The Advances in Molecular and New Point-of-Care (POC) Diagnosis of Schistosomiasis Pre- and Post-praziquantel Use: In the Pursuit of More Reliable Approaches for Low Endemic and Non-endemic Areas

Abstract

Like soil-transmitted helminth infections, schistosomiasis is an important neglected tropical disease (NTD) related to poverty with a major impact on public health in developing countries. Diagnosis of active infection is crucial for surveillance of controlled or post-elimination schistosomiasis areas. In addition, the use of conventional diagnostic tools in non-exposed populations (such as travelers) results in misdiagnoses in the prepatent period of infection. Also, the accuracy of standard tests applied in low-endemicity areas (LEAs) decreases after several rounds of treatment. We aimed to determine whether it would be necessary to replace schistosomiasis conventional diagnostic tests such as parasitological methods in LEAs. Also, we evaluate the use of new tools in non-endemic areas. Reliable, cheap and easy-to-use diagnostic tools are needed to respond to the demands of a new era of elimination and eradication of schistosomiasis. To this end, molecular diagnosis—including nucleic acid-based assays (loop-mediated isothermal amplification, polymerase chain reaction) and circulating cathodic and anodic antigen detection tests have become promising strategies. In this review, we attempt to address the use of alternative diagnostic tests for active infection detection and drug-monitoring after specific schistosomiasis treatment.

Evaluation, Validation, and Recognition of the Point-of-Care Circulating Cathodic Antigen, Urine-Based Assay for Mapping Schistosoma mansoni Infections

“…Aberrant results have also been reported related to the use of the POC-CCA assay in Brazil. 36,37 Some of these results may be attributable to the fact that Brazil requires the assay to be assembled in Brazil using components from the South African supplier, which could result in different levels of quality control of the final product, 37 or this could be related to the issue of different batches of components mentioned earlier.…”

Real-time PCR for diagnosis of imported schistosomiasis

“…The development of molecular methods to improve the diagnosis of parasitic diseases has been encouraging active research in recent years [13,14]. The detection of Schistosoma DNA by PCR in stools and urine appears to be a promising, highly sensitive, and specific tool that could improve and facilitate the diagnosis of schistosomiasis, particularly in non-endemic countries where the parasite burden can be lower [15–18].…”

Case Report: Diagnosis and Assessment of Cure Approaches for Acute Schistosomiasis in Pre-School Children

“…Heavy infections are usually associated with increased clinical severity due to host allergic responses, although high morbidity can also be seen in light/mild infections. Therefore, laboratory-based diagnosis is fundamental for accurate identification of AS cases (2,4,(10)(11)(12)(13)(14).…”

“…During early infection (prepatent phase: 3-7 weeks post exposure), immature forms migrate from the sites of skin penetration to several host systemic compartments, such as the lung, liver, gut, and visceral peritoneum until harboring mature bi-gender forms in the mesenteric veins ( 15 ). In this early phase, eggs are not detectable until ≅40 days post-exposure and alternative diagnostic approaches are usually applied other than parasitological tests ( 14 , 16 ). Routinely, indirect diagnostic assays such as serology and other laboratory markers like eosinophil counts are mostly used ( 1 , 2 , 4 , 17 , 18 ).…”

“…Alternative diagnostic tools, such as tests to detect Schistosoma antigens and DNA, are promising approaches for the diagnosis of schistosomiasis ( 2 , 10 , 13 , 16 ). Studies on travelers and immigrant populations have shown that the detection of Schistosoma antigens and DNA has the potential to improve AS diagnosis, treatment response and determination of cure rates ( 2 , 14 , 24 ).…”