Guinea Worm infection
Guinea worm disease is caused by drinking water contaminated by water fleas (microscopic arthropods known as copepods) that host the Dracunculus larva. Guinea worm disease used to thrive in some of the world’s poorest areas, particularly those with limited or no access to clean water. In these areas, stagnant water sources may still host copepods, which can carry the larvae of the guinea worm.
The larvae develop for approximately two weeks inside the copepods. At this stage the larvae can cause guinea worm disease if the infected copepods are not filtered from drinking water. The male guinea worm is typically much smaller (12–29 mm or 0.47–1.1 in) than the female, which, as an adult, can grow to 2–3 feet (0.61–0.91 m) long and be as thick as a spaghetti noodle.
Once inside the body, stomach acid digests the water flea, but not the guinea worm larvae that are sheltered inside. These larvae find their way to the body cavity where the female mates with a male guinea worm. This takes place approximately three months after infection. The male worm dies after mating and is absorbed.
The female, which contains larvae, burrows into the deeper connective tissues or adjacent to long bones or joints of the extremities.
Approximately one year after the infection began, the worm creates a blister in the human host’s skin—usually on the leg or foot. Within 72 hours the blister ruptures, exposing one end of the emergent worm. This blister causes a very painful burning sensation as the worm emerges. Infected persons often immerse the affected limb in water to relieve the burning sensation. Once the blister or open sore is submerged in water, the adult female releases hundreds of thousands of guinea worm larvae, contaminating the water supply.