TRICHINOSIS 



323 



As this would not explain the transmission among civilized men, the 

 following is the life history: Man obtains his infection from eating raw 

 pork, the embryos encysted in the muscle of the hog being liberated in 

 the stomach, and the males and females developing in the intestine as 

 above described. The hog may gain his infection by eating the meat 

 of other hogs or rats. These rats eat scraps of pork at slaughter houses 

 ad become infected. Being cannibals, rats when once infected, con- 

 tinue to propagate the infection. In man, during the first two or three 

 days while the adults are breeding in the intestine, we have gastroin- 

 testinal symptoms. 



It is during this period or at any rate before the fifth day that purging may be of 

 benefit. About ten to twenty days after infection the embryos begin to wander and 



FIG. 75. Trichina spiralis. (Ziegler.) 



we have the acute muscle pains. In the diagnosis we should try to obtain specimens 

 of the pork which has caused the trouble in order to examine for encysted trichinae, 

 or to feed to white rats or rabbits, subsequently examining the diaphragm of these 

 animals for encysted trichince or the intestine for adult trichinae. Excision of a 

 small piece of the deltoid of man may confirm the diagnosis. The best method is to 

 take blood in 3% acetic acid, centrifuge, and examine for larvae. 



During the diarrhceal stage we may examine the stools for adult worms, in particu- 

 lar dead males or possibly actively motile embryos these latter are about 90 X 6/i. 



Always examine the blood for eosinophilia. 



It is well to remember that the parts of meat which trichinae prefer (muscle of 

 diaphragm, of neck, etc.) are often used in sausage. Unfortunately it is almost 

 impossible to detect the embryos in sausage meat. 



