness of FGS screening strategies, as part of the Zipime-Weka-Schista study in Zambia

Led by Olimpia Lamberti (PhD Candidate)

This economic evaluation aimed to Evaluate the cost-effectiveness of home-based self-sampling and clinic-based sampling for FGS screening compared to a no screening approach (the current standard of care) using a health decision analytical model. To address this, we developed a novel health decision analytical model (the FGS-SCREEN model) to evaluate the cost-effectiveness of different FGS screening strategies. The model was then implemented as part of the Zipime-Weka-Schista study to compare the cost-effectiveness of home-based self-sampling and clinic-based sampling to a no screening approach (current standard of care). Home-based self-sampling had a lower unit cost per woman screened compared to clinic-based sampling. Neither strategy was found to be very cost-effective if implemented individually. However, a combined screening pathway incorporating home-based self-sampling in rural (80% coverage of screening-eligible population) and clinic-based screening in peri-urban areas (20% coverage of screening eligible population) was found to be very cost-effective under conservative thresholds.

Applying computer vision to female genital schistosomiasis to improve visual diagnostics

Led by Morgan Lemin (PhD Candidate)

Visual diagnosis of FGS currently involves inspecting the cervix and surrounding tissue with a colposcope to identify one of the four classic lesion types (grainy sandy patches, homogenous sandy patches, abnormal vessels and rubbery papules). This method suffers from a lack of specificity and is highly subjective. However, in lieu of a gold standard molecular test, and with evidence that older women are more commonly test positive with visual diagnostics rather than molecular, work to improve visual diagnostics is warranted.

This work aims to apply computer vision, a form of machine learning, while developing clinical support tools to enhance visual diagnostics. It is funded through the MRC LID DTP, with the support and supervision of Prof Amaya Bustinduy and Dr Chrissy H Roberts.

Male genital schistosomiasis (MGS)

Male genital schistosomiasis (MGS) typically results from the entrapment of Schistosoma haematobium eggs in the male genital tract. There are no current and accurate estimates of the burden of MGS, due to disease underreporting primarily from diagnostic challenges and a lack of general awareness within the health system. We will recruit male household members of Zipime Weka Schista study participants in order to assess the prevalence of MGS across three communities in Zambia, investigate epidemiological risk factors, and examine clinical manifestations and morbidity associated with MGS.