Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 26, Number 1—January 2020
Research Letter

Autochthonous Human Fascioliasis, Belgium

Sandrine Milas1Comments to Author , Camelia Rossi, Ivan Philippart, Pierre Dorny, and Emmanuel Bottieau
Author affiliations: University Hospital Center Tivoli, La Louvière, Belgium (S. Milas); University Hospital Center Ambroise Paré, Mons, Belgium (C. Rossi); Regional Hospital Mons-Hainaut, Mons (I. Philippart); Institute of Tropical Medicine, Antwerp, Belgium (P. Dorny, E. Bottieau)

Cite This Article


We report 2 cases of human fascioliasis (HF) in Belgium, likely caused by consumption of vegetables from a garden that was flooded by pasture runoff. Because autochthonous HF is rare and the route of transmission was unusual, HF was not diagnosed until 6 months after symptom onset in both cases.

Human fascioliasis (HF) is a plantborne and waterborne infection caused by the trematodes Fasciola hepatica in temperate areas and F. gigantica in tropical areas (1,2). Fasciola spp. trematodes infect herbivorous mammals and humans. The Fasciola life cycle requires 2 hosts; ruminants carry adult worms and excrete eggs into the environment in feces; lymnaeid snails are invaded and release cercariae, which encyst as metacercariae on aquatic vegetation. Humans become infected by ingesting raw aquatic vegetables or consuming plants or water containing metacercariae (3). Symptoms of fascioliasis are stage-specific and related to hepatic migration by larva or obstruction of the biliary ducts by adult worms (1,2).

In Belgium, only 6 cases of HF have been published since 1960 (46). We describe 2 autochthonous cases of HF. The cases were seen in different hospitals and initially were not linked epidemiologically.

Case 1 was in a 72-year-old man with no underlying medical conditions and no history of travel outside the country who was referred to the Regional Hospital of Mons in November 2008. He had fever, abdominal pain, rash, and hypereosinophilia that had lasted for 8 weeks (Table). Fecal egg detection was negative. Several serologic tests targeting parasitic infections were performed (Table); results for Trichinella spiralis were positive, but this diagnosis was discarded in the absence of myalgia and elevated creatine kinase. Eventually, a diagnosis of idiopathic hypereosinophilic syndrome was made. The patient received high doses of corticosteroids, but his condition did not improve. He was reevaluated in March 2009, and HF was considered on the basis of combined clinical, laboratory, and radiologic findings (Table). An indirect hemagglutination test for Fasciola spp. was performed by using ELI.HA Distoma (ELITech Group,, and results were positive. The patient received triclabendazole (10 mg/kg/d) for 2 consecutive days. His symptoms abated, and his eosinophil count was nearly normal 1 month later (Table).

Case 2 was in the index case’s neighbor, who experienced similar symptoms that lasted for 3 months before she was seen at the University Hospital Center Ambroise Paré in Mons in December 2008. She also was misdiagnosed initially (Table). In February 2009, 2 stool examinations were negative for parasite eggs. In March, an indirect hemagglutination test for Fasciola was performed and was highly positive. The patient received a single dose of triclabendazole (15 mg/kg) and recovered fully within 5 months (Table).

A detailed anamnesis revealed that both patients consumed unwashed raw vegetables from case-patient 2’s garden, which was flooded with runoff from a neighboring cattle pasture in August 2008. We hypothesize the vegetables were contaminated by metacercariae, either by Fasciola-infested amphibious snails washed into the garden or directly by runoff. We did not perform sampling of the garden. Cases related to garden vegetables contaminated by flooding have been reported previously, such as in Corsica (3).

HF is not a notifiable disease in Belgium. Among 6 published cases, 3 occurred in a cluster related to consumption of homegrown watercress, and 3 nonclustered cases had a questionable autochthonous nature (46). Consumption of watercress and dandelions is uncommon in Belgium, but common in France, where ≈300 HF cases occur annually (7). However, Fasciola infection in cattle is common in Belgium; herd prevalence is 37.3% in Flemish dairy cattle (8). In addition, a 2008 survey of snails showed 1.31% of Galba truncatula and 0.16% of Radix spp. were infected by F. hepatica trematodes (9).

Both cases in this study experienced an acute invasive stage and a considerable delay in HF diagnosis. Clinicians should be aware of key elements of HF, including potential diet exposure, clinical signs and symptoms, and imaging and laboratory findings. Contrast-enhanced computed tomography scans of the liver sometimes show tortuous subscapular tracts associated with hypodense nodules and hepatomegaly during the acute phase (2). In industrialized countries, human cases occur singly or in small clusters, and diagnosis usually is made during the invasive phase by combined clinical, laboratory, and imaging findings. Serologic tests can detect antibodies within 2 weeks after infection but might have low specificity. Fasciola eggs can appear in stool 3–4 months postinfection, depending on the infection burden and the ability of the flukes to produce eggs. Intermittent shedding can occur (1,2). Co-proantigens are detectable 8 weeks after infection and have a high sensitivity, but 1 negative result despite high egg shedding has been reported (2).

Triclabendazole, licensed in Europe only by Novartis (, at 10–15 mg/kg/day in 1 dose or on 2 consecutive days, is the preferred treatment, and patients usually recover rapidly. Resistance increasingly is described in ruminants and treatment failures have been reported in humans (2,10).

Although overlooked in countries in northern Europe, HF should be considered in cases of unexplained eosinophilia associated with liver symptoms, even in the absence of ingestion of freshwater plants. This zoonotic condition highlights the need for good epidemiologic communication between human and animal health workers.

At the time of this study, Dr. Milas was an infectious disease specialist at University Hospital Center Tivoli, La Louvière, Belgium. She is currently an infectious disease specialist at University Hospital Center of Charleroi, Charleroi, Belgium. Her research interests include general infectious diseases, travel medicine, and infection control.



We thank Quentin Groom from the Botanic Garden Meise, Meise, Belgium, for his contribution to this article.



  1. Mas-Coma  S, Bargues  MD, Valero  MA. Fascioliasis and other plant-borne trematode zoonoses. Int J Parasitol. 2005;35:125578. DOIPubMedGoogle Scholar
  2. Mas-Coma  S, Bargues  MD, Valero  MA. Diagnosis of human fascioliasis by stool and blood techniques: update for the present global scenario. Parasitology. 2014;141:191846. DOIPubMedGoogle Scholar
  3. Mas-Coma  S, Bargues  MD, Valero  MA. Human fascioliasis infection sources, their diversity, incidence factors, analytical methods and prevention measures. Parasitology. 2018;145:166599. DOIPubMedGoogle Scholar
  4. Jeanty  C. [A new focus of hepatic distomatosis due to Fasciola hepatica in Belgium. Extraction of a cutaneous fluke]. Acta Gastroenterol Belg. 1960;23:21027.PubMedGoogle Scholar
  5. Orlent  H, Selleslag  D, Vandecasteele  S, Jalal  PK, Bank  S, Hines  J. Clinical challenges and images in GI. Fasciola hepatica infection and Von Hippel-Lindau disease type 1 with pancreatic and renal involvement. Gastroenterology. 2007;132:156, 467–8. DOIPubMedGoogle Scholar
  6. Pilet  B, Deckers  F, Pouillon  M, Parizel  P. Fasciola hepatica infection in a 65-year-old woman. J Radiol Case Rep. 2010;4:139. DOIPubMedGoogle Scholar
  7. Mailles  A, Capek  I, Ajana  F, Schepens  C, Ilef  D, Vaillant  V. Commercial watercress as an emerging source of fascioliasis in Northern France in 2002: results from an outbreak investigation. Epidemiol Infect. 2006;134:9425. DOIPubMedGoogle Scholar
  8. Bennema  S, Vercruysse  J, Claerebout  E, Schnieder  T, Strube  C, Ducheyne  E, et al. The use of bulk-tank milk ELISAs to assess the spatial distribution of Fasciola hepatica, Ostertagia ostertagi and Dictyocaulus viviparus in dairy cattle in Flanders (Belgium). Vet Parasitol. 2009;165:517. DOIPubMedGoogle Scholar
  9. Caron  Y, Martens  K, Lempereur  L, Saegerman  C, Losson  B. New insight in lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in Belgium and Luxembourg. Parasit Vectors. 2014;7:66. DOIPubMedGoogle Scholar
  10. Cabada  MM, Lopez  M, Cruz  M, Delgado  JR, Hill  V, White  AC Jr. Treatment failure after multiple courses of triclabendazole among patients with fascioliasis in Cusco, Peru: a case series. PLoS Negl Trop Dis. 2016;10:e0004361. DOIPubMedGoogle Scholar




Cite This Article

DOI: 10.3201/eid2601.190190

Original Publication Date: December 02, 2019

1Current affiliation: University Center of Charleroi, Charleroi, Belgium.

Table of Contents – Volume 26, Number 1—January 2020

EID Search Options
presentation_01 Advanced Article Search – Search articles by author and/or keyword.
presentation_01 Articles by Country Search – Search articles by the topic country.
presentation_01 Article Type Search – Search articles by article type and issue.



Please use the form below to submit correspondence to the authors or contact them at the following address:

Sandrine Milas, CHU Charleroi, Infectious Diseases and Infection Control, 140 Chaussée de Bruxelles, 6042 Lodelinsart, Belgium

Send To

10000 character(s) remaining.


Page created: December 18, 2019
Page updated: December 18, 2019
Page reviewed: December 18, 2019
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.