In the first week of April, 1917, I was delegated to investigate an intermittent outbreak of typhoid fever in Bakersfield, Kern County, Calif. The records of the health department of that city showed that for a twelvemonth, beginning June, 1916, cases of typhoid fever had appeared scattered over the city, both sexes had been attacked, and the age range had been from 3 to 46 years. That the outbreak was intermittent was evidenced by the total absence of typhoid in the city during September, October, November and December, 1916. In all, there had occurred twenty-two cases, with a mortality of 9 per cent.
The municipal water supply had been examined from time to time by the state bureau of sanitary engineering, and the typhoid incidence could not be connected with it. The matter of shellfish and of ice cream was also investigated with negative findings. Suspicion was therefore naturally directed