Anaplasmosis

Anaplasmosis
Anaplasma centrale infecting the red blood cells of a cow. The arrow points to typical infected cell.
Classification and external resources
MeSH D000712

Anaplasmosis is a disease caused by a rickettsial parasite of ruminants, Anaplasma spp. The microorganism is gram-negative,[1] and infects red blood cells.[2] It is transmitted by natural means through a number of haematophagous species of ticks. Anaplasmosis can also be transmitted by the use of surgical, dehorning, castration, and tattoo instruments and hypodermic needles that are not disinfected between uses.

Causes

Several species of rickettsia bacteria cause anaplasmosis in ruminants:

Signs and symptoms

Anaemia may be severe and result in cardiovascular changes such as an increase in heart rate. Blood in the urine may occur due to the lysis of red blood cells. General systemic signs such as diarrhea, anorexia and weight loss may also be present. A blood smear stained with Giemsa should be observed for identification of infected red blood cells and will allow definitive diagnosis.[4]

Prevention

Vaccines against anaplasmosis are available. Carrier animals should be eliminated from flocks. Tick control may also be useful although it can be difficult to implement.[4]

Treatment

Treatment usually involves a prescription of doxycycline (a normal dose would be 100 mg every 12 hours for adults) or a similar class of antibiotics. Oxytetracycline and imidocarb have also been shown to be effective. Supportive therapy such as blood products and fluids may be necessary.[4]

Epidemiology

In the United States, anaplasmosis is notably present in the south and west where the tick hosts Ixodes spp. are found. It is also a seemingly increasing antibody in humans in Europe.[1] Although vaccines have been developed, none are currently available in the United States. Early in the 20th century, this disease was considered one of major economic consequence in the western United States. In the 1980s and 1990s, control of ticks through new acaricides and practical treatment with prolonged-action antibiotics, notably tetracycline, has led to the point where the disease is no longer considered a major problem.

In 2005, Anaplasma ovis was found in reindeer populations in Mongolia.[5] This pathogen and its associated syndrome (characterized by lethargy, fever and pale mucous membranes) was previously only observed in wild sheep and goats in the region, and is the first observed event of A. ovis in reindeer.

In Australia, bovine anaplasmosis, caused by Anaplasma marginale, is only found in the northern and eastern parts of Australia where the cattle tick is present. It was probably introduced as early as 1829 by cattle from Indonesia infested with the cattle tick Boophilus microplus.[6]

The veterinarian George P. Broussard of New Iberia, Louisiana, conducted important research anaplasmosis and brucellosis.[7]

References

  1. 1 2 Hartelt, Kathrin; Oehme, Rainer; Frank, Henning; Brockmann, Stefan O.; Hassler, Dieter; Kimmig, Peter (2004-04-01). "Pathogens and symbionts in ticks: prevalence of Anaplasma phagocytophilum (Ehrlichia sp.), Wolbachia sp., Rickettsia sp., and Babesia sp. in Southern Germany". International Journal of Medical Microbiology Supplements. Proceedings of the VII International Potsdam Symposium on Tick-Borne Diseases. 293, Supplement 37: 86–92. doi:10.1016/S1433-1128(04)80013-5.
  2. ↑ Capucille, DJ (2011). "Anaplasmosis". In Haskell, SRR. Blackwell's Five-Minute Veterinary Consult Ruminant. Hoboken: John Wiley & Sons. pp. 50–51. ISBN 9780470961186.
  3. 1 2 3 Boes, KM; Durham, AC (2017). "Anaplasmosis, Ehrlichiosis, Heartwater and Tick-Borne Fever". In Zachary, JF. Pathologic Basis of Veterinary Disease (6th ed.). Elsevier Health Sciences. pp. 749–50. ISBN 9780323357975.
  4. 1 2 3 Anaplasmosis reviewed and published by WikiVet, accessed 10 October 2011.
  5. ↑ Haigh J, Gerwing V, Erdenebaatar J, Hill J. 2008. A novel clinical syndrome and detection of Anaplasma ovis in Mongolian reindeer (Rangifer tarandus). J Wildlife Dis 44(3): 569–577.
  6. ↑ "Bovine anaplasmosis". Tick fever. Department of Agriculture, Fisheries and Forestry, Queensland Government. Retrieved 14 June 2012.
  7. ↑ "George Patout Broussard", A Dictionary of Louisiana Biography, Vol. 1 (1988), Louisiana Historical Association publication, p. 114.
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