149 
Under P4 conditions at Fort Detrick, there were 423 cases of in- 
fection and three deaths in 25 years. Dr. Wedum, the former biosafety 
officer at Fort Detrick, has simply stated that all researchers are 
probably exposed to significant quantities of the agents they work with. 
So what about more recent experiences with P3 facilities? With 
newer P3 facilities, such as those at the CDC, there were four known 
lab-acquired infections in 100 workers from 1960 to 1967, or 0.006 
cases per man-year. This data comes from Dr. Kissling, and it is 
published in Biohazards in Biological Research , and I see some of you 
have that book. 
I talked last week to Dr. John Richardson, who is the director of 
the Office of Biosafety at CDC, and he has reassayed the hazards and 
relooked at the data that Dr. Kissling originally looked at the found 
that there was gross underreporting and probably the number of labora- 
tory-acquired infections is probably on the order of tenfold greater. 
They have had, however, no known infections in P4 sealed-glove 
cabinets. These cabinets, however, have been known to explode, and 
the most dramatic example is that of the cabinets that contained the 
moon rocks. 
Dr. Richardson feels that any type of safety cabinet is at best 
an adjunct to good techniques. I think that is what we should be 
stressing here. Even at such excellent facilities as Building 41 
at NIH, uncontrollable vectors such as cockroaches have been found 
within the high containment areas, and experimental animals have 
escaped from maximum to lower containment zones. 
There is one other area I would like to mention just briefly. There 
are other existing or potential recombinants, and I include here DNA re- 
combinants as well as RNA recombinants not covered by these proposed 
guidelines. Whether they could be included by this committee or by a 
separate committee, I can't say. They may present more of a biological 
hazard than the recombinants that we have been discussing today for two 
reasons. One, the recombinants result in a stable genome versus the 
insertion of foreign excessive genes into E. coli , and two, the investi- 
gators who are working with the recombinants I am going to mention may 
be less aware of the potential biohazards. 
I can only list examples. The first is recombinant influenza viruses 
for the purposes of obtaining vaccines. The second is experimental and 
naturally occurring SV40 adenovirus recombinants and experimental SV40 
reovirus recombinants. The third includes attempts to transform human 
tissue from slow virus diseases and tumors using SV40 to produce long-term 
cultures . 
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