Viral virulence

[Michael Ostrander]

There are a number of viruses that have adopted the strategy of latent or 
persistent infection of their host. The herpesviruses are  prototypic 
examples of viruses that use the latent infection strategy; this enables 
them to evade the host immune defenses.  HIV uses the strategy of 
persistent infection and is not strictly speaking the same as latent 
infection. it is interesting to note that HIV inserts a DNA copy of it's 
RNA genome into the DNA of the host and it is from this proviral genome 
that the virus replicates. To give credit to the acutely infecting 
viruses e.g. most of the RNA viruses, what they lack in subtlety, they 
make up in replicative efficiency producing thousands of progeny virus 
from each infectious center.  In the case of viruses like Ebola it is 
important to realize that man is not the primary host this is a zoonotic 
infection which has spread to man. This is probably the case with Hanta 
virus and a case can be made for HIV as a variant of the simian 
deficiency vius (SIV) which is pathogenic for humans.

Mike