cystic echinococcosis in a domestic cat: an italian case ... · • dyspnea • apathy •...
TRANSCRIPT
Cystic echinococcosis in a domestic cat:
an Italian case report
OIE Reference Laboratory for Echinococcosis
Istituto Zooprofilattico Sperimentale (IZS) of Sardinia
National Reference Laboratory for Cistic Echinococcosis (CE)
13th NRL Workshop, Rome, 24-25 May, 2018
E. canadensis G6
camel strain
E. canadensis G7
pig strain
E. canadensis G8-G10
cervid strain
E. equinus G4
equid strain
E. ortleppi G5
cattle strain
E. granulosus s.s. G1-G3
sheep strain
E. felidis
lion strain
Cystic echinococcosis (CE) is a parasitic disease of global importance caused by the larval stage
of Echinococcus granulosus sensu lato (s.l.). Taxonomic classification is still controversial. E.
granulosus s.l. comprises different genotypes: genotypes G1-G3 (E. granulosus sensu stricto),
G4 (E. equinus), G5 (E. ortleppi), G6-G7, G8, G10 (E. canadensis) and E. felidis (“lion strain”).
E. canadensis G6
camel strain
E. canadensis G7
pig strain
E. canadensis G8-G10
cervid strain
E. equinus G4
equid strain
E. ortleppi G5
cattle strain
E. granulosus s.s. G1-G3
sheep strain
E. felidis
lion strain
Echinococcus granulosus s. l. life cycle is indirect and includes definitive and
intermediate hosts. The adult tapeworm resides in the small intestine of wild and
domestic carnivores. Intermediate hosts, usually ungulates, are infected by ingesting
eggs released in the feces of definitive hosts.
E. granulosus s.s. (G1-G3)
E. granulosus sensu stricto (s.s.), and in particularly
G1 genotype, is responsible for the vast majority of
human CE worldwide (ca. 90%),
G1 is mainly transmitted within a dog–sheep cycle
Accidentally, other animals,
including humans, could
ingest eggs and contract
cystic echinococcosis acting
as aberrant hosts.
E. granulosus s.s. G1
Sardinia is considered an hyperendemic area with the highest hospitalization incidence rates
of human CE (>6,5/105 inhabitants) in Italy
Prevalence in intermediate hosts
More than 3.300.000 sheep in Sardinia
Cystic echinococcosis in cat
Cystic echinococcosis in cats has already been reported in the past few years in South
America, New Zealand and Europe. Recently, cats infected with the larval form of E.
granulosus s.s. were found in Uruguay, Russia, and Turkey.
CLINICAL CASE REPORT
The cat was brought to a private veterinary clinic in Sassari
ANAMNESIS
• 3-years-old neutered female cat
• kept indoor with outdoor access
to suburban surroundings
• Abdominal distension
• Anorexia
• Reluctance to movement
PHYSICAL EXAMINATION
• Dyspnea
• Apathy
• Abdominal palpation
Pain Presence of multiple
rounded masses
Ultrasound imaging reported a voluminous splenic mass with a
multiloculated structure and multiple intraperitoneal vesicles of different
dimension characterized by anechoic content and delimited by a
hyperechoic rim. In hydatids of large dimensions, a bilaminated structure
of the wall appearing as a double echogenic line separated by a
hypoechogenic space was evidenced.
ULTRASOUND IMAGING
CE1
Unilocular cyst, evidence of the wall, considered active
EXPLORATORY LAPAROTOMY
Following general anesthesia (isoflurane in oxygen) and surgical field disinfection the
peritoneal cavity was entered by midline incision and the abdominal organs examined.
Numerous hydatids disseminated in the whole abdominal cavity were found either free
or attached to the omentum, presumably secondary hydatids as a result of the rupture of
the primary splenic cyst.
EXPLORATORY LAPAROTOMY
EXPLORATORY LAPAROTOMY
Peritoneal hydatids, from 5 to 50 mm in diameter, presented thin walls and contained
semitransparent liquid. Fertility of hydatids was determined by microscopical observation of
protoscolices confirming that the parasite can complete full development in cats.
EXPLORATORY LAPAROTOMY
Unfortunately, samples fixation hampered evaluation of their viability.
INTRAPERITONEAL HYDATIDS
Peritoneal hydatids showed the
presence of an outer periodic-
acid-Schiff (PAS) positive
acellular laminated layer with an
inner cellular nucleated germinal
layer regarded as a suggestive
pattern of metacestodes of
Echinococcus genus. Brood
capsules and protoscolices with
their characteristic hooks were
also detected
SPLENIC CYSTS
A distinct encapsuled cystic mass of
65 mm in diameter protruding at
one extremity of the spleen was also
observed. On the cut section it
appeared sponge-like for the
presence of multiloculated cysts
displaying analogous histological
characteristics to peritoneal hydatids
except for the presence of a host-
produced fibrous adventitial layer
surrounded by inflammatory cells.
Molecular identification of DNA
extracted from protoscoleces
was performed by amplification
and sequencing of a short
fragment of the mitochondrial
cytochrome c oxidase subunit1
(cox1) gene.
MOLECULAR ANALYSIS
Sequence alignment showed also that it was 100% identical to the common haplotype
previously reported as dominant in Europe and found to be the most common also in
the Mediterranean basin
CE should be suspected in cats with abdominal distension
and US evidence of multiple peritoneal vesicles especially
in hyperendemic areas and in association with
immunosuppressive diseases
Molecular findings suggest that no specific E. granulosus
haplotype is necessarily related to infection in domestic
cats confirming the host multitropism of E. granulosus G1
genotype
The report of a clinical case of CE in a domestic
cat points out the problems dealing with
environmental contamination in urban contexts
and the implied risk for public health
CONCLUSION
Thank you