[Diagnostic value of the allergy test and precipitation reaction for the intravital diagnosis of trichinelliasis in swine].

A total of twenty-two experimentally infected pigs, presenting from 250 to 12000 Trichinellae per kilogram body weight, were studied by the skin allergy test, the tube precipitation reaction, and the double gel diffusion technique after Ouchterlony in the course of one year following infection. Use was made of a Trichinella antigen obtained by the Tanner and Gregory's modified method. Unspecific allergy reactions were observed in 2.04% of 104 control pigs, and 2 of the infected ones did not react to the antigen diluted 1:1000. To decrease the cases of unspecific reactions a suggestion was made to extend the antigen from 1:5000 to 1:10000 and to read the result of the reactions not earlier than the 45th min. after injecting the antigen and the physiologic saline. The precipitation reaction proved positive in a comparatively short period--up to the fourth month of infection, and in sporadic cases up to the 7 1/2 month. Unspecific precipitation was observed in 18.7% of a total of 53 control sera. Ouchterlony's diffusion technique was shown to be specific, revealing trichinellosis in the animals from the 15th to the 365th day after the infection had been carried out. It was most markedly expressed from the 30th to the 120th day. It is suggested to use the skin allergy test on farms with a record of swine trichinelloses, all positively reacting pigs being serologically studied after Ouchterlony.