Subspecies of the Chimpanzee,
Natural ranges of four chimpanzee subspecies. Note that only chimpanzees belonging to the subspecies
trogodytes and schweinfurthii have been found naturally infected with SIVcpz. The strains of SIVcpz that have been
found cluster into two divergent lineages corresponding to the chimp subspecies lineages, and the strain of SIVcpz found
in troglodytes was the source of HIV-1. Figure has been adapted from Figure 1 in Sharp et al. (2005).
seems clear that HIV-2 represents a separate introduction of
contamination exists, and recent analysis of lots of this vac-
SIVsmm into humans.
cine that had been stored for 40 years by three different labo-
ratories failed to find any trace of SIV/HIV in the vaccine.
Further, given that monkey viruses have repeatedly entered
Repetitive Introductions of Monkey Retroviruses
the human population, it is unnecessary to postulate human
vaccine activity for the origin of HIV. Rumors based upon
It has been found recently that the multiple introductions
this claim, however, have led to suspension of vaccination
of SIV into humans that became HIV-1 and -2 do not rep-
for polio in some African nations, resulting in a resurgence
resent the only human infections by monkey retroviruses.
of poliomyelitis in Africa that has spread to other areas pre-
Studies of bush meat hunters in Cameroon showed that
viously free of polio (see Chapter 3).
at least six retroviruses have crossed from monkeys into
humans who were exposed to fresh bush meat. These include
two previously unknown retroviruses, HTLV-3 (PTLV-3)
VIRUSES ASSOCIATED WITH RODENTS
and HTLV-4 (PTLV-4). Thus, infection of humans by sim-
ian retroviruses has not been a rare event. A book called The
River by Edward Hooper claimed that the HIV epidemic
started because an early version of polio vaccine was con-
Hantaviruses are associated with rodents and infect
taminated by HIV (or its progenitor). No evidence for such
humans through aerosols containing virus from rodent
Search WWH :