Felis ISSN 2398-2950

Encephalitozoonosis

Synonym(s): E. cuniculi, Nosema cuniculi

Contributor(s): Vetstream Ltd, Diane Addie

Introduction

  • CauseEncephalitozoon cuniculi is thought to be a significant cause of neurological signs and renal failure in pet, meat, and laboratory rabbits (Oryctolagus cuniculus),  and an important cause of cataracts and lens-induced uveitis in the rabbit. The incidence in pet rabbits is so far unknown.
  • E. cuniculi is also a cause of uveitis and cataract in cats.
  • It is not known if infection with E. cuniculi alone is sufficient to cause disease, however it is undoubtedly able to cause disease in immunocompromised individuals.
  • Signs: uveitis, cataract, neurological problems, urinary incontinence.
  • Diagnosis: PCR, ELISA, serum protein electrophoresis, biopsy, histopathology and immunohistochemistry for spore detection.
  • Treatment: fenbendazole.
  • Prognosis: moderate for cats provided they can be treated; poor for neurologically affected rabbits.

Pathogenesis

Etiology

  • E. cuniculi (previously known as Nosema cuniculi) is an obligate intracellular microsporidian parasite.

Pathophysiology

  • Central nervous system lesions produce signs related to focal non-suppurative granulomatous meningoencephalomyelitis and perivascular lymphocytic infiltration.
  • Ocular lesions appear to arise from protozoan spores deposited in the developing lens after vertical transmission in utero which, during the rabbit's life, erupt within and from the lens giving cataract and/or lens-induced uveitis from lens rupture.
  • Transmission is by oral consumption of urine infected with spores from the renal lesions caused by the organism in rabbits. Carnivores are infected by consumption of milk containing spores, and infected meat from rabbits, goats, horses, pigs, wild birds, etc.
  • Anecdotal reports of associated renal failure in rabbits have been made.
  • Inhalation of spores and transplacental infection is also thought to be possible.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Addie D D, Tasker S, Boucraut-Baralon C, Belák S, Egberink H, Frymus T, Hartmann K, Hofmann-Lehmann R, Marsilio F,  Lloret A, Lutz H, MG, Thiry E, Truyen U, Hosie MJ, Möstl K. (2020) Encephalitozoon cuniculi in cats. ABCD guidelines on prevention and management.  J Feline Med Surg In press.
  • Sak B, Vecková T, Brdíčková K, Smetana P, Hlásková L, Kicia M, Holubová N, McEvoy J, Kváč M (2019) Experimental Encephalitozoon cuniculi Infection Acquired from Fermented Meat Products. Foodborne Pathog Dis 16(6), 394-398 PubMed.
  • Maestrini G, Ricci E, Cantile C, Mannella R, Mancianti F, Paci G, D'Ascenzi C, Perrucci S. (2017) Encephalitozoon cuniculi in rabbits: Serological screening and histopathological findings. Comp Immunol Microbiol Infect Dis 50, 54-57 PubMed.
  • Kváč M, Tomanová V, Samková E, Koubová J, Kotková M, Hlásková L, McEvoy J, Sak B (2016) Encephalitozoon cuniculi in Raw Cow's Milk Remains Infectious After Pasteurization. Foodborne Pathog Dis 13(2), 777-779 PubMed.
  • Askari Z, Mirjalali H, Mohebali M, Zarei Z, Shojaei S, Rezaeian T, Rezaeian M (2015) Molecular Detection and Identification of Zoonotic Microsporidia Spore in Fecal Samples of Some Animals with Close-Contact to Human. Iran J Parasitol 10(3), 381-388 PubMed.
  • Hein J, Flock U, Sauter-Louis C et al (2014) Encephalitozoon cuniculi in rabbits in Germany: prevalence and sensitivity of antibody testing. Vet Rec 174 (14), 350 PubMed.
  • Neumayerová H, Juránková J, Jeklová E, Kudláčková H, Faldyna M, Kovařčík K, Jánová E, Koudela B (2014) Seroprevalence of Toxoplasma gondii and Encephalitozoon cuniculi in rabbits from different farming systems. Vet Parasitol 204(3-4), 184-190 PubMed.
  • Varga M (2014) Questions around Encephalitozoon cuniculi in rabbits. Vet Rec 174 (14), 347-348 PubMed.
  • Leipig M,  Matiasek K, Rinder H, Janik D, Emrich D, Baiker K, Hermanns W (2013) Value of histopathology, immunohistochemistry, and real-time polymerase chain reaction in the confirmatory diagnosis of Encephalitozoon cuniculi infection in rabbits. J Veterinary Diagnostic Investigation 25(1), 16-26 PubMed.
  • Lonardi C, Grilli G, Ferrazzi V, Dal Cin M, Rigolin D, Piccirillo A (2013) Serological survey of Encephalitozoon cuniculi infection in commercially reared rabbit does in Northern Italy. Res Vet Sci 94(2), 295-298 PubMed.
  • Lallo M A, Calábria P, Milanelo L (2012) Encephalitozoon and Enterocytozoon (Microsporidia) spores in stool from pigeons and exotic birds: microsporidia spores in birds. Vet Parasitol 190 (3-4), 418-422 PubMed.
  • Richardson V (2012) Urogenital diseases in rabbits. In Pract 34 (10), 554-563 VetMedResource.
  • Rebel-Bauder B, Leschnik M, Maderner A, Url A (2011) Generalized encephalitozoonosis in a young kitten with cerebellar hypoplasia. J Comp Pathol 145(2-3), 126-131 PubMed.
  • Benz P, Maass G, Csokai J, Fuchs-Baumgartinger A, Schwendenwein I, Tichy A, Nell B (2011) Detection of Encephalitozoon cuniculi in the feline cataractous lens. Vet Ophthalmol 14 Suppl 1, 37-47 PubMed.
  • Keeble E (2011) Companion animal practice: Encephalitozoonosis in rabbits - what we do and don't know. In Pract 33 (9), 428-435 VetMedResource.
  • Wright I (2011) Encephalitozoon cuniculi: Infecting the rabbit next door. UK Vet: Companion Animal 16, 49-50 VetMedResource
  • Jass A, Matiasek K, Henke J et al (2008) Analysis of cerebrospinal fluid in healthy rabbits and rabbits with clinically suspected encephalitozoonosis. Vet Rec 162 (19), 618-622 PubMed.
  • Keeble E (2006) Common neurological and musculoskeletal problems in rabbits. In Pract 28 (4), 212-218 VetMedResource.
  • Colitz C M (2005) Feline uveitis: diagnosis and treatment. Clin Tech Small Anim Pract (2), 117-120 PubMed.
  • Harcourt-Brown F M & Holloway H K (2003) Encephalitozoon cuniculi in pet rabbits. Vet Rec 152 (14), 427-431 PubMed.
  • Smith M M, Smith E M, La Croix N, Mould J (2003) Orbital penetration associated with tooth extraction. J Vet Dent 20(1), 8-17 PubMed
  • Suter C, Müller-Doblies U U, Hatt J M et al (2001) Prevention and treatment of Encephalitozoon cuniculi infection in rabbits with fenbendazole. Vet Rec 148 (15), 478-480 PubMed.
  • Boot R, Hansen A K, Hansen C K et al (2000) Comparison of assays for antibodies to Encephalitozoon cuniculi in rabbits. Lab Anim 34 (3), 281-289 PubMed.
  • Levkut M, Horváth M, Bálent P et al (1997) Catecholamines and encephalitozoonosis in rabbits. Vet Parasitol 73 (1-2), 173-176 PubMed.
  • Stiles J, Didier E, Ritchie B et al (1997) Encephalitozoon cuniculi in the lens of a rabbit with phacoclastic uveitis - confirmation and treatment. Vet Comp Ophthalmol (4), 233-238 VetMedResource.
  • Thomas C, Finn M, Twigg L et al (1997) Microsporidia (Encephalitozoon cuniculi) in wild rabbits in Australia. Austr Vet J 75 (11), 808-810 PubMed.
  • Feaga W P (1997) Wry neck in rabbits. JAVMA 210 (4), 480 PubMed.
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  • Greenstein G, Drozdowicz C K, Garcia F G et al (1991) The incidence of Encephalitozoon cuniculi in a commercial barrier-maintained rabbit breeding colony. Lab Anim 25 (4), 287-290 PubMed.
  • Kunstyr I & Naumann S (1985) Head tilt in rabbits caused by pasteurellosis and encephalitozoonosis. Lab Anim 19 (3), 208-213 PubMed.
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