13th NRL Workshop, Rome, 24-25 May, 2018 Cystic echinococcosis in a domestic cat: an Italian case report Istituto Zooprofilattico Sperimentale (IZS) of Sardinia National Reference Laboratory for Cistic Echinococcosis(CE) OIE Reference Laboratory for Echinococcosis
sheep strain equid strain cattle strain E. granulosus s.s. G1-G3 E. equinus G4 E. ortleppi G5 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 ). camel strain pig strain cervid strain lion strain E. canadensis G6 E. canadensis G7 E. canadensis G8-G10 E. felidis
sheep strain equid strain cattle strain E. granulosus s.s. G1-G3 E. equinus G4 E. ortleppi G5 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. camel strain pig strain cervid strain lion strain E. canadensis G6 E. canadensis G7 E. canadensis G8-G10 E. felidis
Accidentally, other animals, including humans, could ingest eggs and contract cystic echinococcosis acting as aberrant hosts. E. granulosus s.s. (G1-G3) E. granulosus s.s. G1 E. granulosussensustricto(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
Sardinia is considered an hyperendemic area with the highest hospitalization incidence rates of human CE (>6,5/10 5 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 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.
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.
EXPLORATORY LAPAROTOMY 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 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 periodicacid-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 hostproduced fibrous adventitial layer surrounded by inflammatory cells.
MOLECULAR ANALYSIS 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. 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
CONCLUSION 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
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