Acute Severe Visceral Cysticercosis in Lambs and Kids in Israel

June 9, 2015 — admin
AttachmentSize
visceral_cysticercosis.pdf1.92 MB
Embedded Scribd iPaper - Requires Javascript and Flash Player

Israel Journal of Veterinary Medicine  Vol. 70 (2)  June 2015 49 Acute Cysticercosis Outbreaks
Acute Severe Visceral Cysticercosis in Lambs and Kids in Israel
Perl, S.,
1
* Edery, N.,
1
Bouznach, A.,
1
Abdalla, H.
2
and Markovics, A.
3
1
Department of Pathology, Kimron Veterinary Institute, Beit Dagan, Israel.
2
Veterinary Clinic, Tamra 30811, Israel.
3
Department of Parasitology, Kimron Veterinary Institute, Beit Dagan, Israel.
*
Corresponding Author: Prof. S. Perl, Department of Pathology, Kimron Veterinary Institute, 50250 Bet Dagan, Israel. E-mail address: perls@moag.gov.il
ABSTRACT
Tis report describes two cases of acute outbreaks of cysticercosis in lambs and kids caused by Cysticercus
tenuicollis the larval (metacestode) stage of the tapeworm Taenia hydatigena. Te acute form of cysticercosis
is rare and only a few cases have been described in the literature in the United Kingdom, Greece and Turkey.
In the frst case presented in this report 40% of lambs aged 2-3 months died over a period of 3-4 weeks
during the month of March 2013. In the second case a few months later, 30% of lambs and 20% of kids
succumbed. In both episodes adult sheep and goats were not afected. Pathological investigation revealed
larval cestodes migrating through the liver and lungs. Investigation of the incidents led to the possibility that
the main source of infestation was in the frst case food borne in the concentrated feed manufactured by a
local dealer, and in the second case due to contaminated hay harvested by the farmer and fed to the animals.
Te article describes the outbreaks, macroscopic and microscopic pathology fndings and epidemiological
investigations.
Keywords: Cysticercosis tenuicolis; Taenia hydatigena; Age Susceptibility; Lambs; Kids;
Epidemiological Investigation.
INTRODUCTION
Cysticercosis in small ruminants is caused mainly by
Cysticercus tenuicollis. Cysticercosis the larval (metacestode)
stage of the tapeworm Taenia hydatigena appears in an acute
or chronic form (1). Te chronic form is more common, usu-
ally asymptomatic and is generally diagnosed at the abattoir
(2). Tis form of the disease often results in economic losses
due to condemnation of infected organs or carcasses.
Te acute form of cysticercosis is rare and is usually seen
in natural cases causing the death of a large number of lambs
(1). Only a few cases have been described in the literature,
in the United Kingdom (3), Greece (4), Italy (5) and Turkey
(6). Sporadic cases on the other hand afecting solitary lambs
have been described in Asian countries (7, 8).
Tis article describes two outbreaks of cysticercosis
in lambs and kids which resulted in extensive mortality.
Investigation of the source of infestation led to a high suspi-
cion on the contamination of food fed to these animals. Te
article describes the outbreak, macroscopic and microscopic
pathology fndings and epidemiological investigations.
CASE REPORTS
Case 1
Two lambs were found dead on the farm following a few days
of lethargy were presented to the Pathology Department of
the Kimron Veterinary Institute, Beit Dagan, Israel. Tirty
six out of 90 lambs (40%) aged 2-3 months were reported by
the farmer to have died over a period of 3-4 weeks during the
month of March 2013 in a herd consisting of 400 ewes and
40 goats. Only lambs were afected. Te farm was situated in
the North of Israel in the Galilee. Te ewes were mainly held
Israel Journal of Veterinary Medicine  Vol. 70 (2)  June 2015 Perl, S. 50
in paddocks and occasionally allowed to pasture, whereas the
lambs were held only in the paddock enclosure.
Te enclosure in which the lambs were held was sur-
rounded by high concrete walls of about 1.5 meters and above
which there was fencing up to the height of the roof. On
inspection of the farm it was apparent that no canine access
into the paddock enclosure was possible.
Te farmer reported that the sheep were fed a commercial
diet purchased and packaged by a local dealer. Te farmer also
reported that other farms in the area had complained about
cases of mortality. Investigation of the incident led to the
suspicion that the main source of infestation was probably
food borne in the concentrate food.
Case 2
Two lambs and one kid which died suddenly were presented
to the Pathology Department of the Kimron Veterinary
Institute, Beit Dagan, Israel. Te farm from which they
originated was situated in the centre of Israel and managed
intensively. A total of 600 head were all held in enclosures
without access to pastures. Te farmer harvested hay for the
sheep and goats from an adjacent vicinity just before the
outbreak. On investigation the owner reported that the locale
was known to be frequented by stray dogs and jackals.
Gross Pathology
A description of a typical case among the two outbreaks is
presented.
Te liver was slightly enlarged and swollen, and its cap-
sule covered by a thin layer of blood-tinged fbrin (Figure 1).
Many 5-10 mm semi-translucent white cylindrical parasitic
cysts were attached to the hepatic capsule (Figure 1). Within
the capsule and the hepatic parenchyma there were multiple
dark red streaks and canals, ranging from 1 to 3 cm in length
and longer and 0.1- 0.2 cm in width (subcapsular and intra
parenchymal migration tracts) (Figure 2).
After evisceration, within the pleural and peritoneal
cavities there was approximately 500-800 ml of blood-tinged
transudate with numerous semi-translucent white cysts
(similar to those found on the liver) (Figure 3).
Te lung was slightly edematous, and on the pleural sur-
face a few parasitic migration tracts could be seen (Figure
4). A few cysts were attached to the visceral pleura and
some of them appeared to have migrated through the lung
parenchyma.
HISTOPATHOLOGICAL
DESCRIPTIONS
Liver
Approximately 50% of the hepatic parenchyma was efaced
and replaced by multiple randomly distributed, 2-3 mm
wide, blood-flled cavities which were diagnosed as meta-
zoan migration tracts. Within the cavities there were small
numbers of eosinophils, neutrophils, and erythrocyte laden
macrophages, admixed with necrotic cell debris, fbrin, and
occasionally cestode larvae. Te cestode larvae ranged in
size from 5 to 10 mm in diameter, with a thick integument,
Figure 1: Liver and lung, lamb: Te liver is dark red covered by a
thin layer of blood tinged fbrin. A few cysts are penetrating the
visceral pleura.
Figure 2: Liver, lamb: multifocal, numerous dark red migration tracts.
Case Reports
Israel Journal of Veterinary Medicine  Vol. 70 (2)  June 2015 51 Acute Cysticercosis Outbreaks
numerous calcareous corpuscles and no pseudocoelom or
digestive tract. Te migration tracts were surrounded by a rim
of necrotic hepatocytes and a small numbers of lymphocytes,
plasma cells and macrophages (Figure 5). Multifocally, there
was a mild hepatocellular swelling and clearing with mild
lipidosis.
Lungs
Similar lesions to the liver were seen in the lungs. Tese
consisted of blood-flled cavities randomly distributed in
the lung parenchima. In some of the cavities cestode larvae
were present similar to that seen in the liver (Figure 6). Some
lesions were accompanied by infltration of infammatory
cells, neutrophils macrophages and cell debris.
Laboratory Results
According to their morphological characteristics the cysts
were diagnosed as Cysticercus tenuicollis.
DIAGNOSIS
A diagnosis of acute visceral cysticercosis by Taenia hydatigena
was made based on the marked multifocal acute hemorrhage
and hepatic necrosis and mild to moderate pneumonia due
Figure 3: Lung, lamb: Multifocal hemorrhages and hemorrhagic
streaks in the lung parenchyma due to migration of larvae.
Figure 4: Peritoneal cavity with a large volume of yellowish fuid and
the presence of a large number of larval cysts.
Figure 5: Liver, lamb: liver parenchyma is replaced by a blood flled
cavities (migration tracts) and a cross section of a larval cestode
H&E, x40.
Figure 6: Lung, lamb: a cavity containing cross sections of larval
cestodes H&E, x20.
Case Reports
Israel Journal of Veterinary Medicine  Vol. 70 (2)  June 2015 Perl, S. 52
to metazoan migration tracts, with the presence of a number
of cestode larvae (9).
DISCUSSION
Hepatitis cysticercosa and pneumonitis cysticercosa are
caused by migrating Cysticercus tenuicollis, the intermediate
stage of Taenia hydatigena (1). Sheep, goats, cattle and pigs
are among the species that are considered as the intermediate
hosts in which larval migratory stages causes damage during
their migration through the liver and lungs (10).
Te adults cestode Taenia hydatigena inhabits the gas-
trointestinal tract of carnivores, the fnal host, and does not
usually cause clinical signs (7). Gravid segments are shed by
the adult tapeworms into the environment and their eggs
are immediately infective. Animals acquire infection from
ingestion of food or water contaminated with the sticky eggs,
ingesting of segments or feces containing eggs (10).
In the intermediate host, Cysticercus tenuicollis, migrates
into the peritoneal cavity. Laval cestodes migrate into the
liver and lung and may induce extensive damage if infection
is heavy. Upon the ingestion of the ova by the intermediate
host oncospheres are released and penetrate the wall of the
gut and are then distributed via the blood to virtually any site
in the body. Parasitic cysts continue to develop in the inter-
mediate host and the life cycle of the parasite is completed
when the cysts are ingested by the fnal host. Te liver of the
intermediate host is commonly afected through the fow of
portal blood containing helminth embryos which drains into
the liver before fowing to the systemic circulation.
Tese cases represent unusually severe infestations. In
both cases, neither the afected focks nor the herding dogs
were properly dewormed and several stray dogs roamed in the
vicinity of the farms. Tis situation is not considered unusual
in this district of second case, and therefore it was believed
that in addition to these predisposing factors, there was prob-
ably direct and intense contact and ingestion of infected dog
feces in the food of the afected lambs and kids.
Both liver and lung involvement are commonly observed
in the acute form of cysticercosis however a single case where
only hepatic involvement has been observed is described in
an outbreak from Iran (7).
Investigation of the incidents led to the possibility that
the main source of infestation in both cases was food borne
in the concentrated feed manufactured by a local dealer in
the frst case and in the hay in the second case, respectively.
Tis suspicion was reinforced by the fact that the outbreaks
occurred over a few weeks with a high rate of mortality. It
was proposed that the feed that the animals received, in both
cases, was infested with proglotids of the tapeworm Teania
hydatigena
Adult sheep and goats from both herds were not afected.
Te evidence for age-related diferences in infection preva-
lence and intensity is not clear. It has been found and docu-
mented that the prevalence of hydatidosis and cysticercosis
in sheep is signifcantly lower in sheep up to 1 year of age
compared to adult sheep (2, 11). Te authors suggested that
this may be associated with age and with the foraging activity
of sheep (12). In the frst case of the present study, the adult
animals were also pastured and therefore may have consumed
less infested concentrated food. In the second case, animals
were only fed in paddocks. A more pragmatic approach for
the infestation of the lambs in the frst case may have been
due to the feeding of a specifc bag of food which was highly
infested by proglotids from infested dogs from the premises
of the food distributor.
In summary, this report describes two outbreaks of
cysticercosis in herds of sheep and goats resulting in a
high mortality among lambs and kids. Both the liver and
lung were severely afected resulting in the death of the
animals. Investigation of the source of infestation placed
a strong suspicion on the concentrated food from a local
producer in the one case and contaminated hay in the
second case.
REFERENCES
1. Scala, A., Urrai, G., Varcasia, A., Nicolussi, P., Mulas, M., Goddi,
L., Pipia, A.P., Sanna, G., Genchi, M. and Bandino, E.: Acute
visceral cysticercosis by Taenia hydatigena in lambs and treatment
with praziquantel. J. Helminthol.: 1-4, 2014.
2. Christodoulopoulos, G., Teodoropoulos, G. and Petrakos, G.:
Epidemiological survey of cestode-larva disease in Greek sheep
focks. Vet. Parasitol. 153: 368-73, 2008.
3. Liversey, C.T., Herbert, I.V., Willis, J.M. and Evens, W.T.: Acute
cysticercosis in housed sheep. Vet. Rec. 109: 217, 1981.
4. Koutsoumpas, A., Psychas, V., Papadopoulos, E., Panousis, N.,
Karatzias, H. and Giadinis, N.D.: Acute visceral cysticercosis in
feed-lot lambs. Revue de Medicine Veterinaire. 164: 425-428,
2013.
5. Manfredi, M.T., Ghirardelli, R. and Zanzani, S.: [Cysticercus ten-
uicollis infection in a goat farm]. Parassitologia. 48: 433-6, 2006.
6. Yildirim, A., Ica, A., Beyaz, L. and Atasaver, A.: [Acute hepatitis
Case Reports
Israel Journal of Veterinary Medicine  Vol. 70 (2)  June 2015 53 Acute Cysticercosis Outbreaks
cysticercosa and pneumonitis cysticercosa in a lamb: case report].
Turkiye Parazitol Derg. 30: 108-11, 2006.
7. Nourani, H., Pirali Kheirabadi, K.H., Rajabi, H. and Banitalebi,
A.: An unusual migration of Taenia hydatigena larvae in a lamb.
Trop. Biomed. 27: 651-656, 2010.
8. Radfar, M.H., Tajalli, S. and Jalalzadeh, M.: Prevalence and
morphological characterization of Cysticercus tenuicollis (Taenia
hydatigena cussticerci) from sheep and goats in Iran. Veterinarski
Archiv. 75: 469-476, 2005.
9. Stalker, M.J. and Hayes, M.A.: Liver and Biliary System, in Jubb,
Kennedy and Palmer’s Pathology of Domestic Animals, M.G.
Maxie, Editor, Elsevier: Edinburgh. p. 357-358, 2007.
10. OIE. Cysticercosis, in OIE Terrestrial Manual, OIE. p. 1-12,
2014.
11. Sotiraki, S., Himonas, C. and Korkoliakou, P.: Hydatidosis-
echinococcosis in Greece. Acta Trop. 85: 197-201, 2003.
12. Ruckstuhl, K.E., Festa-Bianchet, M. and Jorgenson, J.T.: Bite rates
in Rocky Mountain bighorn shhep (Ovis canadensis): efects of
season, age, sex and reproductive status. Behav. Ecol. Sociobiol.
54: 167-173, 2003.
Case Reports

Published under a Creative Commons License By attribution, non-commercial