Viruses (high virulence)

[Eric Engelhard]

Clay Comstock asks:

>Does anyone know of a virus that is so virulent that it only 
>takes one virus to infect and defeat the host.  I know one should assume 
>that it only takes one but...

AcNPV, a baculovirus, is an example of an animal virus system with this
level of virulence. We used AcNPV expressing beta-galactosidase as a
reporter gene to follow the progress of infection in a susceptible host
(Engelhard et al., 1995. PNAS USA 91, 3224-3227). We showed that a
single infected midgut epithelial cell could predict eventual viral
induced mortality. This is only indirect evidence of a single
virion-cell event, but pretty convincing. I'll bet someone has
calculated physical particle : plaque forming unit ratios for
bacteriophages that approach one. Any phage people out there?


Eric Engelhard
Insect Pathologist/Brewer/Biker/Beekeeper

My views are my own etc...