Since late last month, the Shanghai Institute of Parasitic Diseases has un-covered 12 patients suffering from lung fluke, while it receives five to six people for checks every week.

This is comparable to figures in 1998-99 when doctors treated 500 to 600 patients a year with lung fluke, thanks to the then new-found fetish for raw and fresh seafood.

"The disease incidence declined to only 50 to 60 in 2000 and 2001 because people became aware about the pitfalls of gorging on squirming seafood like wined shrimp," said Chang Zhengshan, a researcher from the institute.

However, he said lung fluke cases are on the rise again because of the popularity of "spicy crayfish and crab."

Experts explained that the immature parasite existing in the muscle of the crab or crayfish enters the human body through the intestinal wall and migrates to the body cavity, the diaphragm, and on to the thoracic cavity and the lungs. It matures in two to six months, which can destroy the lung tissue and infect the organ, resulting in respiration failure.

"Only when the aquatic food is cooked for at least more than 20 minutes can the parasites be completely eliminated. However, gourmands usually prefer the fresh flavor, risking a close encounter with the disease," said Chang.

Symptoms include pleurisy, a bad cough, bron-chitis, blood in the sputum, mild anemia and tiredness. Since these signs can be confused with tuberculosis, pneumonia or lung cancer, an incorrect diagnosis can delay cure, the institute said.

Once blood and sputum tests confirm evidence of the parasite, patients will be given drugs that can kill the worm over one or two weeks, doctors said.

They advise seafood lovers to ensure their crustaceans are fully cooked, a warning that seems to be reaching home.

Chen Lingling, a spicy crayfish lover, said she was mulling "a change in eating habits," adding that she will choose fully cooked seafood or just avoid the delicacy.

(eastday.com December 13, 2002)