Question

Identify this image.

Answer 1

The given image is of a worm-like organism that causes infections in a lot of mammals, including humans. It is found in almost all parts of the world and can cause a great loss to the farmers of cattle and sheep as those animals are more prone to infections by this organism.

Complete answer:
The image is of Fasciola hepatica. It is also known as a liver fluke and is a parasitic flatworm that can cause a disease called Fasciolosis in a lot of mammals, including humans. However, most of the animals infected by this flatworm are cattle and sheep.

The average adult worm is 30mm in length and is 13 mm wide. It has a peculiar leaf-like body with the anterior portion being broader than the posterior portion. The anterior portion even contains a sucker that is used by the fluke to attach itself to the biliary ducts.

Transmission happens through freshwater vegetation on which the flukes are encysted in their metacercariae. This happens when the water body gets contaminated from the eggs present in the faecal matter of the infected host.

Fascioliasis can be of 2 types -acute and chronic.
- Acute Fascioliasis
In this case, a large number of larvae invade the liver and cause hepatitis. Symptoms include fever, hepatomegaly, abdominal pain, lethargy, and wasting.
- Chronic Fascioliasis
Once the fluke matures, it can lead to an obstructive phase which can be followed by hepatitis, cholangitis, or pancreatitis.

Note: Liver flukes are hermaphrodites and can reproduce cross fertilisation and self-fertilisation. Infections in humans are mostly accidental. The primary targets are domestic and wild ruminants. The infection to cattle results in a substantial economic loss for the farmers. Infection can be prevented by washing and cooking the vegetables properly before consumption.