Host-Parasite Relationships 5

Front 1

Define "Accidental host".

Back 1

A host in which the parasite is not normally found; it is not necessary in the life cycle.

Front 2

Define "Dead-end host".

Back 2

A host that cannot transmit infectious agents to susceptible hosts; the life cycle is incomplete.

Front 3

Give examples of parasites with which humans can act as an accidental/dead-end hosts.

Back 3

Trichinella spiralis

Taenia solium cysticercosis

Toxoplasmosis

Trypanosoma brucei rhodesiense

Front 4

Name the four main categories in which neglected diseases (in poor populations are placed.

Back 4

"Previously" neglected diseases

Neglected tropical diseases

Neglected zoonoses

Food/water-borne diseases

Note: There is a crossover for some disease types in the last 3 categories.

Front 5

Name examples of neglected zoonoses.

Back 5

Anthrax

Brucellosis

Bovine tuberculosis

Cystic echinococcosis

Leishmaniasis

Rabies

Zoonotic trypanosomiasis

Front 6

Who is most affected by neglected zoonoses?

Back 6

Poor farmers

Front 7

What causes trichinellosis outbreaks in humans in Thailand?

Back 7

Raw/undecooked wildlife meat and pigs causes infection after being smuggled into the country, alternatively from those that would scavenge feed.

Front 8

Via what form of transmission is African Trypanosomiasis transmitted?

Back 8

Cyclical

Front 9

What is Ford's paradox?

Back 9

Cattle are mainly distributed around the area where the tsetse fly, which transmits Trypanosomiasis, are present.

Front 10

What does Trypanosomiasis infection in cattle cause?

Back 10

Nagana

Front 11

What does Trypanosomiasis infection in humans cause?

Back 11

Sleeping sickness

Front 12

How can African Trypanosomiasis be controlled?

Back 12

Tsetse control (area-wide or local)

Trypanocidal drugs

Trypanotolerant livestock

Vaccination (be aware of antigenic variation)

Front 13

How is the Tsetse fly controlled?

Back 13

Habitat modification

Aerial insecticide spraying

Sterile insect techniques

"Bait technologies": Traps and targets (stationary), treat cattle with insecticide (mobile).

Front 14

Give an example of, and explain, how stationary bait technologies can be used to target and trap the tsetse fly.

Back 14

Odour baited targets (used in savannah species):

Uses octenol and acetone, effective with around 4 per km2.

Front 15

Why is it difficult to use stationary, odour-baited target methods to trap riverine fly species (e.g. G. fuscipes fuscipes)?

Back 15

Some not attracted to odours

Low density and very localised, so difficult to deploy stationary baits.

Front 16

State an example of how mobile baits can be used to control the tsetse fly and one problem with employing this method.

Back 16

Treat cattle with dips (also used or ticks) - expensive to maintain.

Front 17

What makes cattle dips so expensive? Why might this not be worth the investment?

Back 17

Infrastructure

40,000 litres of water

Cost of acaricide replenishment

Questionable efficacy

Low density of cattle in catchment area

Front 18

What are the pros and cons of using pour-on insecticide as a form of mobile bait control for the tsetse fly?

Back 18

Highly effective synthetic pyrethroid

Too expensive for subsistence farmers

Environmental concerns

Potentially too effective

Front 19

What is the alternative for using pour-on insecticide as a method of mobile bait control of the tsetse fly? Are there disadvantages?

Back 19

Spraying cattle - a more popular option

Still expensive and environemental concerns still present

Front 20

How is Restricted Application of Insecticide implemented and what are its advantages?

Back 20

Apply synthetic pyrethroid to tsetse predilection feeding sites. This uses less insecticide, is affordable by subsistence farmers, lessens environmental concern, is also effective against ticks, and interferes less with natural immunity to tick-borne protozoa.

Front 21

What guidelines are given for the Restricted Application of Insecticide, and what constraint does this overcome?

Back 21

5% deltamethrin diluted 1/1000 (0.005%)

Apply to front legs, belly and ears

20% volume for whole treatment needed

400ml for 200kg animal

Overcomes availability of water constraint

Front 22

Give 3 examples of compounds used to control African Bovine Trypanosomiasis.

Back 22

Homidium bromide/chloride (curative, little prophylaxis)

Isometamidium chloride (Prophylactic, curative)

Diminazene aceturate (Curative)

Front 23

Why might trypanosomiasis drugs fail to work?

Back 23

Incorrect dose/administrtion

Incorrect diagnosis

Substandard product

Counterfeit product

Drug resistance

Front 24

Name two cattle species that are trypanosomiasis tolerant.

Back 24

Bos taurus

Bos indicus

Front 25

How is Leishmaniasis controlled?

Back 25

Sandfly vector controlled via insecticide, environmental management (elimate breeding sites), and avoiding bites with screens and repellants.

Also, treating affected humans and animals with pentavalent antimonials, amphotericin B, paromomycin, and miltefosine. Be aware dogs can act as resevoir for infection.