486 



Major P. S. Lelean 



[April 2; 



1. The Meerid outhreaJc. A cavalry regiment at Meerut (India) 

 contained 200 inoculated and 300 uninoculated men. Sixty cases of 

 enteric occurred in an outbreak among these men, all living under 

 apparently precisely similar conditions in barracks. The cases were 

 distributed among the groups as follows : 



Of the 58 oases among unprotected men, 10 died and 2 had to be 

 invalided out of the Service as permanently incapacitated. 



2. Twenty-four test units. Special medical officers were attached 

 to twenty-four units for twenty months, with instructions to record 



ENTERIC INOCLLATION* 



RE 2 4 LMTS FOR 2 a iWOrVTHS 



ANTI 



RES ULTS __^ 



SHOWING COMPARATIVE CHANCES OF INFECTION AND 



DEATH, (taking THE INOCLLATED MANS CHANCES AS 



LNI TY IN EACH CA SE ). 



IBLACK = INOCLLATED (STRENGTH 10.000) 



IHATCHED = LNINOCLLATED ( .. 9.000) 



10«7 



*NFECTI0N 



DEAl^* 



Fig. 3. 



the incidence of enteric in relation to prophylactic inoculation. The 

 data thus obtained refer to a number of men equivalent to a whole 

 division, living— as regards the groups in each regiments — under 

 similar conditions for a considerable period. They therefore afford 

 evidence on a scale which cannot be regarded as dominated by 

 co-incidence. 



The relative incidences are shown in Fig. 3. If the wholly 

 unprotected group data be compared with data from a group com- 

 prising all the other men — whether fully or i3artially protected by 

 inoculation — the former give 5*6 times as many cases and 10 '7 

 times as many deaths from enteric" as the latter. 



