Drunken crabs might never be the same for you...*cough*
Paragonimus westermani is the most common of fluke worms found in people's lungs and especially common in the Far East, South East Asia and in Oceania, so Aussies beware.
After eating some inadequately cooked, raw or pickled crustaceans, the new host will swallow some nice metacercariae - an intermediate stage between egg and larvae - and will start to hatch in the duodenum. The larvae then will start penetrating the wall of your gut and rest a bit in your peritoneal cavity. After having a wee lie down, it starts the journey of finding its way through your diaphragm into your lungs. There they build themselves a nice little cave communicating with the bronchial tree (probably for the fresh air and the good view) and start hatching. Being hermaphrodites they don't need anybody else to reproduce, and soon you, the host will star coughing up the eggs and releasing them into the open again.
The acute phase of the infection manifests itself with diarrhoea, abdominal pain, fever and skin changes like urticaria. During the chronic phase, coughing up brown sputum is a good sign of something being wrong down there. Changes on chest xrays can often be misdiagnosed as Tuberculosis.
Unfortunately, the flukes can end up in your eyes, causing blindness, in your balls, causing painful infections and other rather unfortunate corners of your body.
Treatment is good ole' Praziquantl, 25mg/ml.
So pleeease, think carefully before biting in that tasty raw crab.
Dion R. Bell, Tropical Medicine, 4th Edition, Blackwell Science, pp 243-246