72 HORN : TYPHOID EPIDEMIC. 



Later investigations failed to reveal any other probable 



primary case than that of L . Water was not only 



excluded by the nature of the onset of the epidemic, but 

 further by the facts that the area infected is supplied by 

 two different water companies drawing water from two differ- 

 ent sources, and that the cases were almost evenly divided 

 between the two water supplies. 



An exhaustive study upon the basis of Widal blood tests 

 was made later by another investigator and reported October 

 5th. Seventy-four persons who had spent some time at the 

 Francis Farm were examined. All gave negative Widals 

 except one child, who was found ill and removed to a hospi- 

 tal. Another child giving two negative Widals was also 

 found ill and sent to a hospital, where the diagnosis of para- 

 typhoid fever was made. Five transients who had spent some 

 time on one of the other supply farms during the Summer 

 (Farm No. 7) also gave negative Widal reactions. 



The L . case had been diagnozed upon the clinical 



symptoms as typhoid fever prior to a positive Widal reac- 

 tion. His blood exhibited a negative Widal reaction on 

 September 8th, and a positive one when tested again Septem- 

 ber 15th. His illness was so pronounced shortly after his 

 return from the Francis Farm that the nurses in charge of the 



H . Day Nursery, in going over the written attendance 



records of all children who had visited the Francis Farm in 

 August, immediately expressed an opinion that he might be 

 ill of typhoid fever. On September 2nd he complained so of 

 headache that he was sent home, or kept at home. 



From the most reliable figures available, it appears that 

 there were in all about 44 cases in this epidemic. The death 

 rate was high — about 18 per cent. All these 44 cases were 

 reported within three weeks, and 31 of them were recognized 

 during the first week of the epidemic. A large proportion of 

 those taken ill were children. 



