Cavitary lesion in the right lower lung with dyspnea with following histopathological appearance. Most likely diagnosis:-

Ans. C. Paragonimus with 2 layersa. Paragonimus westermani is the major species of lung fluke to infects humans, causing paragonimiasis,b. The species sometimes is called the Japanese Lung fluke or Oriental Lung fluke.c. Unembryonated eggs are passed in the sputum of a human or feline. Two weeks later, miracidia develop in the egg and hatches.d. The miracidia penetrate its first intermediate host (snail). Within the snail mother sporocyst form and produce many mother rediae, which subsequently produce many daughter rediae which shed crawling cercariae into fresh water.e. The crawling cercariae penetrate fresh water crabs and encyst in its muscles becoming metacercaria. Humans or felines then eat the infected crabs raw. Once eaten, the metacercaria excyst and penetrates the gut, diaphragm and lung where it becomes an adult worm in pairs,f. The first intermediate hosts of the Paragonimus westermani are freshwater snails.g. Transmission of the parasite P. westermani to humans and mammals primarily occurs through the consumption of raw or undercooked seafoodh. Animals such as pigs, dogs, and a variety of feline species can also harbour P. westermani.i. 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.j. According to the CDC, praziquantel is the drug of choice to treat paragonimiasis.