Discussion

Rapid, straightforward and reliable diagnosis of human helminth infections is essential for ongoing disease surveillance and successful disease control, particularly as control programmes advance towards disease elimination within endemic areas. Current WHO-recommended ‘gold standard’ diagnostic assays are unreliable in these low-endemic settings and typically involve the cumbersome or invasive sampling of bodily fluids such as stool and blood, as well as tissue via biopsy. Not only are these procedures often onerous, painful and carry a risk of infection, but many also require specific equipment and specialist health workers seldom available in endemic areas. A reliable assessment of disease prevalence within a given community can therefore often prove challenging as a result of patient aversions to being assessed, as well as through a lack of resources. In contrast, the sampling of urine is generally painless, low risk and relatively inexpensive. It negates the need for specialist staff, can usually be obtained immediately and is better tolerated by communities. Further to these clear practical advantages, in some instances, urine-based diagnostic assays have also been shown to provide a much more sensitive diagnosis of helminth infection when compared to gold standard methods that require alternative and more invasive bodily samples, particularly in low-endemicity settings. One approach to detecting helminth infections using urine samples is to target and amplify trans-renal helminth-derived DNA. Although highly sensitive even in low-endemicity settings, assays traditionally used to achieve this, such as conventional- and quantitative-PCR, are expensive and rely on specially trained technicians and sophisticated laboratory infrastructure; often preventing their application at the point-of-care. The recent development of alternative and field-deployable methods to target and amplify DNA, such as LAMP and RPA assays, however, offer a promising means of rapid, straightforward and reliable diagnosis of human helminth infections using non-invasive urine samples at the point-of-care in low-endemicity settings. Given the relative benefits in ease of collection, better community acceptance and improved diagnostic performance, we review current research literature and evaluate whether non-invasive urine sampling is currently exploited to its full potential in the development of molecular diagnostic tools for human helminthiase.