A total of 1040 individuals has been examined for the typhoid carrier state by the O, H and Vi agglutination tests. Some observations have been made upon the technique of the Vi test.
Estimation of the O and H agglutinins proved unsuitable as a preliminary test owing to the high proportion of positive reactors. The Vi test, in contrast, gave a positive result in only a small percentage of those tested and brought the cultural work subsequently required within practical limits. All positive reactors were examined by cultural methods, and in no case were the organisms of enteric fever recovered.
The relative merits of the various tests available for the detection of carriers are discussed and certain tentative conclusions are expressed.