Dracunculus medinensis

Question 1

Classification

Answer 1

Metazoa

Question 2

Indirect or direct:

Hosts

Answer 2

Indirect life cycle

Human is final host
Copepad is intermediate host

Question 3

Transmission and life cylce

Answer 3

Humans become infected by ingestion of water containing copepods with larvae. Also possible if humans eat undercooked fish that have ingested these contaminated copepods.

Once ingested, copepods die and release the larvae which penetrate the hosts stomach and intestinal wall and enter the abdominal cavity and retroperitoneal space.

The larvae mature and reproduce sexually in subcutaneous tissues.

The male worms die and the female worms migrate to the skin surface. Approximately one year after infection, the female worm induces a blister on the skin.

When this lesion comes into contact with water, the female worm emerges and releases larvae These larvae are again ingested by a copepod where they develop into infective larvae.

Question 4

Diagnosis

Answer 4

Visual examination of the worm coming out of the foot.

Microscopy of larvae detection.

Intradermal test for antigen detection

Serology for antibodies during active infection.