Paragonimus westermani is the major species of lung fluke to infects humans, causing paragonimiasis. The species sometimes is called the Japanese Lung fluke or Oriental Lung fluke. Human infections are most common in eastern Asia and in South America.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. The prevalence of many snail-borne and vector-borne parasitic diseases has been dramatically diminished in many areas where they were once common.
Diagnosis is based on microscopic demonstration of eggs in stool or sputum, but these are not present until 2 to 3 months after infection. However, eggs are also occasionally encountered in effusion fluid or biopsy material. Furthermore, you can use morphologic comparisons with other intestinal parasites to diagnose potential causative agents. Finally, antibody detection is useful in light infections and in the diagnosis of extrapulmonary paragonimiasis. In the United States, detection of antibodies to Paragonimus westermani has helped physicians differentiate paragonimiasis from tuberculosis in Indochinese immigrants. Further research is being conducted to determine the drugs for the Paragonimus and how long it can affect humans.