Lapis ISSN 2398-2969

Cryptosporidium spp

Contributor(s): David Vella, Ron Rees Davies, Lesa Thompson

Introduction

Classification

Taxonomy

  • Phylum: Apicocomplexa. 
  • Order: Eucoccidiorida.
  • Suborder: Eimeriorina. 
  • Family: Cryptosporidiidae. 
  • Genus:Cryptosporidium.
  • Species: uncertain. Some classifiers place rabbit isolates asC. cuniculibut most current workers regard most mammal isolates as strains ofC. parvum. Full genomes forC. parvumandC. hominishave been identified and classification may become better understood in the future.

Etymology

  • European rabbits are the natural hosts ofC. cuniculi.

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Clinical Effects

Epidemiology

Habitat

  • Oocysts are found in the feces of many animal species. 
  • Other stages are obligate parasites in the intestinal tract.

Lifecycle

  • Similar to that of other intestinal coccidia: 
    • Oocysts, each containing 4 sporozoites, are liberated in feces. 
    • Ingestion    →   sporozoites invade microvillous brush border of enterocytes.
    • Develop into trophozoites    →    differentiate    →    to become schizonts containing 4-8 merozoites. 
    • Gametogeny follows 1-2 generations of schizogeny. 
    • Oocysts are produced in 72 h.

Transmission

  • Oocysts by feco-oral route.
  • May be intensified by overcrowding or unsanitary conditions.

Pathological effects

  • Severity of disease is inversely proportional to immunocompetence of host.
  • Blunting and fusion of intestinal villi results in diarrhea.
  • Clinical disease is rare in rabbits   Cryptosporidiosis  . Transient diarrhea or emaciation may occur in neonates or young stresses individuals, often due to concominant bacterial or parasitic infections, but otherwise most cases are asymptomatic.

Other Host Effects

  • Subclinical infection is common.
  • Lethargy and/or weight loss may be seen in clinical cases.

Control

Control via animal

  • Optimize healthy immune system with good husbandry.

Control via chemotherapies

  • There is no known specific treatment.
  • Spiramycin may be of some value.

Control via environment

  • Regular cleaning to remove (infective) fecal material.
  • 5% ammonia solution or desiccation to kill oocysts.
  • Temperatures <0°C or >65°C destroy oocysts.

Other countermeasures

  • Reduce stocking density.

Diagnosis

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Nolan M J, Jex A R, Haydon S R et al (2010) Molecular detection of Cryptosporidium cuniculus in rabbits in Australia. Infect, Gen & Evo 10 (8), 1179-1187 PubMed.
  • Robinson G, Wright S, Elwin K et al (2010) Re-description of Cryptosporidium cuniculus (Apicomplexa: Cryptosporidiidae): Morphology, biology and phylogeny. Int J Parasitol 40 (13), 1539-1548 PubMed.
  • Shi K, Jian F, Lv C et al (2010) Prevalence, genetic characteristics, and zoonotic potential of Cryptosporidium species causing infections in farm rabbits in China. J Clin Microbiol 48 (9), 3263-3266 PubMed.
  • Xiao L (2010) Molecular epidemiology of cryptosporidiosis: an update. Exp Parasitol 124 (1), 80-89 PubMed.
  • Chalmers R M, Robinson G, Elwin K et al (2009) Cryptosporidium rabbit genotype, a newly identified human pathogen. Emerg Infect Dis 15 (5), 829-30 PubMed.
  • Robinson G, Elwin K, Chalmers R M et al (2008) Unusual Cryptosporidium genotypes in human cases of diarrhea. Emerg Infect Dis 14 (11), 1800-1802 PubMed.
  • Shiibashi T, Imai T, Sato Y et al (2006) Cryptosporidium infection in juvenile pet rabbits. J Vet Med Sci 68 (3), 281-282 PubMed.
  • Mosier D A, Cimon K Y, Kuhls T L et al (1997) Experimental cryptosporidiosis in adult and neonatal rabbits. Vet Parasitol 69 (3-4), 163-169 PubMed.
  • Dubey J P (1993) Intestinal protozoal infections. Vet Clin North Ame - Small Anim Pract 23 (1), 37-55 PubMed
  • Moore J A, Blagburn B L, Lindsay D S et al (1988) Cryptosporidiosis in animals, including humans. Comp Contin Educ Pract Vet 10 (3), 275-87 VetMedResource
  • Moon H W & Woodmansee DB (1986) Cryptosporidiosis. JAVMA 189 (6), 643-6 PubMed
  • Ryan M J, Sunberg J P, Sauerschell R J et al (1986) Cryptosporidium in a wild cottontail rabbit (Sylvilagus floridanus). J Wildlife Dis 22 (2), 267 PubMed.
  • Inman L R & Takeuchi A (1979) Spontaneous cryptosporidiosis in an adult female rabbit. Vet Pathol 16 (1), 89-95 PubMed.
  • Rehg J E, Lawton G W, Pakes S P (1979) Cryptosporidium cuniculus in the rabbit (Oryctolagus cuniculus). Lab Anim Sci 29 (5), 656-660 PubMed.

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