bovis - Articles
Besnoitiosis
Synonym(s): sarcocystidae, sporozoan, besnoitia
Introduction
- Besnoitosis is caused by the protozoal parasite Besnoitia besnoitia, closely related to Neospora caninum and Toxoplasma gondii.
- Historically its distribution was confined to Sub-Saharan Africa, Asia, the Middle East and South West Europe. However, since 2010 it has been classified as an emerging disease by the European Food Safety Authority, (EFSA), following disease incursions into Western Europe.
Geographic incidence
- Historically cases have been confined to Africa, Asia, the Middle East and South West Europe.
- Since 2010, it has been classified as an emerging disease by the European Food Safety Authority (EFSA) due to incursions into Western Europe.
Age predisposition
- Cases predominantly occur in adult animals aged 18 months to 6 years.
- Clinical disease is uncommon in young animals, possibly due to maternally acquired antibodies.
Breed/Species predisposition
- All cattle are susceptible, although higher disease prevalence has been reported in beef animals.
Public health considerations
- None.
Cost considerations
- The main cost of disease is attributed to reduced animal performance to include reduced milk and meat production, weight loss, possible permanent infertility in bulls and hide damage.
Pathogenesis
Etiology
- Besnoitosis is caused by the protozoal parasite Besnoitia, closely related to Neospora caninum Neospora caninum and Toxoplasma gondii Toxoplasma gondii.
- The definitive host remains unknown, although domestic and wild cats and rodents, have been implicated.
- Cattle, wild bovids and red deer, serve as intermediate hosts.
- Both direct and indirect horizontal transmission routes are involved in the pathogenesis of disease with a seasonal incidence of disease from spring to autumn, typical of insect borne disease.
Predisposing factors
General
- Movement of infected cattle or infected wildlife into a naïve population.
Specific
- Subclinically infected, or carrier state cattle serve as a reservoir of infection for blood sucking arthropods.
- Presence of appropriate climatic conditions to support the presence of arthropod vectors.
Pathophysiology
- A cell mediated immune response is likely to play a major role because a T cell response has been observed around several tissue cysts.
- To what extent the humoral immune response might reflect protection status requires further research.
- Clinical cases rarely occur in calves under 6 months of age, the most feasible, but yet to be clarified reason being the presence of protective maternal antibodies.
- Fast multiplying tachcyzoites are present in the blood in the acute phase and slowly multiplying bradyzoites in tissue cysts which may serve as a source of infection to in contact, naive animals.
Timecourse
- The incubation period is between 1-13 days.
- The initial post infection pyrexia and edema may last 4-5 weeks post infection, whilst tissue cysts and hyperkeratinization persisting for several weeks post infection.
Epidemiology
- Once infected, it is thought individuals remain infected for life although they will be immune to further disease outbreaks.
- Infected animals serve as a reservoir of infection for naïve individuals.
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.
- Gutiérrez-Expósito D, Arnal M C, Martínez-Durán D et al (2016) The role of wild ruminants as reservoirs of Besnoitia besnoiti infection in cattle. Vet Parasitol 223, 7-13 PubMed.
- Álvarez-García G, Fernández-García A, Gutiérrez-Expósito D, Ruiz-Santa Quinteria J A, Aguado-Martínez A & Ortega-Mora L M (2014) Seroprevalence of Besnoitia besnoiti infection and associated risk-factors in cattle from an endemic region in Western Europe (Navarra, Spain). Vet J 200, 328–331 PubMed.
- Frey C F, Gutiérrez-Expósito D, Ortega-Mora L M, Benavides J, Marcén J M, Castillo J A, Casasúse I, Sanz E, García-Lunar P, Esteban-Gil A, Álvarez-Garcia G (2013) Chronic bovine besnoitiosis: Intra-organ parasite distribution, parasite loads and parasite-associated lesions in subclinical cases. Vet Parasitol 197, 95-103 PubMed.
- Milnes A, Mitchell S, Bell S (2012) Emerging skin diseases in cattle. In Pract, 588-597.
- Jacquiet P, Lienard E, Franc M (2010) Bovine besnoitiosis: Epidemiological and clinical aspects. Vet Parasitol 174, 30-36 PubMed.
Other sources of information
- European Food Safety Agency (2010) http://www.efsa.europa.eu accessed 03/04/2016.