Transactions of the Royal Society of Tropical Medicine and Hygiene 2004 98, 193—194Case report: unusual presentation of Fasciolopsis buski in a Viet Namese child a Institute of Biotechno
Trang 1Transactions of the Royal Society of Tropical Medicine and Hygiene (2004) 98, 193—194
Case report: unusual presentation of Fasciolopsis buski in a Viet Namese child
a
Institute of Biotechnology (IBT), Hanoi, Viet Nam
b
National Institute for Malariology, Parasitology and Entomology (NIMPE), Hanoi, Viet Nam
c
Centre for Control of Malaria and Parasites, Nghe an Province, Viet Nam
d
School of Tropical Biology, James Cook University, Townsville, Queensland, Australia
e
Molecular Parasitology Laboratory, Australian Centre for International and Tropical Health and
Nutrition, Queensland Institute of Medical Research and University of Queensland, 300 Herston Road, Q4029, Brisbane, Queensland, Australia
Received 9 May 2003 ; received in revised form 23 June 2003; accepted 24 June 2003
KEYWORDS
Fasciolopsis buski;
DNA analysis;
Praziquantel;
Viet Nam
Summary A Viet Namese child presented with a history of abdominal pain Shortly afterwards, he vomited eight live trematode flukes that were collected and
morpho-logically identified as Fasciolopsis buski The identification was confirmed by DNA analysis Adult worms of F buski from humans are very rarely seen except at autopsy,
and this is the first such report from Viet Nam
© 2003 Royal Society of Tropical Medicine and Hygiene Published by Elsevier Ltd All rights reserved
1 Introduction
Fasciolopsis buski is a duodenal digenetic
trema-tode (Family: Fasciolidae) parasite occurring in
humans but also in pigs, equines, bovines, caprines
and ovines that act as reservoir hosts for infection
(Chandra, 1984; Segal et al., 1968) Its general
mor-phology is similar to that of the common liver fluke,
Fasciola hepatica, but it lacks the thickened
ante-rior cone and its intestinal caeca are unbranched
(Smyth, 1994) It is widespread in Asia, occurring
in Taiwan, Thailand, Laos, Bangladesh, India and
Viet Nam (Chandra, 1984) The intermediate hosts
are freshwater planorbid snails that feed on water
*Corresponding author Tel.: +61-7-3362-0401;
fax: +61-7-3362-0104.
E-mail address: donm@qimr.edu.au (D.P McManus).
plants such as lotus (Nelumo nucifera), water cal-trop (Trapa bicornis), water chestnut (T natana)
and other species, much cultivated for food and fertilized with human faeces (night soil) Lar-val stages (cercariae), periodically released from snails, anchor themselves to water plants where they transform into metacercariae which become enclosed in cysts secreted by the metacercariae The metacercariae-laden water plants are eaten raw and the metacercariae excyst in the small intestine where they develop into adult flukes
2 Case report
A two and a half-year-old boy from Vinh City, Nghe an Province, Viet Nam, presented at a local clinic in October 2001, with a prolonged history
0035-9203/$ — see front matter © 2003 Royal Society of Tropical Medicine and Hygiene Published by Elsevier Ltd All rights reserved.
doi:10.1016/S0035-9203(03)00022-1
Trang 2194 T.H Le et al.
of abdominal pain Shortly afterwards, he vomited
eight live trematode flukes that were collected
and forwarded to the Centre for Control of Malaria
and Parasites, Nghe an Province for identification
The child was treated with praziquantel (25 mg/kg
bodyweight/d for 3 d) and completely recovered
In association with the National Institute for
Malari-ology, Parasitology and Entomology (NIMPE), Hanoi,
Viet Nam, the parasites were fixed, mounted,
stained and examined microscopically They were
provisionally identified as the giant intestinal fluke,
F buski The flukes had the following
morphologi-cal features: length, 41 mm; width, 13 mm;
thick-ness, 2 mm; and mouth, 0.4 mm; characteristics
that were identical to adult specimens of F buski,
routinely collected from the intestines of pigs in
Viet Nam
The provisional identification was confirmed by
molecular analysis at The Institute of
Biotech-nology, Hanoi, Viet Nam Total genomic DNA was
extracted from one of the adult flukes using a
DNeasy Tissue Kit (Qiagen, Hilden, Germany) A
1.9 kbp fragment of 18S rDNA was amplified by
polymerase chain reaction (PCR) using conserved
oligonucleotide primers After purification, PCR
products were cloned using a TA cloning kit
(Invit-rogen) and plasmids were extracted using QIAprep
Spin Miniprep Kits (Qiagen, Hilden, Germany) DNA
inserts were subsequently sequenced using T7 and
M-13 reverse primers and an ABI 377 automated
DNA sequencer and BigDye sequencing chemistry
(ABI, Foster City, CA, USA) The sequences were
aligned with a sequence for F buski 18S rDNA
de-posited in the GenBank database (Accession No
L06668) The sequences were almost identical, with only two nucleotide substitutions evident (2/1900
=0.1%) between the Viet Namese samples and the sequence deposited in GenBank, indicating that
the flukes obtained from the child were indeed F.
buski Although human cases of F buski infection
have been recorded previously in Vietnam, this was
by identification of the egg stage in faeces Adult
worms of F buski from humans are very rarely seen
except at autopsy, and this is the first such report from Viet Nam The combination of morphological and molecular methods provided a very elegant approach to the formal and definitive identifica-tion of this important species of flukes Formal consent to undertake the study and for publication
of this article was obtained from the parents of the child
Acknowledgements
This work was supported in part by Wellcome Trust (Ref: 068762) and by the National Health and Med-ical Research Council of Australia
References
Chandra, S.S., 1984 Epidemiology of Fasciolopsis buski in Uttar
Pradesh Indian J Med Res 78, 55—59.
Segal, D.B., Humphrey, J.M., Edwards, S.J., Kirby, M.D., 1968 Parasites of man and domestic animals in Vietnam, Thailand, Laos, and Cambodia Exp Parasitol 23, 412—464.
Smyth, J.D., 1994 Introduction to Animal Parasitology Cam-bridge University Press, CamCam-bridge.