A lung fluke is a parasitic flatworm that can be found throughout Africa, Asia and Latin America, but rarely in North America. This kind of disease may enter the body as encysted larvae in crabs and crayfish. But mostly this will occur both in animals (parasites) and of course to human.
Commonly this is caused by Paragonimus Westermani or the Lung Fluke Parasite. This parasitic worm is 0.3 to 0.5 inches long and has been reported that it can also be found here in the Philippines and Indonesia. Its life cycle begins just like mosquitoes that the eggs will hatch into larvae and infect water snails. The larvae then emerge from the snails and go on to infect fresh water crabs and crayfish just as stated above. The worm makes its way to the lungs when humans ingest undercooked crabs and crayfish that are harboring the lung fluke parasite. There it produces small cysts with fibrous walls. These cysts will rupture and the eggs of the worm, which are contained inside, are then coughed up. Some of the eggs are swallowed and then passed in the host’s feces, which eventually end up back in the water and at this point, the life cycle starts over.
So how does the infection starts up? Once inside the lungs, the worm covers itself in granulation tissue, forming a capsule around itself. These capsules can eventually ulcerate and then heal. The infection caused by the lung fluke parasite resembles tuberculosis in many respects. Infection also starts when raw or partially cooked fresh water crabs and crayfish containing infected larvae are eaten.
Among of the symptoms include a bad cough, bronchitis and coughing up blood. In heavy infestations, lessions may also be found in the lungs, liver and brain. Parasites in the intestinal wall may cause abdominal pain, diarrhea and dysentery. Those in the central nervous system, depending on their location may cause seizures.
So when there is an infection there is also a treatment on how to get rid in this kind disease. This infection is diagnosed by finding lung fluke eggs in the sputum or feces. A radiological method is sometimes used also to look for worms in the chest cavity, but this is a less definite way to diagnose the disease. In order also to prevent this kind of infection, shellfish should be thoroughly cooked in order to kill any larvae.