Anaplasmosis
| Anaplasmosis | |
|---|---|
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| Anaplasma centrale infecting the red blood cells of a cow: The arrow points to typical infected cell. | |
| Specialty | Veterinary medicine |
Anaplasmosis is a disease caused by a rickettsial parasite of ruminants, Anaplasma spp and is therefore related to rickettsial disease.[1] The microorganisms are Gram-negative,[2] and infect red blood cells.[3] They are transmitted by natural means through a number of haematophagous species of ticks. The Ixodes tick that commonly transmits Lyme disease also spreads anaplasmosis.
Transmission
Anaplasmosis is known as a tick-borne disease because tick bites can transmit various species of Anaplasma bacteria. The most common Anaplasmosis-causing tick is Ixodes scapularis, also known as the black-legged tick or the deer tick.[4][5] It carries Anaplasma phagocytophilum. Anaplasmosis can also be contracted from biting flies. Once infected with Anaplasma, cattle will continue to carry the bacterium.[6]
Anaplasmosis can also be contracted from blood transfusions, as well as using surgical, dehorning, castration, and tattoo instruments and hypodermic needles that are not disinfected between uses.[4]
Signs and symptoms
Classic signs and symptoms of anaplasmosis include fever, a decreased number of white blood cells, platelets in the bloodstream, and abnormally elevated levels of liver enzymes. The erythema chronicum migrans rash may be seen with anaplasmosis as it is co-transmitted in 10% of Lyme disease cases.
Anemia 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. Paleness around the eyes, muzzle, lips, and teats of the cattle may also be exhibited. [7]
All cattle are susceptible to infection by Anaplasma marginale, but the severity worsens with age increase. Older cattle tend to exhibit the most severe clinical symptoms, which cattle aged 1-3 may also show severe symptoms but are able to recover easier. [7]
Causes
The two major species that cause anaplasmosis in ruminants include Anaplasma marginale and Anaplasma phagocytophilum. Anaplasma marginale is found worldwide and is transmitted by Rhipicephalus ticks. Anaplasma phagocytophilum is also found worldwide, mainly transmitted by Ixodes ticks.[8] Other species that cause anaplasmosis in specific species include:
- Cattle:
- Anaplasma centrale - found mainly in South America, Africa and the Middle East[9]
- Sheep and goats:
- Anaplasma ovis - found worldwide[9]. There is a prevalence of 82.9% in sheep, and 74.9% in goats. This species is the most prevalent for causing anaplasmosis in sheep and goats, although Anaplasma phagocytophilium can also cause the disease. Anaplasma phagocytophilium has a prevalence of 11.9% in sheep, and 15.2% in goats.[10]
Morphology
There are many strains of Anaplasma marginale, all with differing morphology, antigenic properties, protein sequence, and ability to be transmitted by ticks. Major surface proteins (MSP) have been found to play a major role in the infection by Anaplasma marginale. Out of the six MSP found on this species, three of the major surface proteins do not seem to differ between all strains, those including MSP1a, MSP4, and MSP5. msp1a gene, which codes for MSP1a is used as a marker for the identification of Anaplasma marginale because it has shown to be conserved in the multiplication of rickettsia in cattle and ticks and has been shown to be involved in adhesion of to bovine erythrocytes and tick cells.[6]
Anaplasma phagocytophilum is a gram-negative bacterium that does not have lipopolysaccharides or peptidoglycan. The outer membrane does not have a capsule, and is coarse with irregular periplasmic spaces. This species was originally included in the genus Ehrlichia (Ehrlichia phagocytophilium), but is now included in the genus Anaplasma (Anaplasma phagocytophilium).[8]
Prevention
There are currently no live or killed vaccines approved by the USDA that is effective against all strains of A. marginale. There are vaccines that rely on erythrocyte-derived antigen sources to provide immunity or prevent clinical disease, although these do not prevent cattle from being infected with A. marginale. Other means of prevention can include testing all ruminants in a herd and eliminate any individuals who test positive for anaplasmosis, leading to an anaplasmosis-free herd. There are also means of vector control that can be used. Tick control is widely used in some countries, including Africa, but rarely used in the United States due to the fact that this prevention method is labor-intensive and expensive. In contrast, the control of flies is effective and there are many ways to do this. Chemical agents can be used, sanitation methods (such as cleaning stalls/pens regularly, manure management, and protecting feed), as well as biological control by natural enemies of flies (including bees, mites, parasitoids). There are also ways to prevent iatrogenic transmission, by avoiding re-using of needles, and sanitizing medical equipment between uses. Antimicrobial treatment can also be used, although it is more commonly used in the case of active infection. This includes the drugs tetracycline and imidocarb, and is used in healthy ruminants to decrease the clinical effects of an active infection.[6]
Treatment
The most common source of treatment is the use of tetracycline drugs (including tetracycline, chlortetracycline, oxytetracycline, rolitetracycline, doxycycline, and minocycline) and imidocarb. An injection of tetracycline drugs can give ruminants immunity to Anaplasma species for at least eight months. Imidocarb has been shown to be highly effective against Anaplasma marginale, but has been identified as a possible carcinogen and is not approved in the United States or Europe. Countries such as South Africa, Australia, Israel, and South America have used live vaccines containing infectious Anaplasma centrale to prevent infection of Anaplasma marginale. Live vaccines are prohibited in the United States, and there has been production of vaccines consisting of nonliving Anaplasma marginale pulled from infected bovine erythrocytes, which can provide some immunity but leaves cattle susceptible to other strains of Anaplasma marginale.[11] Supportive therapy such as blood products and fluids may be necessary.[12]
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.[2] 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. The disease affects immunoglobulin G, therefore G-specific antibody levels can be used to diagnose the disease.[13]
In 2005, A. ovis was found in reindeer populations in Mongolia.[14] This pathogen and its associated syndrome (characterized by lethargy, fever, and pale mucous membranes) was previously observed in only wild sheep and goats in the region, and is the first observed occurrence of A. ovis in reindeer.
In Australia, bovine anaplasmosis, caused by A. marginale, is found in only 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.[15]
The veterinarian George P. Broussard of New Iberia, Louisiana, conducted important research on anaplasmosis and brucellosis.[16]
References
- ^ "Ehrlichiosis and Anaplasmosis - Infectious Diseases". Merck Manuals Professional Edition. Retrieved 2019-04-02.
- ^ a b 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.
- ^ Capucille, DJ (2011). "Anaplasmosis". In Haskell, SRR (ed.). Blackwell's Five-Minute Veterinary Consult Ruminant. Hoboken: John Wiley & Sons. pp. 50–51. ISBN 9780470961186.
- ^ a b "Transmission | Anaplasmosis | CDC". www.cdc.gov. 2019-01-11. Retrieved 2019-04-02.
- ^ "Anaplasmosis | ALDF". www.aldf.com. Retrieved 2019-04-02.
- ^ a b c Aubry, P.; Geale, D. W. (2011). "A Review of Bovine Anaplasmosis". Transboundary and Emerging Diseases. 58 (1): 1–30. doi:10.1111/j.1865-1682.2010.01173.x. ISSN 1865-1682.
- ^ a b "Keep a watchful eye out for anaplasmosis in cattle herds — Division of Agricultural Sciences and Natural Resources". www.dasnr.okstate.edu. Retrieved 2021-11-16.
- ^ a b Atif, Farhan Ahmad (2015-11-01). "Anaplasma marginale and Anaplasma phagocytophilum: Rickettsiales pathogens of veterinary and public health significance". Parasitology Research. 114 (11): 3941–3957. doi:10.1007/s00436-015-4698-2. ISSN 1432-1955.
- ^ a b Boes, KM; Durham, AC (2017). "Anaplasmosis, Ehrlichiosis, Heartwater and Tick-Borne Fever". In Zachary, JF (ed.). Pathologic Basis of Veterinary Disease (6th ed.). Elsevier Health Sciences. pp. 749–50. ISBN 9780323357975.
- ^ Alessandra, Torina; Santo, Caracappa (2012-08-01). "Tick-borne diseases in sheep and goats: Clinical and diagnostic aspects". Small Ruminant Research. Supplement: SIPAOC Congress 2010. 106: S6 – S11. doi:10.1016/j.smallrumres.2012.04.026. ISSN 0921-4488.
- ^ "Anaplasmosis - Circulatory System". Merck Veterinary Manual. Retrieved 2021-11-14.
- ^ Anaplasmosis reviewed and published by WikiVet, accessed 10 October 2011.
- ^ Srivastava, Siddhartha; Evans, Gerald; Guan, T. Hugh; Edginton, Stefan (2018-03-26). "Human granulocytic anaplasmosis acquired from a blacklegged tick in Ontario". CMAJ. 190 (12): E363 – E366. doi:10.1503/cmaj.171243. ISSN 0820-3946. PMC 5871440. PMID 29581163.
- ^ Haigh, Jerry C.; Gerwing, Victoria; Erdenebaatar, Janchivdorj; Hill, Janet E. (July 2008). "A novel clinical syndrome and detection of A. ovis in Mongolian reindeer (Rangifer tarandus)". Journal of Wildlife Diseases. 44 (3): 569–577. doi:10.7589/0090-3558-44.3.569. PMID 18689641.
- ^ "Bovine anaplasmosis". Tick fever. Department of Agriculture, Fisheries and Forestry, Queensland Government. Retrieved 14 June 2012.
- ^ "George Patout Broussard", A Dictionary of Louisiana Biography, Vol. 1 (1988), Louisiana Historical Association publication, p. 114.