Download Dicrocoelium dendriticum: a true infection?

Le Infezioni in Medicina, n. 2, 115-116, 2009
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Case
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Dicrocoelium dendriticum:
a true infection?
Dicrocoelium dendriticum: una vera infezione?
Barbara Magi1, Elena Frati2, Laura Bernini1, Anna Sansoni1,
Giacomo Zanelli1
1
Infectious Diseases Clinic, Department of Molecular Biology, Siena University;
Clinic of Rheumatology, Department of Clinical Medicine and Immunology,
University of Siena, Italy
2
n INTRODUCTION
eosinophilia (9.7%) and slightly elevated bilirubin (1.5 mg/dl). Other laboratory results were
within the normal range. Abdominal ultrasonography was negative for liver and biliary
abnormalities. Total IgE count was normal and
there was no history of allergy. Microscopical
examinations of three stool specimens after
concentration revealed Dicrocoelium dendriticum
eggs (Figures 1, 2). She denied liver consumption, travel or animal contact within the past
weeks. She did not complain of abdominal discomfort except for a long history of constipation. She was treated with albendazole (400 mg
twice a day for 7 days) and 4 weeks later parasitological examination was negative and blood
parameters had returned to normal.
D
icrocoelium dendriticum is the most widespread liver fluke in cattle and sheep in
Italy [1]. Adult forms live in the gall bladder and bile ducts of their final hosts (ruminants).
Eggs are passed in faeces and ingested by land snails which excrete cercaria in mucous balls,
which are eaten by ants. Infestation usually occurs by ingestion of ants that carry metacercariae
by animals and occasionally humans [2]. Here we
describe a rare case of asymptomatic human dicrocoeliasis.
n CASE REPORT
A 55-year-old Italian woman was admitted to
the Rheumatology unit (Siena University Hospital, Italy) in June 2007 with a chronic history
of cervical and lumbar pain and was diagnosed
with osteoarthritis. Blood tests showed mild
n DISCUSSION
Despite the widespread nature of the liver fluke
Dicrocoelium dendriticum, dicrocoeliasis is rarely
Figures 1, 2 - Dicrocoelium dendriticum: two small (40 mm X 20 mm), thick-walled, yellowish-brown operculate eggs containing miracidium (40X).
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2009
encountered in clinical practice [2]. Infections
occur by ingestion of the second intermediate
host (ants) contaminating raw fruit and vegetables.
Metacercariae migrate into the bile system
causing chronic irritation of the liver and bile
ducts [2]. Symptoms associated with human infection include chronic constipation or diarrhoea, hepatomegaly, bile duct obstruction, hypereosinophilia and possibly urticaria [2-5].
Asymptomatic infection has been documented
in animals.
Detection of parasite eggs in human stools is
not always associated with real infection, but
may indicate “spurious infection” or
pseudoparasitism due to ingestion of raw or
undercooked infected liver [2, 4].
Re-examination of stools after three days of liver-free diet is generally conclusive [6]. In the
present case, there was no history of liver consumption. Although the patient was symptomfree, eosinophilia and elevated bilirubin (either
reported in dicrocoeliasis) that returned to normal after antiparasitic therapy, suggest true infection with initial involvement of the bile
ducts.
Imidazole therapy was effective in eradicating
the parasite as reported in a prior study [2]. In
our opinion, the present was a rare case of
asymptomatic dicrocoeliasis and to our knowledge there has been no prior report from Italy.
Key words: dicrocoeliasis, human infection, liver
fluke.
SUMMARY
Dicrocoelium dendriticum is a liver parasite of ruminants. Humans are occasionally infected by ingestion of intermediate hosts.
We report a rare case of dicrocoeliasis in a 55-year-
old woman who presented with eosinophilia and
elevated bilirubin. Therapy with albendazole
eradicated the parasite and normalized blood parameters.
RIASSUNTO
Dicrocoelium dendriticum è un parassita epatico dei ruminanti.
L’uomo si infetta occasionalmente attraverso l’ingestione di ospiti intermedi. Descriviamo un raro caso di di-
croceliasi in una donna di 55 anni che ha presentato eosinofilia ed aumento della bilirubina. Il trattamento con
albendazolo ha eradicato il parassita con normalizzazione dei parametri laboratoristici.
n REFERENCES
[3] Rack J., Adusu E., Jelinek T. Humane infektion
mit Dicrocoelium dendriticum. Dtsch. Med. Wochenschr. 129, 2538-2540, 2004.
[4] Sing A., Tybus K., Facler I. Acute urticaria associated with Dicrocoelium dendriticum infestation. Indian J. Med. Microbiol. 26, 96-98, 2008.
[5] El-Shiekh Mohamed A.R., Mummery V. Human
dicrocoeliasis. Report on 208 cases from Saudi Arabia. Trop. Geogr. Med. 42, 1-7, 1990.
[6] Helmy M.M., Al-Mathal E.M. Human infection
with Dicrocoelium dendriticum in Riyadh district (Saudi Arabia). J. Egypt Soc. Parasitol. 33, 139-144, 2003.
[1] Cringoli G., Rinaldi L., Veneziano V., Capelli G.,
Malone JB. A cross-sectional coprological survey of
liver flukes in cattle and sheep from an area of the
southern Italian Apennines. Veterinary Parasitology
108, 137-143, 2002.
[2] Karadag B., Bilici A., Doventas A., Kantarci F.,
Selcuk D., Dincer N., Oner Y.A., Erdincler D.S. An
unusual case of biliary obstruction caused by Dicrocoelium dendriticum. Scand. J. Infect. Dis. 37, 385-388,
2005.
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