New diagnostic tools in schistosomiasis

Abstract

Schistosomiasis is a water-based parasitic disease that affects over 250 million people. Control efforts have long been in vain, which is one reason why schistosomiasis is considered a neglected tropical disease. However, since the new millennium, interventions against schistosomiasis are escalating. The initial impetus stems from a 2001 World Health Assembly resolution, urging member states to scale-up deworming of school-aged children with the anthelminthic drug praziquantel. Because praziquantel is safe, efficacious and inexpensive when delivered through the school platform, diagnosis before drug intervention was deemed unnecessary and not cost-effective. Hence, there was little interest in research and development of novel diagnostic tools. With the recent publication of the World Health Organization (WHO) Roadmap to overcome the impact of neglected tropical diseases in 2020, we have entered a new era. Elimination of schistosomiasis has become the buzzword and this has important ramifications for diagnostic tools. Indeed, measuring progress towards the WHO Roadmap and whether local elimination has been achieved requires highly accurate diagnostic assays. Here, we introduce target product profiles for diagnostic tools that are required for different stages of a schistosomiasis control programme. We provide an update of the latest developments in schistosomiasis diagnosis, including microscopic techniques, rapid diagnostic tests for antigen detection, polymerase chain reaction (PCR) assays and proxy markers for morbidity assessments. Particular emphasis is placed on challenges and solutions for new technologies to enter clinical practice.

Sustaining the Control of Schistosoma mansoni in Western Côte d'Ivoire: Baseline Findings Before the Implementation of a Randomized Trial

“…9,10 Here, we report the baseline parasitologic situation and village characteristics before the onset of the trial and show the challenge of categorizing communities based on a rapid assessment procedure with a relatively small sample size (50 children) and an insensitive diagnostic method (Kato-Katz technique). 31 Examining single stool samples with duplicate Kato-Katz thick smears, we observed an overall S. mansoni prevalence of 15.8% in 13-to 14-year-old children at the eligibility survey. When 9-to 12-year-old children were examined with at least quadruplicate Kato-Katz thick smears at the baseline survey, the overall prevalence of S. mansoni was 22.1%.…”

Validation of a Point-of-Care Circulating Cathodic Antigen Urine Cassette Test for Schistosoma mansoni Diagnosis in the Sahel, and Potential Cross-Reaction in Pregnancy

“…Hence, the World Health Organization (WHO)'s plan for global elimination of schistosomiasis will require additional diagnostic tools, characterized by high sensitivity, high specificity, ease of use at the point-of-care (POC), and low costs. 4 First products developed within this spirit are already available on the market. One of them is a POC circulating cathodic antigen (CCA) urine cassette test for the diagnosis of S. mansoni.…”

“…The most widely used diagnostic methods for S. haematobium are urine filtration with microscopy and reagent strip testing for microhematuria, whereas the diagnosis of S. mansoni heavily relies on Kato-Katz thick smear examination under a microscope. 4 In rural areas of Africa, where most of the worldwide Schistosoma infections occur, the capacity of health centers is insufficient to provide even these basic laboratory diagnostics. Hence, the World Health Organization (WHO)'s plan for global elimination of schistosomiasis will require additional diagnostic tools, characterized by high sensitivity, high specificity, ease of use at the point-of-care (POC), and low costs.…”

Synthesis and SAR Studies of New Oxadiazole-2-oxide Derivatives with Remarkable In Vitro Activity against Schistosoma japonicum

“…It is still a neglected tropical disease because of various control effects did not work well. Mostly, three species are responsible for particular relevance; Schistosoma mansoni, which is endemic in Africa, the Arabian Peninsula, South America and the Caribbean, Schistosoma haematobium, which occurs in Africa and the Arabian Peninsula, and Schistosoma japonicum, which is only restricted to China, the Philippines and Indonesia [3,4]. The only World Health Organization (WHO) recognized drug Praziquantel (PZQ) cannot stop reinfection and doesn't work against juvenile schistosomiasis [5].…”