154 THE METHOD OF COMPLEMENT FIXATION. 



that 75 per cent, of the children of these apparently healthy women gave 



luetic manifestations immediately or shortly after birth. 

 Serum Diag- * n c ^ ose association with the serum diagnosis of syphilis, com- 

 noJFs of Dis- plement fixation has been employed as a means for the diagno- 

 eases Caused sis of conditions caused by the animal parasites and especially 

 by Animal by the echinococcus. In the serum of patients suffering 

 ' es * from these infections, substances are found closely allied to 



the "lues reagine." They bind complement with an antigen consisting of 



an extract of the respective worms or hydatid fluid. 



Ghedini, Weinberg and Parvu and others have found that in most cases of echino- 

 coccus disease, the reaction is positive. If by operation the cyst is only incised the re- 

 action becomes stronger or in few cases appears positive for the first time. After com- 

 plete excision of the cyst, the reaction disappears. According to Parvu and Laubry, a 

 positive test is found in the spinal fluid only when the echinococcus cysts have invaded the 

 brain. 



Ghedini described similar findings, caused by the ascaris, ankylostoma, 

 etc. 



