الرحيم الرحمن الله بسم

University of Bahri

College of Veterinary Medicine

Department of Veterinary Internal Medicine

Presentation About:

Theileriosis

Theileriosis

Theileriosis are those tick-borne protozoan

diseases associated with Theileria spp.

In Sudan, most cases of Bovine theileriosis

are caused by Th. annulata (tropical or

Mediterranean theileriosis) and Th. mutans

(benign theileriosis), and Th. parva (ECF)

may exist in Southern Sudan.

Theileriosis of sheep and goat are caused by

Th. hirci (Th. lestoquardi - Malignant ovine

theileriosis) and Th. ovis (mild theileriosis).

Equine theileriosis are caused by Th. equi.

Transmission: Stage to stage

(Transtadial Transmission).

Vector

Rhipicephalus Spp. Hyalomma Spp.

Life Cycle

4) Lymphocyte lymphoblast (enlarged lymphocyte) and…

3) Sporozoite enters lymphocyte (WBC) schizont

6) 10-15 days post-infection, schizont merozoite (invades erythrocyte (RBC))

1) Sporozoites produced in tick salivary glands

2) Sporozoites transfer to ungulate if tick is attached for 48-72 hrs

5) …divides with schizont inside 2 infected daughter cells

7) In RBC, merozoite piroplasm (infect ticks)

8) RBCs ingested by nymphs during feeding

Incubation PeriodExperimentally Infected: 8-12 daysNaturally Infected: up to 3 weeks

9) Once in gut, undergoes sexual reproduction motile stage, moves to tick’s salivary gland

* 5-8 days post-infection: found in lymph nodes* Schizonts increase 10-fold every 3 days

Pathogenesis Tick inoculation of sporozoites lymphocytes

in local lymph node schizonts lymphoid

proliferation merozoites erythrocytes

piroplasms ticks.

Damage mainly by schizonts.

Clinical Pictures Swelling of the draining lymph node, usually

the parotid.

Generalized lymphadenopathy.

Fever 40 – 41o C

Poor condition and severe lymphadenopathy in

heifer

Lacrimation and corneal opacity

Dyspnea

Diarrhoea

Recumbency

Death usually within three weeks of infection

In case of Equine theileriosis there is fever,

anaemia, jaundice and haemoglobinuria.

Jaundice in a horse’s eye

Occasional cases of brain involvement

occur and are characterized by circling,

hence 'turning sickness' or cerebral

theileriosis due to the presence of schizont

in the cerebral capillaries.

At necropsy Splenic enlargement.

Severe pulmonary emphysema and edema along

with hydrothorax and hydropericardium.

Generalized lymphoid hyperplasia.

Small lymphoid nodules (the so-called pseudo-

infarcts) are present in liver, kidney, and

alimentary track.

The carcass is emaciated and hemorrhages are

evident in a variety of tissues and organs.

The Ln. is enlarged and diffusely pale, and contains numerous petechiae.

Pulmonary emphysema and edema

Multiple pale foci on the

cortical surface of the kidney

are lymphoid infiltrates.

Emaciated Carcass Kidney, There are multiple petechiae on the surface of the cortex. The lymph node near the hilus is markedly enlarged

Hydropericardium

Diagnosis East Coast Fever only occurs where R.

appendiculatus is present, although

occasionally outbreaks such areas have

been recorded due to the introduction of

tick-infected cattle from an enzootic area.

Test Don’t Guess!!!

Without laboratories Men

of Science are Soldiers

without Armies

In sick animals, macroschizonts are

readily detected in biopsy smears of

lymph nodes and in dead animals in

impression smears of lymph nodes and

spleen.

There are two types of schizonts (Koch’s Blue

Bodies)

• Macroschizont: one with large chromatin

granules gives (8-16 macromerozoites).

• Microschizont: one with small chromatin granules

gives (50-120 Micromerozoites) (Sexually

differentiated) and infect RBCs.

In the field, diagnosis is usually achieved by finding Theileria parasites in Giemsa-stained blood smears and lymph node needle biopsy smears

Theileria Piroplasmosis

Lymphoblasts containing Theileria parasites

The indirect fluorescent antibody test is

of value in detecting cattle which have

recovered from ECF.

Differential diagnosis1. Heartwater because of pulmonary edema and

hydrothorax. Examination of brain smears and lymph

node or spleen impression smears can differentiate

between the two diseases.

2. Trypanosomiasis because of edema, lymphadenopathy,

and anemia. Blood and lymph node smear examination

will normally differentiate between the two diseases.

3. Babesiosis and anaplasmosis because of anemia.

These diseases can easily be differentiated from

theileriosis on examination of blood smears.

4. Malignant catarrhal fever because of

lymphadenopathy and corneal opacity. Examination of

blood and lymph node smears will clearly differentiate

between the two diseases.

Treatment

Tetracyclines have a therapeutic effect

if given at the time of infection but they

are of no value in the treatment of

clinical cases.

Parvaquone and Buparvaquone

Are Drugs of choice

in treating the clinical cases.

Control Integrated approach involving resistant

animal breeds.

Vaccination by infection-and-treatment

methods.

Strategic application

of acaricides.

Dipping

Recommended actions if theileriosis is

suspected

• Notification of authorities

Theileria species including Th. annulata

have been reported in Sudan; however, Th.

parva, is exotic. East Coast fever and

diseases caused by other exotic Theileria

spp. must be reported to state or federal

authorities immediately upon diagnosis or

suspicion of the disease.

References:-1) Books:

1. Roger W. Blowey and A. David Weaver. Color atlas of diseases and disorders of cattle,

3rded. PP. 234.

2. O. M. Radostits, C. C. Gay, K. W. Hinchcliff, P. D. Constable. VETERINARY

MEDICINE A textbook of the diseases of cattle, horses, sheep, pigs and goats, 10th ed.

PP. 1526 – 1531.

3. G.M.URQUHART, J. ARMOUR, J.L.DUNCAN, A.M.DUNN, F.W.JENNINGS:

Veterinary parasitology. 2nd ed. PP. 246 – 249. Blackwell Science,1996.

2) Online references

1. http://www.cfsph.iastate.edu/DiseaseInfo/clinical-signs-photos.php?name=

theileriosis

2. http://www.vetnext.com/search.php?s=aandoening&id=73289151820%20

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Prepared by:Ahmed Abdulkadir Hassan