Strongyloides stercoralis in the non-endemic setting and beyond: an epidemiological, diagnostic and treatment challenge

Project summary

Strongyloides stercoralis is a soil-transmitted helminth widely distributed in areas of the world where sewage disposal is inadequate, and human waste contaminates the environment. The infection caused by S. stercoralis, strongyloidiasis, has recently been included in the WHO list of Neglected Tropical Diseases (NTD), which are conditions disproportionally affecting people living in poverty. Relatively poor resources are available for research and effective interventions against strongyloidiasis and the other NTD.

My work aims at addressing some of the main gaps of knowledge about key aspects of strongyloidiasis in the endemic and non-endemic setting. This PhD research has gathered a set of systematic reviews with sometimes meta-analysis and original diagnostic studies and trials to improve the general knowledge on strongyloidiasis in Europe and beyond.  The main findings can be summarized as follow: (1) The global prevalence of strongyloidiasis has been so far largely underestimated; the condition likely affects more than 600 million individuals and its actual burden in non-endemic countries such as Italy should not been overlooked.; (2) Moreover, the systematic review on clinical and laboratory features highlighted that a large proportion of infected individuals present symptoms and/or eosinophilia, underlining that morbidity is significant. (3) This work also highlighted that serology has a prominent role for screening and individual diagnosis of strongyloidiasis, and, as importantly, can be useful for post-treatment monitoring; PCR in contrast has high specificity, but its sensitivity still needs improvement, making it a suitable tool only when infection needs to be confirmed; (4) Finally, a robust randomized controlled trial has demonstrated that a single dose of ivermectin (200 µg/kg) should be the treatment of choice for uncomplicated strongyloidiasis in travelers and immigrants.