After a year, adult worm reaches skin surface of lower extremities. Female comes in contact with water, then discharges larvae into water. None reported Paragonimiasis Worms living in pulmonary cysts lay eggs in human lungs, which are coughed up and then swallowed. Worm eggs are passed out in feces and break when in fresh water. Larvae find snail host in which to replicate, then move into freshwater crab or crayfish.
Humans eat uncooked seafood.
Worms migrate in pairs from stomach through intestinal wall and diaphragm to lungs, where they mate. Eggs hatch on contact with water, releasing the parasite miracidium. Parasite moves into a freshwater snail, where it replicates. It is released back into water, then penetrates human skin within seconds and moves into blood vessels. Within 30 to 45 days, miracidium grows into worm, which can lay 200 to 2,000 eggs per day for an average of 5 years.