theileriasis

Theileriasis: A Tick-Borne Disease

Theileriasis, also known as Theileriosis, is a group of tick-borne diseases caused by protozoan parasites of the genus Theileria. These parasites are transmitted to susceptible animals through the bite of infected ticks.

• Transmission: Theileriasis is primarily spread through the saliva of infected ticks, which attach to a host animal for an extended period (usually 48-72 hours) before becoming infective.
• Species Affected: Theileria species can infect a wide range of wild and domestic ruminants, including cattle, sheep, goats, and other Bovidae. Canine theileriosis is also a notable tick-borne disease affecting dogs.

Types of Theileriasis

Several species of Theileria are responsible for different forms of theileriasis:

• East Coast Fever: Caused by T. parva, this is one of the most severe forms, with mortality rates reaching 90-100% in Africa.
• Tropical Theileriosis: T. annulata causes a milder disease, primarily affecting cattle along the Mediterranean and Middle Eastern regions.

Economic Impact

Theileriasis poses significant economic challenges to the livestock industry worldwide, particularly in Europe, Africa, and Asia. The disease can lead to substantial losses due to mortality, reduced productivity, and decreased market value of infected animals.

• Mortality Rates: Up to 90% mortality has been reported for some species, highlighting the severity of this tick-borne disease.
• Production Losses: Infected animals may experience reduced milk production, weight loss, and decreased fertility, further exacerbating economic losses.

References

[1] Theileria is a genus of parasites closely related to Plasmodium. [2] T. annulata causes tropical theileriosis, while T. parva causes East Coast fever. [3] The genomes of T. orientalis Shintoku and Theileria equi WA have been studied. [4] Canine theileriosis is a notable tick-borne disease affecting dogs.

[5] Dolan 35 conducted a comprehensive review of theileriasis, highlighting its global distribution and impact on wild and domestic Bovidae.

Clinical Signs and Symptoms of Theileriasis

Theileriasis, also known as tropical theileriosis, is a tick-borne disease caused by protozoan parasites of the genus Theileria. The clinical signs and symptoms of theileriasis can vary depending on the species of Theileria involved, the age and immune status of the animal, and other factors.

Common Symptoms:

• Fever: A high fever is a common symptom of theileriasis, often accompanied by chills and sweating. [1][2]
• Lymph node swelling: Enlarged lymph nodes are a characteristic sign of theileriasis, particularly in the neck and shoulder region. [3][4]
• Anemia: Theileriasis can cause anemia due to the destruction of red blood cells by the parasite. [5][6]
• Weakness and lethargy: Infected animals may exhibit weakness, lethargy, and a lack of appetite. [7][8]
• Dyspnea: Difficulty breathing is a common symptom of theileriasis, particularly in severe cases. [9][10]
• Abortion: Pregnant females may experience abortion due to the infection. [11]

Other Clinical Signs:

• Lacrimation and corneal opacity
• Nasal discharge and terminal dyspnea
• Diarrhea and recumbency (lying down) before death

Incubation Period and Course of Disease:

The incubation period of theileriasis can range from 8 to 12 days, with a course of disease lasting for 10-19 days. The first sign is often an enlargement of lymph nodes draining the site of tick feeding, followed by fever and other symptoms.

References:

• [1] Search result 2
• [2] Search result 5
• [3] Search result 7
• [4] Search result 8
• [5] Search result 10
• [6] Search result 12
• [7] Search result 13
• [8] Search result 14
• [9] Search result 11
• [10] Search result 15