Strongyloidiasis in clinical practice: challenges in diagnostics and treatment (brief review and clinical observations)

Abstract

High priority of soil-transmitted helminths worldwide and in the Russian Federation is due to their vast distribution and the severe pathological features they induce in humans. Recently, it was observed that awareness of clinicians regarding this disease category was markedly decreased, although no significant decline of the disease occurrence has been recorded, whereas rate of imported cases of parasitic diseases including soil-transmitted helminths like strongyloidiasis mainly originating from subtropical or tropical countries rose in non-endemic regions. Lack of alertness on diseases like strongyloidiasis impedes timely diagnostics and treatment. Global prevalence of strongyloidiasis was estimated to range within 30—100 million people, however the World Health Organization (WHO) suggests that it was underestimated as precise data in endemic countries remain unknown. The occurrence of these helminths has been recorded in regions of temperate-continental climate: Western Ukraine, Belarus, Moldova, the Caucasus, Central Asia, as well as in Eastern Europe and the Mediterranean region. In the Russian Federation locally acquired infections are frequently recorded in the Krasnodar Territory and Rostov Region. Here, based on multi-year experience in management of patients with strongyloidiasis we present our data and brief review of publications and systematic literature related to the challenges of its clinical picture, diagnostics and treatment. Life cycle, basic biological parameters of free-living helminth in nature and distinctive features of autoinfection related to strongyloidiasis were reviewed. Special attention was paid to the risk of developing severe forms (hyperinfection and disseminated strongyloidiasis) especially in immunocompromised hosts: HIV infection, radiotherapy followed by chemotherapy, long-term corticosteroid use. Difficulties in diagnosing Strongy-loides stercoralis infection are due to its polymorphic and non-specific clinical manifestations, as well as the lack of clinical knowledge and awareness about the disease. Clinical importance of parasitological methods for larvae detection was underlined. It was noted that the drug of choice in therapy of strongyloidiasis is ivermectin unapproved yet in Russia, whereas albendazole as an alternative drug exerts poorer efficacy, justifying a need to repeat treatment courses to establish full recovery from the disease.

Keywords

• strongyloidiasis
• strongyloides stercoralis
• immunodeficiency
• autoinfection
• hyperinfection
• disseminated strongyloidiasis
• baermann funnel technique
• ivermectin