I. TABLE 1 (SUPPLEMENT) EXAMPLES OF MULTIPLE 
LABORATORY INFECTIONS IN ONE INSTITUTION 
The use of Escherichia coli in the study of recombinant DNA molecules 
has caused concern that infection of laboratory personnel by a pathogenic 
hybrid might result in person-to-person transmission that would endanger the 
health of the surrounding community. In evaluating the extent of this 
possible hazard, it is useful to examine the extent to which laboratory- 
acquired intestinal disease has caused secondary cases. Table 1 (Supplement) 
identifies two small microepidemics of 4 and 6 cases and 4 surveys by German 
authors that included, with possibly a few minor exceptions, presumably only 
European laboratories. There were 265 cases. An important aspect of each 
survey, as far as the present discussion is concerned, is that the survey 
questionnaire included a query as to whether there were secondary cases. 
There were none, except as noted in Table 1 (Supplement). 
TABLE 1 (SUPPLEMENT) 
EXAMPLES OF MULTIPLE LABORATORY INFECTIONS IN ONE INSTITUTION 
Disease or Agent 
Probable Source 
Persons 
Infected 
Reference 
Ref. Date 
Shigellosis 
Presumably mouth pipetting 
6 
16 
1954 
Typhoid fever 
"No direct accident" 
4 
10 
1947 
Typhoid fever 
*Survey of European labs. 
50 
7a 
1915 
Typhoid; Paratyphoid; 
Shigellosis 
*1 3-year survey of European 
labs. 
75 
7b 
1929 
Typhoid; Paratyphoid 
*Survey of European labs. 
70 
8 
1939 
Typhoid; Salmonellosis 
*Survey of laboratories 
70 
9 
1950 
*The survey included a question as to whether other persons were infected. 
Replies: Typhoid - (1) Patient's nurse (Ref. 7a); (2) Patient's residential 
roommate (Ref. 8); (3) "Three other people infected themselves or were 
infected either by the woman or directly by other means" (Ref. 7a). 
(4) Patient's nurse (Ref. 9). 
Cholera - (1) Wife of the patient (Ref. 7b) 
[3991 
