Paragonimus Westermani also known as the “Oriental Lung Fluke” is found throughout Asia, and to a lesser extent, in Japan, Korea, the Philippines, and Thailand. It is a parasite transmitted by eating raw or undercooked crustaceans such as crabs and crayfish. The Chinese Mitten Crab also called a Chinese Hairy Crab is a major source for oriental lung flukes.
IT IS ESTIMATED THAT OVER 20 MILLION PEOPLE IN CHINA ARE INFECTED. The disease is sometimes mistaken for Tuberculosis. Primary infection is asymptomatic and patients may remain asymptomatic for years, during which time lung lesions may be discovered incidentally on a chest x-ray. Cysts and cystic release of antigenic material may cause symptoms such as fever, chest pain, cough, and bloody sputum. Cysts may also become secondarily infected by other respiratory pathogens resulting in acute pneumonia.
Paragonimus westermani was discovered when two Bengal tigers died of paragonimiasis in zoos in Europe in 1878. Several years later, infections in humans were recognised in Formosa.