3 
etiologic agents of tularemia, typhus, Venezuelan encephalitis, and others 
(9). 
The absence of proved laboratory-initiated public hazard also is re- 
flected in the Godber Report (10), which, from among all the agents listed 
in Table 1, places only Marburg virus in Category A, "Pathogens presenting 
hazards primarily or significantly to the human community." 
The one exception to the above discussion is the recent instance in 
England of fatal smallpox transmitted to two visitors by a hospitalized 
vaccinated laboratory technician mildly ill with smallpox undiagnosed at 
the time of the visit (11). The Godber Report was a consequence of the two 
deaths. However, the infection of the two visitors is primarily an affair 
of medical practice and hospital epidemiology. For the purpose of evaluating 
the efficacy of P4 containment, the value of this unique episode is its 
indication that the only publically hazardous recombinants will be those 
that carry the genes that insure person-to-person transmission typically 
demonstrated by such diseases as smallpox, chicken pox, and measles. Without 
that gene (if there is such), the recombinant disease will be controlled by 
the usual hygienic and public health practices of our civilization. Further- 
more, if person-to-person transmission is going to happen, early warning will 
be given by the appearance of carriers or illnesses in the laboratory popula- 
tion. This warning would not occur if all laboratory-associated personnel 
were effectively vaccinated against the contagious recombinant, which is a 
most unlikely situation. Examination of the report by Pike (12) on 3,921 
laboratory infections shows that at least 95% were noncontagious diseases, 
and, if one excludes tuberculosis, less than 5% consisted of diphtheria, 
Neisserian meningitis, plague, syphilis, and viral respiratory (e.g., influenza), 
enteric (e.g., coxsackie), or exanthematous (e.g., vaccinia-smallpox) diseases. 
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