Trypanosomes

Question 1

What is the main trypanosome species that infects humans?

Answer 1

T.cruzi

Question 2

What are the main trypanosome species that infects livestock?

Answer 2

• T. brucei evansi
• T. equiperdum

Question 3

What is a kinetoblast?

Answer 3

a single large mitochondrion associated with the base of flagellum
Characteristic of trypanosome and leishmania parasites

Question 4

What kind of disease is african trypanosomiasis?

Answer 4

• Very serious disease of humans and livestock in sub-saharan africa
• causes substantial economic losses

Question 5

What kind of parasite are trypanosomes?

Answer 5

• Protozoa
• Haemoflagellates
• live in the blood and lymph

Question 6

What kind of fly can carry trypanosomes?

Answer 6

Tsetse fly

Question 7

What is the main form of transmission for a trypanosome?

Answer 7

Salivarian transmission from a tstetse fly

Question 8

What are some other routes of transmission for trypanosomes?

Answer 8

• Transplacental transmission
• Mechanical transmission via other blood-sucking insects (this is important for T.vivax)
• accidental infections in laboratories via needle sticks
• transmission via sexual contact

Question 9

What are four important facts about tsetse flies?

Answer 9

• Obligatorily haematophagous (males and females)
• Females bear live young
• Up to 20% of flies are infected by trypanosomes
• They are infected for life

Question 10

What are the three types of glossina vector species

Answer 10

Morsitans, Palpalis, Fusca

Question 11

What are the three glossina species habitats?

Answer 11

• Palpalis- Riverine forest
• Fusca- Forest
• Morsitans- Savannah

Question 12

What hosts carry African animal trypanosomiasis?

Answer 12

Cattle, horses, camels

Question 13

What are the two most pathogenic parasite species (trypanosomes)

Answer 13

• T.vivax
• T.congolese

Question 14

What are the clinical signs of nagala?

Answer 14

• Anaemia
• Weight loss
• Hair loss
• Poor Milk yield
• Abortion
• Paralysis
• Death

Question 15

How may you diagnose nagala?

Answer 15

• Clinical signs
• The geographical location
• observing the blood
• ELISA antibody testing

Question 16

When can chemotherapy be used?

Answer 16

for Sporadic trypanosomiasis when combined with anti-tsetse measures

Question 17

What are the limitations of chemotherapy?

Answer 17

• More doses are needed than are available
• toxicity in certain host species
• development of drug resistance

Question 18

What is the definition of trypanotolerance I?

Answer 18

ability of a few livestock breeds to survive, reproduce and produce in tsetsetrypanosome infested areas where others cannot, without recourse to use of chemical drugs

Question 19

What is trypanotolerance II?

Answer 19

It helps to control the levels of parisiteamia by preventing the characteristic anaemia and production loss

Question 20

What determines trypanotolerance II?

Answer 20

Determined by the 18 quantitative trait loci (stretches of DNA)
can also improve the tolerance through crossbreeding

Question 21

What does T. brucei brucei cause?

Answer 21

Causes surra in camels, horses and dogs
(anaemia, weight loss and death)

Question 22

How is T.brucei brucei transmitted?

Answer 22

Transmitted mechanically by biting flies

Question 23

What does T. equiperdum cause?

Answer 23

causes dourine in horses and donkeys
(genital and abdominal oedema, emaciation)

Question 24

How is T.equiperdum transmissed?

Answer 24

sexual transmission

Question 25

What is Human african trypanosomiasis also known as?

Answer 25

sleeping sickness

Question 26

What is the epidemiology of sleeping sickness?

Answer 26

* 779 new cases were recorded in 2022 * severe morbidity and mortality * affects principally poor, rural areas * 36 countries are affected

Question 27

What are the two types of sleeping sickness?

Answer 27

* Trypanosoma brucei rhodesiense * Trypanosoma brucei gambiense

Question 28

What are the symptoms of early stage sleeping sickness?

Answer 28

* The haemolymphatic stage * Non-specific symptoms (fever and headache) * joint pain/ itching

Question 29

What are the symptoms of secondary/late stage sleeping sickness?

Answer 29

This occurs after parasites cross the blood-brain barrier and enter the CNS * Headache, Mental changes * Disruption of the sleep cycle, coma and death

Question 30

What is the principal reservoir for T. b. rhodesiense

Answer 30

Ungulates, but domestic cattle in agricultural areas

Question 31

How may you diagnose Trypanosomes?

Answer 31

* Microscopy * Agglutination testing * PCR * Field- appropriate diagnostics

Question 32

How can you stage trypanosomiasis?

Answer 32

* Determine stage of infection * Examine cerebrospinal fluid for elevated WBC, elevated Protein, visualisation of parasites

Question 33

How can you treat human Trypanosomiasis?

Answer 33

Requires long hospital stays

Question 34

Whare the current control options for Trypanosomiasis?

Answer 34

* Vector control * Control in animal reserves * Case finding and treatment

Question 35

What would you use for tstetse trapping?

Answer 35

* Blue and or Black Cloth * Odour baiting * Insecticide treatments

Question 36

Name two other methods of tsetse trapping

Answer 36

* Aerial spraying with insecticide * Sterile insect technique