bio 597 theileriosis

7/30/2019 BIO 597 Theileriosis

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By Julie Murchie and Victoria Paesani


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Phylum Apicomplexa

Caused by a tick-borne obligate intracellular parasite, Theileria parva, in sub-

Saharan Africa, infecting ungulates

Major constraint to livestock production & food security in many developing countries

Causes high morbidity & mortality, killing 1 million cattle every year

Prevents introduction of very productive but disease-susceptible breeds of cattle

Expensive to control

Places a huge economic burden on poor smallholder farmers

Costs nearly $170 million yearly

Some African counties use the cattle as forms of currency

T. parvahas ability to induce cancer in host cell in a way that is reversible Studies have provided clear links to cancer biology in humans

Studying this parasite has given researchers clues for the right direction

Vaccines have the power to eradicate the disease

Not hazardous to human health

Brown Ear Tick


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Threat mostly in eastern,central, & southern Africa


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Cattle *

Waterbuck

Indian Water Buffalo* African Buffalo

*develop symptomatic infections


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4) Lymphocyte lymphoblast (enlargedlymphocyte) and

3) Sporozoite enterslymphocyte (WBC) schizont

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

1) Sporozoites producedin tick salivary glands

2) Sporozoites transfer toungulate if tick is attachedfor 48-72 hrs

5) divides with schizont inside 2 infected daughter cells

7) In RBC,merozoitepiroplasm (infectticks)

8) RBCsingested bynymphs duringfeeding

Incubation Period

Experimentally Infected: 8-12 days

Naturally Infected: up to 3 weeks

9) Once in gut, undergoessexual reproduction motile stage, moves to

ticks salivary gland

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

fold every 3 days


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FirstSigns

appear 7-25 days after tick attaches

Parotid gland swells Ear is preferred feeding site

Fever

Anorexia & decrease in overall condition

Later Signs

Lacrimation, corneal opacity

Nasal discharge, terminal dyspnea

Interlobular emphysema & sever pulmonary edema

Before death, temperature falls & dyspnea intensifies

Some develop neurologic disease turning sickness

Due to affected cells blocking circulation in capillaries within the CNS

Death (18-30 days after infestation by ticks)

The few survivors become lifelong immune carriers. Majority of these

cases, asymptomatic carriers can be recognized with little or no effect on

their productivity. Minority develop chronic disease problems that result in stunted

growth in calves and lack of productivity in adult cattle.


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Vaccination

Infect animal with the sporozoite form of theparasite while at the same time treating the cattlewith an antibiotic drug to lessen the severity ofthe infection

Pasture Management

Herd-Selection of Resistant Animals

Tick Control & Eradication


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Induction of Acquired Immunity in Pastoral

Zebu Cattle Against East Coast Fever After

Natural Infection by Early Diagnosis andEarly Treatment

Matovelo et al. 2003


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1. Examine efficiency of

chemotherapy of natural ECF

cases to look at protective

immunity against ECF in cattle.

2. Design a regimen farmers can use to help

minimize cattle loss due to ECF. This is done by

establishing early disease diagnosis and early

treatment.


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Two villages in the Morogoro Rural District

Two seasons (April and November)

Ear tagged 280 calves


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Farmers were trained to monitor the animals for

clinical symptoms of ECF.Qualifying clinical symptoms: enlargement of

superficial lymph nodes, increase in

body temperature, dullness, and

respiratory distress.

Animals diagnosed with ECF

were treated with buparvaquone.

Severity of the disease at the time of treatment

was categorized based on the criteria set for ECF

clinical reactions with some modifications.


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Indicator

Variable

Clinical

status

Rectal

Temperature

Lymph node

status

Respiratory

performance

Demeanor

Mild Above 39.5 C Swollen

parotidlymph-node

Normal Normal

Moderate Above 39.5 C Swollen

parotid and

Prescapular

node

Slight

labored

breathing

Nasal

discharges

Normal

Severe Above 39.5 C Swelling off

all superficial

lymph nodes

Respiratory

distress

Reluctant to

move/

recumbence


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Treatment responses were categorized as

prompt/rapid, slow, or died.

Examined serum antibodies to T. parva, with

samples at the beginning and end of study,using ELISA.

Studied blood and

lymph node smears forT. Parva parasites.


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100 animals were diagnosed with ECF

Most prominent clinical signs were fever andlymph node enlargements.

81% of animals were positive for ECF on atleast one screening method.

During follow-up, only 5 individuals were

diagnosed with ECF a second time.


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Diagnostic

Means

Cases

Tested

Missing

Clinical

Responses

Total Cases Mild Moderate Severe

Clinicalsigns of

ECF

100 0 100(100%) 4 66 30

Lymph

nodesmears

99 1 67(67.68%) 3 42 22

Blood

Smears

98 2 41(41.84%) 1 27 13

No test

detected

__ __ 19(19%) 1 13 5


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Majority of cattle that were treatedrecovered. (98% recovery rate)

Shows that early diagnosis and early

treatment is a reliable means to diagnosecattle with ECF on a basis of clinical signs in

endemic areas.

Reliable early signs of infection are fever and

swollen lymph nodes.


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Use of chemotherapy with the earlydetection and early treatment approach

reduced mortality and helped cattle develop

immunity.

In terms of immunization, the early

detection and early treatment approach is a

reasonable alternative to the infection and

treatment.


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East Coast Fever is caused by Theileria parvaHosts

Intermediate= cattle

Definitive= ticks

Incubation time is anywhere from 8 days to 3weeks.

Very expensive

High morbidity & mortality rates

No harm to human health


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Matovelo, Gwakisa, Gwamaka, Chilongola, Silayo, Mtenga, Maselle, and Kambarage. "Induction of Acquired

Immunity in Pastoral Zebu Cattle Against East Coast Fever After Natural Infection by Early Diagnosis and

Early Treatment." The Journal of Applied Research In Veterinary Medicine. 2003. Web. 23 Mar. 2011.

.

Azeem Photos. 2010. A blue water is looking well with animal Waterbucks. . Accessed 22 March 2011.

Department for International Development Animal Health Programme, University of Edinburgh. 2005. R8042

Integrated control of East Coast fever in cattle of small-holder farmers. . Accessed 21 March 2011.

Food and Agriculture Organization of the United Nations. 1983. Eradication an alternative to tick and tick-

borne disease control. . Accessed 22 March

2011.

International Laboratory for Research on Animal Diseases. 1991. ILRAD 1990: Annual Report of the

International Laboratory for Research on Animal Diseases. Nairobi: International Laboratory for Research on

Animal Diseases.

Malcolm J. G., et al. 2005. Genome Sequence ofTheileria parva, a Bovine Pathogen That Transforms

Lymphocytes. Science 309:134-136.

Melhorn, H. Genus Ripicephalus Brown ear tick. Heinrich-Heine-Dusseldorf University. . Accessed 22 March 2011.

Morzaria, S.P. Identification ofTheileria species and characterization ofTheileria parva stocks. InternationalLaboratory for Research on Animal Diseases. . Accessed

23 March 2011.

Science and Development Network. 2005. Genetic codes of cattle-killing parasites cracked SciDev.Net.

. Accessed 22 March

2011.

Smith, M.C. Special Problems of Meat Goats (VET-595). Ambulatory and Production Medicine, New York State

College of Veterinary Medicine, Cornell University.

.Accessed 22 March 2011.


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bio 597 theileriosis

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