During the early months of the spring of 1914 several cases of typhoid fever occurred in the Minnesota School for Feeble Minded and Colony for Epileptics at Faribault. An exhaustive search through the use of the Widal test in some 1,601 inmates disclosed the presence of a positive reaction in twenty-eight. Further investigation by means of isolation tests revealed the fact that eight of these inmates were active carriers.
To prevent the development of new cases, the administration of typhoid prophylactic was begun immediately. A total of 1,520 patients were inoculated in the usual manner. All patients having given positive Widals were isolated until the completion of the prophylactic treatment. New cases ceased to develop following the administration of the prophylactic until the outbreak of the current epidemic.
In order to determine the agglutinating property of the blood, following the prophylactic treatment, specimens of blood were taken from all who
E. H. TROWBRIDGE, B. A. FINKLE, ELIZABETH M. BARNARD. REPORT OF TYPHOID EPIDEMIC OCCURRING THREE MONTHS AFTER THE USE OF PROPHYLACTIC VACCINE. JAMA. 1915;LXIV(9):728–731. doi:10.1001/jama.1915.02570350022006