APPENDIX B 
20 January 1976 
THE DETRICK EXPERIENCE AS A GUIDE TO THE 
PROBABLE EFFICACY OF P4 MICROBIOLOGICAL CONTAINMENT FACILITIES 
FOR STUDIES ON MICROBIAL RECOMBINANT DNA MOLECULES* 
A. G. WEDUM, M.D. 
I. INTRODUCTION 
Concern has been expressed for safety of the general public and for 
research personnel during research on recombinant DNA hybrid microorganisms 
(1). There appear to be assumptions that, first, a recombinant can, and 
may, be developed that will equal or exceed the virulence, infectivity and 
contagiousness of any presently known microorganism, and, second, that this 
agent will be transmitted to the general public either by infected laboratory 
personnel or by microorganisms leaving the laboratory on clothing, or in 
refuse, dead animals, sewage, or air. 
There is no doubt that the hypothetical hybrid can be hazardous for all 
persons entering the laboratory, as is clearly evident from the many reports 
and analyses on laboratory-acquired infections. The value of containment 
facilities for laboratory-associated persons will be discussed in Section III. 
The second assumption has almost no supporting epidemiological experience. 
Review of the literature yielded 35 accounts of laboratory microepidemics 
(Table 1). These can be examined for their effect upon the general public. 
Almost all of these epidemics occurred in the absence of safety equipment and 
of adequate efforts to control contaminated air, sewage, refuse, and laundry. 
Usually no more than rubber gloves and surgical masks were used during work 
on an open bench top. This is not unique. The history of microbiological 
research is characterized by a primary emphasis upon protecting the experiment 
rather than upon protecting the experimenter. Most work with human disease- 
producing microorganisms has been and is done on open bench tops with few or 
*Research sponsored by the National Cancer Institute under Contract No. 
NO! -CO-25423 with Litton Bionetics, Inc. 
[ 372 ] 
