Fluke: Fascioloa gigantica

Question 1

State 2 differences between F. hepatica and F. gigantica

Answer 1

1. F. g is more pathogenic

2. F.g intermediate host is an aquatic snail

Question 2

What happens during the miracidia stage?

Answer 2

Hatch at beginning of wet season, infect snails and develop by the end of the wet season.

Question 3

What happens during the cercaria stage?

Answer 3

Shed from snail at the beginning of, and during, the dry season.

Question 4

What happens during the metacercaria stage?

Answer 4

Encyst on aquatic plants/water.

Question 5

When does disease occur?

Answer 5

End of dry/beginning of wet season.

Question 6

Treatments?

Answer 6

Similar to those used for F. hepatica.

Question 7

Control measures?

Answer 7

1. Molluscicide
2. Fencing
3. Pump water to troughs from bore holes
4. Parasitic castration

Question 8

What is meant by ‘parasitic castration’?

Answer 8

Infected snails are infected by another parasite which prevents fluke from entering the snails. Schistosomes can be used although these cause disease in humans.

Question 9

What is the PPP?

Answer 9

13-16 weeks