CASES STUDIED AT KOCHESTER, N. Y. 25 



important factor in the greatly increased number of typhoid cases 

 reported during October, November, and December. There was 

 obtained from the health office a list of cases reported during these 

 months in 1911, and January, 1912, and 33 of these cases were per- 

 sonally investigated. Careful inquiry was made as to the possibility 

 of contact, the sanitary conditions of premises, the water and milk 

 used, and whether or not raw oysters were consumed within one month 

 prior to the illness. The weight of evidence obtained as to the 

 probable source of infection gave the following results: 



Oysters, source undetermined , 8 



"Rockaways" 5 



Unknown 8 



Contact 6 



Summer resorts (water) 4 



Water (not Rochester supply) 1 



Milk 1 



Total , 33 



According to this table, oysters appeared to be responsible for 13, 

 or 39.4 per cent, of the 33 cases investigated. The cases were widely 

 scattered throughout the city, and in nearly all instances they 

 appeared among well-to-do families where sanitary conditions were 

 exceptionally good. 



Among the cases reported as eating "Rockaway" oysters, it was 

 almost impossible to trace the oysters back to the specific dealer from 

 whom they were obtained ; however, all of the firms from whom these 

 oysters were purchased handled Rockaways almost to the exclusion 

 of other oysters at the time when they were eaten and when the infec- 

 tion probably began. 



The. visit to Rochester was made on January 8 and 9, about four 

 months after the shipment of oysters in October; thus, owing to the 

 length of time elapsed, it was more difficult to trace the cases directly 

 to any one of the five shipments made at that time. In most cases 

 in which oysters appeared responsible for the infection, other members 

 of the same family were not made ill; however, in nearly every 

 instance the infected person was the only one who ate the oysters raw. 

 Those who ate cooked oysters escaped the infection. In fact, it was 

 generally observed that in most instances oysters were cooked not 

 eaten raw, as is the custom in many coast towns located near oyster 

 grounds. If this is generally true in Rochester, it will explain why 

 more people did not contract typhoid fever from eating these oysters, 

 especially the shipment of October 3, 1911, which came from the same 

 lot served at the Minisink banquet at Goshen, N. Y., on October 5, 

 1911; had they been eaten raw, the same disastrous results would 

 doubtless have followed their consumption. 



It should be said that a number of the cases reported in Rochester 

 had been brought from neighboring towns, and some of those inter- 



