Allergy in Brucella Infections

Abstract

Cutaneous hypersensitiveness to specific antigen as a test for Brucella infection has been used by several authors. 1 - 11 Unfortunately, the diversity of preparations used as antigen makes correlation of results difficult. As a rule, a positive reaction has been considered as denoting past or present infection.

Recently, the authors 12 published a method for the preparation of a purified protein-antigen from Brucella and decided to use the preparation to investigate cutaneous hypersensitiveness to Brucella among milkers and cattle handlers in farms near the city of San Juan, P. R., where endemic abortion in cattle is prevalent. The method used was as follows: The desired amount of the purified protein produced from the Brucella organism is accurately weighed and suspended in a few cc of saline; then enough drops of N/10 hydroxide solution are added until a clear solution is obtained, and this is brought back to neutrality with N/10 HCl. The resulting solution is diluted with saline so that it may contain 0.1 mg per cc. By means of a sterile, tuberculin-type syringe and a 26-gauge needle, 0.1 cc of the diluted protein-solution is injected into the skin over the flexor surface of the forearm. The site of the injection is examined 48 hours later. In subjects that react positively, there is marked erythema and edematous induration. As a rule, the area of edema is much larger than the erythematous area. The size of the reaction varies with its intensity and in some cases there is a constitutional reaction shown by general malaise and slight fever, with pain or itching in the injected arm.

Two hundred and twelve adults occupied as milkers or cattle-handlers were tested. At the same time, 15 cc of blood were drawn and agglutination, complement-fixation, and opsono-cytophagic tests for Brucella were made.