Introduction Life Cycle Pathogenesis Diagnosis Control Questions

Theileriosis

Www.RCVetS.com

OSAMA ZAHID

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsIntroduction

• Tick-brone Disease• Caused by Theileria

Common Names

• Theileriasis• Zimbabwean Tick Fever• African Coast Fever• Corridor Disease• January Disease• East Coast Fever (ECF)

Introduction

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsIntroduction

Common Species

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsLife Cycle

Life CycleLife cycle in tick similar to that of

Babesia. But no transovarial transmission (Multi-host ticks).

Two different cell types are infected in the mammalian blood stream (initially leukocytes, later

on RBCs).

Infection of RBCs is important for transmission and infection of lymphocytes is important for

pathology.

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsLife Cycle

Life Cycle

Two stages are found in the Bovine host:• Koch’s bodies• Piroplasms

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsPathogenesis

A recently divided infected lymphocyteThe arrow indicates the cleavage furrow

at which cytokinesis occurred. Blue (DNA), red (host cell centrioles), green (parasite surface membrane), HN (host

nucleus)

The tight association of parasites with host cell microtubules ensures that they are segregated by the host cell mitotic spindle between the two daughter cells.

Parasites do not egress from (and in the process destroy) their host cells and infect new lymphocytes but proliferate along with them.

Theileria hijacks and exploits two key features of the lymphocyte’s cell biology:Cell Division Growth Control

Pathogenesis

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsPathogenesis

Infiltration of kidney by Theileria

parva infected lymphocytes

Abdominal ulcers due to transformed lymphocytes

• Lymphocytes proliferate heavily invading multiple organs causing disease similar to a lymphoma (cancer of lymphocytes).

• Death is in most cases due to infiltration of the lung resulting in lung edema (the abnormal build up of fluid within the lung)

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsPathogenesis

Lymphoma

• Uncontrolled growth• Loss of differentiation• Immortalization (infected cells

taken into culture will grow indefinitely)

• Growth in the absence of external growth factors

• Enhanced ability to migrate and to infiltrate organs

• When cells are cured from parasite infection they die (by apoptosis -- this suicide response is usually suppressed in cancer cells)

Theileria infection seems to share many of the features seen in the transformation of normal cells into cancer cells:

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsDiagnosis

Clinical Signs & Diagnosis

AnemiaSwelling of the

Superficial Lymph Nodes

Generalized Lymphadenopathy

High Fever Anorexia Decreased milk production

Tachycardia (Rapid Heartbeat)

Weakness/Loss of Condition

Lacrimation & Corneal Opacity

Nasal Discharge Terminal dyspnea Diarrhea

Diagnosis• Stained Blood Smears• Serological

Examination• Biopsy• Gene Diagnosis

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsControl

Drug Treatmen

t

Buparvaquone

Oxytetracycline

Parvaquone

Halofuginone lactate

Control

Tick Control

Vaccination

Introduction Life Cycle Pathogenesis Diagnosis Control QuestionsQuestions

Any Questions?