i 3 4 THOMPSON YATES LABORATORIES REPORT 
On the night of Sunday, March 6, 1898, a second epidemic of diarrhoea 
similar to the first broke out among the in-patients of St. Bartholomew's Hospital, 
there being 144 severe cases. The milk was proved by Dr. Andrewes to be the 
' vehicle of infection.' On bacteriological examination spores of bacillus enteritidis 
ot a virulent character were demonstrated in the evacuations of the patients affected, 
and also in a sample of Sunday morning's milk.* 
On Friday night, August 5, 1898, the hospital was again attacked, eighty-six 
persons were affected, the majority of whom had eaten certain rice pudding. Bacillus 
enteritidis was isolated in a sporing condition from the diarrhoeal evacuations, and in 
a non-sporing condition from a sample of the suspected rice pudding ;f while Dr. 
Klein remarked, 'the conclusion becomes irresistible that this microbe was the 
direct cause of the disease. 'J Clinically, the second and third epidemics resembled 
the first, and every patient recovered. 
Obviously it is important to discover whether a particular organism — the 
bacillus enteritidis sporogenes — is probably or certainly a cause of diarrhoea. 
Now, in the first place, it the existence of enteritidis spores in the evacuations 
ot the patients at St. Bartholomew's can be used as an argument that the bacillus 
was, or probably was, the cause of the diarrhoea, it is clear that the spores should be 
almost or entirely absent in the evacuations of healthy persons, and of those suffering 
from diarrhoea which is casual and commonplace, or secondary to organic disease, as 
cirrhosis of the liver or typhoid. 
Again, as the virulence of B. enteritidis to guinea-pigs is subject to considerable 
variation, one would expect, even if the spores were constantly present in all 
evacuations, that their virulence would be considerably less than the virulence of 
those obtained from the intestines of individuals suffering from diarrhoea directly 
due to the activity of the microbe. 
Therefore it is essential to discover, firstly, whether the spores of enteritidis 
exist in normal and diarrhoeal evacuations generally ; and secondly, if present, 
whether they are equally virulent. 
In the summer ot 1897 Dr. Klein made some observations regarding the 
presence and virulence of bacillus enteritidis in infantile diarrhoea. § He examined 
the stools of eleven cases ; in nine the diarrhoea was acute, generally with symptoms 
of gastro-enteritis ; in the remaining two it was more chronic ; ten of the infants died. 
It was demonstrated that the spores occurred in a virulent form in four out of the ten 
fatal cases, while in the remaining six and in the one that recovered, cylindrical rods 
were discovered on microscopical examination of the bowel contents, which might 
* Medical Officer s Report, Local Government Board, 1897-98, p. 255. 
t Lancet, January 7, 1899, p. 8. 
% Medical Officer's Report, Local Government Board, 1898-99, p. 336. 
§ Medical Officer s Report, Local Government Board, 1897-98, p. 230-233. 
