S. S. KALTER 
967 
Table II. — Continued 
I Foamy Virus (preaentiy included with the myxoviruses) 
(RNA (7), ether sensitive, 100-300 nm, acid labile, no inclu- 
sions, HA — ) 
Type 1 — rhesus, African green 
Type 2 — African green 
Type 3 — African green 
Type 4 — Squirrel 
I Type 5 — galago 
Type 6 — chimpanzee 
Type 7 — chimpanzee 
Miscellaneous viruses 
SAll — African green 
SHF— rhesus 
Marburg agent — African green 
tion is simply one of availability. Usefulness, in 
the sense of satisfying a known experimental 
need, is only too frequently secondary. 
For practical purposes, nonhuman primates 
are subdivided into Old and New World mon- 
keys and apes with the former being further 
I subdivided into Asian and African animals. This 
separation, while based upon a geographic 
existence, has the practical effect of suggesting 
(with a number of exceptions) which simian 
! viruses may be encountered. The SV series 
were derived primarily from Asian macaques, 
whereas the SA numbered viruses* were re- 
covered from African monkeys ( Cercopithecus 
aethiops). Additional viruses have been since 
recovered from numerous other species: chim- 
panzee, baboon and several of the South Ameri- 
can monkeys. Current indications strongly sug- 
gest that, in addition to the geographic separa- 
tion, other biologic parameters exist and should 
be investigated or considered. A phylogenetic 
relationship is recognized by differences in sus- 
ceptibility to various infectious agents and im- 
munologic reactivities. It is important to re- 
member that monkeys and apes, along with man, 
are primates, and as such are biologic entities 
j fully endowed with the various biologic com- 
; plexities that are associated with animals at this 
1 phylogenetic level. 
SIMIAN VIRUSES 
Approximately 75 viruses have been recov- 
ered from tissues and body fluids of various 
nonhuman primates (Table II) . It will be noted 
j that these are, for the most part, counterparts 
of virus families that have been described pre- 
viously as recovered from other animal tissues. 
Thus there are: adenoviruses, picornaviruses 
(although no simian rhino viruses have been re- 
ported), herpesviruses, poxviruses, myxovirus- 
es, papovaviruses, reoviruses and a number that 
are of undetermined classification. Whereas 
these viruses are biologically related to pre- 
viously described human and other animal vi- 
ruses, they are antigenically distinct. Estab- 
lished human and other animal viruses have 
been recovered frequently from various simians. 
A number of the original reports and reviews 
are available describing the recovery and char- 
acteristics of these agents ^-'^^ and they will not 
be discussed at this time. Of the many viruses 
recovered from nonhuman primates, the vast 
majority are apparently of low pathogenicity 
for their original host. The effect on alien hosts 
has been examined only to a very limited extent. 
It is here, however, that apparent problems 
arise, but again the extent has not been defined. 
In certain instances, it is known that crossing 
of the species barrier by one or another of these 
agents does result in an increased pathogenicity, 
even to the extent of producing death. Fortu- 
nately the number of simian viruses in this 
category, as far as man is concerned, are few 
in number — Herpesvirus simiae, Marburg 
agent. Certain of the herpesviruses are also 
lethal for species of monkeys other than the 
original host — H. tamarinus (isolated from the 
squirrel monkey) is fatal for the owl monkey 
and marmoset ; H. hominis may produce fatali- 
ties in various species of monkeys and apes. To 
this list should be added those viruses, especially 
in general, yellow fever and Kyasanur forest. 
These two viruses are highly pathogenic for 
man and monkey alike. Also, there is always 
the question of the unknown pathogenic po- 
tential simian viruses may have. For example, 
thousands of individuals have received live 
SV40 virus in conjunction with their poliovirus 
vaccine. This virus, when introduced into new- 
born hamsters, is carcinogenic. No known tu- 
mors have ever been recorded as related to this 
virus in its original simian host nor in any of 
these recipients. However, the question of pos- 
sibility still remains unanswered. 
Following is a brief review of pertinent 
aspects of these infections to acquaint those in- 
vestigators utilizing nonhuman primates in 
