APPENDIX B 
2 
There is no evidence that polyoma virus can infect humans (Hartley, 
J., Huebner, R., Parker, J. and Rowe, W. P., unpublished data). Thus no 
antibodies to the virus have been detected in people living in buildings 
that are infested with virus-infected mice, nor in laboratory workers who 
have been exposed to the virus for a number of years. 
At most, a small segment of polyoma virus DNA shows weak homology 
with a portion of the late region of SV40 DNA (Ferguson, J. and Davis, R. 
W. , J. Mol. Biol., 94_, 135-150, 1975). However, there appears to be no 
genetic interaction between the two viruses and there is no immunological 
cross-reaction between the gene products of the two viruses. 
SV40 causes persistent but apparently harmless infections of the 
kidneys of virtually all adult rhesus monkeys (Hsiung, G. D., Bact. Revs. 
32 , 185-205, 1968), it causes tumors when injected into newborn hamsters 
(Girardi, A. J., Sweet, B. H., Slotnick, V. B. and Hillemann, M. R., Proc. 
Soc. Exp. Biol. Med., 105 , 420-427, 1964) and transforms cells of several 
mammalian species (including human). SV40 is able to infect humans since 
antibodies to the virus are found in a small proportion of the human 
population (Shah, K. V., Goverdhan, M. K. and Ozer, H. L., Am. J. Epid. 
93 , 291-298, 1970) and serum conversions have been noted in many laboratory 
personnel who have been exposed to the virus (Horvath, L. B., Acta Microbiol. 
Acta Sci. Hung. JT2, 201-206, 1965). 
Isolations of SV40 have been reported from humans, twice from patients 
suffering from the rare demyelinating disease, progressive multifocal 
leukoencephalopathy (Weiner, L., Herndon, R., Narayon, 0., Johnson, R. T., 
Shah, K., Rubinstein, L. G., Prezozisi, T. J. and Conley, F. K., New England 
[ 131 ] 
