Borna Virus

[Len]

Dear Dennis

I think there are two points here.

Humans having Borna virus specific antibodies:

If you test any population with an antibody test one will always have
false positives, depending on how good the test is, so a specificity of
say 95% would not be entirely unusual in a research based assay EIA.
Hence having 4% of the population antibody positive may not be entirely
unusual with an EIA. One needs to validate these reactive samples,
ideally with a neutralisation assay.

Lets assume, though, that this has been done and the antibodies
detected are truly Borna virus specific. My own feeling is that to have
an antibody response in this situation would mean that at some stage
there had at least been some limited viral replication to initiate the
antibody response. However assuming the virus is cleared relatively
rapidly I would argue that it is unlikely to cause chronic disease
unless one evokes some auto-immune pradigm (Although the infection may
be associated with an acute illness).

Chronic carriage of an RNA virus:

I was unaware of the data showing that a general population had a
prevalence of 4% Borna virus RNA carriage rate. (Could I have the
reference). I guess that this could all represent acute self limiting
disease, but that would be unusual. So, lets assume that at least a
proportion are chronic carriers. I firmly believe that it is unlikely
that one could be a chronic carrier of an RNA virus and not develop a
disease syndrome, eventually. The only real model we have for this is
hepatitis C virus, and I would argue that most people that are infected
will eventually develop disease (contentious).

I guess as virologists we all know that viruses will ultimately be
found to cause all disease and I think the Borna virus story is
exciting.

Any one out there who wants to debate whether you can have a 'latent'
RNA virus infection is welcome to enter into a discussion,

Len Moaven