1586 



PARAGONIMIASIS 



and also perhaps by the skin. The worms become adult in the 

 lungs and other organs. 



The disease appears to be very widespread in certain districts, 

 and the old idea that it is more common in males than in females 

 requires reinvestigation. 



Pathology, — ^The pathology of the disease is by no means clear, 

 and how the various pathological changes are evolved is unknown. 



Musgrave has classified the lesions into: — 



1. The non-suppurating lesion. 



2. The tubercle-like lesion. 



3. The suppurating lesion. 



4. The ulcerative lesion — 



{a) in the skin; 



(b) in the bronchial mucosa ; 



(c) in the intestinal mucosa; 



(d) in the bile-duct. 



The simplest lesion appears to be an infiltration of the connective 

 tissue of an organ with eggs, without any histological changes at 

 first, but later with a proliferation of the connective tissue and the 

 formation of a cirrhosis or a round-celled infiltration, with some- 

 times many eosinophiles, which may lead to abscess-formation, and 

 finally to ulceration. The abscess-formation may at times produce 

 caseous material, giving a tubercular appearance. 



The non-suppurating lesion may therefore be simple infiltration 

 of the tissue by eggs, with or without inflammation. On the other 

 hand, cirrhotic changes may be seen, especially in the liver. In serous 

 membranes an adhesive inflammation is often produced, associated 

 with the presence of eggs in brown patches at the points of contact. 



The inflammation of the organ may, however, proceed to pus- 

 formation, resulting in a typical abscess. On the other hand, the 

 tissues generally attempt to circumscribe this abscess by a fibrous 

 wall, and thus produce what is called the typical lesion of the 

 disease. In the centre of the abscess will be seen degenerated cells, 

 blood, eggs, and perhaps a parasite. Then comes a capsular wall 

 of fibrous connective tissue, smooth towards the centre, and join- 

 ing the rest of the organ externally. Around this wall the connec- 

 tive tissue of the organ is proliferating and congested. In this way 

 the typical little cysts, with dull blue-grey walls, smooth internally, 

 and containing a thick, reddish fluid, with or without eggs or a 

 parasite, are formed. These lesions may work their way to a 

 cutaneous or mucous surface, and so open into a bronchus, or into 

 the intestine, or the bile-duct, or on to the skin, thus giving rise 

 to ulcers in those regions. The intestinal ulcers closely resemble 

 dysenteric ulcers, and, indeed, may become secondarily infected 

 with amoebae or bacteria. 



In course of time these lesions may show some attempt at healing 

 and scar-formation, but generally this is not very successful. 



The blood may show a deviation of complement with worm-body used as 

 antigen. 



