Theileriosis

Report
By Julie Murchie and Victoria Paesani


Phylum Apicomplexa
Caused by a tick-borne obligate intracellular parasite, Theileria parva, in subSaharan Africa, infecting ungulates
Brown Ear Tick
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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. parva has ability to induce cancer in host cell in a way that is reversible
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Studies have provided clear links to cancer biology in humans
Studying this parasite has given researchers clues for the right direction
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Vaccines have the power to eradicate the disease
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Not hazardous to human health
Threat mostly in eastern,
central, & southern Africa
Cattle *
Indian Water Buffalo*
*develop symptomatic infections
Waterbuck
African Buffalo
5) …divides with schizont inside  2 infected daughter cells
4) Lymphocyte  lymphoblast (enlarged
lymphocyte) and…
3) Sporozoite enters
lymphocyte (WBC)  schizont
2) Sporozoites transfer to
ungulate if tick is attached
for 48-72 hrs
1) Sporozoites produced
in tick salivary glands
Incubation Period
Experimentally Infected: 8-12 days
Naturally Infected: up to 3 weeks
6) 10-15 days postinfection, schizont 
merozoite (invades
erythrocyte (RBC))
* 5-8 days post-infection:
found in lymph nodes
* Schizonts increase 10fold every 3 days
7) In RBC,
merozoite 
piroplasm (infect
ticks)
8) RBCs
ingested by
nymphs during
feeding
9) Once in gut, undergoes
sexual reproduction 
motile stage, moves to
tick’s salivary gland
First Signs
appear 7-25 days after tick attaches

Parotid gland swells

Ear is preferred feeding site

Fever
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Anorexia & decrease in overall condition
Later Signs

Lacrimation, corneal opacity
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Nasal discharge, terminal dyspnea
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Interlobular emphysema & sever pulmonary edema
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Before death, temperature falls & dyspnea intensifies
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Some develop neurologic disease “turning sickness”
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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.
 Vaccination

Infect animal with the sporozoite form of the
parasite while at the same time treating the cattle
with an antibiotic drug to lessen the severity of
the infection
 Pasture
Management
 Herd-Selection
 Tick
of Resistant Animals
Control & Eradication
Matovelo et al. 2003
Induction of Acquired Immunity in Pastoral
Zebu Cattle Against East Coast Fever After
Natural Infection by Early Diagnosis and
Early Treatment
 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.
 Two
villages in the Morogoro Rural District
 Two seasons (April and November)
 Ear tagged 280 calves
 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.
Indicator
Variable
Clinical
status
Rectal
Temperature
Lymph node
status
Respiratory
performance
Demeanor
Mild
Above 39.5 ºC
Swollen
parotid
lymph-node
Normal
Normal
Moderate
Above 39.5 ºC
Swollen
parotid and
Prescapular
node
Slight
labored
breathing
Nasal
discharges
Normal
Severe
Above 39.5 ºC
Swelling off
all superficial
lymph nodes
Respiratory
distress
Reluctant to
move/
recumbence
 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 for
T. Parva parasites.
 100
animals were diagnosed with ECF
 Most
prominent clinical signs were fever and
lymph node enlargements.
 81%
of animals were positive for ECF on at
least one screening method.
 During
follow-up, only 5 individuals were
diagnosed with ECF a second time.
Diagnostic
Means
Cases
Tested
Missing
Clinical
Responses
Total Cases Mild
Moderate
Severe
Clinical
signs of
ECF
100
0
100(100%)
4
66
30
Lymph
node
smears
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
 Majority
of cattle that were treated
recovered. (98% recovery rate)
 Shows
that early diagnosis and early
treatment is a reliable means to diagnose
cattle with ECF on a basis of clinical signs in
endemic areas.
 Reliable
early signs of infection are fever and
swollen lymph nodes.
 Use
of chemotherapy with the early
detection 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.
 East
Coast Fever is caused by Theileria parva
 Hosts

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Intermediate= cattle
Definitive= ticks
 Incubation
time is anywhere from 8 days to 3
weeks.
 Very
expensive
 High
morbidity & mortality rates
 No
harm to human health

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.
<http://www.jarvm.com/articles/Vol1Iss2/Matovelo.htm>.

Azeem Photos. 2010. A blue water is looking well with animal Waterbucks. <http://azeemphotos.blogspot.com/2010/09/blue-water-is-looking-well-with-animal.html>. 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. <http://www.dfidahp.org.uk/index.php?section=4&subsection=48>. Accessed 21 March 2011.

Food and Agriculture Organization of the United Nations. 1983. Eradication – an alternative to tick and tickborne disease control. <http://www.fao.org/docrep/004/x6538e/X6538E00.htm#TOC>. 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 of Theileria parva, a Bovine Pathogen That Transforms
Lymphocytes. Science 309:134-136.

Melhorn, H. Genus Ripicephalus Brown ear tick. Heinrich-Heine-Dusseldorf University. <http://www.butoxinfo.com/ectoparasites/ripicephalus.asp>. Accessed 22 March 2011.

Morzaria, S.P. Identification of Theileria species and characterization of Theileria parva stocks. International
Laboratory for Research on Animal Diseases. <www.fao.org/Wairdocs/ILRI/x5549E/x5549e0t.htm>. Accessed
23 March 2011.

Science and Development Network. 2005. Genetic codes of cattle-killing parasites cracked – SciDev.Net.
<http://www.scidev.net/en/news/genetic-codes-of-cattlekilling-parasites-cracked.html>. 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.
<http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2002&Category=&PID=5736&O=Generic>.
Accessed 22 March 2011.

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