Unexpected hosts: imaging parasitic diseases

Abstract

Radiologists seldom encounter parasitic diseases in their daily practice in most of Europe, although the incidence of these diseases is increasing due to migration and tourism from/to endemic areas. Moreover, some parasitic diseases are still endemic in certain European regions, and immunocompromised individuals also pose a higher risk of developing these conditions. This article reviews and summarises the imaging findings of some of the most important and frequent human parasitic diseases, including information about the parasite’s life cycle, pathophysiology, clinical findings, diagnosis, and treatment. We include malaria, amoebiasis, toxoplasmosis, trypanosomiasis, leishmaniasis, echinococcosis, cysticercosis, clonorchiasis, schistosomiasis, fascioliasis, ascariasis, anisakiasis, dracunculiasis, and strongyloidiasis. The aim of this review is to help radiologists when dealing with these diseases or in cases where they are suspected. Teaching Points • Incidence of parasitic diseases is increasing due to migratory movements and travelling. • Some parasitic diseases are still endemic in certain regions in Europe. • Parasitic diseases can have complex life cycles often involving different hosts. • Prompt diagnosis and treatment is essential for patient management in parasitic diseases. • Radiologists should be able to recognise and suspect the most relevant parasitic diseases.

Case Report: Hepatic Fascioliasis in a Young Afghani Woman with Severe Wheezing, High-Grade Peripheral Eosinophilia, and Liver Lesions: A Brief Literature Review

“…13 The distinctive CT imaging findings in the liver, especially subcapsular hematoma, suggested fascioliasis as well. 10,14,15 The patient was treated successfully with triclabendazole. This agent is preferred, as it is the only one known to kill both early and mature forms of this helminth, although resistance has been reported.…”

“…It is important to emphasize that in the setting of significant eosinophilia and appropriate epidemiology, CT imaging of the liver can be nearly pathognomonic. 10,14,15 Warfare and civil strife in Afghanistan and the adjacent regions have potential to generate more imported cases of this disease. Easier access to Fasciola serology testing when supported by clinical evidence and characteristic liver imaging, as well as prompt ID consultation, could obviate costly, unnecessary other testing, such as those that our patient received (e.g., molecular probes for eosinophilic leukemia).…”

“…Subcapsular hematomas along with tortuous or tubuliform, hypo-attenuating, and frequently subcapsular tracts occasionally coalescing into irregular nodules are the most characteristic features pointing toward hepatic fascioliasis. 10,14,15…”

Parasitic diseases as a cause of acute abdominal pain: imaging findings

“…Ingestion of raw or undercooked fish or other seafood may cause a rare parasitic disease, Anisakiasis [75]. There is a controversy in previous reports about the ability of the larvae of genus Anisakis during penetration of the gastrointestinal wall.…”

“…Imaging findings raised suspicion for the involvement of visceral larva migrans. The definitive diagnosis was achieved with the identification of Ascaris eggs in the stool examination while others emphasize the penetrating ability of the parasite [75][76][77]. Attachment of larvae in the gastrointestinal wall causes local tissue damage including ulceration, granulomatous inflammation, or perforation while an allergic reaction of the gastrointestinal wall or IgE-mediated systemic allergic reaction may also occur [76].…”